Smoking cigarettes more dangerous today than several decades ago … At least in the United States – because of changes in the composition of the tobacco mixture.
Up to half of cases of lung cancer in the country had its reason for these changes, said Professor at the University of California at San Diego David Burns at a meeting of the Society for Research on Nicotine and Tobacco.
Scientists are not first come to the conclusion that the movement for the low content of tar in cigarettes, ensuing in the 1960’s led to unexpected consequences. It was found an increase in pulmonary adenocarcinoma. Previous lung cancer occurred as a rule, bronchitis, and then the cases of cancer in the bronchiole. Scientists have linked this to the fact that smokers, with a lighter cigarettes are stronger drag.
David Burns, in turn, discovered that in the United States pulmonary adenocarcinoma registered more than Australia, although both countries have switched to a lighter cigarettes at about the same time. In the United States is 65-70% of cases of lung cancer, and in Australia – 40%. Academic sure: this is due to the fact that Australian cigarettes contain 20% less nitrosamines – known carcinogens.
Nitrosamines are a by-product of industrial processing of tobacco. The contents of these substances in cigarettes varies considerably depending on the type of tobacco and the method of manufacture of cigarettes.
Scientists who read the study, believe that deep procrastination are not to be discounted. In addition, experts warn that the reduction of nitrosamines reduce the risk of adenocarcinoma, but did not make cigarettes safe.
A study prepared for publication in a medical journal.