Biomonitoring of Hydroxylated Polycyclic Aromatic Hydrocarbon Metabolites in Workers at a Waste-to-Energy Incinerator, Turin, Italy

Abstract

This paper presents the results of the human biomonitoring of ten urinary OH-PAHs (hydroxylated polycyclic aromatic hydrocarbon) in a cohort of workers at an incinerator in Turin, Italy. Long-term exposure was assessed through repeated measurements at three time points: before the startup (T0), after 1 year (T1), and after 3 years (T2). Paired data were available for 26 subjects, seven administrative workers (AWs) and 19 plant workers (PWs). Short-term exposure was assessed by comparing start-end shift measurements. Due to the non-normal distribution of the data, the nonparametric Cuzick's test for trend and the Wilcoxon signed-rank test for paired samples were used. Neither the trend nor the T0-T2 comparison tests resulted in statistically significant outputs in the two groups (q-value > 0.05), even when controlling for smoking habits. In relation to PWs, some of the metabolites were higher at T2 with respect to T0, but no linear increase was found. Conversely, 1-OH-PYR (ng/g creatinine) showed lower median values at T1 (61.5) and T2 (67) compared to the baseline (151.3). Similarly, short-term comparisons yielded no significant results, with rather overlapping distributions of values. Overall, no significant increases in metabolite levels were detected as a result of occupational exposure in the incinerator workers considered. These findings align with previous results for metals and ambient air measurements.

Keywords: exposure biomarkers; longitudinal study; occupational exposure; polycyclic aromatic hydrocarbons; waste-to-energy plant.

Figure 1

OH-PAH concentrations (ng/g creatinine) by exposure group and monitoring period; analysis limited to seven AWs and 16 PWs who had not changed the category of smoking habit from T0 to T2. ^a Sum of 2-OH-FLU, 3-OH-FLU, and 9-OH-FLU (medium bound approach); ^b Sum of 1-OH-PHE, 2-OH-PHE, 3-OH-PHE, and 4-OH-PHE (medium bound approach); ^c Sum of 1-OH-NAP, 2-OH-NAP, 2-OH-FLU, 3-OH-FLU, 9-OH-FLU, 1-OH-PHE, 2-OH-PHE, 3-OHPHE, 4-OH-PHE, and 1-OH-PYR (medium bound approach).