Genetic damage and lipid peroxidation in workers occupationally exposed to organic bentonite particles

Objectives: It has been found that bentonite particles (BPs) could induce the cyto-genotoxicity and oxidative stress in vitro, but these effects on population exposed to BPs remain unclear. The aim of the present study was to investigate whether the genetic damage and lipid peroxidation can be detected in workers occupationally exposed to organic BPs. Methods: Sixty subjects were divided into three groups: (i) exposure group I consisted of 20 workers exposed to high concentrations of organic BPs in air; (ii) exposure group II were composed of 20 workers exposed to moderate concentrations of organic BPs in air; (iii) control group included 20 healthy unexposed subjects. Genetic damage was examined by comet assay and cytokinesis-block micronucleus cytome (CBMNcyt) assay. Lipid peroxidation was detected by malondialdehyde (MDA) assay. Results: The % tail DNA, MDA, the frequencies of micronucleus (MNF), micronucleated cell (MCF), nucleoplasmic bridges (NPBs), nuclear buds (NBUDs), apoptotic cell rate (ACR) and necrotic cell rate (NCR) in two exposure groups were significantly higher than those in control group (P<0.01 or P<0.05). Moreover, the % tail DNA, MDA, MNF, MCF, NPBs, NBUDs, ACR and NCR in exposure group I with higher exposure level of organic BPs in air were significantly higher than those in exposure group II with lower level of organic BPs (P<0.01). The order of nuclear division index (NDI) was: exposure group I < exposure group II < control group. Correlation analysis showed that there were good correlations among the above nine parameters (P<0.01). Age had a significant effect on genetic damage in controls. Conclusion: The genetic damage and lipid peroxidation are detectable in population occupationally exposed to organic BPs, which may be influenced by the air exposure concentrations of organic BPs. (C) 2012 Elsevier B.V. All rights reserved.