Divided CASAC Spars On PM Review But Leans Toward Retaining NAAQS

摘要

Over the advice of agency staff, a majority of EPA's Clean Air Scientific Advisory Committee (CASAC) appears ready to recommend that officials retain existing particulate matter (PM) standards, but some members are questioning how to interpret the latest data and whether they can or should complete their review by the agency's tight deadline. At an Oct. 24 meeting in Cary, NC, four of the seven CASAC members spoke in favor of retaining the national ambient air quality standards (NAAQS) for PM, while two members spoke to back agency staff's call for tightening the NAAQS. The standards must meet a Clean Air Act mandate to protect public health with an adequate margin of safety. A seventh CASAC member has been announced but is yet to join the panel. In addition to the split on the standard, a deep divide on procedural issues emerged at the meeting, with the same two panelists backing stricter NAAQS also calling for a halt to CASAC's review of the PM standards. A halt or delay would risk pushing completion of the review past the Trump administration's goal of finalizing a decision by late 2020 on whether to change the standards.