Last month, I noted that EPA’s Office of Air Quality Planning and Standards had released a draft reassessment of the particulate matter NAAQS. In a bold moment of speculation, I indicated that it would be difficult for EPA to avoid lowering the PM2.5 NAAQS to between 8.0 and 10.0 micrograms/cubic meter. Following issuance of the draft, and in order to ensure that EPA does not ignore the emerging scientific consensus,… More