air pollution

Professor Receives $6 Million from NIH to Study Air Pollution, Noise, and Dementia Risk

The first of its kind in the US study is led by Jennifer Weuve, associate professor of epidemiology, and explores air pollution and community noise exposure as risk factors for Alzheimer’s disease and related dementias.

Jennifer Weuve, associate professor of epidemiology, has received two grants from the National Institute on Aging (part of the National Institutes of Health) to explore links between environmental exposures and Alzheimer’s disease and related dementias (ADRD).

Totaling more than $6 million, the grants fund a four-year study on air pollution and community noise exposure as risk factors for ADRD, as well as a five-year study on whether the olfactory system acts as a pathway for environmental toxicants to reach the brain and cause ADRD.

Few studies have determined if a combined exposure to air pollution and ambient noise amplifies one’s risk of cognitive decline and ADRD. In the Air-Noise-Dementia project, Weuve is focusing on the effects of combined exposure to aircraft noise and traffic-related air pollution such as fuel combustion pollutants from tailpipes and dust generated by tire and brake wear.

Weuve is utilizing data from the Chicago Health and Aging Project and the Parent Offspring Resilience and Cognitive Health study, two population-based cohort studies of older adults.

“This project will further advance our understanding of air pollution, noise, and ADRD by studying the effects of both exposures on brain structure and cerebrovascular disease that can be viewed on brain imaging,” she says.

In a study published in Alzheimer’s & Dementia, the journal of the Alzheimer’s Association, a team co-led by Weuve finds that 10 decibels more daytime neighborhood noise is associated with 36 percent higher odds of mild cognitive impairment and 30 percent higher odds of Alzheimer’s disease. The study is one of the first of its kind in the US.

“We remain in early stages in researching noise and dementia, but the signals so far, including those from our study, suggest we should pay more attention to the possibility that noise affects cognitive risk as we age,” says Weuve. “If that turns out to be true, we might be able to use policy and other interventions to lower the noise levels experienced by millions of people,” she says, noting that the US Environmental Protection Agency last set community noise level guidelines back in the 1970s. “Those guidelines were set to protect against hearing loss. Many of our participants were exposed to much lower levels.”

The study included 5,227 older adults participating in the Chicago Health and Aging Project (CHAP), which has followed a total of 10,802 individuals 65 years old or older living on the South Side of Chicago since the 1990s. Participants were interviewed and their cognitive function tested in three-year cycles.

For neighborhood noise levels, the researchers used a Chicago-area model from a previous study that gathered samples of A-weighted noise (the important frequencies for human hearing) at 136 unique locations during daytime, non-rush-hour periods between 2006 and 2007. The study then used these samples—combined with data on other geographic factors including land use and proximity to roadways and bus stops—to estimate noise levels in any Chicago-area location. Follow-up sampling found that the model was still accurate in CHAP participant neighborhoods in 2016.