Lifestyle determinants of cancer among Danish mastic asphalt workers

Three reports suggest that asphalt workers, especially young mastic asphalt workers, in Denmark experience an increase in incidence and mortality from cancer and in mortality from other conditions. The methodology described in these reports raises questions about their validity and the data presented are limited and difficult to interpret. The cancers and the causes of death that are increased are highly correlated with those seen among men in the general population who use alcohol in excess, who smoke, and who engage in other risk-taking behaviors. The effects of these lifestyle causes of disease were largely not controlled in the reported studies. These behaviors, which cluster in young men, rather than exposure to asphalt fumes, probably caused the disease patterns that were reported. Policy makers who use epidemiologic results for risk assessment and regulation should do so with care. Working men and women sometimes die at high rates and their occupational exposures may or may not be responsible. The distinction is crucial if occupational health is to be improved. If asphalt workers die young from excessive drinking and smoking, we are not protecting their health by controlling asphalt fume exposures.