Assessment of DNA Damage in WBCs of Workers Occupationally Exposed to Fumes and Aerosols of Bitumen

Abstract

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-2V-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.

Dose-Response Modeling of Occupational Exposure to Polycyclic Aromatic Hydrocarbons with Biomarkers of Exposure and Effect

“…But a few conflicting results were reported (55) and critical comments were added from the methodologic point of view (56). Concentrations of 8-oxodGuo in this study were found to be higher than in construction and bitumenexposed workers, when measured with the same method and in the same laboratory (57). However, we could not find an association between 8-oxodGuo in WBC and any measure of exposure at the level of individual data in highly PAH-exposed workers.…”

Repeated Measurements of Urinary Methylated/Oxidative DNA Lesions, Acute Toxicity, and Mutagenicity in Coke Oven Workers

“…As shown in Fig. 2B, the urinary 8-oxodG at the end of work week had relatively lower levels compared with the other working days, probably because the biomarker of effect (e.g., 8-oxodG) may not only reflect the exposure during a week-shift but also a much longer period of exposure (43). Subsequently, the absence of significant correlation between 1-OHP and 8-oxodG in published studies could be also explained by that, in addition to polycyclic aromatic hydrocarbons, coke oven emissions also contain a variety of nitrosamines, coal tar, metal compounds, and so forth.…”

Respiratory Symptoms and Lung Functional Impairments Associated with Occupational Exposure to Asphalt Fumes

“…1,[4][5][6] Additionally, asphalt workers are exposed to emissions from the exhaust of passing vehicles. 4,[7][8][9] Respiratory effects of exposure to asphalt fume have been evaluated in a few studies. 5 However, conclusive results have not been obtained yet.…”

“…5 The respiratory effects of asphalt fumes have so far been studied in a few countries such as USA, 10,12,16 , Germany, 7 and Norway. 1,4 However, for differences in the chemical structure and composition of asphalt concrete mixtures, the concentration of asphalt fumes to which workers were exposed, air temperature, mechanical rather than manual processing of asphalt, good occupational health practices in these countries and many other differences, the results of these studies are not necessarily comparable with those of other studies.…”