Revisions for pm-monitoring-regulations
| 32 CURRENT | mathew |
April 18, 2016 20:06
| about 8 years ago
Small airborne particles can become lodged in the lungs and cause a variety of respiratory and cardiac health impacts, so air quality regulations are concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5, which are particles of less than 10 microns (millionths of a meter) and particles less than 2.5 microns in diameter, respectively. PM is one of six ‘criteria pollutants’ defining National Ambient Air Quality Standards. U.S. federal EPA PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official protocols, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs, and those deemed similar enough to FRMs are classified as Federal Equivalent Methods (FEMs). A list of FRMs and FEMs is available here. The intent of technology-based regulation is to create data that is comparable across space and time by using a single consistent technique. However, technology-based regulation also restricts regulatory judgements on data collected with any tools that have not been approved by federal regulators. Regardless of the demonstrated correlation between a particle monitoring technique and Federal Reference Methods, data may be rejected if it is not collected with the federally specified device. Examples of this occurrence include the case of Air Alliance Houston's rejected data, and Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring. There are countless other stories of citizen-collected data being rejected on the grounds of improper or incompatible sample collection or analysis, regardless of their data quality. Understanding technology-based regulation of particulate matter, and how it differs from what would truly be health-based regulation, will assist in strategically moving towards regulatory judgements against polluters, using particle monitoring tools and/or other advocacy leverage points. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10 μm; PM2.5 as the fraction less than or equal to 2.5 μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles; PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM, according to the conventions promulgated by the EPA, is a standardized indicator of particle pollution, but is not a full representation of particle pollution itself. All measurement techniques have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
PM2.5 FRM monitor is identical to PM10, except for a second impactor for PM2.5 after the impactor for PM10.
As shown in the figure above, PM2.5 is mostly droplets (formed through atmospheric reactions) and combustion byproduct aerosols, but PM2.5 also captures the smallest range of coarse “primary” particles (emitted directly as fine particles, not formed in the atmosphere). PM2.5 is often comprised of sulfate and nitrate aerosols that form as gaseous emissions of sulfur dioxide and nitrogen dioxide react with moisture in the atmosphere to form acidic aerosols (which can further condense to form acid rain).
citation: EPA 454-R-04-002, Fig 2. The Federal Reference Methods:Federal Reference Methods (FRMs) are the technology-based methods that have been approved by the EPA to produce data that is sufficient for regulatory grounds. The technique and the tool are part of the FRM, if either the tool itself or the technique used do not match the specifications outlined by the EPA, the method can not be considered an FRM. Federal regulations include specific designs for instrument construction that are required for FRMs. Since the regulations are set by specific methods, PM10 and PM2.5 are defined by the output of those specific techniques, and they are referred to as “operational defined.” Operational definitions of substances do not necessarily correspond with what is found in nature.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). FRM PM10 monitor in the Code of Federal Regulations:
The FRM instrument collects particles with with a distributed size range, described by a cut point where 50% of particles at the cut point diameter (μm) are entrained into the sample, and 50% are not. This distribution is skewed, however, impacting a higher proportion of particles larger than the cut point, so there is a skewed higher proportion of smaller particles that are collected in the sample. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a laboratory and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the instrument, PM concentrations are calculated and expressed in micrograms of particles per cubic meter of air (μm/m3). The FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. Their function is described in Filter-based PM monitoring tools.
Particle Size: real particles & idealized particlesFederal Reference Methods assume that particles are spherical for the sake of computer modeling, so sizes are given in reference to their similarity to the aerodynamic performance of a perfect sphere. Read more here. Federal Equivalent MethodsSome Federal Equivalent Methods (FEMs) for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass of particles may be measured or calculated based on data from an optical PM monitor, or less requently by a beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site. SilicaThere are no national standards for respirable silica in ambient air, although several states have implemented silica standards. Read more on respirable silica and how it relates to PM10 and PM2.5. The ‘action level’ (which used to be a NAAQS) for PM10 is an annual mean of 50 μg/m3, and by assuming 10% PM is silica, that translates as 5 μg/m3 silica. Research has shown that people exposed to ambient PM10 silica concentrations of ~15 μg/m3 is correlated with significant increases in silicosis, but the authors suggest that chronic exposure to 5 μg/m3 silica would be reasonable. It is important to note that these findings are for silica in PM10, not respirable silica, which is only a fraction of the silica in PM10 samples. For respirable silica, ambient exposure guidelines are lower. |
Revert | |
| 31 | gretchengehrke |
February 16, 2016 17:27
| about 8 years ago
Small airborne particles can become lodged in the lungs and cause a variety of respiratory and cardiac health impacts, so air quality regulations are concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5, which are particles of less than 10 microns (millionths of a meter) and particles less than 2.5 microns in diameter, respectively. PM is one of six ‘criteria pollutants’ defining National Ambient Air Quality Standards. U.S. federal EPA PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official protocols, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs, and those deemed similar enough to FRMs are classified as Federal Equivalent Methods (FEMs). A list of FRMs and FEMs is available here. The intent of technology-based regulation is to create data that is comparable across space and time by using a single consistent technique. However, technology-based regulation also restricts regulatory judgements on data collected with any tools that have not been approved by federal regulators. Regardless of the demonstrated correlation between a particle monitoring technique and Federal Reference Methods, data may be rejected if it is not collected with the federally specified device. Examples of this occurrence include the case of Air Alliance Houston's rejected data, and Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring. There are countless other stories of citizen-collected data being rejected on the grounds of improper or incompatible sample collection or analysis, regardless of their data quality. Understanding technology-based regulation of particulate matter, and how it differs from what would truly be health-based regulation, will assist in strategically moving towards regulatory judgements against polluters, using particle monitoring tools and/or other advocacy leverage points. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10 μm; PM2.5 as the fraction less than or equal to 2.5 μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles; PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM, according to the conventions promulgated by the EPA, is a standardized indicator of particle pollution, but is not a full representation of particle pollution itself. All measurement techniques have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
PM2.5 FRM monitor is identical to PM10, except for a second impactor for PM2.5 after the impactor for PM10.
As shown in the figure above, PM2.5 is mostly droplets (formed through atmospheric reactions) and combustion byproduct aerosols, but PM2.5 also captures the smallest range of coarse “primary” particles (emitted directly as fine particles, not formed in the atmosphere). PM2.5 is often comprised of sulfate and nitrate aerosols that form as gaseous emissions of sulfur dioxide and nitrogen dioxide react with moisture in the atmosphere to form acidic aerosols (which can further condense to form acid rain).
citation: EPA 454-R-04-002, Fig 2. The Federal Reference Methods:Federal Reference Methods (FRMs) are the technology-based methods that have been approved by the EPA to produce data that is sufficient for regulatory grounds. The technique and the tool are part of the FRM, if either the tool itself or the technique used do not match the specifications outlined by the EPA, the method can not be considered an FRM. Federal regulations include specific designs for instrument construction that are required for FRMs. Since the regulations are set by specific methods, PM10 and PM2.5 are defined by the output of those specific techniques, and they are referred to as “operational defined.” Operational definitions of substances do not necessarily correspond with what is found in nature.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). FRM PM10 monitor in the Code of Federal Regulations:
The FRM instrument collects particles with with a distributed size range, described by a cut point where 50% of particles at the cut point diameter (μm) are entrained into the sample, and 50% are not. This distribution is skewed, however, impacting a higher proportion of particles larger than the cut point, so there is a skewed higher proportion of smaller particles that are collected in the sample. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a laboratory and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the instrument, PM concentrations are calculated and expressed in micrograms of particles per cubic meter of air (μm/m3). The FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. Their function is described in Filter-based PM monitoring tools.
Particle Size: real particles & idealized particlesFederal Reference Methods assume that particles are spherical for the sake of computer modeling, so sizes are given in reference to their similarity to the aerodynamic performance of a perfect sphere. Read more here. Federal Equivalent MethodsSome Federal Equivalent Methods (FEMs) for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass of particles may be measured or calculated based on data from an optical PM monitor, or less requently by a beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site. SilicaThere are no national standards for respirable silica in ambient air, although several states have implemented silica standards. Read more on respirable silica and how it relates to PM10 and PM2.5. The ‘action level’ (which used to be a NAAQS) for PM10 is an annual mean of 50 μg/m3, and by assuming 10% PM is silica, that translates as 5 μg/m3 silica. Research has shown that people exposed to ambient PM10 silica concentrations of ~15 μg/m3 is correlated with significant increases in silicosis, but the authors suggest that chronic exposure to 5 μg/m3 silica would be reasonable. It is important to note that these findings are for silica in PM10, not respirable silica, which is only a fraction of the silica in PM10 samples. For respirable silica, ambient exposure guidelines are lower. |
Revert | |
| 30 | gretchengehrke |
February 16, 2016 17:11
| about 8 years ago
Small airborne particles can become lodged in the lungs and cause a variety of respiratory and cardiac health impacts, so air quality regulations are concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5, which are particles of less than 10 microns (millionths of a meter) and particles less than 2.5 microns in diameter, respectively. PM is one of six ‘criteria pollutants’ defining National Ambient Air Quality Standards. U.S. federal EPA PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official protocols, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs, and those deemed similar enough to FRMs are classified as Federal Equivalent Methods (FEMs). A list of FRMs and FEMs is available here. The intent of technology-based regulation is to create data that is comparable across space and time by using a single consistent technique. However, technology-based regulation also restricts regulatory judgements on data collected with any tools that have not been approved by federal regulators. Regardless of the demonstrated correlation between a particle monitoring technique and Federal Reference Methods, data may be rejected if it is not collected with the federally specified device. Examples of this occurrence include the case of Air Alliance Houston's rejected data, and Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring. There are countless other stories of citizen-collected data being rejected on the grounds of improper or incompatible sample collection or analysis, regardless of their data quality. Understanding technology-based regulation of particulate matter, and how it differs from what would truly be health-based regulation, will assist in strategically moving towards regulatory judgements against polluters, using particle monitoring tools and/or other advocacy leverage points. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10 μm; PM2.5 as the fraction less than or equal to 2.5 μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles; PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM, according to the conventions promulgated by the EPA, is a standardized indicator of particle pollution, but is not a full representation of particle pollution itself. All measurement techniques have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
PM2.5 FRM monitor is identical to PM10, except for a second impactor for PM2.5 after the impactor for PM10.
