I want to see if diatoms and a bio-bubbler can help reduce indoor silica dust.

proposal for mitigating indoor silica dust

After reading #eustatic’s ingenious bubbler for improving indoor air [ see: https://publiclab.org/notes/eustatic/12-21-2015/air-plant-bio-bubbler ], it occurred to me that algae, specifically, diatoms, a/k/a brown algae, could be used in a similar way to mitigate indoor silica. Diatoms eat silica and use it to build their cells.

My proposal is to create a bubbler like the one #eustatic made for his office; but one with a larger surface area of water in order to increase light exposure to help diatoms/brown algae thrive. An infusion of diatoms will substitute for the water plant. An aquarium should do for the initial experiment, and grow lights for brown algae photosynthesis. In addition, I plan to add some water plants, goldfish, and maybe a little dirt to help provide other nutrients for the diatoms.

My hope is that the diatoms will absorb the crystalline silica dust found in homes near frack sand mines and trans-load facilities.. Also, I hope that grow lights will be strong enough to enable the diatoms to thrive.

If this works, the residents should be able to scoop out the brown scum in order to get rid of silica and allow light through for continuing growth photosynthesis. The literature I read indicates that brown algae/diatoms like lots of light, even though there are some species which live underground

The diatoms/brown algae can easily be acquired from local ponds near frack sand mines which have to clean up brown algal growths several times a growing season. Diatoms/brown algae usually grow in a boom/bust cycle, as mining does.

In addition, the person who volunteered to host the experiment has a Dylos, which measures pm levels in the air. So if the diatom bubbler works, I hope to see lower pm when it is operating, and lower pm readings than in other areas of the house. Of course, indoor dust/ pm levels are influenced by HVAC systems in the house, the wood-burning stove, cooking & baking, and so forth.

Given the difficulties of measurement, I propose to set up the same equipment in my house, which is in an area where it is believed that there is less silica dust. There is certainly less household dust at our house than the frack sand country house. In addition, last winter, the sand country house had visible dust lying on top of the snow, which is a common sight near frack sand mines. Many people left a bucket out and collected sand from snowfall, but this was not taken seriously by town governments or the WDNR.

The fish pond in the sand country house has a lot of brown scum, a phenomenon which only began when frack sand mining began. The water in the pond has been tested last summer and high silica levels were verified; Also, there were silica deposits at the bottom. Therefore, I think it a reasonable assumption that there are silica eating brown algae/diatoms present. Of course, to go beyond a trial, that assumption needs to be verified. I’m hoping to enlist the department of health and/or university extension if preliminary results look promising.

Fun fact: Diatoms and kelp are both brown algae.

My attempt and results

We plan to attempt this in the beginning of January.

Questions and next steps

I wonder what other nutrients the diatoms will need in addition to silica. I wonder whether room temperature is warm enough for plenty of diatom growth. I wonder if the bubbler will be enough to introduce silica into the water. Perhaps dust falling from room air will also get in the water..

Why I'm interested

I'm interested because a number of people near the sand mines/transloads have developed asthma and some other medical problems that silica dust can cause. Children appear more vulnerable to asthma than adults; but I don't have good statistical evidence of changes in asthma rates of any group. The picture here is an aerial view I photographed of the transload facility in Augusta, Wisconsin.