“…An update study with 10 more years of followup among Sardinia silicotics was excluded from the analysis because only lung cancer SMR was shown among smoking silicotics (regional rates as reference), and the interaction indices could not be estimated. 45 Except for the studies of Chinese granite workers in Singapore and the refractory brick industry in Mainland, China, 12,42 the occupational exposures involved in the other studies were quite mixed, and might involve concomitant exposures to other occupational lung carcinogens. The cases of silicosis came from silicosis registries for the purpose of compensation 10,13,16,21,22,42,43 or from medical surveillance programs at the workplace.…”