Breathing in toxic air fumes could increase dementia risk, a study claims.

　　一项研究称，吸入有毒空气会增加患痴呆症的风险。

　　Scientists found mental decline was greater in people exposed to higher pollution levels.

　　科学家发现，暴露于更高污染程度的人，其智力下降幅度更大。

　　They fear inhaling poisonous particles and gases could heighten the chances of irreversible damage to the brain. The findings were published in the journal Proceedings of the National Academy of Sciences.

　　他们担心吸入有毒颗粒和气体会增加对大脑不可逆转伤害的几率。其研究结果发表在《美国国家科学院院刊》上。

　　Previous studies have estimated air pollution causes an estimated 40,000 premature deaths a year in Britain from lung disease and heart attacks.

　　此前的研究已经估算出，英国每年约有4万人因空气污染死于肺病和心脏病。

　　Now scientists from Beijing University say toxic air also harms the brain. They gathered data from 16,000 households that took part in a three-year health study.

　　现在，北京大学的科学家说有毒的空气也会伤害大脑。他们收集了16000个家庭的数据，这些家庭参与了一项为期三年的健康研究。

　　Researchers compared air pollution levels with scores on memory tests and maths questions.

　　研究人员将空气污染程度，记忆力测试分数和数学测试分数进行了比较。

　　Those exposed to the highest levels of toxic pollutants in the air saw the biggest decline in mental ability.

　　那些暴露于最浓污染空气物中的人群。其智力下降幅度最大。

　　Men fared worse than women, the study revealed.

　　研究显示，男性的情况比女性更糟。

　　The researchers said: “Our findings imply the effect on social welfare could be much larger than previously thought.”

　　研究人员说:“我们的研究结果表明，对社会福利的这种影响可能比之前想象的要大得多。”