New Evidence Links Pollution to Dementia Risk

"New research suggests that the quality of the air we breathe also has a significant impact on our cognitive health. A systematic review published earlier this year in The Lancet Planetary Health finds that exposure to outdoor air pollution significantly increases the risk of developing dementia. The journal article is the most extensive review to date of the relationship between long-term air pollution exposure and dementia risk. It compiles data from 51 studies conducted in high-income countries in Europe, North America, Asia, and Australia, involving nearly 30 million participants."

"Based on a complex statistical analysis, the researchers estimate that approximately 3 percent of dementia cases could potentially be prevented by eliminating air pollution exposure. And they found that geography matters. For example, the data suggest that dementia risk would be approximately 9 percent lower in a city like Edinburgh compared with London, purely based on air pollution differences."

"Researchers found three main sources of air pollution that affect cognitive health: fine particulate matter with diameters of 2.5 microns or less, primarily from vehicle exhaust; nitrogen dioxide released from vehicles and power plants; and black carbon produced by diesel engines, wildfires, and wood stoves. Data show the risk of dementia increases as exposure level increases, especially for the tiny particulate matter, which is so small it can be inhaled deeply into the lungs."

Data from 51 studies in high-income countries across Europe, North America, Asia, and Australia involve nearly 30 million participants. Long-term exposure to outdoor air pollution is associated with a significant increase in dementia risk. Approximately 3 percent of dementia cases could potentially be prevented by eliminating air pollution exposure. Geographic differences in air quality can alter dementia risk—for example, estimates suggest about 9 percent lower risk in Edinburgh compared with London based solely on air pollution. Three pollution sources are implicated: fine particulate matter (PM2.5), nitrogen dioxide, and black carbon. Risk rises with higher exposure, especially for tiny particles that penetrate deep into the lungs.

Read at Psychology Today