The Internal Combustion Engine Is Bad For Your Health — What Should We Do About It?

I've written a lot about how the developing science around particulate exposure supports making the PM2.5 NAAQS more stringent.  So it won't come as a surprise that a new study published in the Proceedings of the National Academy of Sciences indicates that the benefits of on-road emissions reductions from 2008 to 2017 could be measured in the hundreds of billions of dollars and almost 10,000 fewer deaths.  The authors go on to note that more stringent regulation would provide additional benefits in economic savings and reduced mortality.

It's pretty clear to me that the study supports lowering the PM2.5 NAAQS.  However, I think it does more – it supports getting rid of the NAAQS system completely.  The Clean Air Act requires that NAAQS be set to protect the public health "with an adequate margin of safety".  Unfortunately, the PNAS study suggests – and this is not unique to particulate pollution – that the level that would truly provide "an adequate margin of