FRIDAY, May 3 (HealthDay News) -- Molecules emitted by trees
interact with man-made air pollution and create tiny particles that
can get lodged in the lungs, potentially leading to lung cancer and
asthma, researchers suggest.
Trees produce and emit isoprene, a molecule that protects leaves
from oxygen damage and temperature fluctuation. But after isoprene
is chemically altered by exposure to the sun, it reacts with
pollutants called nitrogen oxides to create the tiny harmful
particles, called fine particulate matter, scientists discovered.
Nitrogen oxides are emitted by vehicles, aircraft, coal plants and
The study was published in a recent online issue of the journal
Proceedings of the National Academy of Sciences.
"The work presents a dramatic new wrinkle in the arguments for
reducing man-made pollutants worldwide," study author Jason
Surratt, an assistant professor of environmental sciences and
engineering at the University of North Carolina at Chapel Hill,
said in a university news release.
"Isoprene evolved to protect trees and plants, but because of
the presence of nitrogen oxides, it is involved in producing this
negative effect on health and the environment," Surratt said.
"We certainly can't cut down all the trees, but we can work on
reducing these man-made emissions to cut down the production of
fine particulate matter," he added.
Understanding how this process works will help researchers
better predict air quality and climate effects, which can lead to
improved regulations that affect the public and the environment,
the study authors suggested.
"We observe nature's quirks, but we must always consider that
our actions do have repercussions," Surratt said. "It's the
interaction between these natural and man-made emissions that
produces this air pollution, smog and fine particulate matter --
and now we know one reason for how it happens."
The World Health Organization has more about
air quality and health.