In the present article we assessed exposure to polycyclic aromatic hydrocarbons (PAHs) in Italian asphalt workers (AW, n = 100), exposed to bitumen fumes and diesel exhausts, and in roadside construction workers (CW, n = 47), exposed to diesel exhausts, by means of environmental and biological monitoring. 1-hydroxypyrene (OH-Py) was determined in urine spot samples collected, respectively, after 2 days of vacation (baseline), before, and at the end of the monitored work shift, in the second part of the workweek. Median airborne levels during the work shift of 15 PAHs (both vapor and particulate phases), from naphthalene (NAP) to indeno(1,2,3-cd)pyrene, ranged from below 0.03 to 426 ng/m(3). Median excretion values of OH-Py in baseline, before- and end-shift samples were 228, 402, and 690 ng/L for AW and 260, 304, and 378 ng/L for CW. Lower values were found in nonsmokers compared to smokers (e.g., in AW 565 and 781 versus 252 and 506 ng/L in before-shift and end-shift samples, respectively). In all subjects a weak correlation between personal exposure to the sum of airborne 15 PAHs and OH-Py was observed (r = 0.30). The results of this article show that AW experienced a moderate occupational exposure to airborne PAHs, resulting in a significant increase of urinary OH-Py during the workday and the workweek. The contribution of working activities to internal dose was in the same order of magnitude of the contribution of cigarette smoking.