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Seeking GIS / Data folks: Help us create a nation Lead Exposure Risk map.

by read_holman | 11 months ago | 7 | 6

Background on lead at:


Quite a bit of public data exists now that, if brought together, can paint the picture of lead exposure within neighborhoods across the country. This information is useful to a couple audiences: Concerned citizens can see what their risk is; this is general. More specifically and strategically: Community scientists and activists can prioritize where they work. And Public Health officials can prioritize where they work.

There are a few efforts out there, but much of it is local (particular to one city and/or state), or is incomplete or due for an upgrade. We’re seeking data scientists, epidemiologists, and GIS folks to build on these efforts.

The output is a simple map with lead risk scores presented by a geographical unit (census track, neighborhood, etc). The effort should be done in the open and documented (presumably on github, but maybe also here on

If this is interesting to you, let us know and we can figure out how to work together.

The following are examples of work in this area. Each is useful and has strengths but (I think) insufficient.

Example 1: Washington State Department of Health

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Childhood Lead Risk Map For this measure we combined two variables: Percent people living below the 125% Federal Poverty Level (FPL) and Percent Housing built before 1980 (and weighted by era built).

Information About the Data In addition to the census of every U.S. household every 10 years, as required by the U.S. Constitution, the Census Bureau has a sub-sample, yearly survey called the American Community Survey (ACS). This representative sample-based survey gathers characteristics for a subset of the entire population of the U.S. each year.

You can find supporting documentation on code lists, subject definitions, data accuracy, and statistical testing on the ACS website, Data and Documentation section. You can find sample size and data quality measures (including coverage rates, allocation rates, and response rates) on the ACS website in the Methodology section.

Example 2: Vox (with Washington State Department of Health)

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Source: Github:

From the article: “The trouble is that exposure risk is surprisingly difficult estimate, due to a variety of state-by-state differences in reporting standards. So we worked with epidemiologists in Washington state to estimate risk levels in every geographic area in America…

Our map uses a methodology that Washington State’s Department of Health pioneered earlier this year to estimate kids’ risk of lead exposure in different neighborhoods. Their mission was to determine how to focus scarce public health dollars on the kids most at risk of being poisoned by lead. We worked with one of the chief epidemiologists who created the map, Rad Cunningham, to replicate the state’s methodology nationally and apply it to all 72,241 census tracts in the United States.”

Example 3: Reuters

Screen shot of national map made by Reuters


From the article: “Most U.S. states disclose data on the percentage of child blood tests that show elevated levels of lead. Yet this data, often for statewide or county-wide populations, is too broad to identify neighborhoods where children face the greatest risk.

Instead, Reuters sought testing data at the neighborhood level, in census tracts or zip code areas, submitting records requests to all 50 states.

U.S. census tracts are small county subdivisions that average about 4,000 residents apiece. Zip codes have average populations of 7,500. In each area, a relatively small number of children are screened for lead poisoning each year.

Reuters found 2,606 census tracts, and another 278 zip code areas, with a prevalence of lead poisoning at least twice Flint’s rate."

If you're a data guru, GIS epidemiologist, or just someone who wants to contribute to this effort, post a comment below or reach out to Read Holman at Thanks!

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Experiment with polarizing filters to view crystalline dust

by warren | 11 months ago | 3 | 2

Over the years, a lot of people have been looking at crystalline particles under a microscope (like the DIY Community Microscope Kit), and the idea has come up a few times to try using polarizing filters -- for example to try to distinguish crystalline particles from other types of particles.

See #10493, #17785, and others under #polarized-light-microscopy:

How does it work?

The idea (I think) is that crystals "twist" the polarity of light, and so shining polarized light through them, and then re-filtering it with a second polarizer would... block or allow light differently through crystalline particles when compared to non-crystalline particles.

I'd love to hear more specifics from folks on what's happening here, but in any case the effect is that crystalline particles look really different, and change color pretty dramatically when the polarizers are rotated.

You can read a lot more on this, and see some early tests, here: #10493


Crystalline #silica is dangerous to breathe in; please be careful, and plain sand may be a safer thing to test this on unless you're specifically looking for crystalline silica. You can use a respirator as recommended on containers of grout, joint compound, cement or mortar.

What I did was to look at this while wet, so there's very little chance of it getting airborne. I got some from washing out some grout from a tile project, but you can collect dust samples too -- #dust-sampling.

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I took these polarizers from a pair of 3d glasses from a movie theater (they appear kind of grey, not red and blue) - I think we used the left and right lenses. I believe in these the left and right are circularly polarized clockwise and counterclockwise, but I don't know exactly what that means; I also have some linear polarizing film but haven't tried it yet.

