Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2022 Apr 15:206:112271.
doi: 10.1016/j.envres.2021.112271. Epub 2021 Oct 25.

Do temporal trends of associations between short-term exposure to fine particulate matter (PM2.5) and risk of hospitalizations differ by sub-populations and urbanicity-a study of 968 U.S. counties and the Medicare population

Chen Chen  1 , Alisha Chan  2 , Francesca Dominici  3 , Roger D Peng  4 , Ben Sabath  3 , Qian Di  5 , Joel Schwartz  3 , Michelle L Bell  6
Affiliations

Do temporal trends of associations between short-term exposure to fine particulate matter (PM2.5) and risk of hospitalizations differ by sub-populations and urbanicity-a study of 968 U.S. counties and the Medicare population

Chen Chen et al. Environ Res. .

Abstract

While associations between short-term exposure to fine particulate matter (PM2.5) and risk of hospitalization are well documented and evidence suggests that such associations change over time, it is unclear whether these temporal changes exist in understudied less-urban areas or differ by sub-population. We analyzed daily time-series data of 968 continental U.S. counties for 2000-2016, with cause-specific hospitalization from Medicare claims and population-weighted PM2.5 concentrations originally estimated at 1km × 1 km from a hybrid model. Circulatory and respiratory hospitalizations were categorized based on primary diagnosis codes at discharge. Using modified Bayesian hierarchical modelling, we evaluated the temporal trend in association between PM2.5 and hospitalizations and whether disparities in this trend exist across individual-level characteristics (e.g., sex, age, race, and Medicaid eligibility as a proxy for socio-economic status) and urbanicity. Urbanicity was categorized into three levels by county-specific percentage of urban population based on urban rural delineation from the U.S. Census. In this cohort with understudied less-urban areas without regulatory monitors, we still found positive association between circulatory and respiratory hospitalization and short-term exposure to PM2.5, with higher effect estimates towards the end of study period. Consistent with current literature, we identified significant disparity in associations by race, socioeconomic status and urbanicity. We found that the percentage change in circulatory hospitalization rate per 10 μg/m3 increase in PM2.5 was higher in the 2008-2016 time period compared to the 2000-2007 period by 0.33% (95% posterior credible interval 0.22, 0.44%), 0.52% (0.33, 0.69%), and 0.67% (0.53, 0.83%) for low, medium and high tertiles of urban areas, respectively. We also observed significant differences in temporal trends of associations across socioeconomic status, sex, and age, indicating a possible widening in disparity of PM2.5-related health burden. This study raises the importance of considering environmental justice issues in PM2.5-related health impacts with respect to how associations may change over time.

Keywords: Fine particulate matter; Hospitalization; Temporal trend; Urbanicity; Vulnerable sub-population.

PubMed Disclaimer

Conflict of interest statement

Declaration of interests

The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Figures

Figure 1.
Figure 1.
Temporal trend of the association between PM2.5 and hospitalizations. Percentage change in risk of hospitalization per 10 μg/m3 increase in L02 PM2.5 based on non-linear model.
Figure 2.
Figure 2.
Temporal trend of the association between PM2.5 and hospital admissions by levels of urbanicity. Percentage change in risk of hospitalization per 10 μg/m3 increase in L02 PM2.5 based on non-linear model.
Figure 3.
Figure 3.
Temporal trend of the association between PM2.5 and hospital admissions by eligibility for Medicaid. Percentage change in risk of hospitalization per 10 μg/m3 increase in L02 PM2.5 based on non-linear model.
Figure 4.
Figure 4.
Temporal trend of the association between PM2.5 and cause-specific hospital admissions by sex. Percentage change in risk of hospitalization per 10 μg/m3 increase in L02 PM2.5 based on non-linear model.
See this image and copyright information in PMC

References

    1. Atkinson RW, Mills IC, Walton HA, Anderson HR, 2015. Fine particle components and health—a systematic review and meta-analysis of epidemiological time series studies of daily mortality and hospital admissions. J Expo Sci Environ Epidemiol 25, 208–214. 10.1038/jes.2014.63 - DOI - PMC - PubMed
    1. Bell ML, Dominici F, 2008. Effect modification by community characteristics on the short-term effects of ozone exposure and mortality in 98 US communities. Am J Epidemiol 167, 986–997. 10.1093/aje/kwm396 - DOI - PMC - PubMed
    1. Bell ML, Ebisu K, 2012. Environmental inequality in exposures to airborne particulate matter components in the United States. Environ Health Perspect 120, 1699–1704. 10.1289/ehp.1205201 - DOI - PMC - PubMed
    1. Bell ML, Ebisu K, Leaderer BP, Gent JF, Lee HJ, Koutrakis P, Wang Y, Dominici F, Peng RD, 2014. Associations of PM2.5 constituents and sources with hospital admissions: analysis of four counties in Connecticut and Massachusetts (USA) for persons ≥ 65 years of age. Environ Health Perspect 122, 138–144. 10.1289/ehp.1306656 - DOI - PMC - PubMed
    1. Bell ML, Ebisu K, Peng RD, Walker J, Samet JM, Zeger SL, Dominici F, 2008. Seasonal and regional short-term effects of fine particles on hospital admissions in 202 US counties, 1999–2005. Am J Epidemiol 168, 1301–1310. 10.1093/aje/kwn252 - DOI - PMC - PubMed

Publication types