Chrysotile fibre concentration and lung cancer mortality: a preliminary report.

After checking on the accuracy of work histories and estimating prevailing fibre concentrations by relevant time and place, all 244 deaths from lung cancer (ICD 162-164) in the Quebec mortality cohort were compared with internal controls matched for date of birth, mining area and smoking habit. Further studies of other causes of death and of lung cancer with controls unmatched for smoking are in progress. In the meantime, we consider that a useful estimate of lung cancer risks is given by the equation: RR = 1 + 0.00038 (+/- 0.00013) fibres/ ml.yr.