Highway air linked to brain damage in mice

LOS ANGELES, April 7 (UPI) -- In a study using mice, short-term vehicle pollution exposure showed brain damage and signs of memory loss and Alzheimer's, U.S. researchers say.

Senior author Caleb Finch and co-author Constantinos Sioutas, both of the University of Southern California, developed a unique technology for collecting freeway particulates in a liquid suspension and recreating polluted air in the laboratory making it possible to conduct a controlled study on cultured brain cells and live animals.

The researchers recreated air laden with freeway particulate matter inside the laboratory and found whether in a test tube or in live mice, brain cells showed similar responses:

-- Neurons involved in learning and memory showed significant damage.

-- The brain showed signs of inflammation associated with premature aging and Alzheimer's disease.

-- Neurons from developing mice did not grow as well.

The freeway particles -- a mix of tiny particles from burning of fossil fuel and weathering of car parts and pavement -- measured between a few dozen to 200 nanometers, roughly one-thousandth the width of a human hair and too small for car filtration systems to trap.

"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," Finch says in a statement.

"Of course this leads to the question, 'How can we protect urban dwellers from this type of toxicity?' And that's a huge unknown."

The findings are published in the journal Environmental Health Perspectives.