To get the filters out, I just broke the glasses and carefully pulled out the lenses, which are flexible film.

You can buy these as an add-on in the Public Lab store here:

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I've drawn the polarizers at 90° angles, but we tried rotating them back and forth to see the color-changing effects pictured. Try different arrangements and report back what you see!


@peasepoint took some great ones at the last #community-microscope workshop at AS220 in Providence, shown below. Post your own in the comments!

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Outreachy 2018 Week 2 and 3

by cess | 12 months ago | 5 | 3


The last two weeks have been quite good. I have made some progress.

I manged to refactor the statistics controller by using scopes in the user, node and revision models so that the queries are quite simple hence less code. e.g This was one instance variable on the statistics controller.

@weekly_notes = type status))
      .where(type: 'note', status: 1, created: @time.to_i - 1.weeks.to_i..@time.to_i)

I made some scopes in the Nodes controller

 scope :status_one, -> { where(status: 1) }
 scope :weekly, -> { status_one.where("created > ?", ( - 7.days).to_i) }

Which changed the method to

 @weekly_notes = 'note').count(:all)  

You can now select a range to view statistics on the /stats/range page. You can do it for past week, month, year or select from a calendar.

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You can also see the statistics on the number of questions answered and asked within a certain period on /questions. image description

I am finishing up on moving statistics methods in the user model to a concern so that its not so long. I am almost done just fixing code climate issues on refactoring some code blocks.

Everybody Struggles

Last week Outreachy requested we share our struggles and the mentors to also share about their struggles. Thanks to the community for sharing your struggles and making me see that I am not alone. Here is a link to the week check-in where some of the contributors shared their struggles.

Here is some of my struggles.

  • I struggled with was date-picker positioning..sounds pretty simple but it was a pain to get it to appear where I wanted, asked for help from the community though the suggestions I got did not solve it I had to make some comprises.

  • Another major struggle was a brakeman issue User controlled method execution it looked critical to ignore. I tried to tweak it a couple of times and much much later solved it by making the method a private method.

  • Currently I am struggling on getting to refactor some two methods that gets code climate complaining. The methods look similar but have varying parts.

Next weeks plans:

Now that the statistics controller is looking a little cleaner, I will be implementing the new ui design for /stats page. I am currently working on a mockup and will attach it here for input when am done. Later on, after the new ui is up, I will implement downloads of stats as csv and json.

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Outreachy 2018: Week One

by cess | about 1 year ago | 6 | 7


This first week I started with attending an open hour on Monday, which was awesome I got to meet members of the community and we discussed about Usability Feedback for PublicLab . Discuss is a bad term to use because I mostly listened in rather than gave ideas. But it was great to hear and see how people use the site and what could be made better and interesting features coming up like the map for the content in the site.

I created a milestone(Extend Community Statistics system) thanks @bansal_sidharth2996 for the suggestion. I like the milestone plan, I just have to keep adding my issues there and it makes me visualize the project more and I can track my progress because the percentage of completion increases with every closed issue.

Initially my plan for week one was to implement the download of statistics by csv and json #963. I started working on it on Tuesday and was making awesome progress and I even got to get the data to display on a page as json and download notes and wikis as a csv and json. But then...
I realized in the end a lot is gonna change in the stats controller and me writing this code now will mean I will have to rewrite everything after I am done with the stats index page. Plus I also realized that the stats controller required a some refactoring.
Time was running out and I had to accomplish something for week 1 so I resulted to refactoring stats page#4147 and also implement issue #4137 which was on the questions page. This gets to give statistics on the questions asked versus the questions answered and can filter by a period say week, monthly and yearly. I do not expect a lot to change on this page during the project and this is an independent feature so implementing this seemed like a visible idea. But all was not in vain for the the raw data stats implementation. I preserved the code I had written to download the content on stats page as json and csv so that when the page is done i will just have to find the right place to insert my code and admins and moderators will be able to download the stats in json and csv format.

Plans for next week

  • Thanks @warren for adding me as one of the reviewers. I plan to be reviewing at least two PRs each day so I can help others get started on plots
  • Finish refactoring the stats controller.
  • Implement consolidation existing "range pages" like with the main stats page#4139
  • Get started on caching of data weekly issue #4138

Thoughts/Clarifications needed/Questions from mentors

  • Thoughts on daru gem? I came across this gem daru which does analysis manipulation and visualization of data in Ruby. Any advice if we should consider incorporating it in the statistics page or if anyone has used it and seen its advantages.
  • Caching of data weekly. I realized this issue was not clear on which pages and content exactly was to be cached. Kindly clarify on this

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Fighting the Flood: Community Activism and Education in Pensacola

by joyofsoy | about 1 year ago | 1 | 3

A version of this story by @stevie is published in Public Lab's Community Science Forum, Issue 15. Photos courtesy of Dr. Gloria Horning.

