Search

The respiratory tract is the main target organ of the inhaled hexavalent chromium (Cr-VI) and nickel (Ni) contained in stainless steel (SS) welding fumes (WFs). The aim of this study was to investigate the Cr and Ni content of the exhaled breath condensate (EBC) of SS tungsten inert gas (TIG) welders, and relate their concentrations with oxidative stress and inflammatory biomarkers. EBC and urine from 100 SS TIG welders were collected pre-(T 0 ) and post-shift (T 1 ) on a Friday, and pre-shift (T 2 ) on the following Monday morning. Both EBC and urinary Cr concentrations were higher at T 1 (0.08 μg/L and 0.71 μg/g creatinine) and T 0 (0.06 μg/L and 0.74 μg/g creatinine) than at T 2 (below the limit of detection [LOD] and 0.59 μg/g creatinine), and EBC Ni concentrations generally remained 2 O 2 ) concentration increased from 0.18 μM at T 0 to 0.25 μM at T 1 , but had decreased to 0.16 μM by T 2 . EBC malondialdehyde (MDA) concentrations were higher at T 0 (2.79 nM) and T 1 (2.98 nM) than at T 2 (2.43 nM), and EBC 4-hydroxy-nonenal (HNE) concentrations were higher at T 0 (0.53 nM) than at T 2 (0.51 nM). These findings confirm that, unlike Ni-EBC, Cr-EBC is a reliable biomarker of exposure even at very low environmental concentrations. However, given the weak relationship between the biomarkers and effects of exposure, we speculate that other substances generated during SS TIG welding also play a role in generating lung oxidative stress., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Plating industry is an important productive sector in all the national territory, because of its contribution to a high number of industrial products and crafts. In the chrome plating sector there is a specific chemical risk due to the exposure to compounds containing hexavalent Chromium [Cr(VI)]. Exhaled breath condensate (EBC) has been used to study both acute and long term exposure to Cr(VI) in chrome plating workers. Cr-EBC correlates with specific oxidative stress biomarkers. Moreover, both total Cr and its hexavalent fraction can be measured in EBC, which therefore is a promising biological fluid to assess the absorbed dose at the target organ level, the pulmonary reduction kinetics of Cr(VI) and in general its local pneumotoxic effects. EBC collection and analysis could give additional information to the traditional measures performed during biomonitoring.

Chromium (Cr) levels measured in exhaled breath condensate (EBC-Cr) and urine (Cr-U) at the beginning and end of working shifts were related to those measured in erythrocytes (Cr-RBC) and plasma in 14 non-smoking male chrome-plating workers exposed to Cr(VI) in soluble aerosol form who did not report any significant current or past respiratory disease. Cr-U mainly correlated with Cr-P (Cr in plasma) at the end of the working shift (r(2) = 0.59, p < 0.01), whereas Cr-RBC correlated with EBC-Cr (r(2) = 0.32, p < 0.05); at the beginning of the shift, the only significant correlation was between Cr-U and Cr-RBC (r(2) = 0.74, p < 0.01). The clearance of Cr(iii) arising from Cr(VI) reduction was rapid, thus making Cr-U and Cr-P ideal biomarkers of the most recent exposure, whereas Cr-RBC may represent the fraction of Cr(VI) that reaches the bloodstream in non-reduced form and therefore depends on the airway inhaled dose represented by EBC-Cr. Cr-RBC clearance is slower and not only involves the free diffusion of Cr(iii) from RBC to plasma, but probably also involves more complicated kinetic phenomena involving other tissues and organs, which may explain the correlation between Cr-RBC and Cr-U and the lack of correlation Cr-RBC and Cr-P at least 36 h after the last exposure. In conclusion, our findings reinforce the idea that measuring Cr in EBC can significantly contribute to traditional biomonitoring by providing specific information at the target organ level and integrating our knowledge of Cr toxicokinetics.

