Within company 1, dismantling workers had significantly higher air concentrations (p ≤ 0.05) of all the 13 metals, except for Tl, than the other two work tasks. In company 2, the work task dismantling showed significantly higher exposure concentrations of all metals, except Co and Pb, than indoors. For company 3, we observed no differences by recycling work tasks. We collected blood and urine from 55 recycling workers and 10 office workers at the first sampling occasion and from 25 recycling workers and 7 office c-Met inhibitor workers at follow-up. We failed to collect blood samples from two recycling workers at the first occasion. The median blood concentrations

of Pb (32 μg/l; range: 9.5–230 μg/l) and Cr (1.4 μg/l, range: 0.34–5.0 μg/l) were significantly higher (p < 0.05) in recycling workers than in the office workers, as shown in Table 4 and supplementary Table S2. At the second sampling occasion, only the Pb median concentration (33 μg/l, range: 7.1–240 μg/l) remained significantly higher among the recycling workers, but also the Co concentrations were significantly higher in recycling

workers (0.073 μg/l; range 0.012–0.16 μg/l) than in office workers (0.017 μg/l, range: 0.0014–0.063 μg/l) see more (Supplementary Table S3). The plasma concentrations of Cr (0.81 μg/l) and In (0.0043 μg/l) were significantly higher in recycling workers than in office workers at the first, but not at the second, sampling occasion. Concerning the urine samples, Pb (1.8 μg/l) and Hg (1.4 μg/l) were significantly higher among recycling workers during the first occasion, and Pb (2.4 μg/l, range 0.031–17 μg/l) remained higher also at the second sampling (Supplementary Table S3). The concentrations of As in urine showed wide concentrations ranges in both recycling workers (median 13 μg/l, range: 2.4–410 μg/l) and office workers (median 19 μg/l, range: 2.5–200 μg/l) ( Table 4). We observed no statistically significant differences in Buspirone HCl biomarker concentrations between the three recycling work tasks (dismantling,

indoors, and outdoors. We found that non-smoking workers urinary Cd concentration was significantly lower (β = − 614, p < 0.001) than the smoking workers concentration. Age affected the urinary concentration of Cd (β = 0.025, p < 0.001), but not gender (β = − 0.002, p = 0.994). Adjusting for age the non-smoking workers still had lower Cd concentrations in the urine (β = − 0.027, p = 0.014). Among the non-smoking workers, the office workers had lower urinary concentrations of Cd compared to those in recycling workers (β = − 0.010, p = 0.5); however, this difference was not statistically significant. We compared metal concentrations in the exposure biomarkers from the recycling workers with the concentration in the corresponding inhalable fraction (Fig. 1). At sampling occasion 1, the concentration in the inhalable fraction correlated significantly with the blood concentration for In (rs = 0.42, p = 0.