Even relatively low quantities of air pollution increase the risk of premature death, according to an article published in Thorax. Black smoke and sulphur dioxide were found to have the closest associations with raising the risk of early death.
Air quality in different British electoral wards were checked over long and varying periods, say the researchers. They also examined national data on causes of death. The study involved over 5,000 adults, all aged over 30.
The data was divided into four groups, extending over 16 years in each group, commencing in 1966-1970 and ending in 1994-1998.
Even though the level of air pollutants dropped over the study period, the researchers found that the risk of premature death was still there, even at comparatively low levels. Respiratory illnesses appear to be the most common cause of death.
Premature death risk from respiratory disease rose by almost 4% per 10 ug/m3 increase in black smoke, the article states. For every increase of 10 parts per billion in sulphur dioxide during the 1982-1998 period the risk of early death went up 13%.
The scientists pointed out that even after adjusting for factors which are known to increase premature death risk, e.g. social deprivation, the numbers still stood.
They concluded that these findings confirm the lasting legacy of air pollution on health. The findings “point to continuing public health risks even at the relatively low levels of black smoke and sulphur dioxide that now occur.”
“Long term associations of outdoor air pollution with mortality in Great Britain”
Online First Thorax 2007; doi:10.1136/thx.2006.076851
http://thorax.bmj.com
Written by: Christian Nordqvist