Preventive health program for nickel workers.

The possible hazards of exposure to certain nickel compounds during nickel refining have been recognized for over 40 years. Much progress has been made in worker protection by cleaning up the process and by other protective means, and improved personal hygiene. The problem in the past has been determining those employees who are most exposed. This has been accomplished in this project by regular plasma and urine nickel determinations, demonstrating that nickel process workers absorb nickel which can be measured in plasma and urine. It was found that the highest plasma and urine nickel levels were seen in workers in those departments in which the greatest incidence of respiratory cancer occurs. Whether persistently elevated plasma nickel can be correlated with the eventual development of respiratory tract cancer is the subject for continued years of follow-up. It is not possible to conclude at this time that there is any association between the raised plasma and urine nickel and the incidence of cancer.