As shown in the figure above, PM2.5 is mostly droplets (formed through atmospheric reactions) and combustion byproduct aerosols, but PM2.5 also captures the smallest range of coarse “primary” particles (emitted directly as fine particles, not formed in the atmosphere). PM2.5 is often comprised of sulfate and nitrate aerosols that form as gaseous emissions of sulfur dioxide and nitrogen dioxide react with moisture in the atmosphere to form acidic aerosols (which can further condense to form acid rain).
citation: EPA 454-R-04-002, Fig 2. The Federal Reference Methods:Federal Reference Methods (FRMs) are the technology-based methods that have been approved by the EPA to produce data that is sufficient for regulatory grounds. Since the regulations are method-specific, PM10 and PM2.5 have an “operational definition,” meaning they are defined as the output of specific techniques, but that doesn't mean that definition corresponds what is found in nature. Federal regulations have exacting diagrams of FRM instrument construction for operational analyses.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). FRM PM10 monitor in the Code of Federal Regulations:
The FRM instrument collects particles with with a distributed size range, described by a cut point where 50% of particles at the cut point diameter (μm) are entrained into the sample, and 50% are not. This distribution is skewed, however, impacting a higher proportion of particles larger than the cut point, so there is a skewed higher proportion of smaller particles that are collected in the sample. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a laboratory and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the instrument, PM concentrations are calculated and expressed in micrograms of particles per cubic meter of air (μm/m3). The FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. Their function is described in Filter-based PM monitoring tools.
Particle Size: real particles & idealized particlesFederal Reference Methods assume that particles are spherical for the sake of computer modeling, so sizes are given in reference to their similarity to the aerodynamic performance of a perfect sphere. Read more here. Federal Equivalent MethodsSome Federal Equivalent Methods (FEMs) for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass of particles may be measured or calculated based on data from an optical PM monitor, or less requently by a beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site. SilicaThere are no national standards for respirable silica in ambient air, although several states have implemented silica standards. Read more on respirable silica and how it relates to PM10 and PM2.5. The ‘action level’ (which used to be a NAAQS) for PM10 is an annual mean of 50 μg/m3, and by assuming 10% PM is silica, that translates as 5 μg/m3 silica. Research has shown that people exposed to ambient PM10 silica concentrations of ~15 μg/m3 is correlated with significant increases in silicosis, but the authors suggest that chronic exposure to 5 μg/m3 silica would be reasonable. It is important to note that these findings are for silica in PM10, not respirable silica, which is only a fraction of the silica in PM10 samples. For respirable silica, ambient exposure guidelines are lower. |
Revert | |
| 29 | stevie |
February 16, 2016 15:11
| about 8 years ago
Small airborne particles can become lodged in the lungs and cause a variety of respiratory and cardiac health impacts, so air quality regulations are concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5, which are particles of less than 10 microns (millionths of a meter) and particles less than 2.5 microns in diameter, respectively. PM is one of six ‘criteria pollutants’ defining National Ambient Air Quality Standards. U.S. federal EPA PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official protocols, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs, and those deemed similar enough to FRMs are classified as Federal Equivalent Methods (FEMs). A list of FRMs and FEMs is available here. The intent of technology-based regulation is to create data that is comparable across space and time by using a single consistent technique. However, technology-based regulation also restricts regulatory judgements on data collected with any tools that have not been approved by federal regulators. Regardless of the demonstrated correlation between a particle monitoring technique and Federal Reference Methods, data may be rejected if it is not collected with the federally specified device. Examples of this occurrence include the case of Air Alliance Houston's rejected data, and Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring. There are countless other stories of citizen-collected data being rejected on the grounds of improper or incompatible sample collection or analysis, regardless of their data quality. Understanding technology-based regulation of particulate matter, and how it differs from what would truly be health-based regulation, will assist in strategically moving towards regulatory judgements against polluters, using particle monitoring tools and/or other advocacy leverage points. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10 μm; PM2.5 as the fraction less than or equal to 2.5 μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles; PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM, according to the conventions promulgated by the EPA, is a standardized indicator of particle pollution, but is not a full representation of particle pollution itself. All measurement techniques have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
PM2.5 FRM monitor is identical to PM10, except for a second impactor for PM2.5 after the impactor for PM10.
As shown in the figure above, PM2.5 is mostly droplets (formed through atmospheric reactions) and combustion byproduct aerosols, but PM2.5 also captures the smallest range of coarse “primary” particles (emitted directly as fine particles, not formed in the atmosphere). PM2.5 is often comprised of sulfate and nitrate aerosols that form as gaseous emissions of sulfur dioxide and nitrogen dioxide react with moisture in the atmosphere to form acidic aerosols (which can further condense to form acid rain).
citation: EPA 454-R-04-002, Fig 2. The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 have an “operational definition,” meaning they are defined as the output of specific techniques referred to as Federal Reference Methods (FRM), but are without a more comprehensive definition in nature. Federal regulations themselves have exacting diagrams of FRM instrument construction for operational analyses.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). FRM PM10 monitor in the Code of Federal Regulations:
The FRM instrument collects particles with with a distributed size range, described by a cut point where 50% of particles at the cut point diameter (μm) are entrained into the sample, and 50% are not. This distribution is skewed, however, impacting a higher proportion of particles larger than the cut point, so there is a skewed higher proportion of smaller particles that are collected in the sample. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a laboratory and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the instrument, PM concentrations are calculated and expressed in micrograms of particles per cubic meter of air (μm/m3). The FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. Their function is described in Filter-based PM monitoring tools.
Particle Size: real particles & idealized particlesFederal Reference Methods assume that particles are spherical for the sake of computer modeling, so sizes are given in reference to their similarity to the aerodynamic performance of a perfect sphere. Read more here. Federal Equivalent MethodsSome Federal Equivalent Methods (FEMs) for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass of particles may be measured or calculated based on data from an optical PM monitor, or less requently by a beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site. SilicaThere are no national standards for respirable silica in ambient air, although several states have implemented silica standards. Read more on respirable silica and how it relates to PM10 and PM2.5. The ‘action level’ (which used to be a NAAQS) for PM10 is an annual mean of 50 μg/m3, and by assuming 10% PM is silica, that translates as 5 μg/m3 silica. Research has shown that people exposed to ambient PM10 silica concentrations of ~15 μg/m3 is correlated with significant increases in silicosis, but the authors suggest that chronic exposure to 5 μg/m3 silica would be reasonable. It is important to note that these findings are for silica in PM10, not respirable silica, which is only a fraction of the silica in PM10 samples. For respirable silica, ambient exposure guidelines are lower. |
Revert | |
| 28 | stevie |
February 16, 2016 15:03
| about 8 years ago
Small airborne particles can become lodged in the lungs and cause a variety of respiratory and cardiac health impacts, so air quality regulations are concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5, which are particles of less than 10 microns (millionths of a meter) and particles less than 2.5 microns in diameter, respectively. PM is one of six ‘criteria pollutants’ defining National Ambient Air Quality Standards. U.S. federal EPA PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official protocols, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs, and those deemed similar enough to FRMs are classified as Federal Equivalent Methods (FEMs). A list of FRMs and FEMs is available here. The intent of technology-based regulation is to create data that is comparable across space and time by using a single consistent technique. However, technology-based regulation also restricts regulatory judgements on data collected with any tools that have not been approved by federal regulators. Regardless of the demonstrated correlation between a particle monitoring technique and Federal Reference Methods, data may be rejected if it is not collected with the federally specified device. Examples of this occurrence include the case of Air Alliance Houston's rejected data, and Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring. There are countless other stories of citizen-collected data being rejected on the grounds of improper or incompatible sample collection or analysis, regardless of their data quality. Understanding technology-based regulation of particulate matter, and how it differs from what would truly be health-based regulation, will assist in strategically moving towards regulatory judgements against polluters, using particle monitoring tools and/or other advocacy leverage points. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10 μm; PM2.5 as the fraction less than or equal to 2.5 μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles; PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM, according to the conventions promulgated by the EPA, is a standardized indicator of particle pollution, but is not a full representation of particle pollution itself. All measurement techniques have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
PM2.5 FRM monitor is identical to PM10, except for a second impactor for PM2.5 after the impactor for PM10.
As shown in the figure above, PM2.5 is mostly droplets (formed through atmospheric reactions) and combustion byproduct aerosols, but PM2.5 also captures the smallest range of coarse “primary” particles (emitted directly as fine particles, not formed in the atmosphere). PM2.5 is often comprised of sulfate and nitrate aerosols that form as gaseous emissions of sulfur dioxide and nitrogen dioxide react with moisture in the atmosphere to form acidic aerosols (which can further condense to form acid rain).
citation: EPA 454-R-04-002, Fig 2. The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 have an “operational definition,” meaning they are defined as the output of specific techniques referred to as Federal Reference Methods (FRM), but are without a more comprehensive definition in nature. Federal regulations themselves have exacting diagrams of FRM instrument construction for operational analyses.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). FRM PM10 monitor in the Code of Federal Regulations:
The FRM instrument collects particles with with a distributed size range, described by a cut point where 50% of particles at the cut point diameter (μm) are entrained into the sample, and 50% are not. This distribution is skewed, however, impacting a higher proportion of particles larger than the cut point, so there is a skewed higher proportion of smaller particles that are collected in the sample. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a laboratory and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the instrument, PM concentrations are calculated and expressed in micrograms of particles per cubic meter of air (μm/m3). The FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. Their function is described in Filter-based PM monitoring tools.
