Assessment of DNA damage in WBCs of workers occupationally exposed to fumes and aerosols of bitumen.

We conducted a cross-shift study with 66 bitumen-exposed mastic asphalt workers and 49 construction workers without exposure to bitumen. Exposure was assessed using personal monitoring of airborne bitumen exposure, urinary 1-hydroxypyrene (1-OHP), and the sum of 1-, 2 + 9-,3-,4-hydroxyphenanthrene (OHPH). Genotoxic effects in WBC were determined with nonspecific DNA adduct levels of 8-oxo-7,8-dihydro-2'-deoxyguanosine (8-oxodGuo) and the formation of DNA strand breaks and alkali-labile sites. Concentration of fumes and aerosols of bitumen correlated significantly with the concentrations of 1-OHP and OHPH after shift (r(s) = 0.27; P = 0.03 and r(s) = 0.55; P < 0.0001, respectively). Bitumen-exposed workers had more DNA strand breaks than the reference group (P < 0.0001) at both time points and a significant correlation with 1-OHP and OHPH in the postshift urines (r(s) = 0.32; P = 0.001 and r(s) = 0.27; P = 0.004, respectively). Paradoxically, we measured higher levels of DNA strand breaks, although not significant, in both study groups before shift. 8-OxodGuo adduct levels did not correlate with DNA strand breaks. Further, 8-oxodGuo levels were associated neither with personal exposure to bitumen nor with urinary metabolite concentrations. Significantly more DNA adducts were observed after shift not only in bitumen-exposed workers but also in the reference group. Only low-exposed workers had significantly elevated 8-oxodGuo adduct levels before as well as after shift (P = 0.0002 and P = 0.02, respectively). Our results show that exposure to fumes and aerosols of bitumen may contribute to an increased DNA damage assessed with strand breaks.

Vapours and aerosols of bitumen: exposure data obtained by the German Bitumen Forum.

In a large project of the German Bitumen Forum, almost all branches of industry in Germany that use bitumen have been examined with regard to bitumen exposure. A total of 1272 samples were gathered between 1991 and 2005. The measuring method includes vapours and aerosols emitted from hot bitumen; the proportions of these two components and their dependency on bitumen temperature are described. Whereas in most branches a value of 10 mg m(-3) for the sum of vapours and aerosols is not exceeded, much higher values have been observed for work with mastic asphalt. Polycyclic aromatic hydrocarbons have been analysed in some cases, but exposure is several orders of magnitudes lower than with the earlier use of tar.