EPA Scientists' Advice Disregarded

On December 16, 2019, the Clean Air Scientific Advisory Committee (CASAC) to the Environmental Protection Agency (EPA) published its "Review of the EPA's Policy Assessment for the Review of the National Ambient Air Quality Standards for Particulate Matter." A majority of CASAC members rejected the Policy Assessment's finding that existing limits on fine particulate matter (PM2.5) may not adequately protect public health. The majority asserted that EPA scientists had not "provide[d] a sufficiently comprehensive, systematic assessment of the available science relevant to understanding the health impacts of exposure to PM, due largely to a lack of a comprehensive, systematic review of relevant scientific literature." That view was rejected by one CASAC member, Dr. Mark Frampton, who argued that recent scientific studies " further strengthen the evidence linking PM2.5 exposure with adverse health effects." Dr. Frampton expressed concern that CASAC members were unqualified to assess the science. He emphasized that "[n]one of the current chartered CASAC members are experts in air pollution epidemiology" which is "a scientific discipline . . . of key importance in the review of the PM standards." He further noted that, while 12 independent consultants had been appointed to assist CASAC members, those consultants do not have "sufficient expertise and experience in air pollution epidemiology research."

Update:

EPA's Office of Air Quality Planning and Standards published its final "Policy Assessment for the Review of the National Ambient Air Quality Standards for Particulate Matter" in January 2020. The Assessment stated that, "consistent . . . with the advice from the CASAC in this review, we reach the conclusions that the available evidence does not call into question the adequacy of the public health protection afforded by the current primary PM10 standard and that evidence supports consideration of retaining the current standard in this review."

On April 14, 2020, EPA Administrator Andrew Wheeler announced that the existing limits on PM2.5 would be retained. Administrative Wheeler said that, while there are "a lot of uncertainties," EPA "believe[s] the current standard is protective of public health . . . [and] does not need to be changed." 

On June 10, 2020, the Independent Particulate Matter Review Panel, which was formed by members of the disbanded EPA PM review panel, published an article which concludes "unequivocally and unanimously . . . that the current PM_2.5 standards do not adequately protect public health."