Occupational exposure to Hexavalent chromium:  the portuguese case within the collaborative european human biological monitoring study

Background: The EU human biomonitoring initiative (HBM4EU) aims to coordinate and advance human biomonitoring across Europe. A multicenter study intending to characterize occupational exposure to hexavalent chromium [Cr(VI)], a human carcinogen, was setup in several industrial settings across Europe. In Portugal, the study was developed in one aircraft maintenance company since the substitution of Cr(VI) in this sector is not expected in the near future. Methods: The work processes that could imply exposure to Cr(VI) were characterized and exposure estimation was done. Following the company agreement and the volunteers informed consent, a survey was applied to each worker for detailed information on lifestyle, health status, etc.. Sampling for exposure and effect biomarkers analyses involved industrial hygiene samples (HIS) and biological specimens from 50 workers and 25 non-exposed individuals (controls). Biomarkers of early biological effects were studied in leukocytes from all individuals, involving the analysis of DNA damage (comet assay) and chromosome alterations (micronucleus assays); the results obtained for exposed and control individuals were statistically compared. Results and Discussion: Besides HIS results, Cr (VI) concentrations in biological samples and effect biomarkers results will be presented. The complementarity of the environmental and biological sampling, together with the sensitivity and specificity of the biomarkers used, is expected to allow exposure characterization and possible early genotoxic effects identification. Potential associations between exposure and effect biomarkers will be explored. Conclusions: An association between the levels of exposure to Cr(VI) and the early effects characterized in workers, if existent, is expected to predict potential health outcomes for Cr(VI)-exposed workers, particularly, on the long-term. All the information generated will help to support new priorities and investments regarding risk management measures to apply in this company and in the aircraft maintenance sector, in general.