New results from U.S. Medicare study of low-level exposure to air pollution and health

A new article published June 26 in the journal Science Advances —  “Evaluating the impact of long-term exposure to fine particulate matter on mortality among the elderly” by Wu and colleagues — reports on results from an HEI-funded study of the health effects of low levels of air pollution in some 68 million Medicare recipients (led by Francesca Dominici of the Harvard T.H. Chan School of Public Health). The analysis, which will be submitted this June as part of the investigators’ final (Phase 2) report to HEI and subsequently reviewed rigorously by HEI’s Low-Exposure Epidemiology Studies Review Panel, implements many of the recommendations from that Panel following their review of the Phase 1 report, published in November 2019, in time to inform the review by the U.S. EPA of the National Ambient Air Quality Standards (NAAQS) for PM_2.5 and ozone.

The HEI Review Panel’s detailed review of the completed study is expected to enable the issuance of a final HEI report and Commentary putting these results in context, discussing their strengths and weaknesses, and informing future standard-setting decisions. The investigators of these Medicare results are also developing processes and databases for ensuring that the methods and data used for this research can, to the maximum extent possible, be scrutinized and reproduced, including providing opportunities for data sharing, record linkage, and statistical software.

The Harvard study in the Medicare population is one of three studies of low-level exposure to air pollution and its potential health effects selected competitively for funding by HEI in 2016 to examine such relationships in very large populations in the United States, Canada, and Europe. Using a variety of exposure assessment, epidemiological, and statistical techniques, the studies are designed to address current major uncertainties in air pollution health effects at low levels. HEI expects the results will inform future air quality standards decisions in North America, Europe, and other regions.