Occupational risk assessment of oxidative stress and genotoxicity in workers exposed to paints during a working week

Abstract

Paints are complex mixtures of solvents and metals that can induce health damages in workers exposed to them. The aim of the present work was to evaluate possible oxidative and genotoxic effects in workers exposed to paints. Peripheral blood and buccal cell samples were collected from 33 workers exposed to paints and 29 non-exposed workers (controls) during an ordinary working week (Monday morning and Friday evening). Oxidative markers were assessed using thiobarbituric acid assay, carbonylated proteins, superoxide dismutase and catalase activities. Hippuric acid and delta-aminolevulinic acid were determined as biomarkers of toluene and lead exposure, respectively. Genotoxicity was measured through comet assay and micronucleus (MN) frequencies. The exposed group showed higher hippuric acid and delta-aminolevulinic acid levels (Friday samples) and lower superoxide dismutase activity (Monday samples) in relation to control group. DNA damage index (comet assay) was higher in the exposed group, both in Monday and Friday samples, compared to the control group. No differences were observed in frequency of micronuclei (MN) between the groups, either in lymphocytes or buccal cells. However, the exposed group presented an increase (Monday samples) in nuclear buds frequency in lymphocytes - a marker of gene amplification - as well as an increase in condensed chromatin in the buccal cells (Monday and Friday samples), suggesting induction of apoptosis. Furthermore, a decrease in the nuclear division index (Friday samples) was observed in the exposed group, indicating that paint exposure induces cytostatic effects in lymphocytes. The results suggest that individuals exposed to paints have increased levels of DNA damage.