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. 2004 Apr;112(5):557–561. doi: 10.1289/ehp.6431

Is the association of airborne particles with daily deaths confounded by gaseous air pollutants? An approach to control by matching.

Joel Schwartz 1
PMCID: PMC1241921  PMID: 15064161

Abstract

Although particulate air pollution has been associated with increased numbers of daily deaths in dozens of cities around the world, issues still remain about the association. Some have questioned the complex modeling used to control for season in Poisson regression or the role of gaseous air pollutants as potential confounders of the association. I examined the association between deaths and particulate matter with an aerodynamic diameter less than or equal to 10 microm (PM10) using a case-crossover design. In this approach, the pollution on the day of each death is contrasted with the pollution level on control days when the subject did not die. Season and gaseous air pollutants were controlled by matching. Control days were chosen within the same month of the same year to control for season, and matched on either sulfur dioxide (SO2; within 1 ppb), nitrogen dioxide (within 1 ppb), maximum ozone (within 2 ppb), or carbon monoxide (within 0.03 ppm). The analysis was conducted in 14 U.S. cities that have daily PM10 monitoring. After matching, there were about 400,000 deaths in each analysis. Results were combined across cities using a maximum likelihood method. PM10 was a significant predictor of mortality when controlling for gaseous air pollutants, with effect sizes ranging from a 0.45% increase per 10 microg/m3 increment of PM10 [95% confidence interval (CI), 0.12-0.79%] when matched on maximum hourly ozone levels, to a 0.81% increase per 10 microg/m3 increment of PM10 (95% CI, 0.47-1.16%) when matched on 24-hr average SO2.

