It's well-established that dirty, sooty air is no good for your lungs and probably not great for your skin. But research indicates that it can damage your brain, too.
A study in the journal of the Archives of Internal Medicine shows that air pollution accelerates cognitive decline in women. And with a federal report showing Southern Californians are at the highest risk of death from air pollution, this study adds to the growing body of grim evidence showing air pollution and healthy bodies don't mix.
"We keep learning about more adverse effects (from pollution) than we thought possible," said Jean Ospital, health effects officer with the South Coast Air Quality Management District, who was not involved with the current research.
"I'm not sure I find these results surprising," he said, "but I'm also not sure I would have expected them if you'd asked me 10 years ago."
The research, conducted by a team of researchers from Chicago, Boston, Baltimore and Philadelphia, looked at the effect of coarse particulate matter in the air on the cognitive health of older women.
"We, as a society, are on the verge of dealing with an unprecedented number of people having dementia," said Jennifer Weuve, lead author of the study and a researcher at Chicago's Rush University Medical Center. "We know relatively little about how to prevent dementia, but we do know cognitive decline is related to dementia."
Weuve pointed to research showing a link between air pollution and cardiovascular disease.
"It turns out that cardiovascular disease may play a role in cognitive decline," said Weuve, who is a researcher at Rush's Institute for Healthy Aging. "So if we understand how to prevent or delay these cognitive increments, maybe we can prevent or delay dementia."
Weuve and her team turned to one of the largest epidemiological data sets and cohorts in medical research, the Nurses' Health Study, to begin looking for links between pollution and cognitive health.
The Nurses' Health Study, which researchers began in 1976, is a data set based on information collected over time from 121,700 female registered nurses ages 30 to 55 living in 11 states.
From 1995 to 2001, Weuve and her colleagues invited participants of the Nurses' Health Study to participate in a study of cognition. The team was able to get data from nearly 20,000 women.
To establish pollutant exposure, the team collected air pollution exposure data from the Environmental Protection Agency, which they correlated with the location of each woman's home and place of employment. Then they called each woman six times on the phone, over six years, and tested their cognitive abilities.
They found that higher levels of long-term exposure to air pollution particles was associated with significantly faster cognitive decline.
California Watch is a project of the nonprofit Center for Investigative Reporting.
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