Human biomonitoring in occupational setting – Cr VI

As for environmental studies, occupational studies performed by different researchers in individual countries are usually not aligned with respect to sampling, analytical methodologies or data collection, which hampers the comparison of the findings and the use of the data e.g. in regulatory risk assessment at European level. In addition, many national human biomonitoring (HBM) studies can recruit only limited numbers of workers. Therefore, combining national surveys using harmonized study designs and methodologies can potentially greatly improve the information collected and bring added value for the global data interpretation. Hexavalent chromium (Cr(VI)) is an important occupational carcinogen. Although Cr(VI) compounds are authorized in Europe under the European regulation (EC 1907/2006) concerning the Registration, Evaluation, Authorization and Restriction of Chemicals (REACH), these compounds are still widely used in different applications. In addition, workers may be exposed to Cr(VI) formed during hot processes, like welding. These exposures are regulated in Europe by a binding occupational limit value (BOELV) recently set under EU Directive 2004/37/EC. It is, however, unclear how well workplaces comply with levels stated in legislation. The current study has been conducted in eight European countries using harmonized procedures. Up to 400 workers performing Cr(VI) surface treatment or welding activities were recruited. In addition to the collection of urinary chromium data, new methods for Cr biomonitoring were included, specifically the analysis of Cr(VI) in exhaled breath condensate (EBC) and Cr in red blood cells (RBC). Exposure biomarkers were complemented with early biological effect biomarkers and dermal and air monitoring data. According to preliminary results, chrome platers showed the highest urinary chromium levels, in some cases more than 10-times higher than levels measured in the control population. In the control population urinary chromium levels remained usually below 1 µg/g creatinine, in surface treatment workers the levels varied from these background levels up to 10 µg/g creatinine. In some cases, pre-shift chromium levels were also higher than in controls. Although welders showed elevated levels, their levels were lower than chrome platers. EBC samples exhibited the same trend as seen in urinary chromium: chrome platers showed higher levels than welders, although welders also had elevated levels compared to the controls. Analysis of the results from the air samples and wipe samples (collected from the hands of workers) provided information on the exposure routes, which will be used to give recommendations for the minimization of the exposure at workplaces.