Particle Size: real particles & idealized particlesFederal Reference Methods assume that particles are spherical for the sake of computer modeling, so sizes are given in reference to their similarity to the aerodynamic performance of a perfect sphere. Read more here. Federal Equivalent MethodsSome Federal Equivalent Methods (FEMs) for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass of particles may be measured or calculated based on data from an optical PM monitor, or less requently by a beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site. SilicaThere are no national standards for respirable silica in ambient air, although several states have implemented silica standards. Read more on respirable silica and how it relates to PM10 and PM2.5. The ‘action level’ (which used to be a NAAQS) for PM10 is an annual mean of 50 μg/m3, and by assuming 10% PM is silica, that translates as 5 μg/m3 silica. Research has shown that people exposed to ambient PM10 silica concentrations of ~15 μg/m3 is correlated with significant increases in silicosis, but the authors suggest that chronic exposure to 5 μg/m3 silica would be reasonable. It is important to note that these findings are for silica in PM10, not respirable silica, which is only a fraction of the silica in PM10 samples. For respirable silica, ambient exposure guidelines are lower. |
Revert | |
| 27 | stevie |
February 16, 2016 15:01
| about 8 years ago
Small airborne particles can become lodged in the lungs and cause a variety of respiratory and cardiac health impacts, so air quality regulations are concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5, which are particles of less than 10 microns (millionths of a meter) and particles less than 2.5 microns in diameter, respectively. PM is one of six ‘criteria pollutants’ defining National Ambient Air Quality Standards. U.S. federal EPA PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official protocols, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs, and those deemed similar enough to FRMs are classified as Federal Equivalent Methods (FEMs). A list of FRMs and FEMs is available here. The intent of technology-based regulation is to create data that is comparable across space and time by using a single consistent technique. However, technology-based regulation also restricts regulatory judgements on data collected with any tools that have not been approved by federal regulators. Regardless of the demonstrated correlation between a particle monitoring technique and Federal Reference Methods, data may be rejected if it is not collected with the federally specified device. Examples of this occurrence include the case of Air Alliance Houston's rejected data, and Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring. There are countless other stories of citizen-collected data being rejected on the grounds of improper or incompatible sample collection or analysis, regardless of their data quality. Understanding technology-based regulation of particulate matter, and how it differs from what would truly be health-based regulation, will assist in strategically moving towards regulatory judgements against polluters, using particle monitoring tools and/or other advocacy leverage points. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10 μm; PM2.5 as the fraction less than or equal to 2.5 μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles; PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM, according to the conventions promulgated by the EPA, is a standardized indicator of particle pollution, but is not a full representation of particle pollution itself. All measurement techniques have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
PM2.5 FRM monitor is identical to PM10, except for a second impactor for PM2.5 after the impactor for PM10.
As shown in the figure above, PM2.5 is mostly droplets (formed through atmospheric reactions) and combustion byproduct aerosols, but PM2.5 also captures the smallest range of coarse “primary” particles (emitted directly as fine particles, not formed in the atmosphere). PM2.5 is often comprised of sulfate and nitrate aerosols that form as gaseous emissions of sulfur dioxide and nitrogen dioxide react with moisture in the atmosphere to form acidic aerosols (which can further condense to form acid rain).
citation: EPA 454-R-04-002, Fig 2. The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 have an “operational definition,” meaning they are defined as the output of specific techniques referred to as Federal Reference Methods (FRM), but are without a more comprehensive definition in nature. Federal regulations themselves have exacting diagrams of FRM instrument construction for operational analyses.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). FRM PM10 monitor in the Code of Federal Regulations:
The FRM instrument collects particles with with a distributed size range, described by a cut point where 50% of particles at the cut point diameter (μm) are entrained into the sample, and 50% are not. This distribution is skewed, however, impacting a higher proportion of particles larger than the cut point, so there is a skewed higher proportion of smaller particles that are collected in the sample. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a labortory and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the instrument, PM concentrations are calculated and expressed in micrograms of particles per cubic meter of air (μm/m3). The FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. Their function is described in Filter-based PM monitoring tools.
Particle Size: real particles & idealized particlesFederal Reference Methods assume that particles are spherical for the sake of computer modeling, so sizes are given in reference to their similarity to the aerodynamic performance of a perfect sphere. Read more here. Federal Equivalent MethodsSome Federal Equivalent Methods (FEMs) for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass of particles may be measured or calculated based on data from an optical PM monitor, or less requently by a beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site. SilicaThere are no national standards for respirable silica in ambient air, although several states have implemented silica standards. Read more on respirable silica and how it relates to PM10 and PM2.5. The ‘action level’ (which used to be a NAAQS) for PM10 is an annual mean of 50 μg/m3, and by assuming 10% PM is silica, that translates as 5 μg/m3 silica. Research has shown that people exposed to ambient PM10 silica concentrations of ~15 μg/m3 is correlated with significant increases in silicosis, but the authors suggest that chronic exposure to 5 μg/m3 silica would be reasonable. It is important to note that these findings are for silica in PM10, not respirable silica, which is only a fraction of the silica in PM10 samples. For respirable silica, ambient exposure guidelines are lower. |
Revert | |
| 26 | stevie |
February 16, 2016 14:58
| about 8 years ago
Small airborne particles can become lodged in the lungs and cause a variety of respiratory and cardiac health impacts, so air quality regulations are concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5, which are particles of less than 10 microns (millionths of a meter) and particles less than 2.5 microns in diameter, respectively. PM is one of six ‘criteria pollutants’ defining National Ambient Air Quality Standards. U.S. federal EPA PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official protocols, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs, and those deemed similar enough to FRMs are classified as Federal Equivalent Methods (FEMs). A list of FRMs and FEMs is available here. The intent of technology-based regulation is to create data that is comparable across space and time by using a single consistent technique. However, technology-based regulation also restricts regulatory judgements on data collected with any tools that have not been approved by federal regulators. Regardless of the demonstrated correlation between a particle monitoring technique and Federal Reference Methods, data may be rejected if it is not collected with the federally specified device. Examples of this occurrence include the case of Air Alliance Houston's rejected data, and Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring. There are countless other stories of citizen-collected data being rejected on the grounds of improper or incompatible sample collection or analysis, regardless of their data quality. Understanding technology-based regulation of particulate matter, and how it differs from what would truly be health-based regulation, will assist in strategically moving towards regulatory judgements against polluters, using particle monitoring tools and/or other advocacy leverage points. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10 μm; PM2.5 as the fraction less than or equal to 2.5 μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles; PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM, according to the conventions promulgated by the EPA, is a standardized indicator of particle pollution, but is not a full representation of particle pollution itself. All measurement techniques have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
PM2.5 FRM monitor is identical to PM10, except for a second impactor for PM2.5 after the impactor for PM10.
As shown in the figure above, PM2.5 is mostly droplets (formed through atmospheric reactions) and combustion byproduct aerosols, but PM2.5 also captures the smallest range of coarse “primary” particles (emitted directly as fine particles, not formed in the atmosphere). PM2.5 is often comprised of sulfate and nitrate aerosols that form as gaseous emissions of sulfur dioxide and nitrogen dioxide react with moisture in the atmosphere to form acidic aerosols (which can further condense to form acid rain). citation: EPA 454-R-04-002, Fig 2. The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 have an “operational definition,” meaning they are defined as the output of specific techniques referred to as Federal Reference Methods (FRM), but are without a more comprehensive definition in nature. Federal regulations themselves have exacting diagrams of FRM instrument construction for operational analyses.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). FRM PM10 monitor in the Code of Federal Regulations:
The FRM instrument collects particles with with a distributed size range, described by a cut point where 50% of particles at the cut point diameter (μm) are entrained into the sample, and 50% are not. This distribution is skewed, however, impacting a higher proportion of particles larger than the cut point, so there is a skewed higher proportion of smaller particles that are collected in the sample. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a labortory and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the instrument, PM concentrations are calculated and expressed in micrograms of particles per cubic meter of air (μm/m3). The FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. Their function is described in Filter-based PM monitoring tools.
Particle Size: real particles & idealized particlesFederal Reference Methods assume that particles are spherical for the sake of computer modeling, so sizes are given in reference to their similarity to the aerodynamic performance of a perfect sphere. Read more here. Federal Equivalent MethodsSome Federal Equivalent Methods (FEMs) for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass of particles may be measured or calculated based on data from an optical PM monitor, or less requently by a beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site. SilicaThere are no national standards for respirable silica in ambient air, although several states have implemented silica standards. Read more on respirable silica and how it relates to PM10 and PM2.5. The ‘action level’ (which used to be a NAAQS) for PM10 is an annual mean of 50 μg/m3, and by assuming 10% PM is silica, that translates as 5 μg/m3 silica. Research has shown that people exposed to ambient PM10 silica concentrations of ~15 μg/m3 is correlated with significant increases in silicosis, but the authors suggest that chronic exposure to 5 μg/m3 silica would be reasonable. It is important to note that these findings are for silica in PM10, not respirable silica, which is only a fraction of the silica in PM10 samples. For respirable silica, ambient exposure guidelines are lower. |
Revert | |
| 25 | stevie |
February 16, 2016 14:57
| about 8 years ago
Small airborne particles can become lodged in the lungs and cause a variety of respiratory and cardiac health impacts, so air quality regulations are concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5, which are particles of less than 10 microns (millionths of a meter) and particles less than 2.5 microns in diameter, respectively. PM is one of six ‘criteria pollutants’ defining National Ambient Air Quality Standards. U.S. federal EPA PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official protocols, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs, and those deemed similar enough to FRMs are classified as Federal Equivalent Methods (FEMs). A list of FRMs and FEMs is available here. The intent of technology-based regulation is to create data that is comparable across space and time by using a single consistent technique. However, technology-based regulation also restricts regulatory judgements on data collected with any tools that have not been approved by federal regulators. Regardless of the demonstrated correlation between a particle monitoring technique and Federal Reference Methods, data may be rejected if it is not collected with the federally specified device. Examples of this occurrence include the case of Air Alliance Houston's rejected data, and Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring. There are countless other stories of citizen-collected data being rejected on the grounds of improper or incompatible sample collection or analysis, regardless of their data quality. Understanding technology-based regulation of particulate matter, and how it differs from what would truly be health-based regulation, will assist in strategically moving towards regulatory judgements against polluters, using particle monitoring tools and/or other advocacy leverage points. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10 μm; PM2.5 as the fraction less than or equal to 2.5 μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles; PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM, according to the conventions promulgated by the EPA, is a standardized indicator of particle pollution, but is not a full representation of particle pollution itself. All measurement techniques have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
PM2.5 FRM monitor is identical to PM10, except for a second impactor for PM2.5 after the impactor for PM10.