After several iterations of stormwater projects in the New Orleans area, exploring monitoring tools and strategies, and the challenges with sharing out about localized flooding events, I was surprised to hear about the remarkable parallels happening with stormwater in Pensacola, Florida. Earlier this year, a mapping project in the Indian Bayou area highlighted the problems Pensacola Bay has with stormwater runoff from new roadway development, and friends at the Pensacola NAACP started talking to me about the stormwater flooding and wastewater contamination issues in the communities.

Dr. Gloria Horning came to Pensacola more than eight years ago as an AmeriCorps volunteer following the BP oil disaster. She has worked with disenfranchised communities in CERT (Community Emergency Response Teams) training and has come to know, firsthand, the impacts of development, and subsequent flooding in her local community. "A quick glance into the stormwater problems of the recent past, is in the influx of building and housing construction, and the lack of construction of infrastructure. We have constant flooding in several areas, especially in downtown," says Gloria. "I live here, my house is impacted by it. We can have a ten minute rain event and my street will flood."

Early last summer, Gloria and a small group of concerned residents started down a new path to thinking about what a stormwater project in Pensacola could look like. Exploring the range of issues locally, researching past and ongoing projects, and thinking about outcomes they wanted to see, the group identified a main goal: raising awareness about stormwater issues in Pensacola and what people can do about them.

Runoff problems in Pensacola run the environmental gamut, especially in the historic Tanyard neighborhood, once home to the original port. It was also the site of a sewage treatment plant that was recently moved, but the transition has not been fully completed. The existing stormwater infrastructure runs alongside the sewage pipes; often when there's a problem with either system, both are affected. The result is raw sewage ending up in the stormwater, flooding the community, and spilling into the bay. A recent rain event sent 44,000 gallons of raw sewage into the neighborhood, littering lawns with toilet paper and feminine hygiene products that were never cleaned up.

New development has further exacerbated the problem; the creeks running through the neighborhood and uptown have been filled in, paved over, and built on. Last summer, the city, expecting more housing development, resurfaced the roads, putting pavement on top of pavement. Not only did they not level the new pavement down to the existing storm drains, they also failed to do a pressure test on the road. The added pressure from the new paving burst the sewage pipe that ran underneath it, which had been put in by the Emerald Coast Utility Authority (ECUA) just one year before. From this event alone, 10,000 gallons of raw sewage flooded the neighborhood and a newly finished park, before draining into the bay.

The oversight of Pensacola infrastructure is split between governing bodies. The ECUA manages the sewage system, the county oversees the stormwater system, and the city manages development. Gloria remarks that the distributed management leads to "a lot of finger pointing."

The project that the NAACP and other partners scoped earlier this summer involves a campaign for how to clean storm drains, report flooding events, and educate on the sources of stormwater pollution. "I believe it is up to the citizens to understand what's going on, and to take action. We need to get more people involved---to go and clean the stormwater drains, to attend meetings, and to speak up," says Gloria.

Gloria is now running for the Emerald Coast Utility Authority board to represent her neighborhood in Pensacola. While her campaign goals include opening direct communication between ECUA and the public, and building partnerships with the city and county to promote best practices, she's also working on the front lines of the stormwater issue with the people in her community. She believes that when people see the storm drains as part of a larger system that helps to keep them from flooding, they can work to clean them and advocate for their maintenance. "I've seen it in other communities, and people seem to get it. It's small, but non-confrontational education." She sees this issue is part of something bigger, saying, "You have to look that the science of climate change, and the impact it's having. It's a marathon to fight this problem. It's important, it's awareness, it's education, and a willingness to change a little bit from what we've always been doing." _

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Dr. Gloria Horning, a community activist in Pensacola, is running for a position on her local utility board to help support her residents in her city. Even minor rainfall events are enough to flood neighborhoods in Pensacola, sending raw sewage into the community and out into the bay. image descriptionimage description

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Sustain the Nine: Resilience in the Lower Ninth Ward

by joyofsoy | about 1 year ago | 1 | 0

A version of this story is published in Public Lab's Community Science Forum, Issue 15.

