56, p < 0.001), the plasma concentration for Hg (rs = 0.40, p = 0.004), and the urine concentration for Hg (rs = 0.39, p = 0.005), In (rs = 0.57, p < 0.001), Pb (rs = 0.42, p = 0.001), and V (rs = 0.32, p = 0.02). At sampling occasion 2, the concentration in the inhalable fraction correlated with concentrations of Pb and SB in both blood (rs = 0.64, p = 0.001; rs = 0.49, p = 0.019, respectively) and urine (rs = 0.76, p < 0.001; rs = 0.49, p = 0.017, respectively), and with the concentration of In (rs = 0.48, p = 0.019) in plasma. The results of this study show that recycling workers in three Swedish

e-waste plants were exposed to higher air concentrations of all analyzed metals than were office workers in the same plants. Using exposure Bioactive Compound Library cell line biomarkers, we detected elevated internal doses of Cd, Cr, Hg, In and Pb in the recycling workers compared to the office workers. Correlation analysis of metals in the inhalable fraction and exposure

Akt inhibitor in vivo biomarkers (blood, plasma and urine) showed close to linear correlations also for Sb and V, besides Hg, In, and Pb, supporting occupational exposure to multiple metals at e-waste recycling work, even in modern plants with adequate protection routines. To the best of our knowledge, this is the first study of the formal recycling of e-waste, evaluating multiple elements in both air and exposure biomarkers. Indium is used in electronics, mostly in flat screens as indium-tin oxide (ITO), but little is known of its toxicity and carcinogenicity to humans (Fowler, 2009). Indium 4-Aminobutyrate aminotransferase concentrations in blood, plasma, and urine of the recycling

workers were approximately twice as high as those of the office workers, and the concentrations seemed to increase with increasing concentrations in the inhalable fraction. Indium was the only metal in the inhalable fraction that was significantly higher for dismantling than for either the other two work task categories. This might be attributed to the fact that ITO is used as a thin film in different types of displays, mostly LCDs. Dismantling was also the only work category in which workers came in direct contact with different types of displays, both whole and shattered ones, when recycling the units. No such task-specific difference was seen for the exposure biomarkers; however, recycling workers had about twice as high In concentrations in all biomarkers compared to the office workers. In workers producing, using, and reclaiming ITO in Japan, the United States, and China, blood concentrations of In were found to be above 5 μg/l (Cummings et al., 2012 and Cummings et al., 2013). That is considerably higher than in the recycling workers in the present study with a median of 6 ng/l and maximum of 0.1 μg/l. Since flat screens are rapidly increasing, the continued monitoring of recycling workers for In exposure is important. The previous studies indicated lung effects at a concentration of 3 μg/l In in the blood (Cummings et al., 2012).