As shown in the figure above, PM2.5 is mostly droplets (formed through atmospheric reactions) and combustion byproduct aerosols, but PM2.5 also captures the smallest range of coarse “primary” particles (emitted directly as fine particles, not formed in the atmosphere). PM2.5 is often comprised of sulfate and nitrate aerosols that form as gaseous emissions of sulfur dioxide and nitrogen dioxide react with moisture in the atmosphere to form acidic aerosols (which can further condense to form acid rain). citation: EPA 454-R-04-002, Fig 2. The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 have an “operational definition,” meaning they are defined as the output of specific techniques referred to as Federal Reference Methods (FRM), but are without a more comprehensive definition in nature. Federal regulations themselves have exacting diagrams of FRM instrument construction for operational analyses.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). FRM PM10 monitor in the Code of Federal Regulations:
The FRM instrument collects particles with with a distributed size range, described by a cut point where 50% of particles at the cut point diameter (μm) are entrained into the sample, and 50% are not. This distribution is skewed, however, impacting a higher proportion of particles larger than the cut point, so there is a skewed higher proportion of smaller particles that are collected in the sample. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a labortory and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the instrument, PM concentrations are calculated and expressed in micrograms of particles per cubic meter of air (μm/m3). The FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. Their function is described in Filter-based PM monitoring tools.
Particle Size: real particles & idealized particlesFederal Reference Methods assume that particles are spherical for the sake of computer modeling, so sizes are given in reference to their similarity to the aerodynamic performance of a perfect sphere. Read more here. Federal Equivalent MethodsSome Federal Equivalent Methods (FEMs) for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass of particles may be measured or calculated based on data from an optical PM monitor, or less requently by a beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site. SilicaThere are no national standards for respirable silica in ambient air, although several states have implemented silica standards. Read more on respirable silica and how it relates to PM10 and PM2.5. The ‘action level’ (which used to be a NAAQS) for PM10 is an annual mean of 50 μg/m3, and by assuming 10% PM is silica, that translates as 5 μg/m3 silica. Research has shown that people exposed to ambient PM10 silica concentrations of ~15 μg/m3 is correlated with significant increases in silicosis, but the authors suggest that chronic exposure to 5 μg/m3 silica would be reasonable. It is important to note that these findings are for silica in PM10, not respirable silica, which is only a fraction of the silica in PM10 samples. For respirable silica, ambient exposure guidelines are lower. |
Revert | |
| 24 | stevie |
February 16, 2016 14:54
| about 8 years ago
Small airborne particles can become lodged in the lungs and cause a variety of respiratory and cardiac health impacts, so air quality regulations are concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5, which are particles of less than 10 microns (millionths of a meter) and particles less than 2.5 microns in diameter, respectively. PM is one of six ‘criteria pollutants’ defining National Ambient Air Quality Standards. U.S. federal EPA PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official protocols, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs, and those deemed similar enough to FRMs are classified as Federal Equivalent Methods (FEMs). A list of FRMs and FEMs is available here. The intent of technology-based regulation is to create data that is comparable across space and time by using a single consistent technique. However, technology-based regulation also restricts regulatory judgements on data collected with any tools that have not been approved by federal regulators. Regardless of the demonstrated correlation between a particle monitoring technique and Federal Reference Methods, data may be rejected if it is not collected with the federally specified device. Examples of this occurrence include the case of Air Alliance Houston's rejected data, and Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring. There are countless other stories of citizen-collected data being rejected on the grounds of improper or incompatible sample collection or analysis, regardless of their data quality. Understanding technology-based regulation of particulate matter, and how it differs from what would truly be health-based regulation, will assist in strategically moving towards regulatory judgements against polluters, using particle monitoring tools and/or other advocacy leverage points. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10 μm; PM2.5 as the fraction less than or equal to 2.5 μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles; PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM, according to the conventions promulgated by the EPA, is a standardized indicator of particle pollution, but is not a full representation of particle pollution itself. All measurement techniques have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
PM2.5 FRM monitor is identical to PM10, except for a second impactor for PM2.5 after the impactor for PM10.
As shown in the figure above, PM2.5 is mostly droplets (formed through atmospheric reactions) and combustion byproduct aerosols, but PM2.5 also captures the smallest range of coarse “primary” particles (emitted directly as fine particles, not formed in the atmosphere). PM2.5 is often comprised of sulfate and nitrate aerosols that form as gaseous emissions of sulfur dioxide and nitrogen dioxide react with moisture in the atmosphere to form acidic aerosols (which can further condense to form acid rain). citation: EPA 454-R-04-002, Fig 2. The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 have an “operational definition,” meaning they are defined as the output of specific techniques referred to as Federal Reference Methods (FRM), but are without a more comprehensive definition in nature. Federal regulations themselves have exacting diagrams of FRM instrument construction for operational analyses.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). FRM PM10 monitor in the Code of Federal Regulations:
The FRM instrument collects particles with with a distributed size range, described by a cut point where 50% of particles at the cut point diameter (μm) are entrained into the sample, and 50% are not. This distribution is skewed, however, impacting a higher proportion of particles larger than the cut point, so there is a skewed higher proportion of smaller particles that are collected in the sample. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a labortory and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the instrument, PM concentrations are calculated and expressed in micrograms of particles per cubic meter of air (μm/m3). The FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. Their function is described in Filter-based PM monitoring tools.
Particle Size: real particles & idealized particlesFederal Reference Methods assume that particles are spherical for the sake of computer modeling, so sizes are given in reference to their similarity to the aerodynamic performance of a perfect sphere. Read more here. Federal Equivalent MethodsSome Federal Equivalent Methods (FEMs) for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass of particles may be measured or calculated based on data from an optical PM monitor, or less requently by a beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site. SilicaThere are no national standards for respirable silica in ambient air, although several states have implemented silica standards. Read more on respirable silica and how it relates to PM10 and PM2.5. The ‘action level’ (which used to be a NAAQS) for PM10 is an annual mean of 50 μg/m3, and by assuming 10% PM is silica, that translates as 5 μg/m3 silica. Research has shown that people exposed to ambient PM10 silica concentrations of ~15 μg/m3 is correlated with significant increases in silicosis, but the authors suggest that chronic exposure to 5 μg/m3 silica would be reasonable. It is important to note that these findings are for silica in PM10, not respirable silica, which is only a fraction of the silica in PM10 samples. For respirable silica, ambient exposure guidelines are lower. |
Revert | |
| 23 | stevie |
February 16, 2016 14:52
| about 8 years ago
Small airborne particles can become lodged in the lungs and cause a variety of respiratory and cardiac health impacts, so air quality regulations are concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5, which are particles of less than 10 microns (millionths of a meter) and particles less than 2.5 microns in diameter, respectively. PM is one of six ‘criteria pollutants’ defining National Ambient Air Quality Standards. U.S. federal EPA PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official protocols, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs, and those deemed similar enough to FRMs are classified as Federal Equivalent Methods (FEMs). A list of FRMs and FEMs is available here. The intent of technology-based regulation is to create data that is comparable across space and time by using a single consistent technique. However, technology-based regulation also restricts regulatory judgements on data collected with any tools that have not been approved by federal regulators. Regardless of the demonstrated correspondence between a particle monitoring technique and Federal Reference Methods, data may be rejected if it is not collected with the federally specified device. Examples of this occurrence include the case of Air Alliance Houston's rejected data, and Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring. There are countless other stories of citizen-collected data being rejected on the grounds of improper or incompatible sample collection or analysis, regardless of their data quality. Understanding technology-based regulation of particulate matter, and how it differs from what would truly be health-based regulation, will assist in strategically moving towards regulatory judgements against polluters, using particle monitoring tools and/or other advocacy leverage points. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10 μm; PM2.5 as the fraction less than or equal to 2.5 μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles; PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM, according to the conventions promulgated by the EPA, is a standardized indicator of particle pollution, but is not a full representation of particle pollution itself. All measurement techniques have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
PM2.5 FRM monitor is identical to PM10, except for a second impactor for PM2.5 after the impactor for PM10.
