OBJECTIVES: Experimental studies using nanoscale TiO2 have documented lung injury, inflammation, oxidative stress, and genotoxicity. Human health data are extremely scarce. METHODS: In exhaled breath condensate (EBC) and urine of 22 office employees occupationally exposed to TiO2 during their visit in the production workshops for average 14±9 min/day a panel of biomarkers of nucleic acids and proteins oxidation was studied, specifically 8-hydroxy-2-deoxyguanosine (8-OHdG), 8-hydroxyguanosine (8-OHG), 5-hydroxymethyl uracil (5-OHMeU), o-tyrosine (o-Tyr), 3-chlorotyrosine (3-ClTyr), and 3-nitrotyrosine (3-NOTyr). Examination was performed also in 14 comparable controls. RESULTS: The median respirable TiO2 mass concentration in the workshops was 0.40 mg/m3, median number concentration was 2.32×104 particles/cm3 with 80% of the particles being <100 nm in diameter. All 6 markers of oxidation were elevated in EBC in factory office employees relative to controls (p<0.01). Significant association was found between their job in TiO2 production plant and 5 markers of oxidation (except 3-NOTyr) in the EBC in multivariate analysis. No elevation of markers was detected in the urine. CONCLUSION: This pilot study suggests that even short nanoTiO2 exposure may lead to pulmonary oxidative stress; however this effect may be short-term and reversible. The clinical significance of these findings is unclear and more studies are needed.

Charles University 1st Faculty of Medicine Institute of Biophysics and Informatics Prague Czech Republic

Charles University and General University Hospital Prague 1st Faculty of Medicine Department of Occupational Medicine Prague Czech Republic

Charles University Faculty of Physical Education and Sport Department of Kinanthropology and Humanities Prague Czech Republic

Institute of Chemical Process Fundamentals of the CAS CR v v i Prague Czech Republic

Institute of Chemical Technology Prague Czech Republic

J Heyrovský Institute of Physical Chemistry of the CAS CR v v i Prague Czech Republic

Testing Strategies of the In Vitro Micronucleus Assay for the Genotoxicity Assessment of Nanomaterials in BEAS-2B Cells

Three-Year Study of Markers of Oxidative Stress in Exhaled Breath Condensate in Workers Producing Nanocomposites, Extended by Plasma and Urine Analysis in Last Two Years

NanoTiO2 Sunscreen Does Not Prevent Systemic Oxidative Stress Caused by UV Radiation and a Minor Amount of NanoTiO2 is Absorbed in Humans

Deep Airway Inflammation and Respiratory Disorders in Nanocomposite Workers

Markers of Oxidative Stress in the Exhaled Breath Condensate of Workers Handling Nanocomposites