MORTALITY OF IRON FOUNDRY WORKERS .3. LUNG-CANCER CASE-CONTROL STUDY

A nested case-control study was undertaken to identify the determinant s of lung cancer mortality in a cohort of 8147 foundry men among whom an excess of lung cancer deaths was previously observed. The present s tudy consisted of all lung cancer deaths (N = 220) that occurred withi n this cohort between 1950 and 1989. Both living and dead controls, ma tched on race and attained age, were selected in the ratio of 10:1 (N = 2200) by means of the incidence density sampling procedure. All case s and two controls per case, randomly selected from each case's 10 con trols, were included in a smoking history survey. Basic smoking histor y information was obtained for about 71% of these study subjects. For the purpose of this study, formaldehyde exposure levels were categoriz ed as high, medium, and low, and none. Airborne silica exposure was ca tegorized only as high, medium, and low levels, because all foundry wo rkers were known to be exposed to silica. Conditional logistic regress ion analyses indicated that cigarette smoking was a strong predictor o f lung cancer mortality in this cohort. Neither exposure to formaldehy de nor silica exposure level, nor employment in any of the six major w ork areas within the foundry, showed an association with lung cancer.