Even as the current EPA works to reform the abuses of the Obama-era EPA, there are still many flaws in the quantification of benefits attributed to reductions in fine particulate matter (PM2.5). These flaws need to be corrected through the EPA’s rulemaking processes and reforms to the Clean Air Act.

Key points:

  • The Obama-era EPA used supposed health benefits from reducing PM2.5 below the already safe standard of 12 ug/m^3 to inflate the benefits of a wide array of new air quality regulations.
  • Despite toxicological evidence that humans have a natural resistance to PM2.5, the EPA has consistently applied a “no-threshold” assumption and said that there is no level of pollution that is too low to prevent harm. This assumption should be rigorously examined using toxicological studies and abandoned if not upheld in that field.
  • The EPA needs better toxicological studies and clinical trials demonstrating causal connections between ambient levels of a PM2.5 and adverse health effects. Epidemiological studies relying on statistical correlations are not rigorous enough to justify setting new air quality standards.
  • The EPA needs to justify lowering the standard for PM2.5 before it can claim co-benefits from lowering PM2.5 levels through other regulations.