Control of particular forms of air pollution could help to reduce lung cancer rates in the Irish population, irrespective of smoking patterns, a new study has suggested.
The study looked at death rates from lung cancer in the Dublin area in the 10 years prior to a ban being imposed on the sale, distribution and marketing of bituminous coal in 1990 and compared them with death rates from lung cancer in the capital in the 10 years following the ban.
The study found a significant two-thirds of a decline in annual black smoke concentrations recorded in the city in the pre-ban and post-ban years.
Rates of tobacco smoking also declined over this period as did reported deaths from lung cancer. A total of 3,559 lung cancer deaths were reported in the pre-ban period (1981-1990) and 3,353 were reported in the post-ban period (1991-2000).
However, when the researchers looked at these rates, irrespective of tobacco smoking patterns, they found reductions in lung cancer death rates were achievable on the basis of the elimination of smog alone.
One of the study's authors, Prof Luke Clancy, said the overwhelming cause of lung cancer was smoking but the study established there was also a 1 per cent reduction in deaths from lung cancer in Dublin as a result of the ban on bituminous coal.
"We believe that despite the fact that the main decline in lung cancer deaths, particularly in men, is due to the decrease in the smoking rate, nevertheless when we allow for all that, we see a small further reduction in lung cancer which we attribute to the reduction in black smoke," he said. While the reduction in cases was small, any deaths that could be prevented were worthwhile, he added.
A previous study in 2002 showed a 16 per cent decrease in respiratory deaths and a 10 per cent reduction in cardiovascular deaths in Dublin in the aftermath of the ban. It took longer, he said, for the effect on lung cancer to become apparent.
The research on the effect of the coal ban on lung cancer death rates is published in the latest edition of the Irish Medical Journal.