Abstract
Multipollutant models are frequently used to differentiate roles of multiple pollutants in epidemiologic studies of ambient air pollution. In the presence of differing levels of measurement error across pollutants under consideration, however, they can be biased and as misleading as single-pollutant models. Their appropriate interpretation depends on the relationships among the pollutant measurements and the outcomes in question. In situations where two or more pollutant variables may be acting as surrogates for the etiologic agent(s), multipollutant models can help identify the best surrogate, but the risk estimates may be influenced by inclusion of a second variable that is not itself an independent risk factor for the outcome in question. In this paper, these issues will be illustrated in the context of an ongoing study of emergency visits in Atlanta. Emergency department visits from 41 of 42 hospitals serving the 20-county Atlanta metropolitan area for the period 1993–2004 (n=10,206,389 visits) were studied in relation to ambient pollutant levels, including speciated particle measurements from an intensive monitoring campaign at a downtown station starting in 1998. Relative to our earlier publications, reporting results through 2000, the period for which the speciated data are available is now tripled (6 years in length). Poisson generalized linear models were used to examine outcome counts in relation to 3-day moving average concentrations of pollutants of a priori interest (ozone, nitrogen dioxide, carbon monoxide, sulfur dioxide, oxygenated hydrocarbons, PM10, coarse PM, PM2.5, and the following components of PM2.5: elemental carbon, organic carbon, sulfate, and water-soluble transition metals). In the present analysis, we report results for two outcome groups: a respiratory outcomes group and a cardiovascular outcomes group. For cardiovascular visits, associations were observed with CO, NO2, and PM2.5 elemental carbon and organic carbon. In multipollutant models, CO was the strongest predictor. For respiratory visits, associations were observed with ozone, PM10, CO, and NO2 in single-pollutant models. In multipollutant models, PM10 and ozone persisted as predictors, with ozone the stronger predictor. Caveats and considerations in interpreting the multipollutant model results are discussed.
This is a preview of subscription content, access via your institution
Relevant articles
Open Access articles citing this article.
-
Assessing the health estimation capacity of air pollution exposure prediction models
Environmental Health Open Access 17 March 2022
-
The short-term associations of chronic obstructive pulmonary disease hospitalizations with meteorological factors and air pollutants in Southwest China: a time-series study
Scientific Reports Open Access 21 June 2021
-
Systematic review and meta-analysis of case-crossover and time-series studies of short term outdoor nitrogen dioxide exposure and ischemic heart disease morbidity
Environmental Health Open Access 17 July 2020
Access options
Subscribe to this journal
Receive 6 print issues and online access
$259.00 per year
only $43.17 per issue
Rent or buy this article
Get just this article for as long as you need it
$39.95
Prices may be subject to local taxes which are calculated during checkout


References
Adams W.C. Comparison of chamber and face-mask 6.6-h exposures to ozone on pulmonary function and symptoms responses. Inhal Toxicol 2002: 14: 745–764.
Kim E., Hopke P.K., and Edgerton E.S. Improving source identification of Atlanta aerosol using temperature resolved carbon fractions in positive matrix factorization. Atmos Environ 2004: 38: 3349–3362.
Kim E., Hopke P.K., and Edgerton E.S. Source identification of Atlanta aerosol by positive matrix factorization. J Air Waste Manage Assoc 2003: 53: 731–739.
Marmur A., Park S-K., Mulholland J.A., Tolbert P.E., and Russell A.G. Source apportionment of PM2.5 in the southeastern US using receptor and emissions-based models: conceptual differences and implications for time-series health studies. Atmos Environ 2006: 40: 2533–2551.
Marmur A., Unal A., Mulholland J.A., and Russell A.G. Optimization-based source apportionment of PM2.5 incorporating gas-to-particle ratios. Environ Sci Technol 2005: 39: 3245–3254.
McCullagh P., and Nelder J.A. Generalized Linear Models, 2nd edn. Chapman and Hall, New York, USA, 1989.
Metzger K.B., Tolbert P.E., Klein M., Peel J.L., Flanders W.D., Todd K., Mulholland J.A., Ryan P.B., and Frumkin H. Ambient air pollution and cardiovascular emergency department visits. Epidemiology 2004: 15: 46–56.
Peel J., Tolbert P.E., Klein M., Metzger K., Flanders W.D., Todd K., Mulholland J.A., Ryan P.B., and Frumkin H. Ambient air pollution and respiratory emergency department visits. Epidemiology 2005: 16: 164–174.
Sarnat J.A., Marmur A., Klein M., Kim E., Russell A.G., Mulholland J.A., Hopke P.K., Sarnat S.E., Peel J.L., and Tolbert P.E. Associations between source-resolved particulate matter and cardiorespiratory emergency department visits. Epidemiology 2006: 17: S267.
Sarnat J.A., Schwartz J., Catalona P.J., and Suh H. Gaseous pollutants in particulate matter epidemiology: confounders or surrogates? Environ Health Perspect 2001: 109: 1054–1061.
USEPA. Air Quality Criteria for Carbon Monoxide. US Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, Washington Office, Washington, DC, USA, EPA 600/P-99/001F 2000.
Van Loy M., Bahadori T., Wyzga R., hartsell B., and Edgerton E. The Aerosol Research and Inhalation Epidemiology Study (ARIES): PM2.5 mass and aerosol component concentrations and sampler intercomparisons. J Air Waste Manage Assoc 2000: 50: 1446–1458.
Wade K.S., Mulholland J.A., Marmur A., Russell A.G., Hartsell B., Edgerton E., Klein M., Waller L., Peel J., and Tolbert P.E. Instrument error and spatial variability of ambient air pollution in Atlanta, Georgia. J Air Waste Manage Assoc 2006: 56: 876–888.
Acknowledgements
This publication was supported by STAR Research Assistance Agreement no. R82921301–0 from the U.S. Environmental Protection Agency, Grant no. R01ES11294 from the National Institute of Environmental Health Sciences, and Grant no. EP-P4353/C2124 from the Electric Power Research Institute. Although the research described in this article has been funded in part by the U.S. Environmental Protection Agency through Grant agreement no.; R82921301-0 to Emory University, it has not been subjected to the Agency's required peer and policy review and therefore does not necessarily reflect the views of the Agency and no official endorsement should be inferred.
Author information
Authors and Affiliations
Corresponding author
Rights and permissions
About this article
Cite this article
Tolbert, P., Klein, M., Peel, J. et al. Multipollutant modeling issues in a study of ambient air quality and emergency department visits in Atlanta. J Expo Sci Environ Epidemiol 17 (Suppl 2), S29–S35 (2007). https://doi.org/10.1038/sj.jes.7500625
Received:
Accepted:
Published:
Issue Date:
DOI: https://doi.org/10.1038/sj.jes.7500625
Keywords
- air pollution
- cardiovascular disease
- respiratory disease
- emergency department
- multipollutant models
This article is cited by
-
Assessing the health estimation capacity of air pollution exposure prediction models
Environmental Health (2022)
-
The short-term associations of chronic obstructive pulmonary disease hospitalizations with meteorological factors and air pollutants in Southwest China: a time-series study
Scientific Reports (2021)
-
Effects of ambient air pollution on emergency room visits of children for acute respiratory symptoms in Delhi, India
Environmental Science and Pollution Research (2021)
-
Systematic review and meta-analysis of case-crossover and time-series studies of short term outdoor nitrogen dioxide exposure and ischemic heart disease morbidity
Environmental Health (2020)
-
Temperature as a modifier of the effects of air pollution on cardiovascular disease hospital admissions in Cape Town, South Africa
Environmental Science and Pollution Research (2020)