[W]ood dust, solar radiation (the sun), soot, very hot beverages, night shift work and Ginko biloba… can give you cancer according to the International Agency for Research on Cancer (IARC, pronounced eye ark). IARC is part of the World Health Organization.
No matter what happens with the WHO, IARC is more of a long-term problem than its parent. In a sense, it’s not their fault, it’s the fault of the people who use their information incorrectly. Calling something a carcinogen does not mean that it is likely to give you cancer. It means that under a particular type of testing protocol, one that has little to do with human behavior, will give a rodent cancer.
There are several areas in the U.S. where we use IARC pronouncements without going the step further to take into account exposure. One is the Delaney Clause, a 62 year-old law that says that if a substance is found to be carcinogenic in animals or humans, it cannot be a food or color additive. When it is found to be carcinogenic in animals, it means that the animals have been given massive doses to see what happens. When we banned the sweetener saccharin in the late 1970s, astute commenters noticed that the rats were fed the equivalent of 800 cans of soda.
There are also numerous consumer groups who use IARC information to warn consumers about carcinogens in our food and cosmetics. Finally, because of a lack of understanding of the necessary partnership of potency and exposure, juries sometimes hand out awards for carcinogens that do not adequately factor in exposure.
A rolled-up newspaper in the hands of a lethal assassin is a risk – both potency and exposure.