Natural dust particles can cause physical damage to the lungs and trigger an asthma attack. Particles of carbon produced when fossil fuels are burned can lead to similar problems but they are also coated with toxic heavy metals, chemicals and volatile organic compounds.
天然粉塵可能使肺部受損,引發哮喘.燃燒化石燃料時產生的碳微粒可能導致類似問題,但它們外表還包裹著有毒的重金屬、化學物質和揮發性有機物.
These are able to pass from the lungs into the blood stream where it is thought they cause further damage to the body.
這些物質可能從肺部進入血液,據稱這會給身體造成進一步損害.
Areeba Hamid, an air pollution campaigner with environmental group Greenpeace, said: "Toxic air causes havoc to people's health wherever in the world they live.
環境團體綠色和平組織的反空氣污染活動家阿麗芭-哈米德說："有毒空氣給世界各地人們的健康造成嚴重損害."
"We now know fumes from diesel vehicles are a lot more toxic than car companies claimed and this is a big cause of air pollution in Europe and North America.
"我們如今知道,柴油車排放的廢氣毒性比汽車公司宣稱的要大得多,而這是歐洲和北美空氣污染的一大原因."
"These companies have a lot to answer for, but so far they've managed to avoid any real accountability."
"這些公司要承擔很大責任,但到目前為止它們都避免承擔任何真正的責任."
The study of cities in China found the average annual expose to PM2.5 was 56 micrograms per cubic metre, compared to the WHO guideline limit for safe air quality of 10 micrograms.
對中國城市的這項研究發現,PM2.5的年均接觸量為每立方米56微克,而世界衛生組織的空氣質量安全標準為每立方米10微克.
People who were older than 75, had less education or who lived in hotter places were more likely to die.
75歲以上、教育水平較低或生活在較熱地區的人死亡風險更高.
It is thought people in warmer cities were more likely to spend time outside or leave their windows open, thereby breathing more polluted air, the researchers said.
研究人員說,在較熱城市生活的人到戶外去或開窗的時間可能更長,因此會吸入更多的污染空氣.
They also speculated that less well educated people might have poorer access to health care or experience poorer environmental health conditions.
他們還推測說,教育水平較低的人享受醫療服務的機會較少,他們接觸的環境衛生狀況也較差.
英文來源：獨立報