As shown in the figure above, PM2.5 is mostly droplets (formed through atmospheric reactions) and combustion byproduct aerosols, but PM2.5 also captures the smallest range of coarse “primary” particles (emitted directly as fine particles, not formed in the atmosphere). PM2.5 is often comprised of sulfate and nitrate aerosols that form as gaseous emissions of sulfur dioxide and nitrogen dioxide react with moisture in the atmosphere to form acidic aerosols (which can further condense to form acid rain). citation: EPA 454-R-04-002, Fig 2. The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 have an “operational definition,” meaning they are defined as the output of specific techniques referred to as Federal Reference Methods (FRM), but are without a more comprehensive definition in nature. Federal regulations themselves have exacting diagrams of FRM instrument construction for operational analyses.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). FRM PM10 monitor in the Code of Federal Regulations:
The FRM instrument collects particles with with a distributed size range, described by a cut point where 50% of particles at the cut point diameter (μm) are entrained into the sample, and 50% are not. This distribution is skewed, however, impacting a higher proportion of particles larger than the cut point, so there is a skewed higher proportion of smaller particles that are collected in the sample. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a labortory and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the instrument, PM concentrations are calculated and expressed in micrograms of particles per cubic meter of air (μm/m3). The FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. Their function is described in Filter-based PM monitoring tools.
Particle Size: real particles & idealized particlesFederal Reference Methods assume that particles are spherical for the sake of computer modeling, so sizes are given in reference to their similarity to the aerodynamic performance of a perfect sphere. Read more here. Federal Equivalent MethodsSome Federal Equivalent Methods (FEMs) for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass of particles may be measured or calculated based on data from an optical PM monitor, or less requently by a beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site. SilicaThere are no national standards for respirable silica in ambient air, although several states have implemented silica standards. Read more on respirable silica and how it relates to PM10 and PM2.5. The ‘action level’ (which used to be a NAAQS) for PM10 is an annual mean of 50 μg/m3, and by assuming 10% PM is silica, that translates as 5 μg/m3 silica. Research has shown that people exposed to ambient PM10 silica concentrations of ~15 μg/m3 is correlated with significant increases in silicosis, but the authors suggest that chronic exposure to 5 μg/m3 silica would be reasonable. It is important to note that these findings are for silica in PM10, not respirable silica, which is only a fraction of the silica in PM10 samples. For respirable silica, ambient exposure guidelines are lower. |
Revert | |
| 22 | mathew |
February 16, 2016 08:56
| about 8 years ago
Small airborne particles can become lodged in the lungs and cause a variety of respiratory and cardiac health impacts, so air quality regulations are concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5, which are particles of less than 10 microns (millionths of a meter) and particles less than 2.5 microns in diameter, respectively. PM is one of six ‘criteria pollutants’ defining National Ambient Air Quality Standards. U.S. federal EPA PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official protocols, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs, and those deemed similar enough to FRMs are classified as Federal Equivalent Methods (FEMs). A list of FRMs and FEMs is available here. The intent of technology-based regulation is to create data that is comparable across space and time by using a single consistent technique. However, technology-based regulation also restricts regulatory judgements on data collected with any tools that have not been approved by federal regulators. Regardless of the demonstrated correspondence between a particle monitoring technique and Federal Reference Methods, data may be rejected if collected with the federally specified device. Examples of this occurrence include the case of Air Alliance Houston's rejected data, and Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring. There are countless other stories of citizen-collected data being rejected on the grounds of improper or incompatible sample collection or analysis, regardless of their data quality. Understanding technology-based regulation of particulate matter, and how it differs from what would truly be health-based regulation, will assist in strategically moving towards regulatory judgements against polluters, using particle monitoring tools and/or other advocacy leverage points. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10 μm; PM2.5 as the fraction less than or equal to 2.5 μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles; PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM, according to the conventions promulgated by the EPA, is a standardized indicator of particle pollution, but is not a full representation of particle pollution itself. All measurement techniques have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
PM2.5 FRM monitor is identical to PM10, except for a second impactor for PM2.5 after the impactor for PM10.
As shown in the figure above, PM2.5 is mostly droplets (formed through atmospheric reactions) and combustion byproduct aerosols, but PM2.5 also captures the smallest range of coarse “primary” particles (emitted directly as fine particles, not formed in the atmosphere). PM2.5 is often comprised of sulfate and nitrate aerosols that form as gaseous emissions of sulfur dioxide and nitrogen dioxide react with moisture in the atmosphere to form acidic aerosols (which can further condense to form acid rain). citation: EPA 454-R-04-002, Fig 2. The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 have an “operational definition,” meaning they are defined as the output of specific techniques referred to as Federal Reference Methods (FRM), but are without a more comprehensive definition in nature. Federal regulations themselves have exacting diagrams of FRM instrument construction for operational analyses.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). FRM PM10 monitor in the Code of Federal Regulations:
The FRM instrument collects particles with with a distributed size range, described by a cut point where 50% of particles at the cut point diameter (μm) are entrained into the sample, and 50% are not. This distribution is skewed, however, impacting a higher proportion of particles larger than the cut point, so there is a skewed higher proportion of smaller particles that are collected in the sample. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a labortory and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the instrument, PM concentrations are calculated and expressed in micrograms of particles per cubic meter of air (μm/m3). The FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. Their function is described in Filter-based PM monitoring tools.
Particle Size: real particles & idealized particlesFederal Reference Methods assume that particles are spherical for the sake of computer modeling, so sizes are given in reference to their similarity to the aerodynamic performance of a perfect sphere. Read more here. Federal Equivalent MethodsSome Federal Equivalent Methods (FEMs) for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass of particles may be measured or calculated based on data from an optical PM monitor, or less requently by a beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site. SilicaThere are no national standards for respirable silica in ambient air, although several states have implemented silica standards. Read more on respirable silica and how it relates to PM10 and PM2.5. The ‘action level’ (which used to be a NAAQS) for PM10 is an annual mean of 50 μg/m3, and by assuming 10% PM is silica, that translates as 5 μg/m3 silica. Research has shown that people exposed to ambient PM10 silica concentrations of ~15 μg/m3 is correlated with significant increases in silicosis, but the authors suggest that chronic exposure to 5 μg/m3 silica would be reasonable. It is important to note that these findings are for silica in PM10, not respirable silica, which is only a fraction of the silica in PM10 samples. For respirable silica, ambient exposure guidelines are lower. |
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| 21 | mathew |
February 16, 2016 08:55
| about 8 years ago
Small airborne particles can become lodged in the lungs and cause a variety of respiratory and cardiac health impacts, so air quality regulations are concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5, which are particles of less than 10 microns (millionths of a meter) and particles less than 2.5 microns in diameter, respectively. PM is one of six ‘criteria pollutants’ defining National Ambient Air Quality Standards. U.S. federal EPA PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official protocols, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs, and those deemed similar enough to FRMs are classified as Federal Equivalent Methods (FEMs). A list of FRMs and FEMs is available here. The intent of technology-based regulation is to create data that is comparable across space and time by using a single consistent technique. However, technology-based regulation also restricts regulatory judgements on data collected with any tools that have not been approved by federal regulators. Regardless of the demonstrated correspondence between a particle monitoring technique and Federal Reference Methods, data may be rejected if collected with the federally specified device. Examples of this occurrence include the case of Air Alliance Houston's rejected data, and Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring. There are countless other stories of citizen-collected data being rejected on the grounds of improper or incompatible sample collection or analysis, regardless of their data quality. Understanding technology-based regulation of particulate matter, and how it differs from what would truly be health-based regulation, will assist in strategically moving towards regulatory judgements against polluters, using particle monitoring tools and/or other advocacy leverage points. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10 μm; PM2.5 as the fraction less than or equal to 2.5 μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles; PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM, according to the conventions promulgated by the EPA, is a standardized indicator of particle pollution, but is not a full representation of particle pollution itself. All measurement techniques have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
As shown in the figure above, PM2.5 is mostly droplets (formed through atmospheric reactions) and combustion byproduct aerosols, but PM2.5 also captures the smallest range of coarse “primary” particles (emitted directly as fine particles, not formed in the atmosphere). PM2.5 is often comprised of sulfate and nitrate aerosols that form as gaseous emissions of sulfur dioxide and nitrogen dioxide react with moisture in the atmosphere to form acidic aerosols (which can further condense to form acid rain). citation: EPA 454-R-04-002, Fig 2. The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 have an “operational definition,” meaning they are defined as the output of specific techniques referred to as Federal Reference Methods (FRM), but are without a more comprehensive definition in nature. Federal regulations themselves have exacting diagrams of FRM instrument construction for operational analyses.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). FRM PM10 monitor in the Code of Federal Regulations:
The FRM instrument collects particles with with a distributed size range, described by a cut point where 50% of particles at the cut point diameter (μm) are entrained into the sample, and 50% are not. This distribution is skewed, however, impacting a higher proportion of particles larger than the cut point, so there is a skewed higher proportion of smaller particles that are collected in the sample. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a labortory and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the instrument, PM concentrations are calculated and expressed in micrograms of particles per cubic meter of air (μm/m3). The FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. Their function is described in Filter-based PM monitoring tools.
PM2.5 FRM monitor is identical to PM10, except for a second impactor for PM2.5 after the impactor for PM10.
