title: The impact of weather changes on air quality and health in the United States in 1994-2012.
abstract: Air quality is heavily influenced by weather conditions. In this study, we assessed the impact of long-term weather changes on air quality and health in the US during 1994-2012. We quantified past weather-related increases, or 'weather penalty', in ozone (O3) and fine particulate matter (PM2.5), and thereafter estimated the associated excess deaths. Using statistical regression methods, we derived the weather penalty as the additional increases in air pollution relative to trends assuming constant weather conditions (i.e., weather-adjusted trends). During our study period, temperature increased and wind speed decreased in most US regions. Nationally, weather-related 8 h max O3increases were 0.18 ppb per year (95% CI: 0.06, 0.31) in the warm season (May-October) and 0.07 ppb per year (95% CI: 0.02, 0.13) in the cold season (November-April). The weather penalties on O3were relatively larger than PM2.5weather penalties, which were 0.056 µg m-3per year (95% CI: 0.016, 0.096) in warm months and 0.027 µg m-3per year (95% CI: 0.010, 0.043) in cold months. Weather penalties on O3and PM2.5were associated with 290 (95% CI: 80, 510) and 770 (95% CI: 190, 1350) excess annual deaths, respectively. Over a 19-year period, this amounts to 20 300 excess deaths (5600 from O3, 14 700 from PM2.5) attributable to the weather penalty on air quality.
authors: Department of Environmental Health, Harvard School of Public Health, 401 Park Drive, Boston, MA 02215, USA.
authors: Iny
authors: I
authors: Jhun
authors: Department of Biostatistics, Harvard School of Public Health, 655 Huntington Avenue, Boston, MA 02115, USA.
authors: Brent A
authors: BA
authors: Coull
authors: Department of Environmental Health, Harvard School of Public Health, 401 Park Drive, Boston, MA 02215, USA.
authors: Joel
authors: J
authors: Schwartz
authors: Office of Air Quality, Planning, and Standards, US Environmental Protection Agency, 109 TW Alexander Drive, Research Triangle Park, NC27711, USA.
authors: Bryan
authors: B
authors: Hubbell
authors: Department of Environmental Health, Harvard School of Public Health, 401 Park Drive, Boston, MA 02215, USA.
authors: Petros
authors: P
authors: Koutrakis
keywords: air pollution; fine particulate matter; mortality; ozone; trend analysis; weather