Exposure to polycyclic aromatic hydrocarbons (PAH) in Italian asphalt workers

Purpose of the work was the assessment of exposure to Polycyclic Aromatic Hydrocarbons (PAH) in 100 Italian asphalt workers (exposed to bitumen fumes and diesel exhausts) and in 47 ground construction operators (exposed only to diesel exhausts). The protocol included interview by questionnaires, environmental air-monitoring (active personal sampling during the work shift), and biological monitoring (urine collected in three different moments: baseline after two days of vacation, before shift and at the end of shift on a day of the second half of the week). Since dermal exposure has been suggested as a major determinant of the total PAH dose absorbed by road pavers from bitumen fumes, we assessed skin contamination: in both groups, to each subject six polypropylene pads were applied in different parts of the body, during the workshift. Median airborne levels of PAH ranged from 408 to below 0.07 ng/m3. Among different work-tasks and versus the confronted group (ground construction operators), there were not statistically significant differences in air-environmental exposure. The results show that the dermal contamination in asphalt workers is significantly higher than in ground construction operators. We did not found important differences in dose density between pads located on different body region. Cutaneous dose rate is about threefold higher than airborne dose rate, whereas considering the toxicokinetical information (Kp, lag time, experimental dermal absorption data) and the hygienistic data (particle size of bitumen fume), the relevance of dermal absorption is lower than respiratory one. The analysis of the 1-hydroxypyrene was performed in urine samples. The results of this study demonstrate that asphalt road pavers experience a moderate occupational exposure to airborne PAH, by cutaneous and respiratory absorption, resulting in a significant increase of urinary 1-hydroxypyrene during the workweek.