The damage appears to have been caused by fiercely reactive molecules called free radicals. These molecules are generated within cells when cellular enzyme systems try to detoxify some chemical carcinogens. When these molecules interact with DNA they can change the structure of the DNA in such a way that they rewrite the DNA's coded instructions. Malins said that the study's findings support a growing body of evidence that free radical damage to DNA can trigger cancer. Other studies by his research team have found high levels of similar free radical damage in the DNA of women with breast cancer.
Free radicals are molecules that have an unpaired electron in their outermost orbit.
This unpaired state is relatively unstable, and, as a result, most free radicals are eager either to give up or absorb an electron by reacting with other molecules. Free radicals are constantly being produced in normal cellular metabolism and, therefore, the body has developed mechanisms to prevent them from damaging the cells. But when cells are exposed to certain toxic chemicals they produce large amounts of free radicals that can swamp the cell's antioxidant defenses. The research was conducted in cooperation with the University of Washington's Department of Environmental Health and was funded by the National Institutes of Environmental Health Sciences' Superfund Basic Research Program.