Browsing by Author "Tavares, Ana"
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- Caracterização de biomarcadores de genotoxicidade em trabalhadores expostos a crómio hexavalente: um estudo no âmbito da Iniciativa Europeia em Biomonitorização HumanaPublication . Tavares, Ana; Aimonen, Kukka; Ndaw, Sophie; Fucic, Aleksandra; Catalán, Julia; Duca, Radu Corneliu; Godderis, Lode; Gomes, Bruno C.; Janasik, Beata; Ladeira, Carina; Louro, Henriqueta; Namorado, Sónia; Van Nieuwenhuyse, An; Norppa, Hannu; Scheepers, Paul T.; Ventura, Célia; Verdonck, Jelle; Viegas, Susana; Wasowicz, Wojciech; Santonen, Tiina; Silva, Maria JoãoNo âmbito da Iniciativa Europeia em Biomonitorização Humana (HBM4EU) realizou-se um estudo ocupacional, envolvendo trabalhadores com potencial exposição a crómio hexavalente [Cr(VI)], um reconhecido agente carcinogénico. No presente estudo são apresentados os resultados de biomarcadores de genotoxicidade, incluindo a análise de lesão no DNA e de alterações cromossómicas em células sanguíneas. O estudo foi realizado em vários Países Europeus e abrangeu trabalhadores de diversos setores industriais e atividades, bem como um grupo de controlo constituído por trabalhadores administrativos das mesmas empresas (controlo interno) e de outras não relacionadas com produção/aplicação de Cr(VI) (controlo externo). Os resultados mostraram níveis de alterações cromossómicas (ensaio do micronúcleo) e de lesão no DNA (ensaio do cometa) significativamente aumentados nos trabalhadores expostos comparativamente aos controlos externos (p=0,03; p<0,001, respetivamente). Estes resultados sugerem que mesmo um baixo nível de exposição ao Cr(VI) representa um risco acrescido para a saúde dos trabalhadores e, principalmente, para os que realizam cromagem em banho. O grupo controlo interno apresentou níveis médios de lesões no DNA e nos cromossomas comparáveis aos do grupo exposto, salientando a relevância de se considerarem também em risco. O uso de biomarcadores de efeito demonstrou ser crucial para a deteção precoce de efeitos biológicos decorrentes de baixos níveis de exposição ao Cr(VI), contribuindo para a identificação de subgrupos em maior risco. O presente estudo vem apoiar a necessidade de uma reavaliação do limite de exposição ocupacional a Cr(VI), bem como da implementação de medidas de gestão de risco conducentes a uma melhor proteção da saúde dos trabalhadores.
- HBM4EU chromates study: genotoxicity and oxidative stress biomarkers in workers exposed to hexavalent chromiumPublication . Tavares, Ana; Aimonen, Kukka; Ndaw, Sophie; Fučić, Aleksandra; Catalán, Julia; Duca, Radu Corneliu; Godderis, Lode; Gomes, Bruno C.; Janasik, Beata; Ladeira, Carina; Louro, Henriqueta; Namorado, Sónia; Nieuwenhuyse, An Van; Norppa, Hannu; Scheepers, Paul T. J.; Ventura, Célia; Verdonck, Jelle; Viegas, Susana; Wasowicz, Wojciech; Santonen, Tiina; Silva, Maria JoãoA study was conducted within the European Human Biomonitoring Initiative (HBM4EU) to characterize occupational exposure to Cr(VI). Herein we present the results of biomarkers of genotoxicity and oxidative stress, including micronucleus analysis in lymphocytes and reticulocytes, the comet assay in whole blood, and malondialdehyde and 8-oxo-2′-deoxyguanosine in urine. Workers from several Cr(VI)-related industrial activities and controls from industrial (within a company) and non-industrial (outwith company) environments were included. The significantly increased genotoxicity (p = 0.03 for MN in lymphocytes and reticulocytes; p < 0.001 for comet assay data) and oxidative stress levels (p = 0.007 and p < 0.001 for MDA and 8-OHdG levels in pre-shift urine samples, respectively) that were detected in the exposed workers over the outwith company controls suggest that Cr(VI) exposure might still represent a health risk, particularly, for chrome painters and electrolytic bath platers, despite the low Cr exposure. The within-company controls displayed DNA and chromosomal damage levels that were comparable to those of the exposed group, highlighting the relevance of considering all industry workers as potentially exposed. The use of effect biomarkers proved their capacity to detect the early biological effects from low Cr(VI) exposure and to contribute to identifying subgroups that are at higher risk. Overall, this study reinforces the need for further re-evaluation of the occupational exposure limit and better application of protection measures. However, it also raised some additional questions and unexplained inconsistencies that need follow-up studies to be clarified.
- HBM4EU chromates study: the Portuguese integrated and harmonized study on exposure to hexavalent chromium and related early effectsPublication . Viegas, Susana; Martins, Carla; Ribeiro, Edna; Ladeira, Carina; Pinhal, Hermínia; Nogueira, Ana; Santos, Sílvia; Tavares, Ana; Gomes, Bruno Costa; Afonso, Catarina Maia; Louro, Henriqueta; Silva, Maria JoãoIn the scope of the European Union (EU) human biomonitoring initiative, a multicentric study on different occupational settings from several European countries was performed, to provide information on occupational exposure to hexavalent chromium [Cr(VI)], a known lung carcinogen. Biomonitoring approaches were used to obtain exposure data to support the implementation of new risk management measures and policy actions at the national and European levels. This work describes the Portuguese contribution to the study, which aimed to assess workers' exposure to Cr, by using exposure biomarkers (urinary chromium [U-Cr]), and industrial hygiene samples (air and hand wipes) and to link exposure to potential long-term health effects by using effect biomarkers. Exposure determinants influencing exposure were explored from the contextual information and human biomonitoring data. The ultimate goal of the study was to appraise the risk management measures contributing to minimizing exposure and protecting workers' health. Several occupational settings and activities were considered, including plating, welding, and painting. A control group from the Portuguese general population was also included. Data on age, sex, and smoking habits from both groups were considered in the statistical analysis. Information on the risk management measures available for workers was collected and used to identify the ones that mainly contributed to reducing exposure. Environmental monitoring and human biomonitoring revealed that painters were the highest exposed group. The use of respiratory protection equipment showed an influence on total U-Cr levels for workers involved in painting activities. Concerning early health effects, the painters presented also a significantly higher level of DNA and chromosomal damage in peripheral blood cells, as compared to the control group, suggesting a plausible association between exposure to Cr(VI) and early genotoxic effects. The results showed that workers are exposed to Cr(VI) in those occupational settings. These findings point to the need to improve the prevention and risk management measures and the implementation and enforcement of new regulatory actions at the national level.