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
. 2016 Jan;124(1):23-9.
doi: 10.1289/ehp.1408973. Epub 2015 May 15.

Long-term PM2.5 Exposure and Neurological Hospital Admissions in the Northeastern United States

Marianthi-Anna Kioumourtzoglou  1 , Joel D Schwartz, Marc G Weisskopf, Steven J Melly, Yun Wang, Francesca Dominici, Antonella Zanobetti
Affiliations

Long-term PM2.5 Exposure and Neurological Hospital Admissions in the Northeastern United States

Marianthi-Anna Kioumourtzoglou et al. Environ Health Perspect. 2016 Jan.

Abstract

Background: Long-term exposure to fine particles (particulate matter ≤ 2.5 μm; PM2.5) has been consistently linked to heart and lung disease. Recently, there has been increased interest in examining the effects of air pollution on the nervous system, with evidence showing potentially harmful effects on neurodegeneration.

Objective: Our objective was to assess the potential impact of long-term PM2.5 exposure on event time, defined as time to first admission for dementia, Alzheimer's (AD), or Parkinson's (PD) diseases in an elderly population across the northeastern United States.

Methods: We estimated the effects of PM2.5 on first hospital admission for dementia, AD, and PD among all Medicare enrollees ≥ 65 years in 50 northeastern U.S. cities (1999-2010). For each outcome, we first ran a Cox proportional hazards model for each city, adjusting for prior cardiopulmonary-related hospitalizations and year, and stratified by follow-up time, age, sex, and race. We then pooled the city-specific estimates by employing a random effects meta-regression.

Results: We followed approximately 9.8 million subjects and observed significant associations of long-term PM2.5 city-wide exposure with all three outcomes. Specifically, we estimated a hazard ratio (HR) of 1.08 (95% CI: 1.05, 1.11) for dementia, an HR of 1.15 (95% CI: 1.11, 1.19) for AD, and an HR of 1.08 (95% CI: 1.04, 1.12) for PD admissions per 1-μg/m3 increase in annual PM2.5 concentrations.

Conclusions: To our knowledge, this is the first study to examine the relationship between long-term exposure to PM2.5 and time to first hospitalization for common neurodegenerative diseases. We found strong evidence of association for all three outcomes. Our findings provide the basis for further studies, as the implications of such exposures could be crucial to public health.

Citation: Kioumourtzoglou MA, Schwartz JD, Weisskopf MG, Melly SJ, Wang Y, Dominici F, Zanobetti A. 2016. Long-term PM2.5 exposure and neurological hospital admissions in the northeastern United States. Environ Health Perspect 124:23-29; http://dx.doi.org/10.1289/ehp.1408973.

PubMed Disclaimer

Conflict of interest statement

The contents of this publication are solely the responsibility of the grantees and do not necessarily represent the official views of the U.S. EPA. Further, the U.S. EPA does not endorse the purchase of any commercial products or services mentioned in the publication. The authors declare they have no actual or potential competing financial interests.

Figures

Figure 1
Figure 1
Map of the 50 cities included in our analyses. The size of the circles represents the size of the population ≥ 65 years living in each city (U.S. Census Bureau 2000) and the color indicates the average PM2.5 concentrations (μg/m3).
Figure 2
Figure 2
City-specific PM2.5 effect estimates on PD admissions, presented as log(HR) (95% CI) per 1-μg/m3 increase in PM2.5. PD, Parkinson’s disease. The size of the symbol used for the effect estimate is proportional to its precision.
Figure 3
Figure 3
City-specific PM2.5 effect estimates on AD admissions, presented as log(HR) (95% CI) per 1-μg/m3 increase in PM2.5. AD, Alzheimer’s disease. The size of the symbol used for the effect estimate is proportional to its precision.
Figure 4
Figure 4
City-specific PM2.5 effect estimates on dementia admissions, presented as log(HR) (95% CI) per 1-μg/m3 increase in PM2.5. The size of the symbol used for the effect estimate is proportional to its precision.
See this image and copyright information in PMC

References

    1. Adar SD, Klein R, Klein BE, Szpiro AA, Cotch MF, Wong TY, et al. 2010Air pollution and the microvasculature: a cross-sectional assessment of in vivo retinal images in the population-based Multi-Ethnic Study of Atherosclerosis (MESA). PLoS Med 711e1000372; doi:10.1371/journal.pmed.1000372 - DOI - PMC - PubMed
    1. Alzheimer’s Association. 2013 Alzheimer’s disease facts and figures. Alzheimers Dement. 2013;9(2):208–245. - PubMed
    1. Andersen PK, Gill RD. Cox’s regression model counting process: a large sample study. Ann Stat. 1982;10:1100–1120.
    1. Beelen R, Raaschou-Nielsen O, Stafoggia M, Andersen ZJ, Weinmayr G, Hoffmann B, et al. Effects of long-term exposure to air pollution on natural-cause mortality: an analysis of 22 European cohorts within the multicentre ESCAPE project. Lancet. 2014;383:785–795. - PubMed
    1. Berkey CS, Hoaglin DC, Antczak-Bouckoms A, Mosteller F, Colditz GA. Meta-analysis of multiple outcomes by regression with random effects. Stat Med. 1998;17:2537–2550. - PubMed

Publication types

Substances

LinkOut - more resources