Confirmation of an excess of cancer mortality in a cohort of workers of a chromium thin-layer plating

OBJECTIVES: to extend up to year 2013 the follow-up for mortality of a cohort of workers in a chromium and nickel plating plant, where an excess of lung cancers was already identified. DESIGN: 10 years after the first study about cancer mortality in a cohort of workers involved in the chromium thin-layer plating, published in 2006, we updated the evaluation of the mortality of a cohort of workers employed in the same chromiumthin-layer plating factory with at least 6 months of work between 1968 and 1994. The mortality rates are compared with those of the Italian and Veneto Region (Northern Italy) populations. The dose-response relationship between work duration and lung cancer is assessed by adjusted Poisson regression. SETTING AND PARTICIPANTS: 127 unskilled or skilled workers involved in the production process. RESULTS: in the updated follow-up, 35 deaths occurred among the subjects under study: 19 for cancer (of which 11 for lung cancer and 3 for pancreatic cancer). A marked excess ofmortality due to lung cancer is observed. In addition, the new follow-up shows a significant excess of pancreatic cancer mortality. Lung cancer mortality is positively associated with work duration and the risk increases by 13%( 95% CI 1-26) for each additional year of work. CONCLUSIONS: the extension of follow-up confirms that this cohort expresses an increased mortality from cancer deaths, due to a marked excess of lung and pancreatic cancers. The effect of smoking has only a secondary effect in the cancer onset expressed by this cohort. The risk of lung cancer increased with work duration and thus with occupational exposure to chromium and nickel.