How do I measure pollution levels in a particular place?
February 14, 2017 4:41 AM   Subscribe

We're excited about an amazing elementary school for our daughter...but it's right near a freeway. Is there any clever way to measure the level of air pollution on the playground?

There are some trees, walls, and topographical features that might mitigate the pollution somewhat, but roadway pollution is bad news for developing brains and bodies. I am not crafty or handy, so "simple" build-your-own measurement tools like this one are beyond me. In my dream world, I would wander around the school, wave something surreptitiously in the air -- I don't want this school to think I'm crazy, and we're still waiting to see if our application has been accepted -- and then get a sense of how bad the air quality is. The tools I can find online are thousands of dollars, intended for measuring indoor air quality, or both. Help out an anxious parent, please!
posted by anonymous to Health & Fitness (9 answers total)
 
I don't know where you are in the world, but here in the UK the government collects very detailed information on this kind of thing which is publicly accessible. Try contacting your local environmental health department and ask what information they have on the school's pollution levels.
posted by matthew.alexander at 5:23 AM on February 14, 2017


There are some relatively inexpensive hand-held pollution measurement devices, but they aren't very good for gathering high-quality data for comparison to health-based standards. If you want to find out more about it, see this EPA site.
In general, particle pollution is significantly higher very close to a freeway, and drops off quickly over a short distance.
posted by jkent at 5:52 AM on February 14, 2017 [1 favorite]


This FAQ [pdf] from the EPA on near roadway pollution suggests that 500-600 feet away typically brings pollution back to background levels (from their page How Mobile Source Pollution Affects Your Health).

You could check with your local public library to see if they have an air quality sensor to borrow. In my library system I had several results come up under "air quality monitor" ("air sensor" didn't bring up anything for me), but you may have to try a few different search terms or ask your librarian if they or another nearby library has one.
posted by carrioncomfort at 6:14 AM on February 14, 2017 [2 favorites]


I am amused the EPA says 500-600 ft away. I used to live 1600ft from a freeway and it nearly killed me. I'm sensitive to bad air quality, although it's a chicken and egg thing - I don't know if it developed because I lived there, or if I was always sensitive. Also, despite having a fantastic pulmonologist, I got a lot of "Well, this is just part of getting older." (It wasn't.) My feeling about the EPA is that they can't set the guidelines to what the science says because of cost and political factors. I generally use them as a jumping off point to get into the peer review literature.

All my friends in the old neighborhood with kids wound up buying an at-home nebulizer. I didn't realize how pervasive it was until our pediatrician assumed, based on my zip code, that I just owned one already. And also, to my surprise, I already did. We haven't used the nebulizer once since we moved.

You might wonder if it matters if you're just in the building for school compared to living there. I work in a building that's about 50 feet away from a freeway and have measurably worse lung function on those days, as do the guests to the building. However, I don't know if it's the AQ or the fact that it's a "green" building that tries to do clever things with air intake. It's too new, and it gets washed often enough, for me to use the tips outlined below.

There is an air quality speck out of Carnegie Mellon that you can buy for $150 In Pittsburgh, our libraries check them out for free. If, by some miracle, you live in Allegheny County, someone went out and mapped our roads for AQ.

It also matters which way the wind blows. Around here, houses on the west side of freeways are noticeably cleaner than those on the east. Look up your prevailing winds. If you're in the US, that's public information.

Topo features can actually make AQ worse. Imagine the eddies of a river - walls tend to collect eddies of pollution. There IS free modeling software available but it is super not user friendly and I don't recommend it.

The following is not at all scientific, but it is my first step when checking for AQ and deciding if I need to look further. Go to the side of the building that's facing the freeway. Look for black stains. They're usually most obvious on the flat top part of windowsills or if anything's white, you might see drip stains. They also collect in corners and crevices, if you imagine where the wind eddies would be. Those are particulates. It looks a little different than algae, which grows on the shady sides of buildings, like to the north, or anywhere that stays damp, like around foundations, and which has more of a greenish black look to me. (Your algae stains may look different depending on your local species.) Algae will be a little slimy sometimes, if it's recently rained. Particulates are grimy, grey or black, and just give you ick feelings. If you touch it, it's dryer, maybe more powdery and stains your finger. If you try to wipe it off, some will come off but because of acidic conditions, it's my experience that it tends to eat into surfaces (brick, grout, limestone, glass, vinyl) and leave a black residue. I never did figure out how to get particulate stains out of white vinyl and I tried everything I could think of. Algae, on the other hand, usually washes off with a solution of borax and water and a little scrubbing.

