研究：空氣污染使大腦衰老更快

美國南加州大學的研究人員發現，居住在空氣污染嚴重地區的老年人大腦要比實際年齡“老三歲”，因其大腦認知功能受到空氣質量影響衰退更快。這項針對超過1.4萬50歲以上人羣進行的研究發現，空氣污染對大腦健康及其功能都有負面影響。研究人員發現，每立方米空氣中的污染微顆粒增加10微克，大腦認知能力就會下降0.3。而人的年齡每增加一歲，大腦認知能力僅下降0.1。由於老年人在健康和身體功能方面均開始衰退，因此其大腦功能和身體狀況更易受到空氣污染的不良影響。此前已有研究顯示，空氣污染與日益增加心血管疾病和呼吸系統疾病有關。

Elderly people living in areas of high air pollution have brains that are 'three years older' as cognitive function is affected by air quality, a study has found for the first time.

Researchers found that elderly people did worse on thinking tests if they lived in areas with high levels of air pollution, compared to those in areas with relatively clean air.

The team from University of southern California presented their findings at the Gerontological Society of America's annual scientific meeting, in San Diego.

Postgraduate doctoral fellow Jennifer Ailshire conducted the analysis using data from the American Environmental Protection Agency and the Health and Retirement Study.

She said: "As a result of age-related declines in health and functioning, older adults are particularly vulnerable to the hazards of exposure to unhealthy air.

"Air pollution has been linked to increased cardiovascular and respiratory problems, and even premature death, in older populations, and there is emerging evidence that exposure to particulate air pollution may have adverse effects on brain health and functioning as well."

The study of 14,793 men and women aged over 50 matched their results on cognitive tests to maps of air pollution.

The association even remained after accounting for several factors, including age, race/ethnicity, education, smoking behavior, and respiratory and cardiovascular conditions.

Every ten micrograms of fine particle air pollution found per cubic meter was linked to a drop of a third of a point in cognitive scores.

Areas of low air pollution had 4.1 micrograms per cubic meter and areas with the worst had 20.7 micrograms.

The difference was the equivalent of ageing three years, Ms Ailshire said.

This was because one year increase in age was linked to a drop in cognitive scores of just over a tenth of a point.