Silicosis, radon, and lung cancer risk in Ontario miners.
The presence of radiographic silicosis was assessed as a risk factor for lung cancer in a cohort and case-control study of miners in the Ontario Silicosis Surveillance Database. Subjects were 328 miners with silicosis matched on age to 970 miners with normal radiographs. In a cancer incidence follow-up, there was a significant excess of lung cancer among miners with silicosis (Standardized Incidence Ratio 2.55; 95% Confidence Interval 1.43-8.28). Miners with normal radiographs had lung cancer incidence about the same as the Ontario average (Standardized Incidence Ratio 0.90; 95% Confidence Interval 0.51-1.47). In a matched case-control analysis of lung cancer, cumulative radon exposure was associated with lung cancer risk (increase in odds ratio 0.4% per WLM; 95% Confidence Interval -0.3% to 1.1%). When the presence of silicosis was added to the model, silicosis was a highly significant risk factor for lung cancer (Odds Ratio 6.99 95% Confidence Interval 1.91-25) and the risk factor for radon was diminished (increase in Odds Ratio -0.5% per WLM; 95% confidence Interval -1.4% to 0.4%). This finding suggests that additional study is warranted before concluding that radon risk factors derived from mining populations do not need to be modified for application to the general population.
Finkelstein
M M
MM
Health and Safety Studies Unit, Ontario Ministry of Labour, Toronto, Canada.
D016022:Case-Control Studies; D015331:Cohort Studies; D006801:Humans; D015994:Incidence; D008175:Lung Neoplasms / Q000209:etiology*; D008906:Mining; D009784:Occupational Diseases / Q000209:etiology*; D011886:Radon / Q000009:adverse effects*; D012307:Risk Factors; D012829:Silicosis / Q000150:complications* / Q000453:epidemiology
D011886:Radon