Section: ArticlesTitle: Caveats for causal interpretations of linear regression coefficients for fine particulate (PM2.5) air pollution health effects / Louis Anthony Cox Jr.Author: Cox Jr., Louis AnthonyNotes: Sumario: Recent linear regression analyses have concluded that decreasing levels of fine particulate matter (PM2.5) air pollution have increased life expectancy in the United States. These findings have left unresolved questions about the causal relation between reductions in PM2.5 levels and changes in cause-specific (especially, cardiovascular disease, CVD) mortality risks. Their robustness (e.g., sensitivity to deletion of a single data point) has also been questioned. We investigate these issues in the National Mortality and Morbidity Air Pollution Study database. Comparing changes in PM2.5 levels and cause-specific mortality rates for elderly people in 24 cities between two periods separated by a decade (19871989 and 19992000) shows that reductions in PM2.5 were significantly associated with increases in respiratory mortality rates and with decreases in CVD mortality rates. CVD and all-cause mortality risks fell equally for all months of the year over this period, but average PM2.5 levels increased significantly for winter months. This casts doubts on the causal interpretation that declines in PM2.5 over the decade caused reduced short-term mortality risks. Nonlinear regression suggests that reduced or negative marginal health benefits are associated with reductions of PM2.5 below 19992000 levels (about 15 µg/m3). Such nonlinear relations imply that risk communication statements that project a constant incremental reduction in mortality risks per unit reduction in PM2.5 do not adequately reflect the realistic possibility of nonlinear exposure-response relations and diminishing returns to further exposure reductions.Related records: En: Risk analysis : an international journal. - McLean, Virginia : Society for Risk Analysis, 1987-2015 = ISSN 0272-4332. - 02/12/2013 Volumen 33 Número 12 - diciembre 2013 Other categories: 7Rights: In Copyright (InC)Referencias externas:
