engleski

Micronucleus assay and mitotic activity : the methods for determinarion of recent vinyl chloride monomer exposure

In the absence of personal dosimeters for majority of chemical mutagens, biomonitoring should provide reliable data in order to determine period and severity of caused genome damage. According to our previous reports, micronucleus assay (MN) can serve as a suitable indicator of the period which elapsed after the last exposure to elevated concentrations of well known mutagen and carcinogen vinyl chloride (VCM). The aim of our study was to improve method for determination of the period which elapsed after last exposure by means of lymphocyte mitotic activity (MA). The study involved a group of 20 workers from VCM plant exposed to 1 ppm concentration with periodically increasing concentrations up to 70 ppm. The MN was performed on 72h cultures in which 3 microg/ml of Cyt-B was added. MA was analysed on lymphocyte cultures to which BrdU was added. Results show that distribution of MA differs significantly (M1 - 6 ; M2 - 12.5 ; M3 - 80.4) from control values (M1 - 7.9 ; M2 - 36.2 ; M3 - 53.8). Presented in percentages in case of recent VCM exposure and corellate with increased MN frequency or distribution of binucleated cells with more than 2 MN. In spite of different mechanisms of their origin after exposure MN and MA exhibit corresponding decrease of values and approach of control values. It could be therefore assumed that MA could serve as an additional parameter fot the evaluation of the time and dose effect in the monitoring of exposure to chemical mutagens.

micronuclei; mitotic activity; vinly chloride monomer; occupational exposure

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