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Association between PM2.5 and all-cause and specific-cause mortality in 27 US communities


While fine mode particulate matter (PM2.5) forms the basis for regulating particles in the US and other countries, there is a serious paucity of large population-based studies of its acute effect on mortality. To address this issue, we examined the association between PM2.5 and both all-cause and specific-cause mortality using over 1.3 million deaths in 27 US communities between 1997 and 2002. A two-stage approach was used. First, the association between PM2.5 and mortality in each community was quantified using a case-crossover design. Second, meta-analysis was used to estimate a summary effect over all 27 communities. Effect modification of age and gender was examined using interaction terms in the case-crossover model, while effect modification of community-specific characteristics including geographic location, annual PM2.5 concentration above 15 μg/m3 and central air conditioning prevalence was examined using meta-regression. We observed a 1.21% (95% CI 0.29, 2.14%) increase in all-cause mortality, a 1.78% (95% CI 0.20, 3.36%) increase in respiratory related mortality and a 1.03% (95% CI 0.02, 2.04%) increase in stroke related mortality with a 10 μg/m3 increase in previous day's PM2.5. The magnitude of these associations is more than triple that recently reported for PM10, suggesting that combustion and traffic related particles are more toxic than larger sized particles. Effect modification occurred in all-cause and specific-cause deaths with greater effects in subjects ≥75 years of age. There was suggestive evidence that women may be more susceptible to PM2.5 effects than men, and that effects were larger in the East than in the West. Increased prevalence of central air conditioning was associated with a decreased effect of PM2.5. Our findings describe the magnitude of the effect on all-cause and specific-cause mortality, the modifiers of this association, and suggest that PM2.5 may pose a public health risk even at or below current ambient levels.

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  • AHS. Department of Housing and Urban Development, American Housing Survey, Available from:, accessed March, 2006.

  • Allen G., Sioutas C., Koutrakis P., Reiss R., Lurmann F., and Roberts P. Evaluation of the TEOM method for measurement of ambient particulate mass in urban areas. JAWMA 1997: 47(6): 682–689.

    CAS  Google Scholar 

  • AQS TTN. US Environmental Protection Agency, Air Quality System Technology Transfer Network. Available from, accessed March, 2006.

  • Bateson T., and Schwartz J. Control for seasonal variation time trend in case-crossover studies of acute effects of environmental exposures. Epidemiology 1999: 10(4): 539–544.

    CAS  Article  Google Scholar 

  • Bennett W., Zeman K., and Kim C. Variability of fine particle deposition in healthy adults: effect of age gender. Am J Respir Crit Care Med 1996: 153(5): 1641–1647.

    CAS  Article  Google Scholar 

  • Braga A., Zanobetti A., and Schwartz J. The lag structure between particulate air pollution and respiratory and cardiovascular deaths in 10 US cities. J Occup Environ Med 2001: 43(11): 927–933.

    CAS  Article  Google Scholar 

  • Burnett R., et al. Association between particulate- and gas-phase components of urban air pollution and daily mortality in eight Canadian cities. Inhal Toxicol 2000: 12(Suppl 4): 15–39.

    CAS  Article  Google Scholar 

  • Cifuentes L., Vega J., Köpfer K., and Lave L. Effect of the fine fraction of particulate matter versus the coarse mass and other pollutants on daily mortality in Santiago, Chile. JAWMA 2000: 50: 1287–1298.

    CAS  Google Scholar 

  • Dominici F., McDermott A., Daniels M., Zeger S., and Samet J. Revised analyses of the National Morbidity, Mortality, and Air Pollution Study: mortality among residents of 90 cities. J Toxicol Environ Health A 2005: 68: 1071–1092.

    CAS  Article  Google Scholar 

  • Dominici F., McDermott A., Zeger S., and Samet J. National maps of the effects of particulate matter on mortality: exploring geographical variation. Environ Health Perspect 2003: 111(1): 39–44.

    Article  Google Scholar 

  • Dominici F., et al. Fine particulate air pollution and hospital admission for cardiovascular and respiratory diseases. JAMA 2006: 295(10): 1127–1134.

    CAS  Article  Google Scholar 

  • Hong Y., Lee J., Ho K., Ha E., Schwartz J., and Christiani D. Effects of air pollutants on acute stroke mortality. Environ Health Perspect 2002: 110(2): 187–192.

    CAS  Article  Google Scholar 

  • Ito K., and Thurston G. Daily PM10-mortality associations: an investigation of at-risk subpopulations. J Expo Anal Environ Epidemiol 1996: 6(1): 79–95.

    CAS  Google Scholar 

  • Janes H., Sheppard L., and Lumley T. Case-crossover analyses of air pollution exposure data: referent selection strategies and their implication for bias. Epidemiology 2005: 16(6): 717–725.

    Article  Google Scholar 

  • Janssen N., Schwartz J., Zanobetti A., and Suh H. Air conditioning and source-specific particles as modifiers of the effect of PM10 on hospital admissions for heart and lung disease. Environ Health Perspect 2002: 110(1): 43–49.

