Assessment of residual exposure to PCBs in metallurgy

Objective: To evaluate the occupational exposure to polychlorinated biphenyls (PCBs) in 56 workers employed in 6
electric arc furnace steelmaking plants and 2 secondary aluminum smelting plants located in the highly industrialized
area of Brescia, Northern Italy. Methods: Thirty-four PCB congeners were found in both environmental and
biological samples from workers engaged in scrap yards, electric arc furnaces, casting and maintenance departments.
Results: The highest airborne PCB levels were found in the aluminum plant, even 100 times those detected in the
steelwork plants. Dioxin-like PCB congeners (DL-PCBs) were poorly represented in all biological samples, whereas
non Dioxin-Like PCB congeners (noDL-PCBs), in particular environmentally widespread congeners (PCB 153,
138, 180), could be detected in almost all samples. The mean total PCB serum level was 3.9 ng/ml, with a range of
1.3-10.3 ng/ml, while the geometric mean for airborne PCBs levels was 9305 pg/m3, with a range of 1138-217806
pg/m3. Conclusions: Despite the higher PCB values recorded in some metallurgical plant workplaces, we failed to
find any significant difference between serum concentrations in workers from steel or aluminum production, even in
consideration of different tasks or different job seniority, while positive association was found only according to the age
of the workers. A possible explanation may be identified in the effectiveness of the individual and collective preventive
measures adopted in the workplace. Assessment of the occupational exposure to such compounds, in consideration of the
recent classifications as carcinogenic to humans, should be encouraged.