Methods for Detecting and Estimating Population Threshold Concentrations for Air Pollution–Related Mortality with Exposure Measurement Error

Abstract

The association between daily fluctuations in ambient particulate matter and daily variations in nonaccidental mortality have been extensively investigated. Although it is now widely recognized that such an association exists, the form of the concentration–response model is still in question. Linear, no threshold and linear threshold models have been most commonly examined. In this paper we considered methods to detect and estimate threshold concentrations using time series data of daily mortality rates and air pollution concentrations. Because exposure is measured with error, we also considered the influence of measurement error in distinguishing between these two completing model specifications. The methods were illustrated on a 15-year daily time series of nonaccidental mortality and particulate air pollution data in Toronto, Canada. Nonparametric smoothed representations of the association between mortality and air pollution were adequate to graphically distinguish between these two forms. Weighted nonlinear regression methods for relative risk models were adequate to give nearly unbiased estimates of threshold concentrations even under conditions of extreme exposure measurement error. The uncertainty in the threshold estimates increased with the degree of exposure error. Regression models incorporating threshold concentrations could be clearly distinguished from linear relative risk models in the presence of exposure measurement error. The assumption of a linear model given that a threshold model was the correct form usually resulted in overestimates in the number of averted premature deaths, except for low threshold concentrations and large measurement error.

This is a preview of subscription content, log in to check access.

REFERENCES

  1. 1.

    G. A. Thurston, Critical review of PM10-mortality time-series studies. J.Expos.Anal.Environ.Epidem. 61–21(1996).

    Google Scholar 

  2. 2.

    C. A. Pope, III, Synoptic weather modeling and estimates of the exposure-response relationship between daily mortality and particulate air pollution. Environ.Health Perspect. 104414–420(1996).

    PubMed  Google Scholar 

  3. 3.

    C. Spix, J. Heinrich, D. Dockery et al. Air pollution and daily mortality in Erfurt, East Germany. Environ.Health Perspect. 101518–526(1993).

    PubMed  Google Scholar 

  4. 4.

    M. Lippmann and K. Ito, Separating the effects of temperature and season on daily mortality from those of air pollution in London: 1965- 1972. Inhal.Toxicol. 785–97(1995).

    Google Scholar 

  5. 5.

    J. Schwartz, and A. Marcus, Mortality and air pollution in London: A time series analysis. Am.J.Epidemiol. 131185–1941990.

    PubMed  Google Scholar 

  6. 6.

    J. Schwartz, Particulate air pollution and daily mortality in Detroit. Environ.Res. 56204–2131991.

    PubMed  Google Scholar 

  7. 7.

    J. Schwartz, and D. W. Dockery, Particulate air pollution and daily mortality in Steubenville, Ohio. Am.J.Epidemiol. 13512–191992.

    PubMed  Google Scholar 

  8. 8.

    J. Schwartz, and D. W. Dockery, Increased mortality in Phila-delphia associated with daily air pollution concentrations. Am Rev Respir Dis. 145600–6041992.

    PubMed  Google Scholar 

  9. 9.

    P. H. N. Saldiva, C. A. Pope, III, J. Schwartz et al. Air pollution and mortality in elderly people: A time-series study in Sao Paulo, Brazil. Arch.Environ.Health. 50159–1631995.

    PubMed  Google Scholar 

  10. 10.

    B. Ostro, J. M. Sanchez, C. Aranda, and G. S. Eskeland, Air pollution and mortality: results from a study of Santiago, Chile. J.Expos.Anal.Environ.Epidem. 697–1141996.

    Google Scholar 

  11. 11.

    L. G. Chestnut, Human health benefits from sulfate reductions under title IV of the 1990 clean air act amendments. Report to the office of air and radiation office of atmospheric programs acid rain division, U.S. EPA, 1995.

  12. 12.

    US Environ protection agency. The benefits and costs of the clean air act, 1970 to 1990. Prepared for US Congress. 1996.

