A nine-year follow up study of a population occupationally exposed to vinyl chloride monomer.

The presence of structural chromosome aberrations and sister chromatid exchange frequencies (SCE) were studied in lymphocytes from 28 male subjects occupationally exposed to vinyl chloride monomer for a period of 9 years. A significant increase in chromosomal damages and elevated SCE frequencies was detected during the third and fourth year of the follow-up study. During the last 2 years, all examined parameters are approaching control values. This is a result of decreasing vinyl chloride monomer concentrations in the working environment without interrupting the working process.