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Selected References

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  1. Basu Rupa, Samet Jonathan M. An exposure assessment study of ambient heat exposure in an elderly population in Baltimore, Maryland. Environ Health Perspect. 2002 Dec;110(12):1219–1224. doi: 10.1289/ehp.021101219. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Bateson T. F., Schwartz J. Control for seasonal variation and time trend in case-crossover studies of acute effects of environmental exposures. Epidemiology. 1999 Sep;10(5):539–544. [PubMed] [Google Scholar]
  3. Berkey C. S., Hoaglin D. C., Mosteller F., Colditz G. A. A random-effects regression model for meta-analysis. Stat Med. 1995 Feb 28;14(4):395–411. doi: 10.1002/sim.4780140406. [DOI] [PubMed] [Google Scholar]
  4. Braga A. L., Zanobetti A., Schwartz J. The lag structure between particulate air pollution and respiratory and cardiovascular deaths in 10 US cities. J Occup Environ Med. 2001 Nov;43(11):927–933. doi: 10.1097/00043764-200111000-00001. [DOI] [PubMed] [Google Scholar]
  5. Brook Robert D., Brook Jeffrey R., Urch Bruce, Vincent Renaud, Rajagopalan Sanjay, Silverman Frances. Inhalation of fine particulate air pollution and ozone causes acute arterial vasoconstriction in healthy adults. Circulation. 2002 Apr 2;105(13):1534–1536. doi: 10.1161/01.cir.0000013838.94747.64. [DOI] [PubMed] [Google Scholar]
  6. Dominici Francesca, McDermott Aidan, Zeger Scott L., Samet Jonathan M. On the use of generalized additive models in time-series studies of air pollution and health. Am J Epidemiol. 2002 Aug 1;156(3):193–203. doi: 10.1093/aje/kwf062. [DOI] [PubMed] [Google Scholar]
  7. Gardner S. Y., Lehmann J. R., Costa D. L. Oil fly ash-induced elevation of plasma fibrinogen levels in rats. Toxicol Sci. 2000 Jul;56(1):175–180. doi: 10.1093/toxsci/56.1.175. [DOI] [PubMed] [Google Scholar]
  8. Ghio A. J., Kim C., Devlin R. B. Concentrated ambient air particles induce mild pulmonary inflammation in healthy human volunteers. Am J Respir Crit Care Med. 2000 Sep;162(3 Pt 1):981–988. doi: 10.1164/ajrccm.162.3.9911115. [DOI] [PubMed] [Google Scholar]
  9. Gold D. R., Litonjua A., Schwartz J., Lovett E., Larson A., Nearing B., Allen G., Verrier M., Cherry R., Verrier R. Ambient pollution and heart rate variability. Circulation. 2000 Mar 21;101(11):1267–1273. doi: 10.1161/01.cir.101.11.1267. [DOI] [PubMed] [Google Scholar]
  10. Katsouyanni K., Touloumi G., Samoli E., Gryparis A., Le Tertre A., Monopolis Y., Rossi G., Zmirou D., Ballester F., Boumghar A. Confounding and effect modification in the short-term effects of ambient particles on total mortality: results from 29 European cities within the APHEA2 project. Epidemiology. 2001 Sep;12(5):521–531. doi: 10.1097/00001648-200109000-00011. [DOI] [PubMed] [Google Scholar]
  11. Katsouyanni K., Touloumi G., Spix C., Schwartz J., Balducci F., Medina S., Rossi G., Wojtyniak B., Sunyer J., Bacharova L. Short-term effects of ambient sulphur dioxide and particulate matter on mortality in 12 European cities: results from time series data from the APHEA project. Air Pollution and Health: a European Approach. BMJ. 1997 Jun 7;314(7095):1658–1663. doi: 10.1136/bmj.314.7095.1658. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Katsouyanni Klea, Touloumi Giota, Samoli Evangelia, Gryparis Alexandros, Monopolis Yannis, LeTertre Alain, Boumghar Azedine, Rossi Giuseppe, Zmirou Denis, Ballester Ferran. Different convergence parameters applied to the S-PLUS GAM function. Epidemiology. 2002 Nov;13(6):742–743. doi: 10.1097/00001648-200211000-00024. [DOI] [PubMed] [Google Scholar]
  13. Lee J. T., Schwartz J. Reanalysis of the effects of air pollution on daily mortality in Seoul, Korea: A case-crossover design. Environ Health Perspect. 1999 Aug;107(8):633–636. doi: 10.1289/ehp.99107633. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Levy D., Lumley T., Sheppard L., Kaufman J., Checkoway H. Referent selection in case-crossover analyses of acute health effects of air pollution. Epidemiology. 2001 Mar;12(2):186–192. doi: 10.1097/00001648-200103000-00010. [DOI] [PubMed] [Google Scholar]
  15. Levy D., Sheppard L., Checkoway H., Kaufman J., Lumley T., Koenig J., Siscovick D. A case-crossover analysis of particulate matter air pollution and out-of-hospital primary cardiac arrest. Epidemiology. 2001 Mar;12(2):193–199. [PubMed] [Google Scholar]
  16. Liao D., Creason J., Shy C., Williams R., Watts R., Zweidinger R. Daily variation of particulate air pollution and poor cardiac autonomic control in the elderly. Environ Health Perspect. 1999 Jul;107(7):521–525. doi: 10.1289/ehp.99107521. [DOI] [PMC free article] [PubMed] [Google Scholar]
  17. Maclure M. The case-crossover design: a method for studying transient effects on the risk of acute events. Am J Epidemiol. 1991 Jan 15;133(2):144–153. doi: 10.1093/oxfordjournals.aje.a115853. [DOI] [PubMed] [Google Scholar]
  18. Navidi W., Thomas D., Langholz B., Stram D. Statistical methods for epidemiologic studies of the health effects of air pollution. Res Rep Health Eff Inst. 1999 May;(86):1–56. [PubMed] [Google Scholar]
  19. Neas L. M., Schwartz J., Dockery D. A case-crossover analysis of air pollution and mortality in Philadelphia. Environ Health Perspect. 1999 Aug;107(8):629–631. doi: 10.1289/ehp.99107629. [DOI] [PMC free article] [PubMed] [Google Scholar]
  20. Samet J. M., Zeger S. L., Dominici F., Curriero F., Coursac I., Dockery D. W., Schwartz J., Zanobetti A. The National Morbidity, Mortality, and Air Pollution Study. Part II: Morbidity and mortality from air pollution in the United States. Res Rep Health Eff Inst. 2000 Jun;94(Pt 2):5–79. [PubMed] [Google Scholar]
  21. Sarnat J. A., Schwartz J., Catalano P. J., Suh H. H. Gaseous pollutants in particulate matter epidemiology: confounders or surrogates? Environ Health Perspect. 2001 Oct;109(10):1053–1061. doi: 10.1289/ehp.011091053. [DOI] [PMC free article] [PubMed] [Google Scholar]
  22. Schwartz J. Assessing confounding, effect modification, and thresholds in the association between ambient particles and daily deaths. Environ Health Perspect. 2000 Jun;108(6):563–568. doi: 10.1289/ehp.00108563. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Schwartz J., Dockery D. W. Increased mortality in Philadelphia associated with daily air pollution concentrations. Am Rev Respir Dis. 1992 Mar;145(3):600–604. doi: 10.1164/ajrccm/145.3.600. [DOI] [PubMed] [Google Scholar]
  24. Schwartz Joel, Coull Brent A. Control for confounding in the presence of measurement error in hierarchical models. Biostatistics. 2003 Oct;4(4):539–553. doi: 10.1093/biostatistics/4.4.539. [DOI] [PubMed] [Google Scholar]
  25. Sunyer J., Schwartz J., Tobías A., Macfarlane D., Garcia J., Antó J. M. Patients with chronic obstructive pulmonary disease are at increased risk of death associated with urban particle air pollution: a case-crossover analysis. Am J Epidemiol. 2000 Jan 1;151(1):50–56. doi: 10.1093/oxfordjournals.aje.a010121. [DOI] [PubMed] [Google Scholar]
  26. Suwa Tatsushi, Hogg James C., Quinlan Kevin B., Ohgami Akira, Vincent Renaud, van Eeden Stephan F. Particulate air pollution induces progression of atherosclerosis. J Am Coll Cardiol. 2002 Mar 20;39(6):935–942. doi: 10.1016/s0735-1097(02)01715-1. [DOI] [PubMed] [Google Scholar]
  27. Wellenius Gregory A., Coull Brent A., Godleski John J., Koutrakis Petros, Okabe Kazunori, Savage Sara T., Lawrence Joy E., Murthy G. G. Krishna, Verrier Richard L. Inhalation of concentrated ambient air particles exacerbates myocardial ischemia in conscious dogs. Environ Health Perspect. 2003 Apr;111(4):402–408. doi: 10.1289/ehp.5775. [DOI] [PMC free article] [PubMed] [Google Scholar]
  28. Zanobetti A., Schwartz J., Dockery D. W. Airborne particles are a risk factor for hospital admissions for heart and lung disease. Environ Health Perspect. 2000 Nov;108(11):1071–1077. doi: 10.1289/ehp.001081071. [DOI] [PMC free article] [PubMed] [Google Scholar]
  29. Zanobetti Antonella, Schwartz Joel, Samoli Evi, Gryparis Alexandros, Touloumi Giota, Atkinson Richard, Le Tertre Alain, Bobros Janos, Celko Martin, Goren Ayana. The temporal pattern of mortality responses to air pollution: a multicity assessment of mortality displacement. Epidemiology. 2002 Jan;13(1):87–93. doi: 10.1097/00001648-200201000-00014. [DOI] [PubMed] [Google Scholar]

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