Browsing by Author "Oliveira, Ana Cebola de"
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- Exposição ocupacional a mercúrio: associação com a atividade da paraoxonase humana e vitaminas A e EPublication . Oliveira, Ana Cebola de; Pádua, Mário; Viegas, SusanaOs trabalhadores da indústria de reciclagem e valorização de lâmpadas encontram-se ocupacionalmente expostos a mercúrio durante o processo de produção. Neste trabalho foi caracterizada essa exposição na totalidade dos trabalhadores de uma empresa portuguesa, determinando a concentração de mercúrio total no sangue. A concentração de mercúrio foi relacionada com a atividade do enzima PON-1 e com as concentrações das vitaminas A e E, no sangue dos trabalhadores. De forma a desenvolver este estudo, efetuaram-se determinações da concentração de mercúrio no sangue por Espectroscopia de Absorção Atómica Termal, tendo trabalhadores apresentado, em média, concentrações significativamente mais elevadas (p=0,000) de mercúrio no sangue (2,25 μg.L-1) que o grupo de controlo (0,864 μg.L-1), o que confirma a exposição ocupacional a este metal. A atividade da PON-1 foi medida por espectrofotometria Ultra Violeta-Visível (UV-Vis), tendo sido obtidos valores médios de 773 mM.min-1 para os trabalhadores e de 663 mM.min-1, para os controlos. As diferenças destas actividades não são estatisticamente significativas (p=0,562), indicando que a proteção das LDL contra a oxidação se mantém eficaz. Havia, todavia, uma correlação negativa fraca, não significativa (r=-0,422; p=0,298), entre a concentração de mercúrio e a atividade da PON-1 nos trabalhadores, sugerindo a possibilidade de inibição da PON-1 pelo mercúrio. Os níveis séricos de Vitaminas A e E foram determinados por Cromatografia Líquida de Alta Performance (HPLC). Relativamente à concentração de vitamina E, foram detetados valores séricos médios de 37.0 μM nos trabalhadores e 43.7 μM nos controlos, valores que não são estatisticamente diferentes (p=0,160) sugerindo que a capacidade antioxidante lipofílica se mantém intacta. Existe uma correlação negativa fraca, não significativa (r=-0,312; p=0,452) entre as concentrações de mercúrio e vitamina no sangue dos trabalhadores, sugerindo uma ligação entre mercúrio e stress oxidativo. Da comparação da concentração média sérica de vitamina A entre trabalhadores (2.00 μM) e controlos (0.980 μM) foram detetadas diferenças estatisticamente significativas das concentrações de vitamina A entre os dois grupos (p=0,007), sugerindo um efeito da exposição ao mercúrio ao nível da metabolização do retinol. Foi detetada uma correlação negativa fraca, estatisticamente não significativa, entre as concentrações de mercúrio e de vitamina A nos trabalhadores (r=-0,239; p=0,568), podendo significar uma ligação entre mercúrio e stress oxidativo. Foram igualmente estudadas as relações entre a concentração de mercúrio nos trabalhadores e o número de horas de exposição a este metal, verificando-se uma correlação positiva fraca não significativa (r=0,134; p=0,775). Da análise da relação entre a concentração do metal e a antiguidade dos trabalhadores em postos de trabalho com exposição ocupacional, constatou-se uma correlação positiva fraca não significativa (r=0,217; p=0,641). Concluiu-se que a exposição ocupacional destes trabalhadores não apresenta, no presente, riscos para a sua saúde. No entanto, os trabalhadores já exibem concentrações de mercúrio superiores aos controlos e alguns efeitos bioquímicos. Dado o mercúrio ser um metal bioacumulável, é possível que com o tempo, a exposição venha a produzir efeitos mais marcados.
- Exposição profissional a medicamentos antineoplásicos em medicina veterinária: a importância do seu estudoPublication . Oliveira, Ana Cebola de; Costa-Veiga, Ana; Pádua, Mário; Viegas, SusanaComo resultado da melhoria na nutrição e cuidados médicos profiláticos e terapêuticos, os animais de estimação vivem mais tempo. Isto, em combinação com a melhoria das capacidades de diagnóstico, propiciou o aumento da ocorrência de doenças neoplásicas nos animais de companhia, o que resulta numa procura de opções de tratamento com medicamentos antineoplásicos. Segundo a classificação da International Agency for Research on Cancer um grande número destes medicamentos é carcinogénico para os humanos. No entanto, atualmente, existem ainda poucos dados relativos à sua comercialização e condições de utilização em medicina veterinária. Sendo a absorção cutânea uma das principais vias de exposição dos profissionais de saúde a estes medicamentos, importa monitorizar a contaminação das superfícies de trabalho. Este artigo pretende rever o conhecimento atual acerca da exposição dos profissionais de hospitais e clínicas veterinárias a medicamentos antineoplásicos.
