Personal exposure to polyaromatic hydrocarbon and inhalation risk assessment among asphalt hot mixed plant and road paving workers

Abstract

Workers exposed to heated asphalt at paving and hot mixed plant jobs may experience fumes and vapours containing hazardous chemicals, including polycyclic aromatic compounds (PAHs), causing respiratory irritation, carcinogenic and non-carcinogenic risk. 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 ninety-one personal air samples (paving 37 and plant 54) were collected from the worker’s breathing zone. Results were analysed using HPLC, following the NIOSH-5506 method. It was found that the total PAHs (TPAHs) concentration range (composed vapour and particulate phases) was between 0.02-184.71 µg/m3 (mean 21.07 ± 37.36 µg/m3) and the concentration of TPAHs among road paving workers was significantly higher (p 0.05) than the hot mix asphalt plant workers. Among the individual PAHs compound, the mean concentration of Benzo[ghi]perylene (BghiP) was 7.15 ± 17.05 µg/m3 and it was the highest observation value, followed by Benzo[α]Pyrene (BaP) with a mean concentration 3.28 ± 8.46µg/m3, and the exposure level of BghiP and BaP among the paving workers was significantly (p 0.05) higher compared with the plant workers. Health risk assessment suggested increased chances of developing cancer (3.44 x10− 09 to 3.47 x10− 04) in the study area, whereas non-cancer hazard quotients and indexes had values of BaP was 8.095x1002, which implied that these contaminants have adverse effects on health. The results of our study demonstrate that the asphalt workers are exposed to PAHs and their derivatives constantly at their work sites, and since PAHs are considered non-threshold carcinogens, our observed levels may still be harmful.