Monitoraggio biologico dell'esposizione ambientale a benzene in addetti alla vigilanza urbana

Vehicle exhausts are a well known source of aromatic hydrocarbon pollution in urban environments. The paper reports the results of environmental and biological monitoring of benzene exposure in traffic wardens carried out over a 5-hour workshift. Subjects (n=131) were grouped according to smoking habits and job task as follows: group (A) 52 nonsmoking office workers, (B) 43 nonsmoking outdoor workers, subdivided into (B₁) 36 working on foot and (B₂) 7 cyclists; (C) 20 smokers office workers, (D) 16 smokers out-door workers, subdivided into (D₁) 11 working on foot and (D₂) 5 cyclists. The median indoor environmental benzene concentration (26 μg/m³, n=50) was significantly lower than the outdoor concentration (45 mg/m³, n=43) (p3 (n=12). For biological monitoring, urinary excretion of trans, trans-muconic acid was determined in spot samples collected at 7:30 h (MAit) and 12:30 h (MAft). The MAft(A) median value (63 μg/l, range 2-242 μg/l) was not statistically different from MAft(B) (74 mg/l, range 15-216 μg/l), while the MAft(B2) value of 96 μg/l was higher than both MAft(B1) (71 mg/l) and MAft(A). In group (B) there was a relationship between airborne benzene levels and MAft(B) excretion (y=17.2+1.1x, r=0.62, n=35, p3, such as those seen in this study; MA can however be reliably used as a biomarker for higher exposures such as those, for example, due to smoking.