Background: Most people are aware that smoking cigarettes increases the risk of ill health, in particular of lung cancer. The precise way in which they relate amount of exposure to smoke and level of health risk has not, however, been determined.
Methods: A convenience sample of 155 French adolescents and adults ages 15 to 75 rated the risk of "smoker's cancer"--the popular term for lung cancer--in 24 scenarios depicting eight levels of daily cigarette consumption of three concentrations of nicotine. The data were analyzed according to functional measurement methodology to ascertain the forms of the relationship between exposure and perceived risk.
Results: All subjects perceived that the risk of smoker's cancer increased as smoking increased. Yet at high levels of consumption, additional cigarettes were generally judged to result in decreasing increments of risk, regardless of the nicotine content of the cigarettes and the sex and smoking status of the participants. Adolescents, however, were more likely than adults to perceive a linear, rather than a negatively accelerated, relationship.
Conclusions: The actual form of the relationship between the dose of cigarette smoke and risk of lung cancer is either linear or positively accelerated. Public health educators and physicians should be aware that, at least in France, many people, particularly adults, incorrectly perceive this relationship as negatively accelerated.