If you're inside the building, look down at the window ledge and look out the glass. It's easy to see the crud on the outside of the windowsill. If it's an older window, look for signs of acid etching (that'll be NOx and SOx). That'll be like looking through dirty glasses, but evenly, so that it's more like it's just not a very good window. It's not exactly that it's dirty - and washing the window will help but not fix the problem - so much that you're looking through a not-quite smooth surface and everything is just a little blurry.

Finally, at least in Pennsylvania, asthma rates of children for *each* school are available online. They might be in your state, too. I looked up the rates for any elementary school we might have bought into and observed significantly higher levels of asthma in those schools. Sure, that could be because the kids were also living and sleeping near the interstate - but it was a go-away sign for my concerns.

Ultimately, we wound up choosing the school district that didn't have the elementary schools literally right on the freeway. Bad lung function is hereditary, so I tend to be more on the cautious side for it.
posted by arabelladragon at 7:19 AM on February 14, 2017 [2 favorites]


You aren't crazy to worry about air quality. It's a serious issue that affects your health. However, measuring air pollution is typically done over an extended period of time, as whatever you intend to measure will vary greatly depending on traffic intensity, wind direction, temperature, humidity, etc. etc. Understand up front that waving a device will only give you a reading of that one point in time. Without context to help you understand that point in time, you still don't have the answer you want.

I'd suggest you reach out to the county health department. They should have an air quality expert on staff who you can talk to. They may have passive sensors they can leave at the site for a while to collect data. Of course, these agencies tend to be severely understaffed, so don't expect an air quality SWAT team to come charging out to help you...
posted by Patapsco Mike at 7:22 AM on February 14, 2017 [3 favorites]


Agree with most of the above. I'm in environmental consulting and have some experience measuring air quality, though not as much with the kind of pollution you get from roads. The others are right that for something like air pollution from a roadway, this isn't something you are going to just measure once and be done with it. There are many factors to consider. Also the cheaper tools aren't going to give you high quality data anyway, they are more like rough estimates.

If I were in your position, I'd reach out to your local and state agencies and see if any studies have been done already for that neighborhood, via a FOIA request (freedom of information act). Depending on where you live, the best agencies are your state Department of Environmental Protection (DEP) / Department of Environmental Quality (DEQ) / Department of Natural Resources (DNR) / State EPA [every state does this a bit different]. You can also reach out to your county health department...usually the health department has no idea what is going on in my experience, but it's still worth a shot. You can also see if your town has any kind of environmental department - some of them do.

The other thing I want to point out is that typically, you can't just start taking environmental samples on property that isn't yours. Collecting air samples and testing them at a school would require the school's permission which usually private property owners do not do unless forced because this introduces potential liability for them (i.e. If you found something they may have to do something per state/local/federal regulations). This varies by state too. Good luck!
posted by FireFountain at 8:30 AM on February 14, 2017


Update from the OP:
Thank you all so much for the help! We're in the San Francisco area, so weather patterns are definitely a factor. I haven't found any online data about pollution levels that is specific enough, but please do let me know if I'm missing anything. We have one month to decide whether to sign up for this school.
posted by LobsterMitten (staff) at 10:30 AM on February 14, 2017


This is... rudimentary, but I once did an elementary school science project involving Vasline smeared on jar lids placed in different spots and then visually measuring (counting? I don't remember exactly how I quantified it) particulates.

Basically the same idea as arabelladragon's window ledge idea except maybe a little more surreptitious because you could set them around the edge of the school property instead of snooping around window sills. But then your jar lids might get ferreted away, or stepped on, etc, etc.
posted by raspberrE at 6:11 PM on February 14, 2017


Didja find this?
https://sanfrancisco.placeilive.com/airpollution#37.77641361883315/-122.44777679443358/15

Or this?
https://www.sfdph.org/dph/files/EHSdocs/AirQuality/AirPollutantExposureZoneMap.pdf

I don't know SF from anywhere else, so I can't help you any better than those, sorry.

It looks like there ARE people in SF tracking your questions, you just need to tap into them. It would be a question of googling for people who do AQ work, asking them questions, and trawling their connections. I'd start by looking for a citizen's grassroots AQ group (if not calling the health department) and then just make friends from there.

Have fun! Air pollution is a fascinating world to learn about.
posted by arabelladragon at 12:31 PM on February 15, 2017


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