New Orleans' Bayou Bienvenue Wetland Triangle was once a vibrant old-growth cypress swamp, used for everything from boating, camping, and hunting, to bird watching, fishing, and crabbing. It served a vital role in the lives of neighbors in the adjoining Lower Ninth Ward. But in the 1960s, the government wanted to create a faster route from the Gulf of Mexico to the Port of New Orleans so ships could avoid navigating the twists and turns of the Mississippi River to reach the city.

The construction of a 76-mile long canal, the Mississippi River Gulf Outlet (MRGO), destroyed nearly 30,000 acres of wetlands and resulted in saltwater intrusion from the Gulf of Mexico into estuaries, killing the cypress swamps and decimating wildlife habitats. Erosion led to the MRGO quadrupling in width in some areas, affecting more than a million acres of coastal habitat. Even worse, a lack of infrastructure at the ports meant few ships ended up using the channel. Plans to improve the port were quietly forgotten in the 1980s.

With a lack of wetlands to serve as natural protection, the MRGO exacerbated the storm surge during Hurricane Katrina, leading to levee and flood wall failures, devastating huge swaths of land in the Lower Ninth Ward and New Orleans East, and St. Bernard Parish further downstream. Its eventual closure in 2009 took place as a result of the recommendation put forth by NGOs and other key stakeholders. A Congressionally mandated plan was created by the Army Corps of Engineers to help restore the local wetlands to help protect the New Orleans area in future storms. But disagreements between the state and federal government led to lawsuits (still unsettled), with neither side acting to implement the proposed MRGO Ecosystem Restoration Plan. Widespread public support has enhanced restoration efforts, in spite of the legal stalemate, and the state is moving forward with pieces of the plan by using BP dollars in the master plan.

"Our residents deserve to have the bayou restored; it's about creating a healthy ecosystem that can provide some storm surge benefits and recreation, as well as neighborhood beautification," says Happy Johnson, Chief Resilience Officer at the Lower 9th Ward Center for Sustainable Engagement and Development (CSED). "Now that the Mississippi River Gulf Outlet has been closed with a rock dam for some time and the salinity issues are continually evolving, we are optimistic that the Bayou Bienvenue Wetlands Triangle can return to becoming a freshwater cypress swamp through the implementation of key restoration measures. But we have to stay vigilant in our application of engagement and advocacy. We're working closely with National Wildlife Federation, the New Orleans' Office of Resilience and Sustainability, as well as the state's Coastal Protection & Restoration Authority, to push forward comprehensive plans for restoration of the Triangle."

The CSED was founded in 2006 in the aftermath of Hurricane Katrina to help residents of the Lower Ninth Ward rebuild their homes with sustainable and energy-efficient materials, with the help of volunteer and skilled labor. "Our founders sought to support the immediate reconstruction of the Lower Nine in a way that enhanced the health of people and the natural environment; they were also diligent in terms of protecting residents' rights to return," says Happy. "The neighborhood has a strong history of black home-ownership: the highest, at one point, in the entire city. We have fought to sustain the history and culture of this place."

The organization is now focused on creating a sustainable, energy-efficient, and environmentally conscious culture in the ward, with major organizational milestones including the construction and maintenance of the Bayou Bienvenue Observation Deck, the coordination of 5,000 volunteers to rebuild homes and sweep streets, creation of a community garden, and serving as consultants for neighborhood and environmental restoration efforts in the area.

Happy joined members of Public Lab and the Gulf Restoration Network for a recent balloon mapping event on Bayou Bienvenue. "Our staff wanted to balloon map because, while the boundaries of the Triangle have not changed, the ecosystem and wildlife habitat is constantly evolving as a result of climate change and recent hurricane safety measures that control the flow of water in and out of the ecosystem," says Happy. "We want to learn how to track these changes so we can share that knowledge with members of the community and empower them to do something about it. That's why we're out here mapping, and doing soil and salinity testing.

"I'm proud to be a resident of the Lower Ninth Ward with a longtime history here," he continues. "Our residents are committed to a future that involves the complete restoration of our waterways and streets. The key for us with restoration is equity, participation, and inclusion. Design, planning, engineering, construction, and maintenance have to involve residents who live next to the wetlands. That's why we're working with government officials on how to better engage the community. If we try to rebuild the bayou without involving the people around it, then it won't be successful. We want to do this together, in an intentional way."

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Happy Johnson, Chief Resilience Officer at the Lower 9th Ward Center for Sustainable Engagement and Development

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Balloon mapping in the Bayou Bienvenue Wetlands Triangle

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