One end of the spectrum is being too careful, the other end is not taking any kind of precautions. Both are probably a bad way to live. (ie: if everything is equally dangerous, why not let children smoke a pack a day while working in a coal mine? They'll all die eventually anyway).
The leading cause of cancer is life. Everything causes long-term health problems, eventually. People are too risk-averse, How can you enjoy anything if you are perpetually concerned about long-term health risks?