Asbestos mill, Penge, South Africa, 1955-1960.

SOUTH AFRICA - MAY 31: Photograph from the collection of pathologist Dr J C Wagner showing the asbestos mill at Penge, South Africa. The blue asbestos rocks (crocidolite) were crushed at the mill to release the asbestos fibre, which was then graded, bagged and weighed, and distributed from the nearest rail-head. Wagner's research, and that of his colleagues, led to the identification of the causal link between exposure to blue asbestos and the lung cancer mesothelioma. (Photo by SSPL/Getty Images)