Evidence is mounting that air pollution can hurt not only the lungs and the heart but also the developing brain. Animal studies are helping scientists track how tiny particles we breathe in can travel to the brain, causing inflammation and neurodegenerative changes.
University of Montana researcher Lilian Calderon-Garciduenas suspects that early exposure to these particles is a risk factor for Alzheimer's disease.
In a brain imaging study, Dr. Calderon-Garciduenas found that middle-class children from highly polluted Mexico City had significantly more tiny, white matter brain lesions than a second group of children from a Mexican city with cleaner air.
White matter is the wiring of the brain. It connects different regions and allows them to communicate with each other. In the elderly, these types of white matter lesions are often seen in people developing dementia, says Dr. Calderon-Garciduenas, a medical doctor who trained as a neuropathologist at the University of Toronto in the 1970s. She collaborates with the National Institute of Pediatrics in Mexico City.