Results of epidemiologicalm mineralogical and cytotoxicological studies on the pathogenicity of coal-mine custs

Risks of developing abnormalities on chest X-rays differ widely between collieries in the Ruhr, despite comparable dust exposures. Simple pneumoconiosis hazard indices have been determined for thirteen collieries, taking into consideration variations in miners' individual cumulative dust exposures, their ages at start of dust exposure, the residence time of dust in their lungs, and the mineral content of the dust. Fine dust samples were taken in five collieries at places selected as representative of seams worked during the past 20 years. They were used for mineralogical and physical analyses and for cell and animal studies. Cytotoxicity of dusts with comparable composition increased with geological age and rank of coal seams. This finding is consistent with results from epidemiological studies.