I have written extensively on how the developing science around particulate exposure is making the NAAQS PM2.5 more stringent. It’s no surprise then that a new study published in the Proceedings of the National Academy of Sciences indicates that the benefits of on-road emission reductions from 2008 to 2017 could be measured in hundreds of billions of dollars and nearly 10 000 fewer deaths. The authors go on to note that stricter regulations would provide additional benefits in terms of savings and reduced mortality.
It’s pretty clear to me that the study supports lowering PM2.5 NAAQS. However, I think it does more – it supports complete removal of the NAAQS system. The Clean Air Act requires that the NAAQS be defined to protect 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 safety margin” is probably very low, well below all of them. the levels currently being considered by the EPA.
The problem with the NAAQS approach is that once the NAAQS is defined, regulators and the regulated community only have an incentive to control emissions to achieve or maintain the NAAQS. If we recognize that there are negative impacts resulting from ambient concentrations below the NAAQS, we should want to provide incentives to the regulated community on an ongoing basis. Imposing standards that set an NAAQS and then saying “You will not violate the NAAQS” provides no incentive for continuous improvement.
I do not pretend to be the first person to notice this loophole in the system. Among the many smart people who have raised this issue is my friend Dan Esty, whose article “From red light to green light: from 20th century environmental regulation to 21st century sustainability”Largely focuses on changing our regulatory system to provide continued incentives for pollution reduction.
Spoiler Alert: There is a proven way to do this. It’s called the market.
It’s time to lower NAAQS PM2.5. It is also time to replace the NAAQS approach itself with something better.