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Member Research & Reports

Member Research & Reports

Washington Researchers Investigate Effects of Air Pollution on Dementia

Air pollution in America — at the lowest it has been in four decades — is still a major public health problem. It is also a public brain health problem linked to an increased risk of cognitive decline.gailli
[Photo: Dr. Gail Li]

Researchers from the University of Washington School of Public Health have teamed up with UW Medicine and Group Health Research Institute to investigate the role of air pollution exposures on memory and the risk for Alzheimer’s disease and other dementias.

The team of neuroscientists, environmental scientists, epidemiologists and biostatisticians are leveraging an active cohort of aging participants and 40 years of air pollution monitoring data from the Puget Sound Clean Air Agency. The project received more than $3 million over five years from the National Institute of Environmental Health Sciences and the National Institute of Aging.

“While the study focuses on residents in a relatively low-pollution area, the findings will address gaps in our knowledge about the true scope of the risks of air pollution exposure to the brain, even at lower levels,” says Dr. Lianne Sheppard, a professor at the School’s Departments of Environmental and Occupational Health Sciences and Biostatistics She will co-lead the five-year effort with Dr. Gail Li, an associate professor at UW Medicine and lead researcher at the UW Alzheimer’s Disease Research Center.

Ultimately, the researchers hope to provide the strong research findings needed for regulators to even consider reshaping environmental policy with the brain in mind.

“This study is particularly exciting because it adds geographical information systems, or GIS, approaches to the many sources of data we are able to tap into to learn more about the aging brain,” says co-investigator Dr. Paul Crane, adjunct professor in the School’s Department of Health Services and professor at UW Medicine. Along with air monitoring data, researchers will deploy new networks of sensors to take additional measurements of ambient fine particulate matter, ozone and nitrogen oxides in the greater Puget Sound area.

The study’s cohort of aging individuals comes from the Adult Changes in Thought (ACT) study, a joint project between Group Health Research Institute and the UW, which is led by Dr. Crane and Dr. Eric Larson, clinical professor in the School’s Department of Health Services and vice president for research at Group Health.

More than 5,500 aging participants without dementia who live in King County are randomly selected and enrolled in the ACT cohort. Extensive baseline information is collected along with health and cognitive function every two years. To date, more than 1,000 people have developed dementia. Researchers involved in the ACT study are investigating the environmental and genetic factors that determine the risk of degenerative brain disease.

“The ACT study team is so grateful for the people who participate in this study,” says Dr. Larson, “It’s a great resource for this important public health question.”

Evidence already shows that air pollution is associated with an increased risk of heart disease. In previous work in the ACT cohort, Dr. Li found that vascular risk factors for heart disease contributed to an increased risk of dementia. In this new study, she aims to figure out if a reduction of cardiovascular risk factors can be a way to reduce risk of dementia.

“We have control, collectively as a society, over how much pollution is acceptable,” said Dr. Sheppard. “If we change the regulations according to scientific research, we can affect the cognitive health of everybody who breathes the air.”