By Shereen Lehman, June 18, 2014
An airplane flies past the haze covered skyline of New York's Lower
Manhattan as seen from the Eagle Rock Reservation in West Orange, New
Jersey, August 31, 2012.
(Reuters Health) -
The tiny particles in vehicle exhaust and other sources of air
pollution may hasten cognitive decline in older adults, according to a
new U. S. study.
decided to examine the link between air pollution and cognitive
function in older adults because there is growing evidence that fine
particulate matter air pollution affects brain health and development,
but relatively little attention has been given to what this means for
the aging brain,” said Jennifer Ailshire, who co-wrote the report.
is with the Center for Biodemography and Population Health and the
Andrus Gerontology Center at the University of Southern California in
along with Philippa Clarke of the Institute for Social Research at the
University of Michigan, Ann Arbor, say that based on their results,
improvements in air quality may be an important strategy for reducing
age-related cognitive decline.
has been some evidence that people living in more polluted areas have
greater rates of cognitive decline, and the link is not explained by
wealth or other social factors, the researchers point out in The
Journals of Gerontology: Series B.
gathered information from one wave of a large ongoing survey started in
1986, and focused their analysis on 780 participants who were 55 years
of age or older at the time of the 2001/2002 survey.
Routine measurement of air pollution by census tract did not start until the late 1990s, they explain.
function was measured by math and memory tests and participants got a
score based on the number of cognitive errors they made.
pollution levels for each participant’s neighborhood were calculated
using fine particulate levels reported by the U.S. EPA’s Air Quality System. Those pollution particles 2.5 microns or smaller (PM2.5) can
travel deep into the lungs and enter the bloodstream, past research has
Ailshire and Clarke found the average PM2.5 concentrations in the study participants’ environments were 13.8 micrograms per cubic meter, which is above the EPA’s air quality standard of 12 micrograms per cubic meter.
they compared the cognitive error scores to pollution levels and found
that people living in high pollution areas, with 15 micrograms per cubic
meter or more of PM2.5 had error scores one and a half times those of
the participants who lived in low pollution areas with no more than 5
micrograms per cubic meter.
and other social factors as well as health problems can influence
cognitive function, the authors note. And poorer neighborhoods tend to
be more polluted. But after the researchers adjusted for education,
employment, gender, marital status and several other factors, the
differences in cognitive error rates remained.
emerging evidence showing a link between air pollution and cognitive
function suggests air pollution may harm the brain as well as the heart
and lungs,” Ailshire said in an email.
she and Clarke wrote, they would want long-term data and more exact
individual pollution exposures to assess the importance of PM2.5 in
Weuve said the new research joins a growing number of large studies
that suggest “higher exposures to everyday air pollution affect aging
brains’ ability to think.”
who was not involved in the study, is a researcher at the Rush
Institute for Healthy Aging at Rush University Medical Center in
“believe that particulate matter may affect cognitive function in older
adults by its harmful effects on the cardiovascular system - which is
connected to the brain through blood vessels - and possibly by directly
acting on the brain itself,” Weuve said.
type of air pollution is difficult to avoid. The most important action
is the one we take as a society, by regulating the amount of pollution
that gets emitted into our air, not by individual actions, she said.
of confining oneself to an indoor space with filtered air, it is
extraordinarily difficult (and absurd) to imagine any one person being
able to, for example, stop the air pollution that emanates into his or
her environment from an industrial plant tens or hundreds of miles
away,” Weuve said.
finding a link between the air we breathe on a daily basis and our
long-term brain health is alarming, the good news is that we have made
remarkable progress in the last decade in reducing levels of air
pollution across the country, and there are efforts underway to further
reduce air pollution,” Ailshire said.
she added, the public should understand that there are health risks to
living in polluted environments, particularly for older adults, and we
should all be more aware of issues related to air quality.
SOURCE: bit.ly/1y8PRSx The Journals of Gerontology: Series B, online June 6, 2014.