Air pollution on freeways may lead to brain damage: Study

By Dr. Ananya Mandal, MDApr 10 2011

Earlier research has shown that air pollution from cars and trucks on Southern California freeways – that contains soot, pavement dust and other toxic substances - can cause respiratory disease, heart attacks, cancer and premature death. Now a new study has shown that exposure to pollution particles roughly one-thousandth the width of a human hair may lead to brain damage in mice, including signs associated with memory loss and Alzheimer’s disease. The study comes from University of Southern California and is published in the journal Environmental Health Perspectives.

According to senior author Caleb Finch, an expert on the effects of inflammation and holder of USC's ARCO/William F. Kieschnick Chair in the Neurobiology of Aging, You can’t see them, but they are inhaled and have an effect on brain neurons that raises the possibility of long-term brain health consequences of freeway air.”

The team, for the study collected particulates in a liquid suspension and recreated air laden with freeway particulate matter in the laboratory using an unique technology developed at USC. This enabled scientists to conduct controlled experiments on cultured brain cells and live animals. Exposure lasted a total of 150 hours, spread over 10 weeks, in three sessions per week lasting five hours each.

Lead author Todd Morgan, a research professor in gerontology at USC, said, “Our data would suggest that freeway pollution could have a profound effect on the development of neurons and brain health in children and young kids, especially those who attend schools built alongside freeways. So limiting one’s exposure - especially children’s exposure - to freeway pollution, is essential to control asthma, cardiovascular conditions and cognitive development.”

This study was undertaken after earlier research by a separate group in Mexico that noted significant differences in brain samples collected from children and young-adult accident victims in smog-laden Mexico City compared with those in Veracruz, which has cleaner air. In that study brain tissue collected in Mexico City showed more extensive inflammation, oxidized DNA and other pathological markers of Alzheimer’s disease, Morgan said. He added, “As a society, we need to figure out ways to minimize the level of the very, very nasty particulates we are dumping into the air we breathe. It’s having terrible consequences.”