All case studies are based on actual occurrences.
This population of laboring miners has an incidence of a rare cancer many times that of the general population, and those who live near the mine, as well as family members of miners, have a lower, but still elevated, incidence of the same cancer. The incidence of lung cancer in smoking miners is 60 times that in nonsmoking miners, and several times higher than in smokers who are not miners.
This is actually the situation in asbestos miners who were first employed 30 years ago or more. The cancer is mesothelioma. The miners carried home the asbestos fibers on their clothing. Family members, especially the wives who did the family laundry, inhaled these. ...