Urinary 1-hydroxypyrene as a biomarker of internal dose of polycyclic aromatic hydrocarbons in carbon black workers.

In this study, a total of 30 workers were selected, including eight wet pelletizing workers and 22 packaging workers. For all selected workers, urine samples were collected on the first day pre-shift, first day post-shift and fifth day post-shift, and their urinary 1-hydroxylpyrene levels (1-OHP) were determined (denoted as BM1pre, BM1post and BM5post, respectively). Personal respiratory exposures, including both inhalable particle-bound PAHs (Cinh) and gaseous PAHs (Cgas), together with dermal exposure to particle-bound PAHs (Cskin) were measured. Personal background information, including age, sex and smoking habit, was carefully registered. Pyrene exposure was statistically significantly correlated with exposure to PAHs and carcinogenic PAHs. Multiple linear regression analysis results showed that the BM1post values could not be explained by workers' exposures. For BM5post in packaging workers, both the regression model (R2 = 0.73) and the regression coefficients for Cgas, Cinh and Cskin were statistically significant (P < 0.05). For pelletizing workers, the R2 value was higher but was not statistically significant because of the smaller number of workers. The resultant regression coefficients for 'sex', 'smoking habit' and 'age' were statistically insignificant (P >> 0.05), which could be because these variables made relatively small contributions to BM5post. In conclusion, this study suggests BM5post could be a suitable indicator for PAH exposures of carbon black workers, on the condition that both respiratory (including gaseous PAHs and particle-bound PAHs) and dermal exposures have been assessed.