The cytokinesis-block micronucleus (CBMN) assay in human populations exposed to styrene: A systematic review and meta-analysis

Abstract

Styrene is a building-block of several compounds used in a wide array of materials and products. The most important human exposure to this substance occurs in industrial settings, especially among reinforced-plastics industry workers. The effect of occupational exposure to styrene on cytogenetics biomarkers has been previously reviewed with positive association observed for chromosomal aberrations, and inconclusive data for the micronucleus assay. Some limitations were noted in those studies, including inadequate exposure assessment and poor epidemiological design. Furthermore, in earlier studies micronuclei frequency was measured with protocols not as reliable as cytokinesis-block micronucleus (CBMN) assay. Aim of the present systematic review and meta-analysis is to investigate genomic instability and DNA damage as measured by the CBMN assay in lymphocytes of subjects exposed to styrene. A total of 11 studies published between 2004 and 2012 were included in the meta-analysis encompassing 479 styrene-exposed workers and 510 controls. The quality of each study was estimated by a quality scoring system which ranked studies according to the consideration of major confounders, exposure characterization, and technical parameters. An overall increase of micronuclei frequencies was found in styrene-exposure workers when compared to referents (meta-MR 1.34; 95% CI 1.18-1.52), with significant increases achieved in six individual studies. The consistency of results in individual studies, the independence of this result from major confounding factors and from the quality of the study strengthens the reliability of risk estimates and supports the use of the CBMN assay in monitoring genetic risk in styrene workers.

Investigation of Biological Activities and Secondary Metabolites of Hydnum Repandum Acetone Extract

“…Edible mushrooms are regarded as non-toxic and safe, but recent investigations reported that some of them cause DNA damages [27]. Numerous studies showed that the CBMN assay is a valid test for detection of genomic damage caused both in vitro [28,29] and in vivo [30,31]. Our results of CBMN assay showed that the extract was genotoxic in higher tested concentrations.…”

Evaluation of potential health effects associated with occupational and environmental exposure to styrene – an update

“…A recent review and meta-analysis focused on the induction of MN in human subjects was published by Costa et al (2016). The authors concluded that overall there was an increase in MN among styrene-exposed workers and that the findings of an increase were consistent across studies even though the review reported significant heterogeneity in the meta-analysis of all studies.…”

Draft Genome Sequence of Pseudomonas putida CA-3, a Bacterium Capable of Styrene Degradation and Medium-Chain-Length Polyhydroxyalkanoate Synthesis

“…Styrene is a solvent used extensively in the polymer-processing industry. It is a toxic compound which is known to have numerous adverse effects on human health ( 1 – 4 ). As a result of this toxicity, there is considerable interest in styrene waste management solutions, including the potential for microbial bioremediation.…”