    CAS  Article  Google Scholar 

  • Kim C., and Hu S. Regional deposition of inhaled particles in human lungs, comparison between men and women. J Appl Physiol 1998: 84(6): 1834–1844.

    CAS  Article  Google Scholar 

  • Laden F., Neas L., Dockery D., and Schwartz J. Association of fine particulate matter from different sources with daily mortality in six US cities. Environ Health Perspect 2000: 108(10): 941–947.

    CAS  Article  Google Scholar 

  • Mittleman M., Maclure M., and Robins J. Control sampling strategies for case-crossover studies: an assessment of relative efficiency. Am J Epidemiol 1995: 142(1): 91–98.

    CAS  Article  Google Scholar 

  • NCDC. National Oceanic and Atmospheric Association, National Climactic Data Center, Available from, accessed January, 2006.

  • R 2.2.1. A Language and Environment, The R Development Core Team, Copyright © 2005.

  • Samoli E., et al. Investigating regional differences in short-term effects of air pollution on daily mortality in the APHEA project: a sensitivity analysis for controlling long-term trends and seasonality. Environ Health Perspect 2001: 109(4): 349–353.

    CAS  Article  Google Scholar 

  • Sarnat J., Brown K., Schwartz J., Coull B., and Koutrakis P. Ambient gas concentrations and personal particulate matter exposures: implications for studying the health effects of particles. Epidemiology 2005: 16(3): 385–395.

    Article  Google Scholar 

  • Sarnat J., Koutrakis P., and Suh H. Assessing the relationship between personal particulate and gaseous exposures of senior citizens living in Baltimore, MD. JAWMA 2000: 50(7): 1184–1198.

    CAS  Google Scholar 

  • SAS Institute Inc. Version 9.1 of the SAS System for Windows. Copyright © 2002-2003 Cary, NC, USA.

  • Schroeder E., et al. Lung function and incident coronary heart disease: the atherosclerosis risk in communities study. Am J Epidemiol 2003: 158(12): 1171–1181.

    Article  Google Scholar 

  • Schwartz J. Assessing confounding, effect modification, and thresholds in the association between ambient particles and daily deaths. Environ Health Perspect 2000: 108: 563–568.

    CAS  Article  Google Scholar 

  • Schwartz J. Is the association of airborne particles with daily deaths confounded by gaseous air pollutants? An approach to control by matching. Environ Health Perspect 2004: 112(5): 557–561.

    CAS  Article  Google Scholar 

  • Schwartz J., Dockery D., and Neas L. Is daily mortality associated specifically with fine particles? JAWMA 1996: 46: 927–939.

    CAS  Google Scholar 

  • Simpson R., et al. The short-term effects of air pollution on daily mortality in four Australian cities. Aust NZ J Public Health 2005: 29(3): 205–212.

    Article  Google Scholar 

  • van Eeden S., Yeung A., Quinlam K., and Hogg J. Systemic response to ambient particulate matter: relevance to chronic obstructive pulmonary disease. Proc Am Thorac Soc 2005: 2(1): 61–67.

    CAS  Article  Google Scholar 

  • Wellenius G., Schwartz J., and Mittleman M. Air pollution and hospital admissions for ischemic and hemorrhagic stroke among medicare beneficiaries. Stroke 2005: 36(12): 2545–2549.

    Article  Google Scholar 

  • Zanobetti A., and Schwartz J. Race, gender, and social status as modifiers of the effects of PM10 on mortality. J Occup Environ Med 2000: 42(5): 469–474.

    CAS  Article  Google Scholar 

  • Zanobetti A., et al. The temporal pattern of mortality responses to air pollution: a multi-city assessment of mortality displacement. Epidemiology 2002: 13(1): 87–93.

    Article  Google Scholar 

  • Zeger S., et al. Exposure Measurement Error in Time-Series Studies of Air Pollution: Concepts and Consequences. Environ Health Perspect 2000: 108(5): 419–426.

    CAS  Article  Google Scholar 

  • Zeka A., Zanobetti A., and Schwartz J. Short term effects of particulate matter on cause specific mortality: effects of lags and modification by city characteristics. J Occup Environ Med 2005: 62: 718–725.

    CAS  Article  Google Scholar 

  • Zeka A., Zanobetti A., and Schwartz J. Individual modifiers of the effects of particulate matter on daily mortality. Am J Epidemiol 2006: 163(9): 849–859.

    Article  Google Scholar 

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This work was supported by the Harvard School of Public Health Environmental Protection Agency PM Center Grant R827353.

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Correspondence to Meredith Franklin.

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Franklin, M., Zeka, A. & Schwartz, J. Association between PM2.5 and all-cause and specific-cause mortality in 27 US communities. J Expo Sci Environ Epidemiol 17, 279–287 (2007).

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  • PM2.5
  • case-crossover
  • particulate matter
  • mortality
  • specific-cause mortality
  • meta-analysis
  • effect modification

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