The aim of the study was to determine the concentration of hexavalent and trivalent chromium, nickel, manganese, and iron in welding fumes (WFs) and to evaluate the significant association between the concentration of metals in the biological material of welders. The studies were conducted in welders (n = 67) and controls (n = 52). Stainless steel WFs were continuously collected in the workers' breathing zone during a shift. The serum and urine concentrations of Cr and Ni were determined by ICP-MS. The content of Mn in the whole blood was determined using ET-AAS. The content of Cr in the erythrocytes was determined using ICP-MS. The Cr concentration in the welders' urine positively correlated with a work environment concentration of Cr (R = 0.59, p < 0.0001), Cr(VI) (R = 0.58, p < 0.0001), and Cr(III) (R = 0.64, p < 0.0001) in the inhalable fraction. The Ni concentration in the welders' urine positively correlated with the Ni concentration in the inhalable and respirable fraction (R = 0.34, p < 0.005 and R = 0.44, p < 0.002). The correlation between the Mn concentration in the work environment air and the Mn concentration in the welders' whole blood (R = 0.46, p < 0.0001) was observed.

The present observation based research was designed to evaluate the influence of occupational human exposure to metallic mercury (Hg°) vapor on the biomarkers of selenium status involved in the antioxidant defense system. For this purpose we determined Hg and selenium (Se) concentrations in body fluids, the markers of antioxidant effect measured as an activity of Se-dependent enzymes (red blood cell and plasma glutathione peroxidase: GPx1-RBC and GPx3-P), concentration of selenoprotein P in the plasma (SeP-P) and total antioxidant activity in the plasma (TAA-P) in 131 male workers from a chloralkali plant exposed to Hg° and 67 non-exposed males (control group). The mRNA expression levels of glutathione peroxidases (GPX1, GPX3), selenoprotein P (SEPP1), thioredoxin reductase 1 (TRXR1), thioredoxin 1 (TRX1), peroxiredoxins (PRDX1, PRDX2) were also examined in the leukocytes of peripheral blood. Hg concentration in the blood (Hg-B) and urine (Hg-U) samples was determined using the thermal decomposition amalgamation/atomic absorption spectrometry (TDA-AAS) method and Se concentrations in plasma (Se-P) and urine (Se-U) using the inductively coupled plasma mass spectrometry (ICP-MS) method. Activities of GPx1-RBC, GPx3-P and TAA-P were determined using the kinetic and spectrophotometric method, respectively. Gene expression analysis was performed using the quantitative Real-Time PCR. The results showed significant higher Hg levels among the Hg°-exposed workers in comparison to control group (12-times higher median for Hg-B and almost 74-times higher median for Hg-U concentration in chloralkali workers). Se-P was also significantly higher (Me (median): 82.85 μg/L (IQR (interquartile range) 72.03-90.28 μg/L) for chloralkali workers vs. Me: 72.74 μg/L (IQR 66.25-80.14 μg/L) for control group; p = 0.0001) but interestingly correlated inversely with Hg-U in chloralkali workers suggesting depletion of the Se protection among the workers with the highest Hg-U concentration. The mRNA level for GPX1, PRXD1 were markedly but significantly higher in the workers compared to the control group. Moreover, concentrations of Hg-B and Hg-U among the workers were significantly positively correlated with the levels of selenoprotein P at both the mRNA and selenoprotein levels. In the multivariate model, after adjusting to cofounders (dental amalgam fillings, age, BMI, job seniority time, smoking), we confirmed that Hg-U concentration was inversely correlated with genes expression of TRXR1. This is the first comprehensive assessment of the impact of occupational exposure of workers to Hg° at both the mRNA and selenoprotein levels, with investigation of fish intake obtained by means of a questionnaire. These findings suggest that exposure to Hg° alters gene expression of the antioxidant enzymes and the level of Se-containing selenoproteins.

To examine the differences in urinary arsenic metabolism patterns in men affected by occupational exposure, we performed a study on 149 participants—workers of a copper mill and 52 healthy controls without occupational exposure. To elucidate the role of genetic factors in arsenic (As) metabolism, we studied the associations of six polymorphisms: As3MT Met287Thr (T>C) in exon 9; As3MT A>G in 5′UTR; As3MT C>G in intron 6; As3MT T>G in intron 1; GSTP1 Ile105Val and GSTO2 T>C.

The paper’s objective was to estimate weekly Hg intake from fish meals based on intervention research. Total Hg (THg) concentrations in blood and hair samples collected from men (n = 67) from an intervention study as well as muscular tissues of fresh and after heat-treating fish were determined using the thermal decomposition amalgamation atomic absorption spectrometry method (TDA-AAS) using direct mercury analyzer (DMA-80). The mean of the estimated weekly intake (EWI) was estimated at 0.62 μg/kg bw/week in the range 0.36–0.96 μg/kg body weight (bw) /week through the consumption of 4 edible marine fish species every day (for 10 days) by the participants from the intervention research in Lodz, Poland. The Hg intake in the volunteers in our intervention study accounted for 38.6% of the provisional tolerable weekly intake (PTWI) (1.6 μg/kg bw, weekly) value. The average Hg concentration in the analyzed fish ranged from 0.018 ± 0.006 mg/kg wet weight (Gadus chalcogrammus) to 0.105 ± 0.015 mg/kg wet weight (Macruronus magellanicus). The results for the average consumers were within PTWI of methylmercury (MeHg). Moreover, the average concentration of Hg in the selected fish after heat treatment did not exceed the maximum permitted concentrations for MeHg (MPCs = 0.5 mg/kg wet weight) in food set by the European Commission Regulation (EC/1881/2006). Hence, the risk of adverse effects of MeHg for the participants is substantially low.