Even comparatively low levels of air pollution may boost the chances of an early death, according to a British study.
As part of the study, researchers examined more than 5000 adults aged 30 and above on the basis of long term monitoring of air quality in different electoral wards around Britain during different time periods, and national data on causes of death.
The study linked black smoke and sulphur dioxide to the chances of an early death.
Despite a fall in air pollutants over the study period, as measured by the air quality readings, the risk of an early death remained, even at the comparatively low levels of air pollutants during the most recent time frame.
This was especially true for deaths from respiratory illness.
The risk of an early death from respiratory disease rose by almost 4 percent for every 10 ug/m3 increase in black smoke, and by 13 percent for every 10 parts per billion increase in sulphur dioxide during 1982-98.
The figures held true even after adjusting for factors known to increase the chances of an early death, including social deprivation.
The findings of the study were published in Great Britain Online First Thorax.