In other reports, the amount of smoke recorded in air samples was six times that found in other workplaces and four times that found in the home of a smoker, leading researchers to estimate that some hospitality industry employees face as much as a 50 percent increased risk of developing lung cancer. Once inhaled, the smoke's cancerous chemicals come under attack as the body tries to break down the toxic material into less harmful elements that it can digest and reject. This first line of defense can fail. More virulent chemicals can turn the tables. This tight link can mutate DNA, the genetic code found in each of the body's 100 trillion cells.
Genes carry instructions that guide cell growth.
In cases of lung cancer, scientists worry in particular about tampering with two genes. Altering either can make conditions ripe for cancerous tumors to flourish. Researchers aren't sure. That's because a number of factors, such as family history and diet, can affect somebody's susceptibility. But one thing is very clear for Dr. Stephen Hecht, Wallin Professor of Cancer Prevention at the University of Minnesota-Twin Cities Cancer Center.