[DIAGRAM] Particle Size: real particles & idealized particlesFederal Reference Methods assume that particles are spherical for the sake of computer modeling, so sizes are given in reference to their similarity to the aerodynamic performance of a perfect sphere. Read more here. Federal Equivalent MethodsSome Federal Equivalent Methods (FEMs) for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass of particles may be measured or calculated based on data from an optical PM monitor, or less requently by a beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site. SilicaThere are no national standards for respirable silica in ambient air, although several states have implemented silica standards. Read more on respirable silica and how it relates to PM10 and PM2.5. The ‘action level’ (which used to be a NAAQS) for PM10 is an annual mean of 50 μg/m3, and by assuming 10% PM is silica, that translates as 5 μg/m3 silica. Research has shown that people exposed to ambient PM10 silica concentrations of ~15 μg/m3 is correlated with significant increases in silicosis, but the authors suggest that chronic exposure to 5 μg/m3 silica would be reasonable. It is important to note that these findings are for silica in PM10, not respirable silica, which is only a fraction of the silica in PM10 samples. For respirable silica, ambient exposure guidelines are lower. |
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| 20 | gretchengehrke |
February 16, 2016 03:07
| about 8 years ago
Small airborne particles can become lodged in the lungs and cause a variety of respiratory and cardiac health impacts, so air quality regulations are concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5, which are particles of less than 10 microns (millionths of a meter) and particles less than 2.5 microns in diameter, respectively. PM is one of six ‘criteria pollutants’ defining National Ambient Air Quality Standards. U.S. federal EPA PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official protocols, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs, and those deemed similar enough to FRMs are classified as Federal Equivalent Methods (FEMs). A list of FRMs and FEMs is available here. The intent of technology-based regulation is to create data that is comparable across space and time by using a single consistent technique. However, technology-based regulation also restricts regulatory judgements on data collected with any tools that have not been approved by federal regulators. Regardless of the demonstrated correspondence between a particle monitoring technique and Federal Reference Methods, data may be rejected if collected with the federally specified device. Examples of this occurrence include the case of Air Alliance Houston's rejected data, and Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring. There are countless other stories of citizen-collected data being rejected on the grounds of improper or incompatible sample collection or analysis, regardless of their data quality. Understanding technology-based regulation of particulate matter, and how it differs from what would truly be health-based regulation, will assist in strategically moving towards regulatory judgements against polluters, using particle monitoring tools and/or other advocacy leverage points. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10 μm; PM2.5 as the fraction less than or equal to 2.5 μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles; PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM, according to the conventions promulgated by the EPA, is a standardized indicator of particle pollution, but is not a full representation of particle pollution itself. All measurement techniques have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
As shown in the figure above, PM2.5 is mostly droplets (formed through atmospheric reactions) and combustion byproduct aerosols, but PM2.5 also captures the smallest range of coarse “primary” particles (emitted directly as fine particles, not formed in the atmosphere). PM2.5 is often comprised of sulfate and nitrate aerosols that form as gaseous emissions of sulfur dioxide and nitrogen dioxide react with moisture in the atmosphere to form acidic aerosols (which can further condense to form acid rain). citation: EPA 454-R-04-002, Fig 2. The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 have an “operational definition,” meaning they are defined as the output of specific techniques referred to as Federal Reference Methods (FRM), but are without a more comprehensive definition in nature. Federal regulations themselves have exacting diagrams of FRM instrument construction for operational analyses.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). The FRM instrument collects particles with with a distributed size range, described by a cut point where 50% of particles at the cut point diameter (μm) are entrained into the sample, and 50% are not. This distribution is skewed, however, impacting a higher proportion of particles larger than the cut point, so there is a skewed higher proportion of smaller particles that are collected in the sample. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a labortory and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the instrument, PM concentrations are calculated and expressed in micrograms of particles per cubic meter of air (μm/m3). The FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. Their function is described in Filter-based PM monitoring tools. [DIAGRAM] Particle Size: real particles & idealized particlesFederal Reference Methods assume that particles are spherical for the sake of computer modeling, so sizes are given in reference to their similarity to the aerodynamic performance of a perfect sphere. Read more here. Federal Equivalent MethodsSome Federal Equivalent Methods (FEMs) for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass of particles may be measured or calculated based on data from an optical PM monitor, or less requently by a beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site. SilicaThere are no national standards for respirable silica in ambient air, although several states have implemented silica standards. Read more on respirable silica and how it relates to PM10 and PM2.5. The ‘action level’ (which used to be a NAAQS) for PM10 is an annual mean of 50 μg/m3, and by assuming 10% PM is silica, that translates as 5 μg/m3 silica. Research has shown that people exposed to ambient PM10 silica concentrations of ~15 μg/m3 is correlated with significant increases in silicosis, but the authors suggest that chronic exposure to 5 μg/m3 silica would be reasonable. It is important to note that these findings are for silica in PM10, not respirable silica, which is only a fraction of the silica in PM10 samples. For respirable silica, ambient exposure guidelines are lower. |
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| 19 | stevie |
February 15, 2016 23:27
| about 8 years ago
Small airborne particles can become lodged in the lungs, and so regulations are especially concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5; the numbers indicate the median diameter of collected particles in microns (millionths of a meter). US federal PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official guidelines, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs. The intent of technology-based regulation is to create data that is comparable from region to region and across long periods of time by referencing everything back to a single technique. However, technology-based regulation also restricts regulatory judgements to data collected with tools that have been approved by federal regulators. Regardless of the demonstrated correspondence between a particle monitoring tool and Federal Reference Methods, data may be rejected if collected with a device that isn't specifically written into federal regulations. Examples, include the case Air Alliance Houston's rejected data, and [Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring.] @GretchenGehrke @Liz @Stevie throw a better link in here than my note? Understanding technology-based regulation of particulate matter will assist in strategically moving towards regulatory judgements against polluters, either with particle monitoring tools or other organizing strategies. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10μm. PM2.5 as the fraction less than or equal to 2.5μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles. PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM is an standardized indicator of particle pollution not particle pollution itself. All measurement tools have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
As shown in the figure above, although an indicator of fine particles, PM2.5 mostly captures the smallest range of coarse particles. (citation: EPA/600/P-95/001aF, 3-13). The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 are defined as the output of specific machines referred to as Federal Reference Methods (FRM). The federal regulations themselves have exacting diagrams of FRM construction.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). The FRM collects particles with with a distributed size range, with 50% of particles larger than the μm and 50% below the cut point. This distribution is skewed, however, capturing a greater range of particles above the cut point captured than below it. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a lab and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the FRM, PM concentrations are calculated and expressed in micrograms per cubic meter (μm/m3). FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. [DIAGRAM] DESCRIBE IMPACTOR Particle Size: real particles & idealized particlesAerodynamic Diameter By diameter, the literature means "mass median aerodynamic diameter" which is a way of saying particles that fall through the air at the same rate as a perfect sphere of 10μm. Regulatory Judgements: NAAQSCalculating Correspondence with FRMFederal Equivalent MethodsThe FEMs for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass may be measured by the beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site SilicaThe ‘action level’ for PM10 is an annual mean of 50μg/m3, assuming 10%, or 5μg/m3 silica. Research suggests that 1 in 300 people exposed to these levels will develop silicosis, while non-occupatial exposure of ~15μg/m3 of PM10 is correlated with significant increases in silicosis. There are no specific national standards for respirable silica, although several states have implemented silica standards http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3683189/ MORE ON PM4 ignore. extra stuff for now: Types of particle emissionsResearchers speak of two types of emissions that have a blurry line between them, 'process stream' emissions and 'fugitive emissions.' Process stream emissions are inherent to a process, like ash from a fire, and fugitive emissions are ancillary, like the dust kicked up bringing wood to a fire [[EPA 3-2] (http://ofmpub.epa.gov/eims/eimscomm.getfile?p_download_id=4608)]. Monitoring particle sizeParticles of ConcernSilica For silica, particles smaller than 4μm are considered the most dangerous. The family of chemicals that make up Particulate Matter are subdivided into the different regulated pollutants:
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| 18 | mathew |
February 03, 2016 02:50
| about 8 years ago
Small airborne particles can become lodged in the lungs, and so regulations are especially concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5; the numbers indicate the median diameter of collected particles in microns (millionths of a meter). US federal PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official guidelines, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs. The intent of technology-based regulation is to create data that is comparable from region to region and across long periods of time by referencing everything back to a single technique. However, technology-based regulation also restricts regulatory judgements to data collected with tools that have been approved by federal regulators. Regardless of the demonstrated correspondence between a particle monitoring tool and Federal Reference Methods, data may be rejected if collected with a device that isn't specifically written into federal regulations. Examples, include the case Air Alliance Houston's rejected data, and [Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring.] @GretchenGehrke @Liz @Stevie throw a better link in here than my note? Understanding technology-based regulation of particulate matter will assist in strategically moving towards regulatory judgements against polluters, either with particle monitoring tools or other organizing strategies. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10μm. PM2.5 as the fraction less than or equal to 2.5μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles. PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM is an standardized indicator of particle pollution not particle pollution itself. All measurement tools have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
As shown in the figure above, although an indicator of fine particles, PM2.5 mostly captures the smallest range of coarse particles. (citation: EPA/600/P-95/001aF, 3-13). The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 are defined as the output of specific machines referred to as Federal Reference Methods (FRM). The federal regulations themselves have exacting diagrams of FRM construction.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). The FRM collects particles with with a distributed size range, with 50% of particles larger than the μm and 50% below the cut point. This distribution is skewed, however, capturing a greater range of particles above the cut point captured than below it. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a lab and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the FRM, PM concentrations are calculated and expressed in micrograms per cubic meter (μm/m3). FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. [DIAGRAM] DESCRIBE IMPACTOR Particle Size: real particles & idealized particlesAerodynamic Diameter By diameter, the literature means "mass median aerodynamic diameter" which is a way of saying particles that fall through the air at the same rate as a perfect sphere of 10μm. Regulatory Judgements: NAAQSCalculating Correspondence with FRMFederal Equivalent MethodsThe FEMs for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass may be measured by the beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site SilicaThe ‘action level’ for PM10 is an annual mean of 50μg/m3, assuming 10%, or 5μg/m3 silica. Research suggests that 1 in 300 people exposed to these levels will develop silicosis, while non-occupatial exposure of ~15μg/m3 of PM10 is correlated with significant increases in silicosis. There are no specific national standards for respirable silica, although several states have implemented silica standards http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3683189/ MORE ON PM4 ignore. extra stuff for now: Types of particle emissionsResearchers speak of two types of emissions that have a blurry line between them, 'process stream' emissions and 'fugitive emissions.' Process stream emissions are inherent to a process, like ash from a fire, and fugitive emissions are ancillary, like the dust kicked up bringing wood to a fire [[EPA 3-2] (http://ofmpub.epa.gov/eims/eimscomm.getfile?p_download_id=4608)]. Monitoring particle sizeParticles of ConcernSilica For silica, particles smaller than 4μm are considered the most dangerous. The family of chemicals that make up Particulate Matter are subdivided into the different regulated pollutants:
