Breathing an atmosphere contaminated with particulate matter (PM) diameter is <2.5 μm nearly doubles the risk of dementia in older women(Translational Psychiatry). Fossil fuel combustion by-products are a major source of PM2.5 which we recognize as “smog. ” Automobile exhaust emissions are a major source of the air pollution city dwellers inhale and account for 25% of ambient PM2.5..
The researchers focused on the effects of breathing in the tiny particles found in air pollution. They concluded that women who are exposed to levels of particulate matter exceeding federal standards were more likely to develop dementia. Fine particulate matter comes from a range of sources, including burning of fossil fuels.