Clinical and epidemiological data on lung cancer at a chromate plant.
The workforce of the only chromite ore processing plant in the United Kingdom at Eaglescliffe has been the subject of several epidemiological studies. There are also medical data available through a health surveillance program conducted by the plant's medical center. The clinical information has in part been collected to fulfill the requirements of health and safety legislation. Through this system, 18 cases of lung cancer among the workforce have been identified. The mean age at diagnosis was 57 years, with all but two cases occurring in smokers. There were no obvious histological or clinical features that could allow differentiation between the occupational and nonoccupational cancers. The epidemiological studies indicated an excess lung cancer risk among the workers beginning employment on the site before 1960. The risk appeared to have diminished after a major process change in 1960 which removed the addition of calcium carbonate to the process. Further studies including case-control analyses and construction of a job exposure matrix through use of recall by long-term workers and pensioners are in progress. The feasibility of an updated cohort mortality study at Eaglescliffe and possibly using the same protocol for other similar cohorts in U.S. and European plants should be considered.