  13. 13.

    G. Lang, G. Yarwood, F. Lalonde, and R. Bloxam, Environ-mental and health benefits of cleaner vehicles and fuels. Sum-mary report. Prepaired for Canadian Council of Ministers of the Environment, task force on cleaner vehicles and fuels, 1995.

  14. 14.

    Sulphur gasoline diesel fuels study. Report of the health and environmental impact assessment expert panel on the sulphur content in gasoline, Ottawa, Canada, July 25, 1997.

  15. 15.

    W. S. Cleveland, E. Grosse, and W. M. Shyu, Local regression models. In J. M., Chambers and T. J., Hastie, (eds), Statistical Models in S. Wadworth and Brooks, Pasific Grove, California, 309–3761992.

  16. 16.

    Health Effects Institute. Particulate air pollution and daily mortality. The phase I report of the particle epidemiology evaluation project, USA, August 1995.

  17. 17.

    M. Watt, D. Godden, J. Cherrie, and A. Seaton, Individual exposure to particulate air pollution and its relevance to threshold for health effects: A study of traffic wardens. Occup. Environ.Med. 52790–7921995.

    PubMed  Google Scholar 

  18. 18.

    F. M. Lipfert and R. E. Wyzga, The effects of exposure error on environmental epidemiology. Proceedings of 2nd collo-quium on particulate air pollution and human health, J. Lee and R. Phalen (eds.), Park City, UT, May 4295–3021996.

  19. 19.

    R. T. Burnett, J. R. Brook, and S. Cakmak et al. The association between ambient carbon monoxide levels and daily mortality in Toronto, Canada. Air and Waste Manage Assoc. 1997(ac-cepted).

  20. 20.

    H. H. Suh, J. D. Spengler, and P. Koutrakis, Personal exposures to acid aerosols and ammonia. Env.Science Tech. 262507–25171992.

    Google Scholar 

  21. 21.

    M. Brauer, and J. R. Brook, Personal and fixed-site ozone measurements with a passive sampler. Air Waste Manage Assoc. 45529–5371995.

    Google Scholar 

  22. 22.

    B. Ostro, The association of air pollution and mortality: Examining the case for inference. Arch.Environ.Health 48336–3421993.

    PubMed  Google Scholar 

  23. 23.

    SAS/STAT user's guide, SAS Institute Inc. Cary NC 675–7121988.

  24. 24.

    Environmental Protection Agency. Air Quality Criteria for Particulate MatterVol. III. Office of Research and Development, Washington DC, EPA/600/P-95/001bF, April 1996.

  25. 25.

    L. Bouthillier, R. Vincent, P. Goagan, and S. Bjarnason, Alteration of lung macrophage functions in vivoby acute inhalation exposure to urban particulate matter, ozone, or a combi-nation of both agents. Cell.Mol.Biol. 1996;42Suppl. Congress: S76.

    Google Scholar 

  26. 26.

    K. Wilkins, M. Wysocki, C. Morin, and P. Wood, Multiple causes of death. Health Reports 919–291997. Statistics Canada, Catalogue 82- 003-XPB.

    Google Scholar 

  27. 27.

    J. V. Zidek, H. Wong, N. D. Le, and R. Burnett, Causality, measurement error and multicollinearity in epidemiology. Environmetrics 7441–4511996.

    Google Scholar 

Download references

Author information

Affiliations

Authors

Corresponding author

Correspondence to Sabit Cakmak.

Rights and permissions

Reprints and Permissions

About this article

Cite this article

Cakmak, S., Burnett, R.T. & Krewski, D. Methods for Detecting and Estimating Population Threshold Concentrations for Air Pollution–Related Mortality with Exposure Measurement Error. Risk Anal 19, 487–496 (1999). https://doi.org/10.1023/A:1007008914354

Download citation

  • Threshold
  • measurement error
  • mortality
  • air pollution