LUNG-CANCER MORTALITY IN NICKEL CHROMIUM PLATERS, 1946-95/

Objectives-To investigate mortality from lung cancer in nickel/chromiu m platers. Methods-The mortality experience of a cohort of 1762 chrome workers (812 men, 950 women) from a large electroplating and light en gineering plant in the Midlands, United Kingdom, was investigated for the period 1946-95. Ah subjects were first employed in chrome work at the plant during the period 1946-75, and had at least six months emplo yment in jobs associated with exposure to chromic acid mist (hexavalen t chromium). Detailed job histories were abstracted from original comp any personnel records and individual cumulative durations of employmen t in three types of chrome work were derived as time dependent variabl es (chrome bath work, other chrome work, any chrome work). Two analyti cal approaches were used-indirect standardisation and Poisson regressi on. Results-Based on mortalities for the general population of England and Wales, male workers with some period of chrome bath work had high er lung cancer mortalities (observed deaths 40, expected deaths 25.41, standardised mortality ratio (SMR) 157, 95% confidence interval (95% CI) 113 to 214, p<0.01) than did other male chrome workers (observed 9 , expected 13.70, SMR 66, 95% CI 30 to 125). Similar findings were sho wn for female workers (chrome bath workers: observed 15, expected 8.57 , SMR 175, 95% CI 98 to 289, p=0.06; other chrome workers: observed 1, expected 4.37, SMR 23, 95% CI 1 to 127). Poisson regression was used to investigate risks of lung cancer relative to four categories of cum ulative duration of chrome bath work and four categories of cumulative duration of other chrome work (none, <1 y, 1-4 y, greater than or equ al to 5 y). After adjusting for sex, age, calendar period, year of sta rting chrome work, period from first chrome work, and employment statu s (still employed v left employment), there was a significant positive trend (p<0.05) between duration of chrome bath work and risks of mort ality for lung cancer. Relative to a risk of unity for those chrome wo rkers without any period of chrome bath work, risks were 2.83 (95% CI 1.47 to 5.45), 1.61 (95% CI 0.75 to 3.44), and 4.25 (95% CI 1.83 to 9. 87) for the second, third, and fourth exposure categories, respectivel y. Duration of other chrome work was not a useful predictor of risks o f lung cancer. Similar findings for both variables were obtained when adjustment was made for sex and age only. Similar findings for both va riables were obtained relative to risk of chrome nasal ulceration. Con clusions-The findings are consistent with the hypothesis that soluble hexavalent chromium compounds are potent human lung carcinogens.