- Mycotoxins in coffee: what reality?Publication . Viegas, Susana; Viegas, Carla; Oliveira, Ana Cebola de; Twaruzek, Magdalena; Kosicki, Robert; Grajewski, JanCoffee is a valuable product due to the still increasing demand for production and consume. Brazil, Vietnam and Columbia are the bigger producers and Finland, Norway and Netherlands are the countries with higher rates of consumption. Unfortunately, it is subjected to various contaminations that can have an important impact in consumer’s health and economy. The major compound of concern is ochratoxin A (OTA) but other mycotoxins can be present. However, roasting process has an important role in reducing mycotoxins presence, depending upon the combination of time and temperature. Since each European country applies different roasting conditions, significant differences in mycotoxins concentrations occur across the world even when the origin of the coffee beans is the same. Considering the above the aim of this study was to analyze mycotoxins (OTA, aflatoxins (AF) and citrinin (CIT)) in coffee ready to be consumed from different markets and different brands: Portugal (6), Austria (3), United States (2) and Timor (1). Twelve samples were collected from different types of brands sold as roasted beans. The extraction of OTA, CIT and AF was done on the immunoaffinity column Ochraprep (RBiopharm), CitriTest HPLC and AflaTest WB (Vicam), respectively. Mycotoxins were analyzed with HPLC-FLD (Merck-Hitachi). CIT and AF were not detected. OTA was detected in all the samples from Austria (2 results < 0.4 μg/Kg and 0.43 μg/Kg). In one of the Portuguese samples it was detected OTA (< 0.4 μg/Kg). Since the coffee beans have probably the same origin, it seems that indeed the roasting process adopted in each country and coffee industries influence the presence of mycotoxins. Further studies should be developed aiming to analyze other mycotoxins considering the possible climate changes influence. Additionally, a study should be developed to allow identifying how the roasting conditions adopted in each European country impact the presence of mycotoxins in coffee.
- A new approach to assess fungal burden and mycotoxins occupational exposure in waste trucks workersPublication . Viegas, Carla; Faria, Tiago; Oliveira, Ana Cebola de; Caetano, Liliana Aranha; Gomes, Anita Quintal; Twarużek, Magdalena; Kosicki, Robert; Viegas, SusanaBackground - Waste application facilities are considered critical regarding occupational exposure to fungal burden since provide optimal conditions for fungal growth (moisture and decaying matter). Aspergillus genera dominance was already reported in Portuguese waste industry. Waste-sorting the most critical setting, presenting not only the highest load but also the wider diversity of Aspergillus sections. It is important to consider the co-occurrence of mycotoxins in this occupational environment. In waste management industry it is common to use forklifts for waste transportation and workers can spend all their working hours in a forklift cab. In cars, the bioburden filtered from the air stream by the automobile air conditioner filter could proliferate under high humidity conditions and, consequently, presenting a potential exposure source to bioaerosols. When the air conditioning system is turned on, the air stream passing through the vehicle filtration system could re-aerosolize the bioburden and subsequently carry them into the vehicle cabinet increasing the exposure.
- A new approach to assess occupational exposure to airborne fungal contamination and mycotoxins of forklift drivers in waste sorting facilitiesPublication . Viegas, Carla; Faria, Tiago; Oliveira, Ana Cebola de; Caetano, Liliana Aranha; Carolino, Elisabete; Gomes, Anita Quintal; Twarużek, Magdalena; Kosicki, Robert; Soszczyńska, Ewelina; Viegas, SusanaThe waste management industry is an important employer, and exposure of waste-handling workers to microorganisms is considered an occupational health problem. Besides fungal contamination, it is important to consider the co-occurrence of mycotoxins in this setting. Forklifts with closed cabinet and air conditioner are commonly used in waste industry to transport waste and other products within the facilities, possibly increasing the risk of exposure under certain conditions. The aim of this study was to assess the fungal contamination and mycotoxin levels in filters from the air conditioning system of forklift cabinets, as an indicator to assess occupational exposure of the drivers working in a waste sorting facility. Cytotoxicity was also assessed to understand and characterize the toxicity of the complex mixtures as present in the forklift filters. Aqueous extracts of filters from 11 vehicles were streaked onto 2% malt extract agar (MEA) with chloramphenicol (0.05 g/L) media, and in dichloran glycerol (DG18) agar-based media for morphological identification of the mycobiota. Real-time quantitative PCR amplification of genes from Aspergillus sections Fumigati, Flavi, Circumdati, and Versicolores was also performed. Mycotoxins were analyzed using LC-MS/MS system. Cytotoxicity of filter extracts was analyzed by using a MTT cell culture test. Aspergillus species were found most frequently, namely Aspergillus sections Circumdati (MEA 48%; DG18 41%) and Nigri (MEA 32%; DG18 17.3%). By qPCR, only Aspergillus section Fumigati species were found, but positive results were obtained for all assessed filters. No mycotoxins were detected in aqueous filter extracts, but most extracts were highly cytotoxic (n = 6) or medium cytotoxic (n = 4). Although filter service life and cytotoxicity were not clearly correlated, the results suggest that observing air conditioner filter replacement frequency may be a critical aspect to avoid worker's exposure. Further research is required to check if the environmental conditions as present in the filters could allow the production of mycotoxins and their dissemination in the cabinet during the normal use of the vehicles.
- Occupational exposure to cytotoxic drugs: the importance of surface cleaning to prevent or minimise exposurePublication . Viegas, Susana; Oliveira, Ana Cebola de; Carolino, Elisabete; Pádua, MárioHealthcare workers who prepare or administer cytotoxic agents run the risk of exposure, and the risks for health are real even at doses lower than those applied in cancer patients, because, in theory, no dose is safe. The most common and problematic route of exposure is through the skin, especially as work surfaces can remain contaminated even after cleaning. This pilot study aimed to demonstrate the importance of having an effective surface decontamination protocol by determining surface contamination with cyclophosphamide, 5-fluorouracil, and paclitaxel as the most common cytotoxic drugs in an oncology day service. Samples were collected before and after drug handling and analysed with high performance liquid chromatography with diode array detection (HPLC-DAD). Of the 29 samples collected before drug handling 23 were contaminated, five of which with more than one drug. Of the 30 samples collected after drug handling 25 were contaminated, eight of which with more than one drug. The two time points did not significantly differ, which evidences a widespread contamination and ineffective cleaning. This calls for revising the cleaning protocol and handling procedure to place contamination under control as much as possible.