Effects of vinyl chloride in man a cytogenetic follow-up study

Abstract

Summary Cytogenetic studies were performed on 39 workers from a PVC plant in 1974. 16 healthy men without any connection with the plant were chosen as controls. The cytogenetic study was repeated for 37 of the 39 workers 2–2.5 years later. During this time interval the workers had only had a minimal exposure to VCM. This repeated study was performed with 32 matched controls from the office employees in the factory. Breaks, gaps and stable rearrangements were scored in 100 metaphases per person from 48-h lymphocyte cultures. The mean chromosome-breakage frequency for the workers (3.41%) was significantly higher than for the controls (1.79%) in the first investigation. In the repeated study no difference was found in mean chromosome-breakage frequency between the workers and their matched controls. Neither was there any difference between these breakage frequencies and the breakage frequency for the previous control group. These results might indicate a relationship between the reduction in exposure to VCM and the normalized chromosomebreakage frequency. Sister-chromatid exchanges were studied for 16 workers with matched controls in the repeated study. A mean of 7.6 SCEs per cell was found for both workers and controls. Bone-marrow samples from 4 workers were studied in the first investigation. The mean chromosome-breakage frequency was higher in the bone marrows (4.2%) than that reported for normal bone marrows (0.2, 0.4, 1.7%), and higher than for the corresponding lymphocyte cultures.