Background: In recent years a number of studies have examined the short-term association between coarse particulate matter (PM_10–2.5) and mortality and morbidity outcomes. These studies, however, have produced inconsistent conclusions.

Objectives: We estimated both the national- and regional-level associations between PM_10–2.5 and emergency hospitalizations for both cardiovascular and respiratory disease among Medicare enrollees ≥ 65 years of age during the 12-year period 1999 through 2010.

Methods: Using air pollution data obtained from the U.S. Environmental Protection Agency air quality monitoring network and daily emergency hospitalizations for 110 large urban U.S. counties assembled from the Medicare Cohort Air Pollution Study (MCAPS), we estimated the association between short-term exposure to PM_10–2.5 and hospitalizations using a two-stage Bayesian hierarchical model and Poisson log-linear regression models.

Results: A 10-μg/m³ increase in PM_10–2.5 was associated with a significant increase in same-day cardiovascular hospitalizations [0.69%; 95% posterior interval (PI): 0.45, 0.92]. After adjusting for PM_2.5, this association remained significant (0.63%; 95% PI: 0.38, 0.88). A 10-μg/m³ increase in PM_10–2.5 was not associated with a significant increase in respiratory-related hospitalizations.

Conclusions: We found statistically significant evidence that daily variation in PM_10–2.5 is associated with emergency hospitalizations for cardiovascular diseases among Medicare enrollees ≥ 65 years of age. This association was robust to adjustment for concentrations of PM_2.5.

Citation: Powell H, Krall JR, Wang Y, Bell ML, Peng RD. 2015. Ambient coarse particulate matter and hospital admissions in the Medicare Cohort Air Pollution Study, 1999–2010. Environ Health Perspect 123:1152–1158;  http://dx.doi.org/10.1289/ehp.1408720

Address correspondence to R.D. Peng, Department of Biostatistics, Johns Hopkins Bloomberg School of Public Health, 615 North Wolfe St., E3527, Baltimore, MD 21205 USA. Telephone: (410) 955-2468. E-mail: [email protected]

This work was supported by grants R01ES019560, R01ES019587, R21ES020152, and R21ES021427 from the National Institute of Environmental Health Sciences, National Institutes of Health (NIH); T32AG000247 from the National Institute on Aging/NIH; and RD 83479801 from the U.S. Environmental Protection Agency.

The content is solely the responsibility of the authors and does not necessarily represent the official views of the NIH.

The authors declare they have no actual or potential competing financial interests.

Received: 21 May 2014 Accepted: 10 April 2015 Advance Publication: 14 April 2015 Final Publication: 1 November 2015

Note to readers with disabilities: EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected] . Our staff will work with you to assess and meet your accessibility needs within 3 working days.