Impact of exposure to wood dust on genotoxicity and cytotoxicity in exfoliated buccal and nasal cells

Abstract

Wood dust was classified by the IARC as a human carcinogen which causes sinonasal tumours. However, the exposure in different industries varies strongly and the risks of workers depend on the specific situation which can be assessed by the use of biomonitoring methods. The aim of this study was to investigate the workers who are exposed to low dust levels (below the permitted concentrations) with cytogenetic and biochemical methods. Micronuclei (MNi) which are indicative for genomic damage, nuclear buds which reflect gene amplification, binucleated cells which are caused by mitotic disturbances and acute cytotoxicity parameters (pyknosis, karyorrhexis, condensed chromatin, karyolysis) were monitored in buccal and nasal cells of workers of a veneer factory (n = 51) who are exposed to volatile wood-derived compounds, in carpenters of a furniture factory which use no synthetic chemicals (n=38) and in a control group (n = 65). Additionally, markers were measured in blood plasma which reflect inflammations (C-reactive protein, CRP) and the redox status, namely malondialdehyde (MDA) and oxidised low density proteins (oxLDL). No induction of micronucleated cells was observed in both epithelia in the two exposure groups while all other nuclear anomalies except pyknosis were increased; also one health-related biochemical marker (MDA) was significantly elevated in the workers. Taken together, the results of our study show that exposure to low levels of wood dust does not cause formation of MNi indicating that the cancer risks of the workers are not increased as a consequence of genetic damage while positive results were obtained in earlier studies with workers who are exposed to high dust levels. However, our findings indicate that wood dust causes cytotoxic effects which may lead to inflammations.

Cytogenetic Biomonitoring in Buccal Mucosal Cells from Municipal Solid Waste Collectors

“…It has been established that chromatin shrinkage followed by disruption of the nuclear membrane may result in cytotoxicity (21). Some authors have postulated that chronic exposure to genotoxins induced an increase in cell death in buccal epithelium of humans (19,20). Our results are fully in agreement with these findings.…”

“…By comparison, some studies have demonstrated increased frequencies of micronuclei in such cells from agricultural workers exposed to pesticide mixtures in Guerrero state, Mexico (18). On the other hand, no induction of micronucleated cells was observed in buccal epithelia in people exposed to wood dust (19). Similarly, residents in Vietman did not show remarkable differences for micronucleus frequency in buccal mucosa cells after 40 years of dioxin exposure (20).…”

Genomic Instability in Buccal Mucosal Cells of Municipal Street Sweepers as Evaluated by Micronucleus Test

“…Micronuclei confirm mutagenesis in cells and living tissues, which corresponds to the initiation phase of carcinogenesis (18). For this reason, the detection of an elevated frequency of micronuclei in eukaryotic cells indicates genomic instability as far as increased cancer risk (19). Our results demonstrated an increased micronucleus frequency in buccal cells of street sweepers when compared to those from matched controls.…”

Wood dust and urinary 15-F2t isoprostane in Italian industry workers

“…An enhanced risk for chromosomal instability was found in wood workers . Discrepant results have been reported (Wultsch et al, 2015). In that study, no induction of micronuclei was observed in wood workers exposed to 0.39-0.66 mg/m 3 wood dust levels.…”