Markers of oxidative damage of nucleic acids and proteins among workers exposed to TiO2 (nano) particles

• Published in: Occupational and environmental medicine (London, England) Vol. 73; no. 2; pp. 110 - 118
• Main Authors: Pelclova, D, Zdimal, V, Fenclova, Z, Vlckova, S, Turci, F, Corazzari, I, Kacer, P, Schwarz, J, Zikova, N, Makes, O, Syslova, K, Komarc, M, Belacek, J, Navratil, T, Machajova, M, Zakharov, S
• Format: Journal Article
• Language: English
• Published: England BMJ Publishing Group 01.02.2016; BMJ Publishing Group LTD
• Subjects: Adult; Aerosols; Amino acids; Biological effects; Biomarkers; Biomarkers - metabolism; Breath Tests; Cancer; Chemical hazards; DNA Damage; Humans; Male; Middle Aged; Mitochondrial DNA; Nanoparticles; Nanoparticles - adverse effects; Nanotechnology; Nucleic acids; Nucleic Acids - metabolism; Occupational exposure; Occupational Exposure - adverse effects; Oxidation; Oxidation-Reduction; Oxidative stress; Oxidative Stress - drug effects; Particle Size; Particulate Matter - adverse effects; Production workers; Proteins; Proteins - metabolism; Respiratory tract; Surveillance; Titanium; Titanium - adverse effects; Titanium dioxide; Titanium oxides; Toxicity; Work; Workplace; Workplaces; Young Adult; United States > US
• ISSN: 1351-0711; 1470-7926
• DOI: 10.1136/oemed-2015-103161

ObjectiveThe use of nanotechnology is growing enormously and occupational physicians have an increasing interest in evaluating potential hazards and finding biomarkers of effect in workers exposed to nanoparticles.MethodsA study was carried out with 36 workers exposed to (nano)TiO2 pigment and 45 controls. Condensate (EBC) titanium and markers of oxidation of nucleic acids (including 8-hydroxy-2-deoxyguanosine (8-OHdG), 8-hydroxyguanosine (8-OHG), 5-hydroxymethyl uracil (5-OHMeU)) and proteins (such as o-tyrosine (o-Tyr), 3-chlorotyrosine (3-ClTyr) and 3-nitrotyrosine (3-NOTyr)) were analysed from samples of their exhaled breath.ResultsIn the production workshops, the median total mass 2012 and 2013 TiO2 concentrations were 0.65 and 0.40 mg/m3, respectively. The median numbers of concentrations measured by the scanning mobility particle sizer (SMPS) and aerodynamic particle sizer (APS) were 1.98×104 and 2.32×104 particles/cm3, respectively; and about 80% of those particles were smaller than 100 nm in diameter. In the research workspace, lower aerosol concentrations (0.16 mg/m3 and 1.32×104 particles/cm3) were found. Titanium in the EBC was significantly higher in production workers (p<0.001) than in research workers and unexposed controls. Accordingly, most EBC oxidative stress markers, including in the preshift samples, were higher in production workers than in the two other groups. Multiple regression analysis confirmed an association between the production of TiO2 and the levels of studied biomarkers.ConclusionsThe concentration of titanium in EBC may serve as a direct exposure marker in workers producing TiO2 pigment; the markers of oxidative stress reflect the local biological effect of (nano)TiO2 in the respiratory tract of the exposed workers.