Abstract
Background: Concerns about the effects of nanoparticles (NPs) on human health are being raised by researchers because the risks of nanocosmetics like sunscreen are unknown. Methods: We explored the association between urinary oxidative stress markers and exposure of cosmetics salesclerks to 20 cosmetics which might contain titanium dioxide (TiO2)/zinc oxide (ZnO) NPs. We then recruited 40 cosmetics salesclerks and 24 clothing salesclerks and categorized them based on their exposure to ZnO and TiO2 NPs. Results: Nineteen and fifteen samples met the EU definition for TiO2 and ZnO nanomaterials, respectively. Participants with a higher co-exposure index of ZnO and TiO2 NPs had a significantly higher base level of urinary 8-hydroxy-2'-deoxyguanosin (8-OHdG) concentrations than the lower co-exposure group (5.82 vs. 2.85 ng/mL, p < 0.001). After potential confounding factors had been adjusted for, the TiO2 and ZnO NP co-exposure index was significantly positively associated with the urinary 8-OHdG base concentration (β = 0.308, 95% CI = 0.106 to 0.510) and the creatinine-adjusted concentration (β = 0.486, 95% CI = 0.017 to 0.954). Conclusion: Current evidence suggests that the likelihood of harm from using sunscreens containing nanoparticles might result in higher urinary 8-OHdG. However, our limited number and types of sample cosmetics might underestimate the risk.