5 ms·

I wanted to find an account of what the biggest sources of PM2.5 are in the US. This article discusses traffic fumes (24% of PM2.5), but I was surprised to lear

I wanted to find an account of what the biggest sources of PM2.5 are in the US. This article discusses traffic fumes (24% of PM2.5), but I was surprised to learn that by far, the largest source of PM2.5 - 45% - is “unspecified sources of human origin.” Where does that stuff come from? Well, it’s created in the atmosphere via secondary reactions between agricultural NH3 emissions, SO2 and NOx emissions from shipping and industrial activities and power generation, and NMVOCs from industrial processes and consumption of solvents.[1] Those reactions seem like an interesting area of study and those chemicals involved are far less-often discussed as sources of air pollution even though they seem to combine to form the biggest source [1]https://www.sciencedirect.com/science/article/pii/S1352231015303320 https://www.sciencedirect.com/science/article/pii/S135223101...

zibby8 4y ago
I wonder how important the raw amount of emissions is. Density should decrease at a cubic rate of distance, so being close to a small source of emissions might be worse than being somewhat far from a heavier source.
- projectramo 4y ago
  See for yourself. Propublica plotted a "cancer map" of elevated cancer risks, and you can see how it drops off as you go away from certain points. https://projects.propublica.org/toxmap/ https://projects.propublica.org/toxmap/
  - dylan604 4y ago
    Interesting. One question totally non-sequiter to the toxicity conversation, but why do people that use maps orient the image in a direction other than North being up so that they have to add a label to the image indicating the direction of North?
    - throwaway0a5e 4y ago
      For local navigation (e.g. your phone screen, laying a map on a table, etc) it's generally considered best practice to orient the map so that North is North. For abstract purposes North is up is the standard. I can't think of a good reason to do otherwise unless you're trying to illustrate a point specifically about local navigation (e.g. orienting a map so that the headwaters of a navigable river are at the top).
  - mrtweetyhack 4y ago
- treis 4y ago
  It's pretty hard to separate correlation from causation. There's way more sources of carcinogens than just car generated pollution. And lots of them will tend to correlate with poverty/working class which will tend to correlate with living next to highways.
rufius 4y ago
The other thing people don’t often talk of is PM2.5 inside their home while cooking. Lot of people have poor ventilation or insufficient air movement capacity in their kitchens.
- mavhc 4y ago
  From the food, or the fuel?
  - epistasis 4y ago
    A lot of it is from the natural gas combustion, but the food itself also contributes. The day I got an air quality sensor (to assess risk from wildfire smoke), I realized that my kitchen is basically an asthma factory for the kids. (I haven't actually assessed the risk from that, as its different from wildfires smoke, but j just keep the kids out of the kitchen now until the air clears)
    - jwineinger 4y ago
      I have some air filters with air quality sensors on them, and we have an electric range so there's no natural gas combustion happening. Often when cooking (pan frying especially), those sensors will max out and send the air filters into turbo mode for a good while.
      - epistasis 4y ago
        Yes, hot oils trigger the formaldehyde sensor every time for me. For doing wok frying, I got an outdoor propane burner so that it's far more dilute, and that delicious cancer-causing wok hei is delivered only to our stomachs rather than lungs and stomachs. The outdoor wok burner is also far superior to any indoor residential gas stove too for this purpose.
        krallja 4y ago
        The actors at Conner Prairie, an 1836 "living museum" in central Indiana, explain that some of the nicer houses have a separate out-building just for cooking, to keep the heat away from the main living space, and reduce the risk of burning down the whole house too. Maybe we'll move back to that design, to keep the pollution in the main space down.

zibby8 4y ago

I wonder how important the raw amount of emissions is. Density should decrease at a cubic rate of distance, so being close to a small source of emissions might be worse than being somewhat far from a heavier source.

projectramo 4y ago
See for yourself. Propublica plotted a "cancer map" of elevated cancer risks, and you can see how it drops off as you go away from certain points. https://projects.propublica.org/toxmap/ https://projects.propublica.org/toxmap/
- dylan604 4y ago
  Interesting. One question totally non-sequiter to the toxicity conversation, but why do people that use maps orient the image in a direction other than North being up so that they have to add a label to the image indicating the direction of North?
  - throwaway0a5e 4y ago
    For local navigation (e.g. your phone screen, laying a map on a table, etc) it's generally considered best practice to orient the map so that North is North. For abstract purposes North is up is the standard. I can't think of a good reason to do otherwise unless you're trying to illustrate a point specifically about local navigation (e.g. orienting a map so that the headwaters of a navigable river are at the top).
- mrtweetyhack 4y ago
treis 4y ago
It's pretty hard to separate correlation from causation. There's way more sources of carcinogens than just car generated pollution. And lots of them will tend to correlate with poverty/working class which will tend to correlate with living next to highways.

rufius 4y ago

The other thing people don’t often talk of is PM2.5 inside their home while cooking. Lot of people have poor ventilation or insufficient air movement capacity in their kitchens.

mavhc 4y ago
From the food, or the fuel?
- epistasis 4y ago
  A lot of it is from the natural gas combustion, but the food itself also contributes. The day I got an air quality sensor (to assess risk from wildfire smoke), I realized that my kitchen is basically an asthma factory for the kids. (I haven't actually assessed the risk from that, as its different from wildfires smoke, but j just keep the kids out of the kitchen now until the air clears)
  - jwineinger 4y ago
    I have some air filters with air quality sensors on them, and we have an electric range so there's no natural gas combustion happening. Often when cooking (pan frying especially), those sensors will max out and send the air filters into turbo mode for a good while.
    - epistasis 4y ago
      Yes, hot oils trigger the formaldehyde sensor every time for me. For doing wok frying, I got an outdoor propane burner so that it's far more dilute, and that delicious cancer-causing wok hei is delivered only to our stomachs rather than lungs and stomachs. The outdoor wok burner is also far superior to any indoor residential gas stove too for this purpose.
      - krallja 4y ago
        The actors at Conner Prairie, an 1836 "living museum" in central Indiana, explain that some of the nicer houses have a separate out-building just for cooking, to keep the heat away from the main living space, and reduce the risk of burning down the whole house too. Maybe we'll move back to that design, to keep the pollution in the main space down.