Ann Arbor Times

A recent study from the University of Michigan has found that long-term exposure to air pollution can lead to a loss of independence for older adults. Published in JAMA Network Open, the research highlights traffic-related air pollution as a significant risk factor for older adults losing their ability to care for themselves without assistance.

Traffic-related air pollution releases fine particulate matter and gases like nitrogen dioxide, which can harm various parts of the body, including the lungs, heart, and brain. Researchers observed that prolonged exposure to high levels of pollution over periods such as the 10 years studied resulted in an increased need for help with everyday activities.

The study suggests that reducing exposure to air pollution, particularly from traffic sources, could help prolong independent living for older adults. "This research indicates that long-term air pollution exposures can lead to persistent health issues that make it harder for a person to take care of themselves at older ages, leading to a need for help for activities that they once managed on their own," said Sara Adar, senior author and associate professor of epidemiology and global public health at U-M School of Public Health.

"Our research also suggests that where you live can dictate how well you age and indicates that even with our relatively clean air, nearly three-quarters of a million older adults in the United States newly require help with their routine daily activities each year due to their exposures to air pollution. This loss of independence has high emotional and financial costs for families and the health care system."

The findings are based on data from the Health and Retirement Study, funded by the National Institute on Aging and based at U-M's Institute for Social Research. Using data from 25,314 participants or their survivors, researchers documented participants’ need for help with routine life activities such as bathing, dressing, getting in and out of bed or a chair, walking, shopping, cleaning, using a phone or toilet, managing medications or money or transportation; and moving to a nursing home as they aged.

Survey participants' responses were cross-referenced with where they lived and long-term air pollution levels estimated by an advanced exposure model built with information from air pollution monitors and nearby sources. The study found that those who lost their independence were more likely to be white with lower levels of formal education and wealth. They were also more likely to have chronic diseases at baseline and had been exposed to higher median levels of most pollutants. Nearly 40% experienced a new loss of independence during the average 10.2 years they were followed.

"We believe this research extends our understanding of air pollution’s health impacts beyond specific chronic diseases to better capture the cumulative burden of air pollution in late life," said Boya Zhang, first author and research fellow at Harvard T.H. Chan School of Public Health. "These findings are quite important given the global population is aging faster than ever before."

The study also estimated the financial cost associated with lost independence due to air pollution. Applying an annual cost estimate per person needing help with daily activities ($16,028), researchers projected nationwide care expenses due to residential exposures to traffic-related air pollution would amount to $11.7 billion per year.

Co-authors include Kenneth Langa, Jessica Faul, Jennifer D’Souza, Richard Hirth, Lynda Lisabeth and Jiaqi Gao from U-M; Carlos Mendes de Leon from Georgetown University; Jennifer Weuve from Boston University; Adam Szpiro; Joel Kaufman from University of Washington.