6 ms·
This sounds highly implausible for anything other than very crude and not-very-useful measurements. Quantifying air pollution is a fairly hard problem, chemica
by photochemsyn 4y ago
This sounds highly implausible for anything other than very crude and not-very-useful measurements. Quantifying air pollution is a fairly hard problem, chemically speaking. The composition of particulate matter is highly diverse as it may arise from a wide variety of sources, i.e. agricultural, industrial, wildfires, diesel engines, etc. Just looking at the particulate PM2.5/PM10, broadly speaking there's the organic carbon fraction and the inorganic metal fraction. The former is highly complex, e.g.:
> "The considerably increased chromatographic resolution in GC×GC [gas chromatography] allows separation of many UCM [organic carbon] compounds while the TOFMS [mass spectrometer] supplies mass spectral data of all separated compounds. However, the data sets are getting enormously complex. In a typical PM2.5 sample from Augsburg more than 15,000 peaks can be detected... "
https://www.sciencedirect.com/science/article/abs/pii/S0021967303015498 https://www.sciencedirect.com/science/article/abs/pii/S00219...
Some particulate matter may have a heavy metal fraction, some may not and that's also not easy to determine (but was a major factor in leaded gasoline pollution). Here's a sample of the kind of work that has to be done to get reliable measurements:
> "...using quadrupole inductively coupled plasma – mass spectrometry (q-ICP-MS). We report improved measurements of key aerosol elements including Al, V, Cr, Fe, Ni, Cu, and Zn in airborne coarse particulate matter (PM10)... This technique was used to determine the elemental composition of over 150 PM10 samples collected from an industrialized region in Houston, TX."
https://www.sciencedirect.com/science/article/abs/pii/S0003267010014522 https://www.sciencedirect.com/science/article/abs/pii/S00032...
On top of that there's nitrogen oxides and PAN, ozone, etc. The only relatively inexpensive recent innovations seem to be the use of drones to collect samples for lab analysis (would have been useful in East Palestine).
Getting accurate measurements of all the species involved in air pollution requires a modern analytical lab packed with equipment that costs hundreds of thousands of dollars and highly trained technicians to operate. The press release and snippets from the paper don't address such important details at all.
- ddulaney 4y agoMost definitely it's hard to dig into the actual composition of air pollution. But "how much PM2.5 is in the air", while definitely crude, is still extremely useful. That said, decent sensors for PM concentration are already pretty cheap (<$100 for a module; ~$100 for a full package), so unless the price is going way down it's unclear how useful this particular innovation is.
- ckocagil 4y agoA lot of these cheap, portable sensors "cheat" in one way or another. E.g CO2 sensors that assume they'll be subject to open air once every few days, using that minimal CO2 value as a baseline. So while they give numbers which can be useful if the user is aware of its limitations, they're far from being analytical tools. In contrast PM is pretty easy to get right. Shine laser, count particles.
- Severian 4y agoNot only that, but they are deployed on top of automobiles, where the air quality in the surrounding air is going to be worse to begin with. I understand the benefits of using GPS, but I don't see where they mention this being an issue.
- jve 4y agoWell, it is approximately same height our nose is placed.
- whiplash451 4y agoThere might be a difference between the pollution in the middle of the driveway and the pollution just a few meters away on the sidewalk.
- B1FF_PSUVM 4y agoI spent some hours on Amazon and AliExpress looking at cheap (under 100 bucks) air quality devices, and all I found was junk that made up figures for most "measures", if you read carefully the buyer reviews. I suppose the cheap & good device does not exist, but the junk seems to be selling fairly well. The demand is there, but not the product, and this press release seems another way of cashing in ...
- stephen_g 4y agoBig Clive on YouTube has done some videos on devices like these - like a "CO₂ meter" that seemed to actually just contain a VOC sensor - while it was quite good at detecting things like alcohol vapour, it's just useless as an actual CO₂ sensor. I wouldn't trust anything from AliExpress or anything that's not a known quality brand on Amazon. I'm looking at maybe getting a Davis Instruments AirLink to (at different times) do both indoor and outdoor monitoring for PM1, 2.5 and 10, as well as temperature and humidity, but it's pretty pricy (a bit over AU$300). There's also the new Ikea indoor monitoring device [1] coming out next month too, which should be a lot more affordable I think. 1. https://about.ikea.com/en/newsroom/2023/02/14/ikea-launches-vindstyrka-a-smart-sensor-to-measure-indoor-air-quality https://about.ikea.com/en/newsroom/2023/02/14/ikea-launches-...