Divided EPA science panel declares soot standard is adequate

Source: By Sean Reilly, E&E News reporter • Posted: Wednesday, December 18, 2019

A divided EPA advisory panel has officially turned thumbs down on the notion that national soot standards need tightening.

In a report released yesterday, a majority on the seven-member Clean Air Scientific Advisory Committee rejected EPA’s preliminary conclusion that the annual limit on fine particulates isn’t strong enough to protect public health.

Those members again faulted a draft roundup of scientific research by career EPA employees that underpinned that conclusion. The roundup “does not provide a sufficiently comprehensive systematic assessment of the available science relevant to understanding the health impacts of exposure to PM [particulate matter],” they wrote in a cover letter to EPA Administrator Andrew Wheeler.

That letter incorporates changes to a previous version that the committee approved at a meeting earlier this month (Greenwire, Dec. 4). It acknowledges the discord over the adequacy of the yearly fine particulate standard.

In accompanying comments, Dr. Mark Frampton, the one remaining dissenter, wrote that studies published in recent years “further strengthen the evidence” linking exposure to “adverse health effects.” Frampton, a retired pulmonologist and professor of medicine at the University of Rochester, reiterated concerns over knowledge gaps both on the committee and in a pool of specially appointed consultants who are supposed to provide added know-how.

None of the committee members is an expert in air pollution epidemiology, he wrote, while the consultant pool also lacks “sufficient expertise and experience” in that research field.

Fine particulates, often dubbed soot, are technically known as PM2.5 because they are no bigger than 2.5 microns in diameter, or one-thirtieth the width of a human hair. They are tied a variety of cardiovascular and lung problems, including a heightened risk of premature death in some circumstances.

The annual standard is currently 12 micrograms per cubic meter of air. In the draft assessment, EPA staff had tentatively said the evidence warranted cutting the limit by as much as one-third in order to prevent a substantial number of early deaths.

The committee, usually known by its acronym CASAC, is statutorily charged with advising EPA during assessments of the ambient air quality standards for particulate matter and five other pollutants.

With one member absent, the panel had initially voted 4-2 in October to stick with the status quo (E&E News PM, Oct. 25).

At this month’s meeting, James Boylan, a state environmental manager from Georgia who initially sided with Frampton, said he had reconsidered his position. At Boylan’s behest, however, the committee today asked Wheeler for the chance to review a second draft of the preliminary staff conclusions — officially known as a “policy assessment” — once the final version of the research roundup is completed.

In its letter, the panel recommended that EPA also add a discussion of the “exceptional nature” of the current review that includes the decision last year by then-Administrator Scott Pruitt to require its completion by the end of 2020, or roughly two years ahead of a previous timetable, and Wheeler’s decision last fall to disband an adjunct panel of researchers that was helping in the review.

The committee is simultaneously working on a review of the national ozone standards. At this month’s meeting, the panel, with Frampton again in opposition, voted 6-1 to keep the primary benchmark of 70 parts per billion set in 2015 to protect public health (Greenwire, Dec. 9).

That review, also on an unusually fast track, is scheduled for completion by next October.