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| 17 | mathew |
January 22, 2016 02:34
| about 8 years ago
Small airborne particles can become lodged in the lungs, and so regulations are especially concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5; the numbers indicate the median diameter of collected particles in microns (millionths of a meter). US federal PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official guidelines, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs. The intent of technology-based regulation is to create data that is comparable from region to region and across long periods of time by referencing everything back to a single technique. However, technology-based regulation also restricts regulatory judgements to data collected with tools that have been approved by federal regulators. Regardless of the demonstrated correspondence between a particle monitoring tool and Federal Reference Methods, data may be rejected if collected with a device that isn't specifically written into federal regulations. Examples, include the case Air Alliance Houston's rejected data, and [Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring.] @GretchenGehrke @Liz @Stevie throw a better link in here than my note? Understanding technology-based regulation of particulate matter will assist in strategically moving towards regulatory judgements against polluters, either with particle monitoring tools or other organizing strategies. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10μm. PM2.5 as the fraction less than or equal to 2.5μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles. PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM is an standardized indicator of particle pollution not particle pollution itself. All measurement tools have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
As shown in the figure above, although an indicator of fine particles, PM2.5 mostly captures the smallest range of coarse particles. (citation: EPA/600/P-95/001aF, 3-13). The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 are defined as the output of specific machines referred to as Federal Reference Methods (FRM). The federal regulations themselves have exacting diagrams of FRM construction.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). The FRM collects particles with with a distributed size range, with 50% of particles larger than the μm and 50% below the cut point. This distribution is skewed, however, capturing a greater range of particles above the cut point captured than below it. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a lab and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the FRM, PM concentrations are calculated and expressed in micrograms per cubic meter (μm/m3). FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. [DIAGRAM] DESCRIBE IMPACTOR Particle Size: real particles & idealized particlesAerodynamic Diameter By diameter, the literature means "mass median aerodynamic diameter" which is a way of saying particles that fall through the air at the same rate as a perfect sphere of 10μm. Regulatory Judgements: NAAQSCalculating Correspondence with FRMFederal Equivalent MethodsThe FEMs for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass may be measured by the beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site ignore. extra stuff for now: Types of particle emissionsResearchers speak of two types of emissions that have a blurry line between them, 'process stream' emissions and 'fugitive emissions.' Process stream emissions are inherent to a process, like ash from a fire, and fugitive emissions are ancillary, like the dust kicked up bringing wood to a fire [[EPA 3-2] (http://ofmpub.epa.gov/eims/eimscomm.getfile?p_download_id=4608)]. Monitoring particle sizeParticles of ConcernSilica For silica, particles smaller than 4μm are considered the most dangerous. The family of chemicals that make up Particulate Matter are subdivided into the different regulated pollutants:
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| 16 | mathew |
January 22, 2016 02:31
| about 8 years ago
Small airborne particles can become lodged in the lungs, and so regulations are especially concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5; the numbers indicate the median diameter of collected particles in microns (millionths of a meter). US federal PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official guidelines, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs. The intent of technology-based regulation is to create data that is comparable from region to region and across long periods of time by referencing everything back to a single technique. However, technology-based regulation also restricts regulatory judgements to data collected with tools that have been approved by federal regulators. Regardless of the demonstrated correspondence between a particle monitoring tool and Federal Reference Methods, data may be rejected if collected with a device that isn't specifically written into federal regulations. Examples, include the case Air Alliance Houston's rejected data, and [Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring.] @GretchenGehrke @Liz @Stevie throw a better link in here than my note? Understanding technology-based regulation of particulate matter will assist in strategically moving towards regulatory judgements against polluters, either with particle monitoring tools or other organizing strategies. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM10 is often described as the fraction of airborne particles that are less than or equal to 10μm. PM2.5 as the fraction less than or equal to 2.5μm. PM10-2.5 Is described as the 'coarse' fraction of airborne particles. PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM is an standardized indicator of particle pollution not particle pollution itself. All measurement tools have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
As shown in the figure above, although an indicator of fine particles, PM2.5 mostly captures the smallest range of coarse particles. (citation: EPA/600/P-95/001aF, 3-13). The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 are defined as the output of specific machines referred to as Federal Reference Methods (FRM). The federal regulations themselves have exacting diagrams of FRM construction.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). The FRM collects particles with with a distributed size range, with 50% of particles larger than the μm and 50% below the cut point. This distribution is skewed, however, capturing a greater range of particles above the cut point captured than below it. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a lab and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the FRM, PM concentrations are calculated and expressed in micrograms per cubic meter (μm/m3). FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. [DIAGRAM] DESCRIBE IMPACTOR Particle Size: real particles & idealized particlesAerodynamic Diameter Regulatory Judgements: NAAQSCalculating Correspondence with FRMFederal Equivalent MethodsThe FEMs for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass may be measured by the beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site Types of particle emissionsResearchers speak of two types of emissions that have a blurry line between them, 'process stream' emissions and 'fugitive emissions.' Process stream emissions are inherent to a process, like ash from a fire, and fugitive emissions are ancillary, like the dust kicked up bringing wood to a fire [[EPA 3-2] (http://ofmpub.epa.gov/eims/eimscomm.getfile?p_download_id=4608)]. Monitoring particle sizeBy diameter, the literature means "mass median aerodynamic diameter" which is a way of saying particles that fall through the air at the same rate as a perfect sphere of 10μm. Particles of ConcernSilica For silica, particles smaller than 4μm are considered the most dangerous. The family of chemicals that make up Particulate Matter are subdivided into the different regulated pollutants:
From PowerMag/PM2.5: More Than Just Dust EPA Test Methods |
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| 15 | mathew |
January 22, 2016 02:24
| about 8 years ago
Small airborne particles can become lodged in the lungs, and so regulations are especially concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5; the numbers indicate the average diameter of collected particles in microns (millionths of a meter). US federal PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official guidelines, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs. The intent of technology-based regulation is to create data that is comparable from region to region and across long periods of time by referencing everything back to a single technique. However, technology-based regulation also restricts regulatory judgements to data collected with tools that have been approved by federal regulators. Regardless of the demonstrated correspondence between a particle monitoring tool and Federal Reference Methods, data may be rejected if collected with a device that isn't specifically written into federal regulations. Examples, include the case Air Alliance Houston's rejected data, and [Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring.] @GretchenGehrke @Liz @Stevie throw a better link in here than my note? Understanding technology-based regulation of particulate matter will assist in strategically moving towards regulatory judgements against polluters, either with particle monitoring tools or other organizing strategies. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM is an standardized indicator of particle pollution not particle pollution itself. All measurement tools have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
PM10 is often described as the fraction of airborne particles that are less than or equal to 10μm. PM2.5 as the fraction less than or equal to 2.5μm. A third category, PM2.5-10, subtracts PM2.5 from PM10 and is described as the 'coarse' fraction of airborne particles. PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. As shown in the figure above, although an indicator of fine particles, PM2.5 mostly captures the smallest range of coarse particles. (citation: EPA/600/P-95/001aF, 3-13). The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 are defined as the output of specific machines referred to as Federal Reference Methods (FRM). The federal regulations themselves have exacting diagrams of FRM construction.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). The FRM collects particles with with a distributed size range, with 50% of particles larger than the μm and 50% below the cut point. This distribution is skewed, however, capturing a greater range of particles above the cut point captured than below it. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a lab and weighed again to determine the weight of the particulate matter. This process of weighing is called gravimetric analysis . By dividing the weight of the PM by the volume of air pulled through the FRM, PM concentrations are calculated and expressed in micrograms per cubic meter (μm/m3). FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. [DIAGRAM] DESCRIBE IMPACTOR Particle Size: real particles & idealized particlesAerodynamic Diameter Regulatory Judgements: NAAQSCalculating Correspondence with FRMFederal Equivalent MethodsThe FEMs for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass may be measured by the beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site Types of particle emissionsResearchers speak of two types of emissions that have a blurry line between them, 'process stream' emissions and 'fugitive emissions.' Process stream emissions are inherent to a process, like ash from a fire, and fugitive emissions are ancillary, like the dust kicked up bringing wood to a fire [[EPA 3-2] (http://ofmpub.epa.gov/eims/eimscomm.getfile?p_download_id=4608)]. Monitoring particle sizeBy diameter, the literature means "mass median aerodynamic diameter" which is a way of saying particles that fall through the air at the same rate as a perfect sphere of 10μm. Particles of ConcernSilica For silica, particles smaller than 4μm are considered the most dangerous. The family of chemicals that make up Particulate Matter are subdivided into the different regulated pollutants:
From PowerMag/PM2.5: More Than Just Dust EPA Test Methods |
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| 14 | mathew |
January 22, 2016 02:16
| about 8 years ago
Small airborne particles can become lodged in the lungs, and so regulations are especially concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5; the numbers indicate the average diameter of collected particles in microns (millionths of a meter). US federal PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official guidelines, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs. The intent of technology-based regulation is to create data that is comparable from region to region and across long periods of time by referencing everything back to a single technique. However, technology-based regulation also restricts regulatory judgements to data collected with tools that have been approved by federal regulators. Regardless of the demonstrated correspondence between a particle monitoring tool and Federal Reference Methods, data may be rejected if collected with a device that isn't specifically written into federal regulations. Examples, include the case Air Alliance Houston's rejected data, and [Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring.] @GretchenGehrke @Liz @Stevie throw a better link in here than my note? Understanding technology-based regulation of particulate matter will assist in strategically moving towards regulatory judgements against polluters, either with particle monitoring tools or other organizing strategies. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM is an standardized indicator of particle pollution not particle pollution itself. All measurement tools have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable.
