Abstract
A reanalysis of data on chromosomal aberrations among 33 copper smelter workers exposed to arsenic revealed no significant variations due to age, smoking habits or degree of arsenic exposure although the observed deviations were in the expected direction. The arsenic exposed workers showed significantly increased frequencies of chromosomal aberrations when compared with referents without known occupational exposure to genotoxic agents. Eight workers were studied at 3 different occasions, namely, 1976, 1978 and 1979. The levels of urinary arsenic decreased significantly between 1976 and 1978. There was also a significant decrease of chromosomal aberrations between 1976 and 1978 when group data were analyzed. Two individuals showed a significant decrease of breaks with time. One of them had changed from full time to half time work in 1977. In the follow-up study there is some evidence that decreased exposure leads to a lowered frequency of aberrations.