While it’s easy to understand that air pollution may affect our lungs because we breathe in air, it’s not so obvious that there could be links between air pollution and other parts of our body.
Now scientists have established that there is a link between air pollution and Alzheimer’s disease, and they have established that air pollution changes the structure of the brain.
Researchers from the University of Southern California examined data from 998 women aged between 73 to 87 years who had brain scans five years apart as part of the Women’s Health Initiative, a 1993 United States study of women’s health.
The scans were reviewed for patterns similar to those in Alzheimer’s disease. The scientists also collected information about where the participants lived, and collated the information against environment data that allowed them to estimate the women’s exposure to fine particle pollution.
When the information was combined, researchers found an association between higher pollution exposure, brain changes and memory problems, even after adjusting for differences in income, education, race, geographic region, and cigarette smoking.
What exactly is air pollution?
Air pollution is particles and gasses that can reach harmful concentrations in the air, both outside and indoors. Smoke, mould, car exhaust, methan, and mould are common types of air pollutants.
This study looked at PM2.5, or particle matter smaller than 2.5 micrometres. These types of particles are about one-thirtieth of the width of a human hair.
PM2.5 particles can remain in the air for a long time because they are so miniscule. The particles get inside buildings, and are easy to inhale.
PM2.5 particles also reach the brain easily, and can accumulate there.
In previous research, fine particle pollution has also been associated with asthma, heart and lung disease, and premature death. Scientists had also previously established that exposure to air pollution increases the risk of Alzheimer’s disease.
In this latest study, the researchers confirmed that PM2.5 changes the structure of the brain and accelerates memory decline.
“This is the first study to really show, in a statistical model, that air pollution was associated with changes in people’s brains and that those changes were then connected with declines in memory performance,” said Andrew Petkus, assistant professor of clinical neurology at the Keck School of Medicine at the USC.
“Our hope is that, by better understanding the underlying brain changes caused by air pollution, researchers will be able to develop interventions to help people with or at risk for cognitive decline.”
“This study provides another piece of the Alzheimer’s disease puzzle by identifying some of the brain changes linking air pollution and memory decline,” he said.
“Each research study gets us one step closer to solving the Alzheimer’s disease epidemic.”
Alzheimer’s disease is the most common type of dementia, affecting approximately two-thirds of all people living with the condition. It’s estimated there are 400,000 people in Australia living with dementia.
There is currently no cure for dementia.