Personal Exposure to Polycyclic Aromatic Hydrocarbon and Inhalation Risk Assessment among Asphalt Hot Mixed Plant and Road Paving Workers
摘要
The workers working in hot mixing asphalt plants, road paving and tarring work are likely to be exposed to fumes and vapours containing hazardous substances such as polycyclic aromatic compounds (PAHs), which can cause respiratory irritation as well as carcinogenic and noncarcinogenic risks. The study estimated inhalation exposure to PAHs among asphalt workers in hot mixing plants and road paving areas using XAD-2 sorbent tubes and PTFE filter paper. A total of ninety-one personal air samples (paving 37 and plant 54) were collected from the workers’ breathing zone. The results were analyzed using HPLC following the NIOSH-5506 method. The total PAHs (TPAH) concentration range (composed of vapor and particulate phases) ranged from 0.02 to 184.71 µg/m3 (mean 21.07 ± 37.36 µg/m3), and the concentration of TPAHs among road paving workers was significantly greater (p < 0.05) than that among hot mix asphalt plant workers. Among the individual PAH compounds, the mean concentration of benzo[ghi]perylene (BghiP) was 7.15 ± 17.05 µg/m3 it was the highest observed value. The second highest concentration was benzo[α]pyrene (BaP), with a mean concentration of 3.28 ± 8.46 µg/m3. The exposure levels of BghiP and BaP among the paving workers were significantly (p < 0.05) greater than those among the plant workers. A health risk assessment suggested increased chances of developing cancer (3.44 × 10–09 to 3.47 × 10–04) in such populations if exposures are not controlled in the study area, whereas the percentage of noncancer hazard quotients and indices for BaP was 8.10 × 1002, which reflects that these contaminants have adverse effects on health. The results of our study demonstrate that asphalt workers are constantly exposed to PAHs and their derivatives at their work sites, and since PAHs are considered non-threshold carcinogens, our observed levels may still be harmful.