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Fine Particulate Matter and Dementia in the Adult Changes in Thought Study

26 Pages Posted: 14 Oct 2020

See all articles by Rachel M. Shaffer

Rachel M. Shaffer

University of Washington - Department of Environmental and Occupational Health Sciences

Magali Blanco

University of Washington - Department of Environmental and Occupational Health Sciences

Ge Li

VA Puget Sound Health Care System - Geriatric Research Education and Clinical Center

Sara D. Adar

University of Michigan at Ann Arbor - Department of Epidemiology

Marco Carone

University of Washington - Department of Biostatistics

Adam Szpiro

University of Washington - Department of Biostatistics

Joel D. Kaufman

Kaiser Permanente Washington Health Research Institute

Tim Larson

University of Washington - Department of Environmental and Occupational Health Sciences

Eric B. Larson

University of Washington - School of Medicine

Paul Crane

University of Washington - School of Medicine

Lianne Sheppard

University of Washington - Department of Biostatistics

More...

Abstract

Background: Air pollution may be associated with elevated dementia risk, but prior research has limitations that may affect reliability, and no prior studies have evaluated this question in a community-based cohort of men and women in the United States. 

Methods: We evaluated the association of long-term fine particulate matter (PM2.5) exposure with all-cause dementia during the period 1978-2018 in the Adult Changes in Thought (ACT) study based in Seattle, Washington, USA. PM2.5 exposures linked to participant addresses were obtained from a spatiotemporal model spanning 40 years. Research quality dementia diagnoses were made using standardized diagnosis protocols at biennial follow-ups. We conducted multivariate Cox proportional hazards regression to evaluate the association between time-varying, 10-year average PM2.5 exposure and time to event in a model based on age, stratified by apolipoprotein E (APOE) genotype, and adjusted for sex, education, race, neighborhood median household income, and calendar time. 

Findings: Mean (standard deviation) 10-year average PM2.5 was 10.0 (2.9) µg/m3, which is below the current national air quality standard. Each 1 µg/m3 increase in the moving average of 10-year PM2.5 was associated with a 16% greater hazard of all-cause dementia (1.16 (1.03, 1.31). 

Interpretation: In this community-based prospective cohort study with uniquely extensive exposure data and research quality outcome ascertainment, elevated long-term exposure to PM2.5 was associated with an increased hazard of all-cause dementia. These results add to growing evidence on the neurodegenerative effects of air pollution and suggest that reducing exposures across the population could contribute to reducing the burden of dementia. 

Funding: NIEHS F31ES030972-02, NIEHS T32ES015459, NIA T32AG052354, NIEHS and NIA R01ES026187, U01 AG006781, NIEHS ES026187, NIA AG05136, R01 AG056711 and U01 NS091272, the University of Washington Retirement Association Aging Fellowship, and the Seattle Chapter of the Achievement Rewards for College Scientists (ARCS) Foundation.

Declaration of Interests: The authors have no conflicts of interest to disclose.

Ethics Approval Statement: ACT participants signed forms indicating their informed consent to enroll in the study. Study procedures were approved by the University of Washington and Kaiser Permanente Institutional Review Boards.

Keywords: dementia, air pollution, fine particulate matter, Alzheimer's disease, survival analysis

Suggested Citation

Shaffer, Rachel M. and Blanco, Magali and Li, Ge and Adar, Sara D. and Carone, Marco and Szpiro, Adam and Kaufman, Joel D. and Larson, Tim and Larson, Eric B. and Crane, Paul and Sheppard, Lianne, Fine Particulate Matter and Dementia in the Adult Changes in Thought Study. Available at SSRN: https://ssrn.com/abstract=3678619 or http://dx.doi.org/10.2139/ssrn.3678619

Rachel M. Shaffer

University of Washington - Department of Environmental and Occupational Health Sciences ( email )

Seattle, WA
United States

Magali Blanco

University of Washington - Department of Environmental and Occupational Health Sciences ( email )

Seattle, WA
United States

Ge Li

VA Puget Sound Health Care System - Geriatric Research Education and Clinical Center

1660 S. Columbian Way
Seattle, WA 98106
United States

Sara D. Adar

University of Michigan at Ann Arbor - Department of Epidemiology ( email )

500 S. State Street
Ann Arbor, MI 48109
United States

Marco Carone

University of Washington - Department of Biostatistics ( email )

Seattle, WA 98195
United States

Adam Szpiro

University of Washington - Department of Biostatistics ( email )

Seattle, WA 98195
United States

Joel D. Kaufman

Kaiser Permanente Washington Health Research Institute

1730 Minor Ave
Seattle, WA 98195
United States

Tim Larson

University of Washington - Department of Environmental and Occupational Health Sciences ( email )

Seattle, WA
United States

Eric B. Larson

University of Washington - School of Medicine

Box 356340
1925 N.E. Pacific Street
Seattle, WA 98195-6340
United States

Paul Crane

University of Washington - School of Medicine ( email )

Box 356340
1925 N.E. Pacific Street
Seattle, WA 98195-6340
United States

Lianne Sheppard (Contact Author)

University of Washington - Department of Biostatistics ( email )

Seattle, WA 98195
United States

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