By Gretchen Goldman
The Independent Particulate Matter Review Panel has released their consensus recommendations to the EPA administrator on the National Ambient Air Quality Standards for Particulate Matter. The group of 20 independent experts, that were disbanded by Administrator Wheeler last October and reconvened last week, hosted by the Union of Concerned Scientists, has now made clear that the current particulate pollution standards don’t protect public health and welfare.
The Clean Air Scientific Advisory Committee (CASAC) — the remaining seven-person committee that is providing science advice to the EPA on the particulate matter standards — meets this week to discuss their recommendations on whether the current standards are adequate. The letter from the Independent Panel will be the elephant in the room.
The Elephant in the CASAC Meeting
CASAC has already acknowledged that they don’t have the expertise to conduct the review but you know who does? The Independent Panel. The Panel has more than double the experts of CASAC, and importantly, it has multiple experts in each of the necessary scientific disciplines critical to ensure a comprehensive, robust review of the science supporting the standards.
As a result, we should watch whether or not CASAC aligns with the panel in their recommendations on the standards. If CASAC doesn’t decide this week to make a similar recommendation as the Independent Panel, they’ll have to explain why they disagreed with a larger, more experienced, and more diverse set of experts on the topic. In any event, the administrator will have access to both CASAC and the Independent Panel’s recommendations when he ultimately makes the decision of where to set particulate pollution standards. The panel’s recommendations should hold the administrator’s feet to the fire.
The Fine Particulate Matter Standards Don’t Protect Public Health
The standards of greatest interest are the primary PM2.5 standards. These are the standards for particulate matter less than 2.5 micrometers (fine particulate matter) that are designed to protect public health. The panel supported the preliminary conclusions of a Draft EPA Policy Assessment that the current standards aren’t requisite to protect public health.
The letter cited new and consistent epidemiological findings, supported by human and animal studies and other studies with natural experiments, as providing “clear and compelling scientific evidence” for tighter standards. Since the last particulate matter review, several new large-scale epidemiological studies provide powerful evidence that particulate matter is causing adverse health outcomes (such as early death, heart attacks, and respiratory stress) at locations and during time periods with concentrations at or below the level of the current standards.
They write, “New and compelling evidence that health effects are occurring in areas that already meet or are well below the current standards.” Notably, this evidence cuts across different locations with different study populations, different study designs, and different statistical approaches.
Given the weight of the evidence from new studies across scientific disciplines and consistent with the decision-making process that EPA and its science advisers have used for many years, the panel recommends a particulate matter standard between 8 µg/m3 and 10 µg/m3 for the annual PM2.5 standard (compared to the current standard of 12 µg/m3) and between 25 µg/m3 and 30 µg/m3 for the 24-hour standard (compared to the current standard of 35 µg/m3) to protect public health. These ranges are tighter than those recommended in EPA’s Draft Policy Assessment.
