Research of the biomarker of the exposure to organochlorine compounds in employees of the vinyl chloride and polyvinyl chloride manufacture

This article presents results of the quantitative assessment of the blood content of organochlorine compounds (vinyl chloride, 1,2-dichloroethane) and its metabolite thiodiacetic acid (TDAA) in the urine of workers of the production of vinyl chloride (VC) and polyvinyl chloride(PVC). The studies were executed in two phases: in the first phase, 65 persons were surveyed at the time of the periodic medical examination, at the second phase — 10 workers of basic professions (apparatchiks of gas separation and polymerization and cleaners) werу observed in the dynamics of 12-hour shifts. The sample consisted of persons, who regularly passed bioassay test before the work shift, and after the shift and the next day before the shift. The purpose of the study was the evaluation of the content of chlorinated hydrocarbons in the organism of workers of VC and PVC productions. The studies were conducted using the methods developed in our laboratory with using a gas chromatograph Agilent 7890A with a flame ionization detector, docked with the Headspace Sampler Agilent 7694E and gas chromatograph Agilent 7890A with a Mass Selective Detector Agilent 5975C. Statistically significant differences in TDAA urine content were found between workers and cases from the control group. There was detected its dependence on the levels of as well exposure to toxic substances, the production, and occupation, as the duration of the post-exposure period. The average value of the urine content of TDAA in workers of the workshop of VC production authentically was shown to be 2.57 times higher than in workers of the workshop of the PVC production. The average urine concentration of TDAA in workers of both workshops were 5.0 and 19.9 times higher than in cases from the control group (0.27±0.02 mg/dm³). Th urine TDAA content in panmen was authentically 2 times higher than in workers from the group of the subsidiary occupations. It should be noted that the largest percentage of urine samples with exceeding TDAA levels in the control group — 84.8% was observed in panmen, in the group of auxiliary occupation the percentage of these samples amounted to 75.0%. Increased levels of the urinary TDAA excretion was observed during the work after 12 hours after the end of the shift, before starting the next shift period and during a medical examination 24 hours after the cessation of the exposure to toxicants, which may be the optimal time urine collection during biomonitoring studies.