Objective: Chromium in exhaled breath condensate (EBC) has recently been proposed as a biomarker of pulmonary exposure. The aim of this study was to measure the Cr levels in the EBC and pulmonary tissue of patients with early, operable non-small cell lung cancer (NSCLC) who had not been occupationally exposed to Cr before and after tumour resection and to correlate Cr in lung tissue with that in EBC., Methods: Cr levels in the EBC and pulmonary tissue of 20 NSCLC patients were measured by means of electrothermal atomic absorption before and after tumour resection. Cr levels were also measured in the urine of 15 of these patients., Results: The pre-surgery EBC Cr levels of the NSCLC patients were not different from those of the controls, but both EBC and urinary Cr levels increased after surgery. There was a significant correlation between Cr levels in EBC and pulmonary tissue (R = 0.55, P = 0.01), but not between these and urinary Cr levels., Conclusion: Cr levels in EBC and urine of NSCLC patients were increased after surgical intervention. Measured Cr EBC levels were by one order of magnitude lower than those observed in moderately exposed workers. This fact, together with the correlation between Cr in EBC and in pulmonary tissue, confirms that EBC is a promising biological fluid to test pulmonary exposure to Cr, giving complementary information to that provided by urinary Cr, not correlated with EBC and tissue.

Intracellular reduction of hexavalent chromium [Cr(VI)] is associated with the production of reactive oxygen species (ROS) and subsequent oxidative damage to different intracellular molecules like DNA, proteins and lipids is believed to contribute to the process of carcinogenesis. Aim of this study was to develop a model to establish a relationship between intracellular and macromolecule-bound chromium and some biomarkers of oxidative stress in two in vitro cell lines. Human lung adenocarcinoma (A549) and human bronchial epithelial (BEAS2B) cells were exposed for 3, 8 and 24 hours to relatively low doses (0.5--1--2 microM) of Cr(VI), i.e., to concentrations similar to what measured and reported by some authors in unexposed subjects and chromate workers. The results show that the differential cytotoxicity of Cr(VI) on the A549 and BEAS2B cell lines may be related both to their different polymorphism of Glutathione S-transferases genes and probably to their unlike permeability to Cr(VI). The glutathione decrease and the induction of HO-1 observed only in BEAS2B cells after Cr(VI) exposure strengthen the idea that glutathione S-transferases activity may accelerate the reduction of Cr(VI) to Cr(III) with the concomitant induction of oxidative stress. In conclusion, the determination of intracellular Cr in cellular models can be considered an important step in comparing in vitro and in vivo models on the basis of target doses and a promising approach to study the effects of pneumotoxic compounds.

Chromium is corrosive, cytotoxic, and carcinogenic for humans and can induce acute and chronic lung tissue toxicity. The aim of this study was to investigate Cr levels in exhaled breath condensate (EBC) of workers exposed to Cr(VI) and to assess their relationship with biochemical changes in the airways by analyzing EBC biomarkers of oxidative stress, namely, hydrogen peroxide (H2O2) and malondialdehyde (MDA). EBC samples were collected from 24 chrome-plating workers employed in a chrome-plating plant both before and after the Friday work shift and before the work shift on the following Monday. Cr-EBC levels increased from the beginning (5.3 microg/L) to the end of Friday (6.4 microg/L) but were considerably lower on Monday morning (2.8 microg/L). A similar trend was observed for H2O2-EBC levels (which increased from 0.36 microM to 0.59 microM on Friday and were 0.19 microM on Monday morning) and MDA-EBC levels (which increased from 8.2 nM to 9.7 nM on Friday and were 6.6 nM on Monday). Cr-EBC levels correlated with those of H2O2-EBC (r = 0.54, p < 0.01) and MDA-EBC (r = 0.59, p < 0.01), as well as with urinary Cr levels (r = 0.25, p < 0.05). The results of this study demonstrate that EBC is a suitable matrix that can be used to investigate both Cr levels and biomarkers of free radical production sampling the epithelial-lining fluid of workers exposed to Cr(VI).

The article focuses on the biological monitoring of metallic elements in the electroplating industry. It evaluates the risk of exposure to hexavalent chromium by the workers in the chromium plating industry. It also discusses innovative techniques used to measure the exposure to hexavalent chromium including exhaled breath condensate (EBC), which assess the absorbed dose at the target organ level, its pneumotoxic effects and the pulmonary reduction kinetics of the metal.