Incidence of cytogenetic damage in lead-zinc mine workers exposed to radon

The purpose of this study was to detect cytogenetic damage in mine workers working in a lead-zinc mine, which could be associated with a combined exposure to radon and heavy metals. Our study involved 70 mine workers from the lead-zinc mine. We used peripheral blood lymphocytes as the target material. The total share of structural chromosome aberration (SCA) decreased significantly over the 3 years of monitoring, from 5.08/200 analyses of metaphases in 1995 to 3.28 in 1997, owing to the decrease in exposure during the process of mine closure. The share of SCA was significantly different from the group of local people, who had never worked in the mine (1.43), as well as from the control group of Slovene residents (1.88). The share of micronuclei (MN) in mine workers also decreased in the monitored period, from 14.65/500 cytokinesis-blocked cells in 1995 to 11.77 in 1997, while the sister chromatic exchange (SCE) level did not change much (from 8.105/50 analysed cells in 1995 to 7.73 in 1997). Owing to the closure activities, the received concentrations of contaminants were falling constantly, particularly concentrations of radon. This was particularly evident in the level of SCA and the MN incidence, while the SCE values remained nearly on the same level. This indicates that the incidence of SCE is probably more strongly influenced by heavy metals than by radon.