Air pollution, chiefly from traffic exhaust fumes in cities could have serious and sometimes fatal effect on health, according to two studies that link it to lung cancer and heart failure.
Although smoking is a far bigger cause of lung cancer, a significant number of people will get the disease because of where they live.
The study, codenamed Escape, combined data from 17 cohort studies in nine European countries covering a total of almost 313,000 people. The size of the research gives it greater authority than previous work.
It looked at the effect of long-term exposure to nitrogen oxides and particulate matter PM2.5, which has a diameter of less than 2.5 micrometres, and PM10, with a diameter less than 10 micrometres.
Among the participants, 2,095 developed lung cancer during an average 13 years of follow-up.
The researchers, led by Ole Raaschou-Nielsen from the Danish Cancer Society Research Centre, found that for every increase of five micrograms per cubic metre of PM2.5 pollution, the risk of lung cancer rose by 18%, and for every increase of 10 micrograms per cubic metre in PM10 pollution the risk increased by 22%.
The second study published by the Lancet, shows that short-term exposure to air pollution increases the risk of being admitted to hospital with and dying of heart failure.
The scientists behind the two studies say that their findings indicate that current safety limits on air pollution are still too high and need to be lowered.
“Everybody is exposed to air pollution and it is difficult to escape,” said Dr Anoop Shah. “Our results indicate that the lower the levels, the better it is.