Current concentrations of fine particulate matter pollution, which mostly meet the national ambient air quality standard, are still associated with mortality and loss of life expectancy in the US, with larger impacts in poorer counties, according to a study published July 23 in the open-access journal PLOS Medicine by an international team of researchers from the Center for Air, Climate, and Energy Solutions led by Majid Ezzati of Imperial College London, UK.
Exposure to fine particulate matter pollution (PM2.5) is hazardous to health, and reducing PM2.5 is likely to lower mortality, especially from cardiorespiratory diseases. Yet there is not only resistance to more stringent control of PM2.5, but also attempts to roll back current standards. In the new study, Ezzati and colleagues set out to directly estimate the health and longevity impacts of current PM2.5 concentrations, and the benefits of reductions from 1999 to 2015, nationally and at county level, for the entire contemporary population of the contiguous United States. To do so, they used vital registration and population data with information on sex, age, cause of death and county of residence, as well as statistical models to directly estimate mortality and life expectancy loss.
Even though reductions in PM2.5 since 1999 have lowered mortality in the great majority of counties, PM2.5 pollution in excess of the lowest observed concentration (2.8 μg/m3) was responsible for an estimated 15,612 deaths (95% credible interval 13,248-17,945) in females and for 14,757 deaths (95% credible interval 12,617-16,919) in males. These deaths would lower national life expectancy by an estimated 0.15 years (95% credible interval 0.13-0.17) for women and 0.13 years (95% credible interval 0.11-0.15) for men. The life expectancy loss due to PM2.5 was largest around Los Angeles and in some southern states, such as Arkansas, Oklahoma and Alabama. At any PM2.5 concentration, life expectancy loss was, on average, larger in counties with lower income than in wealthier counties. According to the authors, further lowering PM2.5 pollution is likely to benefit the health of the entire US population, and lower health inequalities.
This study was funded by the US EPA as part of the Center for Clean Air Climate Solution (CACES) (assistance agreement number R835873) (RB, CAP, JM, and ME). The spatial and health impact analyses methods were also funded by the Wellcome Trust (grants 205208/Z/16/Z and 209376/Z/17/Z and Institutional Strategic Support Fund) (JEB, RMP, ME). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.
I have read the journal's policy and the authors of this manuscript have the following competing interests: ME reports a charitable grant from AstraZeneca Young Health Programme, and personal fees from Prudential, Scor, and Third Bridge, all outside the submitted work. All other authors declare no competing interests.
Bennett JE, Tamura-Wicks H, Parks RM, Burnett RT, Pope CA III, Bechle MJ, et al. (2019) Particulate matter air pollution and national and county life expectancy loss in the USA: A spatiotemporal analysis. PLoS Med 16(7): e1002856. https://doi.org/10.1371/journal.pmed.1002856
Department of Epidemiology and Biostatistics, School of Public Health, Imperial College London, London, United Kingdom
MRC Centre for Environment and Health, Imperial College London, London, United Kingdom
Population Studies Division, Health Canada, Ottawa, Ontario, Canada
Department of Economics, Brigham Young University, Provo, Utah, United States of America
Department of Civil & Environmental Engineering, University of Washington, Seattle, Washington, United States of America
Harvard T. H. Chan School of Public Health, Boston, Massachusetts, United States of America
WHO Collaborating Centre on NCD Surveillance and Epidemiology, Imperial College London, London, United Kingdom
In your coverage please use this URL to provide access to the freely available paper: https://journals.plos.org/plosmedicine/article?id=10.1371/journal.pmed.1002856