Concentration-Response Function for Ozone and Daily Mortality: Results from Five Urban and Five Rural UK Populations.

TitleConcentration-Response Function for Ozone and Daily Mortality: Results from Five Urban and Five Rural UK Populations.
Publication TypeJournal Article
Year of Publication2012
AuthorsAtkinson RW, Yu D, Armstrong BG, Pattenden S, Wilkinson P, Doherty RM, Heal MR, Anderson RH
JournalEnviron Health Perspect
Date Published2012 Jul 19
ISSN1552-9924
Abstract

Background: Short-term exposure to ozone has been associated with increased daily mortality. The shape of the concentration-response relationship and, in particular, if there is a threshold, is critical for estimating public health impacts. We investigated the concentration-response relationship between daily ozone and mortality in five urban and five rural areas in the UK from 1993-2006. Methods: We used Poisson regression controlling for seasonality, temperature and influenza to investigate associations between daily maximun 8-hour ozone and daily all-cause mortality assuming linear, linear-threshold and spline models for all-year and season-specific periods. Sensitivity to adjustment for particles (urban areas only) and alternative temperature metrics was examined. Results: In all-year analyses, we found clear evidence for a threshold in the concentration-response relationship between ozone and all-cause mortality in London at 65 µg/m3 (95% CI: 58, 83) but little evidence of a threshold in other urban or rural areas. Combined linear effect estimates for all-cause mortality were comparable for urban and rural areas: 0.48% (95% CI 0.35, 0.60) and 0.58% (95% CI: 0.36, 0.81) per 10 µg/m3 increase in ozone concentrations, respectively. Seasonal analyses suggested thresholds in both urban and rural areas for effects of ozone during summer months. Conclusions: Our results suggest that health impacts should be estimated across the whole ambient range of ozone using both threshold and non-threshold models, and models stratified by season. Evidence of a threshold effect in London but not in other study areas requires further investigation. The public health impacts of exposure to ozone in rural areas should not be overlooked.

DOI10.1289/ehp.1104108
PubMed ID22814173