Exposure to fine particles would affect the brain

Living next to high traffic areas is not ideal. In addition to the hearing pollution that this causes, the damage to health, particularly at the respiratory level, is not insignificant. A study by researchers at the University of Southern California shows that women in their 70s and 80s exposed to higher levels of pollution than others suffered from greater memory decline and brain atrophy , as in Alzheimer’s disease. As a reminder, Alzheimer’s disease is currently incurable and kills millions of people worldwide each year. The results of the study have been published in the journal Brain.

According to Andrew Petkus, assistant professor of clinical neurology at the University of Southern California, “this is the first study to show, using a statistical model, the association between air pollution and changes in the people’s brains, and that these changes are linked to memory decline.”

When air becomes a problem

According to Andrew Petkus, researchers hope to better understand the changes caused by air pollution in the brain, in order to develop new therapies and interventions for people at risk of cognitive decline. The main threat comes from PM2.5 fine particles, which are 1/30th the size of human hair. The minute size of these particles, which come from traffic exhaust, factories, smoke and dust, allows them to remain suspended in the air for long periods of time. The longer they stay in the air, the more they irritate the respiratory system of people who inhale them. These particles eventually reach the brain and accumulate there. Fine particulate matter can cause asthma, cardiovascular and lung disease, and premature death.

Although previous research has established the risk of Alzheimer’s disease and related dementia caused by fine particle pollution, it has not been clearly established whether PM2.5 alters brain structure and the decline of memory.

For the study, the research team collected data from a sample of 998 women aged 73 to 87, who underwent up to two brain scans five years apart as part of the Women’s Health Initiative. More than 160,000 women have signed up for this initiative, launched in 1993 by the National Institutes of Health, to answer questions about heart disease, cancer and osteoporosis.

The researchers used a machine learning tool, trained from the brain scans of people with Alzheimer’s disease, to rate people’s brain scans based on their similarity to Alzheimer’s disease. At the same time, the researchers analyzed information on the place of residence and the fine particle pollution levels of the 998 women.

Prior warnings

Taking into account variables such as income, level of education, ethnicity, geographical location and smoking, among others, researchers have established a link between high levels of pollution, changes in the brain and memory decline. Andrew Petkus believes the study is another piece of the Alzheimer’s puzzle, linking brain changes to air pollution and memory decline.

The fact that bad air leads to bad health is not new. Since the 1970s, scientists have known about the harmful effects of air pollution on cardiovascular and respiratory health. However, awareness of the effects of air pollution on the brain is recent. Previous studies have shown that air pollution not only worsens cognitive decline in adults, but also damages cognitive abilities in children. Air pollution has been shown to be a causative factor in depression.