哪怕一天的空氣污染都能增加中風風險

Air pollution — even for just one day — significantly increases the risk of stroke, a large review of studies has found.

一項大型研究綜述發現，空氣污染可顯著增加中風的風險，即使只是短短一天也依然如此。

Researchers pooled data from 103 studies involving 6.2 million stroke hospitalizations and deaths in 28 countries.

研究人員彙總了103項研究的數據，共計涉及28個國家中的620萬例因中風住院和死亡病例。

The analysis, published online in BMJ, found that all types of pollution except ozone were associated with increased risk for stroke, and the higher the level of pollution, the more strokes there were.

這項在線發表於《英國醫學雜誌》(BMJ)上的分析發現，除臭氧外，所有類型的污染物均與中風風險增加相關，且污染物水平越高，中風病例越多。

Daily increases in pollution from nitrogen dioxide, sulfur dioxide, carbon monoxide and particulate matter were associated with corresponding increases in strokes and hospital admissions. The strongest associations were apparent on the day of exposure, but increases in particulate matter had longer-lasting effects.

二氧化氮、二氧化硫、一氧化碳和顆粒物污染的日增加量與中風和入院的相應增加相關。暴露當天的相關性最強，不過，顆粒物的增加可造成較爲持久的影響。

The exact reason for the effect is unclear, but studies have shown that air pollution can constrict blood vessels, increase blood pressure and increase the risk for blood clots. Other research has tied air pollution to a higher risk of heart attacks, stroke and other ills.

這種影響的確切原因尚不清楚，但研究表明，空氣污染可引起血管收縮、血壓升高，並會增加血栓風險。另有一項研究發現，空氣污染與心肌梗死、中風和其他疾病的風險較高相關。

The lead author, Dr. Anoop Shah, a lecturer in cardiology at the University of Edinburgh, said that there was little an individual could do when air pollution spikes. “If you’re elderly or have co-morbid conditions, you should stay inside,” he said. But policies leading to cleaner air would have the greatest effect, he said. “It’s a question of getting cities and countries to change.”

研究的主要作者，愛丁堡大學(University of Edinburgh)的心臟病學講師亞努皮·沙阿(Anoop Shah)博士說，當空氣污染激增時，單個人所能做的非常有限。“如果你是老人或患有併發症，你應該呆在家裏。”但可令空氣更清潔的政策將產生巨大的效果，他說。“會讓城市和國家發生改變。”