Tiny Killers

Tiny particulates are increasing in the air, and at the same time are being recognized more and more as dangerous to human health. The January/February issue of Discover magazine contains a story called Killer Pollution, which says, "recent studies show that long-term exposure to this fine-particle pollution at levels far below what current EPA standards allow is associated with premature death."

For example, we've just had stories in the past few days about children dying in part because of particulate exposure (here and here). And a large-scale analysis by researchers at the Harvard School of Public Health found people with matched demographics had different mortality outcomes depending on their proximity to worse or better air quality. As the Discover writer put it:

Their work showed that tightening annual EPA air quality standards for fine-particulate matter by about 17 percent — from 12 micrograms to 10 micrograms per cubic meter of air — would save 143,257 lives in one decade. The data overwhelmingly confirm that [EPA] standards of this pollutant are too loose...

As for the increase in recent years, check out this data-mapping from the Discover article. This is the change between the 2000 and 2016, just 16 years:

Huge swaths of the country saw their level double and in some areas (like the part of New York I'm from) it looks like the level has tripled. It may not be readable even if you click to enlarge the image, but the difference between 12 and 10 micrograms (the line that the Harvard researchers identified as significant for decreasing mortality) is located just about where the map starts to turn orange on the color scale. It was in a sprinkling of places on the 2000 map. In the 2016 map, at least two-fifths of the lower 48 states' geography and probably 60 percent or more of our population is at or above that unhealthy level.

What's going on? 

I'm sure it's many things, but for much of the increase, I think some of it's from forest fires, some from people burning wood on purpose for heat or outdoor fun fires, while some is from bigger, heavier vehicles. As this article says, electric vehicles won't save us from pollution because the "emissions from tire, brake, clutch, and road wear" combine with stirred up particulates that are already on the road surface. EVs, remember, tend to be heavier because of their batteries, plus we have the whole SUV-tank obsession gripping American car buyers. Heavier vehicles wear out their tires and the road faster and that wear goes into the air.

An OECD study found that "emissions from road traffic might even be worse for health than those from other sources, like burning coal, because they are concentrated in areas with the greatest population density and the most traffic... causing an estimated 4.2 million premature deaths in 2015."

For me, the upshot of all that is that EVs should be condiments, not the main course, of a transportation system transformation to a low-carbon future. If they are passenger vehicles, especially, they should be small and light, not Teslas or Hummers or F150s. And there's a lot you can do with an ebike, especially an cargo ebike, especially if there were fewer dangerous heavy motorized vehicles on the roads.

Decreasing vehicle miles traveled through land use and localism is the way to go.