Tuesday, November 09, 2004

Community Ozone Pollution and Mortality

The study abstracted below found an increase in total, respiratory and cardiovascular deaths with increasing ozone. This is one of a long series of community studies correlating mortality and air pollution.

The value of the 90th percentile for 8-hour summer ozone for 5 of the 23 cities was close or above 120 µg/m3, the value of the World Health Organization Air Quality Guideline for ozone. The rest were below. If I've done the arithmetic right, that's about 0.06 ppm, exceeded for 18 days. The EPA limit is 0.08 ppm for eight hours; I don't know the excedence criteria. Therefore the limit is an effect level for increased all cause mortality. Exposure limits should be set with an uncertainty factor below a no effect level. The uncertainty factor may consider an extrapolation from an unacceptable risk rate.

BrooklynDodger imagines the reader is asking "What does this have to do with occupational environment?" The answer is, compare the WHO level to the TLV of 0.05 ppm for heavy work, higher for lighter work, or 0.2 ppm over 2 hours. There remains an argument whether the community mortality is all babies and old, sick people; even if it were, perhaps their measurable mortality is the "song of the canary" for healthy adults at work.

American Journal of Respiratory and Critical Care Medicine Vol 170. pp. 1080-1087, (2004)

Acute Effects of Ozone on Mortality from the "Air Pollution and Health A European Approach" Project

Alexandros Gryparis, Bertil Forsberg, Klea Katsouyanni, Antonis Analitis, Giota Touloumi, Joel Schwartz, Evangelia Samoli, Sylvia Medina, H. Ross Anderson, Emilia Maria Niciu, H.-Erich Wichmann, Bohumir Kriz, Mitja Kosnik, Jiri Skorkovsky, Judith M. Vonk and Zeynep Dörtbudak

Department of Hygiene and Epidemiology, University of Athens Medical School, Athens, Greece; Department of Biostatistics, Department of Public Health and Clinical Medicine, and Department of Environmental Health, Harvard School of Public Health, Boston, Massachusetts; Umeå University, Umeå, Sweden; Institut de Veille Sanitaire, Paris, France; St. George's Hospital Medical School, University of London, London, United Kingdom; Department of Environmental Health, Institute of Public Health, Bucharest, Romania; GSF, National Research Center for Environment and Health, Munich, Germany; Charles University, Prague; Institute of Hygiene, Teplice, Czech Republic; Institute of Public Health, Ljubljana, Slovenia; Department of Epidemiology and Statistics, University of Groningen, Groningen, The Netherlands; and Koç University, School of Health Sciences, Istanbul, Turkey

In the Air Pollution and Health: A European Approach (APHEA2) project, the effects of ambient ozone concentrations on mortality were investigated. Data were collected on daily ozone concentrations, the daily number of deaths, confounders, and potential effect modifiers from 23 cities/areas for at least 3 years since 1990. Effect estimates were obtained for each city with city-specific models and were combined using second-stage regression models. No significant effects were observed during the cold half of the year. For the warm season, an increase in the 1-hour ozone concentration by 10 µg/m3 was associated with a 0.33% (95% confidence interval [CI], 0.17-0.52) increase in the total daily number of deaths, 0.45% (95% CI, 0.22-0.69) in the number of cardiovascular deaths, and 1.13% (95% CI, 0.62-1.48) in the number of respiratory deaths. The corresponding figures for the 8-hour ozone were similar. The associations with total mortality were independent of SO2 and particulate matter with aerodynamic diameter less than 10 µm (PM10) but were somewhat confounded by NO2 and CO. Individual city estimates were heterogeneous for total (a higher standardized mortality rate was associated with larger effects) and cardiovascular mortality (larger effects were observed in southern cities). The dose-response curve of ozone effects on total mortality during the summer did not deviate significantly from linearity.

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