
U.S. Air Quality Was Improving. Now It’s Getting Worse - pseudolus
https://www.bloomberg.com/news/articles/2019-10-22/u-s-air-quality-was-improving-now-it-s-getting-worse
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sawaruna
> Muller and co-author Karen Clay looked at the substances hanging over U.S.
> cities and found evidence for three potential sources of the pollution
> rebound: increased economic activity, virulent wildfires and a smaller
> number of EPA enforcement actions. It is important to note that the pair
> have not made any causal links between the three suspects and the increase
> of air pollution.

>The U.S. economy has picked up steam overall since 2017. More economic
activity means more vehicles on the roads, driving more miles and emitting
more pollutants. It also means more factories producing emissions along with
consumer goods.

>Soot is another contributor to the pollution jump. The economists traced a
rise in airborne carbon particles in part to wildfire activity in the West
since 2016. (Wildfire activity didn’t play a role in the pollution decline
through 2016, they said.)

>Finally, they also looked at pollution and enforcement trends. If polluters
for some reason fail to follow Clean Air Act rules, PM2.5 can pick up. Clay
and Muller found that EPA enforcement activity has trended down since at least
2009.

