Biomonitoring of workers employed in a titanium dioxide production plant: Use of buccal micronucleus cytome assay as noninvasive biomarker to evaluate genotoxic and cytotoxic effects

Abstract

We aimed to evaluate whether TiO 2 production process induces genotoxic and cytotoxic effects on the first target organ of inhalable particles by a sensitive and noninvasive biomarker of effect. Final aim was to find a useful and suitable tool to assess and manage the risk of TiO 2 occupational exposure. We enrolled 40 workers

Evaluation of Systemic Genotoxic/Oxidative and Proinflammatory Effects in Workers of a Titanium Dioxide Production Plant

“…The comparison between the lack of genotoxicity found by the Fpg-comet assay parameters (TM, TL, and tail DNA%), able to detect direct DNA damage, and the induction of MN in buccal cells, found by BMCyt assay in the biomonitoring of the same workers previously published [ 18 ], seems contrasting. These different results could be explained by the difference in the biological matrices, and buccal cells represent a direct target of exposure by inhalation, whereas probably lymphocytes are more difficult to be reached by the particles, particularly nonrespirable particles (>4 μ m).…”

“…Control subjects and potentially exposed subjects did not show statistically significant differences relatively to smoking habits, age (41.55 ± 8.86 years for exposed workers in respect to 40.33 ± 12.50 for external controls), and job seniority (14.31 ± 9.71 years for exposed workers) [ 18 ]. Regarding gender, more than 90% of exposed workers and external controls were males in respect to the 40% of the office workers.…”

“…The present investigation focused on the very sensitive biomarker Fpg-comet assay which is able to detect early direct and oxidative DNA damage, because several in vitro and in vivo studies demonstrated genotoxic effects of TiO 2 using this assay [ 8 ] and on the detection of proinflammatory IL-6, IL-8, and TNF α , since inflammation represents one of the key mechanisms of toxicity of TiO 2 [ 20 ]. On the same workers enrolled in our first study [ 18 ], we performed Fpg-comet assay on lymphocytes obtained by peripheral blood collected simultaneously to buccal cells. The present study demonstrates that Fpg-comet assay on lymphocytes did not detect statistically significant direct or oxidative DNA damage in the tested workers involved in the production process of TiO 2 particles although this assay found higher comet percentages and higher percentage of subjects positive to oxidative DNA damage, in workers producing TiO 2 compared to controls.…”

“…This research, representing the second part of Ursini et al's [ 18 ] study, was performed on the same workers involved in the steps from calcination to bagging (performed in the white area of industrial plant) and employed in five different tasks (maintainers, technicians, industrial cleaners, mobile operators, and bagging operators).…”

“…Recently, we published the first results of a biomonitoring study with Buccal Micronucleus Cytome (BMCyt) assay performed on workers involved in the production process of TiO 2 particles where we found micronucleus induction in exfoliated buccal cells, demonstrating the suitability of this assay in the evaluation of early genotoxic and cytotoxic effects of TiO 2 particles at the first contact site of inhalation exposure [ 18 ]. These workers were also simultaneously biomonitored detecting titanium and oxidized bases in urine after work shift by Buonaurio et al who demonstrated the occurred exposure to TiO 2 and the inducted oxidative stress [ 19 ].…”