Human biomonitoring of metals in workers at the waste-to-energy incinerator of Turin: An Italian longitudinal study.

Evidence of negative health effects of solid waste management is uncertain. Available reviews suggests the use of biomarkers in human biomonitoring (HBM) to detect low exposure levels. In September 2013, a waste-to-energy plant located in the Turin (Italy) went into operation. The SPoTT (acronym for Population health Surveillance in the Turin incinerator's area) monitoring program was set up to assess the potential health impact caused by the plant. The paper illustrates the results of HBM of metals in the workers before the plant went into operation and then at 1 year and 3 years. This study is one of the few focusing on workers with a longitudinal design (the first in Italy). Eighteen metals in urine and lead in blood were determined by sector field inductively coupled plasma mass spectrometry. Information on participant habits and other characteristics that could potentially affect metals concentrations were collected via a structured questionnaire. Subjects were classified according to their work role at the facility: administrative staff workers (AW); plant workers (PW). Nonparametric methods were used to evaluate the changes in metals concentration over time. Comparison of the metals concentration in the samples taken at baseline and at the following two-time points shows a general decrease in levels: urinary concentration of beryllium (Be), cobalt (Co), mercury (Hg), Ir, nickel (Ni), tin (Sn), thallium (Tl), and blood level of lead (Pb) among the PW and Ir and Pd among the AW were significantly lower at T2 versus baseline. A decrease was also recorded in arsenic (As) among the PW and in cadmium (Cd), chromium (Cr), palladium (Pd), rhodium (Rh), and zinc (Zn) for both groups, whereas the levels of copper (Cu) and vanadium (V) remained unchanged over time. The downward trend remained also after taking confounding factors into account. The only exceptions were Mn, Pt, Sb among the PW: increase levels between T0 and T2 were recorded, which cannot be specifically attributable to the plant activity. The median urinary and blood concentrations of the metals were lower than those reported in the literature and were below the occupational reference values at all three-time points. Our results are consistent with those reported for the cohort of local residents and with the ambient air measurements.