 A 1996 study provided molecular evidence linking components in tobacco smoke to lung cancer.B"a"P was shown to cause genetic damage in lung cells that was identical to the damage observed in the DNA of most malignant lung tumours.Regular consumption of cooked meats has been epidemiologically associated with increased levels of colon cancer (although this in itself does not "prove" carcinogenicity),
A 2005 NCI study found an increased risk of colorectal adenomas was associated with B"a"P intake, and more strongly with B"a"P intake from all foods.