PM10 is often described as the fraction of airborne particles that are less than or equal to 10μm. PM2.5 as the fraction less than or equal to 2.5μm. A third category, PM2.5-10, subtracts PM2.5 from PM10 and is described as the 'coarse' fraction of airborne particles. PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. As shown in the figure above, although an indicator of fine particles, PM2.5 mostly captures the smallest range of coarse particles. (citation: EPA/600/P-95/001aF, 3-13). The Federal Reference Methods:Technology-based regulation means that PM10 and PM2.5 are defined as the output of specific machines referred to as Federal Reference Methods (FRM). The federal regulations themselves have exacting diagrams of FRM construction.
EPA monitoring site in Houston, TX with PM2.5 monitor (left) and Total Suspended Particles sampler (right). PM2.5 FRM consists of a stack of four components: an inlet impactor, screen, and filter, and pump. [DIAGRAM] DESCRIBE IMPACTOR The FRM collects particles with with a distributed size range, with 50% of particles larger than the μm and 50% below the cut point. This distribution is skewed, however, capturing a greater range of particles above the cut point captured than below it. The rate at which the collection drops off above the cut point is referred to as the sharpness of the cut point.
FRMs collect particles for 24-hours onto a pre-weighed filter. The filter is then taken to a lab and weighed again to determine the weight of the particulate matter. The filter is then dissolved and the particulate matter collected and analyzed in a mass spectrometer. PM concentrations are is expressed in micrograms per cubic meter (μm/m3). Particle Size: real particles & idealized particlesRegulatory Judgements: NAAQSFederal Equivalent MethodsAerodynamic diameter and measured diameter Types of particle emissionsResearchers speak of two types of emissions that have a blurry line between them, 'process stream' emissions and 'fugitive emissions.' Process stream emissions are inherent to a process, like ash from a fire, and fugitive emissions are ancillary, like the dust kicked up bringing wood to a fire [[EPA 3-2] (http://ofmpub.epa.gov/eims/eimscomm.getfile?p_download_id=4608)]. Monitoring particle sizeBy diameter, the literature means "mass median aerodynamic diameter" which is a way of saying particles that fall through the air at the same rate as a perfect sphere of 10μm. David Mack clarifies with summaries of the regulations for PM10 and PM2.5 via EPA 40 CFR Part 50 as summarized in Air Quality Criteria for Particulate Matter (Final Report, April 1996): "The 50% cut point refers to the EFFICIENCY at which particles are removed by the selective inlet at the given size. So for PM10, the inlet removes 50% of particles at 10 microns but above 10 microns the removal efficiency increases and below 10 microns removal efficiency declines. Thus the resultant fraction is not a normal distribution (e.g. 50% above and 50% below) but a skewed distribution (see graph below). Also, the rate at which removal efficiency changes is referred to as the cut point SHARPNESS."
Particles of ConcernThere are a lot of problematic dust particles. Generally speaking, particles smaller than 10μm get lodged in the lungs. But shape, material, and the sharpness of the particles matters. For instance, recently broken particles are sharper and more dangerous than dust that's been blowing around a while and been rounded out. Silica For silica, particles smaller than 4μm are considered the most dangerous. The family of chemicals that make up Particulate Matter are subdivided into the different regulated pollutants:
From PowerMag/PM2.5: More Than Just Dust EPA Test MethodsEPA approved instruments are designated as either a Federal Reference Method (FRM) or Federal Equivalent Methods (FEM). For PM testing, the FRM is typically a manual test method whereby PM is collected on a filter for 24-hours (daily). The mass is determined by gravimetric analysis (weighing the filter before and after sample collection) and the sample volume is calculated based on the air flow rate multiplied by the sample duration. Then the mass concentration (typically in microgram per cubic meter, ug/m3) is calculated as the mass collected divided by the sample volume. The FEMs for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass may be measured by the beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site |
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| 13 | mathew |
January 21, 2016 23:52
| about 8 years ago
Small airborne particles can become lodged in the lungs, and so regulations are especially concerned with respirable particulate matter, abbreviated as PM. Common regulatory categories of PM are PM10 and PM2.5; the numbers indicate the average diameter of collected particles in microns (millionths of a meter). US federal PM regulations are technology-based regulations. Categories of particle pollution are defined by the type of particles captured in specific machines operated according to official guidelines, known as Federal Reference Methods (FRMs). All other measurements are judged in correspondence to FRMs. The intent of technology-based regulation is to create data that is comparable from region to region and across long periods of time by referencing everything back to a single technique. However, technology-based regulation also restricts regulatory judgements to data collected with tools that have been approved by federal regulators. Regardless of the demonstrated correspondence between a particle monitoring tool and Federal Reference Methods, data may be rejected if collected with a device that isn't specifically written into federal regulations. Examples, include the case Air Alliance Houston's rejected data, and [Chippewa Valley Concerned Citizens' mixed success in using DIY monitoring to compel FRM-grade monitoring.] @GretchenGehrke @Liz @Stevie throw a better link in here than my note? Understanding technology-based regulation of particulate matter will assist in strategically moving towards regulatory judgements against polluters, either with particle monitoring tools or other organizing strategies. Read more on strategic thinking and action-oriented resources. Pollutants and Indicators: confusion about PMPM is an standardized indicator of particle pollution not particle pollution itself. All measurement tools have limits, and sometimes pollutants of concern can't be measured directly or can only be measured incompletely. When environmental scientists rely on incomplete or indirect measurements that indicate the presence of a pollutant, they call these measurements indicators. Airborne particles are not equally distributed by size and cluster into three rough size categories: Coarse, Fine, and Ultrafine. Only a subset of airborne particles are respirable. * PM10 is a standardized indicator of respirable particles * PM2.5 an indicator of fine respirable particles that are hardest to clear from the lungs. (citation: EPA/600/P-95/001aF, 3-13)
Notice that although an indicator of fine particles, PM2.5 mostly captures the smallest range of coarse particles. By mass, PM2.5 does capture the majority of respirable particles. PM is stuff on a filter, there is no other definition.
While the small pink spheres the CDC uses to represent PM10 and PM2.5 appear as generic stand-ins for other particles, they are actually describe the theoretical constructs of the PM regulation. PM is NOT a description of airborne particles, is the residue from airborne particles deposited on the filters. This residue PM material captured in the filter of a Federal Reference Method particle monitor sampler and assumed to be spherical and of uniform size. Material captured in the filter of a Federal Reference Method particle monitor sampler and assumed to be both spherical and of uniform size for the purposes of modeling. The three most used indicators of particle pollution are PM10, PM2.5, and PM2.5-10. PM10 is often described as the fraction of airborne particles that are less than or equal to 10μm. PM2.5 as the fraction less than or equal to 2.5μm. A third category, PM2.5-10, subtracts PM2.5 from PM10 and is described as the 'coarse' fraction of airborne particles. PM2.5 is described as the 'fine' fraction. While these conventions are used in public materials by both the EPA and CDC as well as the federal Air Quality Index, they are simplistic explanations that can be misleading. PM10 (Particulate Matter less than 10μm) fine respirable particulate matter: PM2.5 (Particulate Matter less than 2.5μm) nuisance dust: TSP (Total Suspended Particles) Respirable particulate matter and regulatory intentParticle Size: real particles & idealized particlesFederal Reference MethodsFederal Equivalent MethodsStudy DesignAerodynamic diameter and measured diameter Types of particle emissionsResearchers speak of two types of emissions that have a blurry line between them, 'process stream' emissions and 'fugitive emissions.' Process stream emissions are inherent to a process, like ash from a fire, and fugitive emissions are ancillary, like the dust kicked up bringing wood to a fire [[EPA 3-2] (http://ofmpub.epa.gov/eims/eimscomm.getfile?p_download_id=4608)]. Monitoring particle sizeBy diameter, the literature means "mass median aerodynamic diameter" which is a way of saying particles that fall through the air at the same rate as a perfect sphere of 10μm. David Mack clarifies with summaries of the regulations for PM10 and PM2.5 via EPA 40 CFR Part 50 as summarized in Air Quality Criteria for Particulate Matter (Final Report, April 1996): "The 50% cut point refers to the EFFICIENCY at which particles are removed by the selective inlet at the given size. So for PM10, the inlet removes 50% of particles at 10 microns but above 10 microns the removal efficiency increases and below 10 microns removal efficiency declines. Thus the resultant fraction is not a normal distribution (e.g. 50% above and 50% below) but a skewed distribution (see graph below). Also, the rate at which removal efficiency changes is referred to as the cut point SHARPNESS."
Particles of ConcernThere are a lot of problematic dust particles. Generally speaking, particles smaller than 10μm get lodged in the lungs. But shape, material, and the sharpness of the particles matters. For instance, recently broken particles are sharper and more dangerous than dust that's been blowing around a while and been rounded out. Silica For silica, particles smaller than 4μm are considered the most dangerous. The family of chemicals that make up Particulate Matter are subdivided into the different regulated pollutants:
From PowerMag/PM2.5: More Than Just Dust EPA Test MethodsEPA approved instruments are designated as either a Federal Reference Method (FRM) or Federal Equivalent Methods (FEM). For PM testing, the FRM is typically a manual test method whereby PM is collected on a filter for 24-hours (daily). The mass is determined by gravimetric analysis (weighing the filter before and after sample collection) and the sample volume is calculated based on the air flow rate multiplied by the sample duration. Then the mass concentration (typically in microgram per cubic meter, ug/m3) is calculated as the mass collected divided by the sample volume. The FEMs for PM utilize detectors capable of real time reporting. The air sample volume is usually determined by air flow rate and duration akin to the FRM. However, the mass may be measured by the beta ray attenuation method (BAM) or tapered element oscillation method (TEOM). The complete list of approved instruments for NAAQS evaluating is provided on the EPA Ambient Monitoring Technology Information Center (AMTIC) web site |
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