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- Determination of glyphosate bioconcentration in lettuce (Lactuca sativa) simultaneously exposed to cylindrospermopsin in a soil systemPublication . Lessa, P.; Sengupta, S.; Pinto, Edgar; Freitas, Marisa; Azevedo, J.; Oliveira, F.; Campos, A.; Vasconcelos, V.Glyphosate has become the most widely used herbicide worldwide. The mode of action of this herbicide is linked to the inhibition of 5-enolpyruvylshikimate-3-phopsphate synthase enzyme, which blocks the plant’s biosynthesis of aromatic amino acids.
- Modelo pedagógico Problem Based Learning aplicado na licenciatura em Saúde AmbientalPublication . Rodrigues, Matilde A.; Nunes, Mafalda; Freitas, Marisa; Santos, Joana; Silva, Manuela V.No ano letivo 2017/18 iniciou-se o processo de transição do plano de estudos do curso de Licenciatura em Saúde Ambiental, na Escola Superior de Saúde do Instituto Politécnico do Porto. A nova estrutura curricular do curso assenta no modelo pedagógico Problem Based Learning (PBL). Este modelo é muitas vezes definido em oposição às abordagens ditas como “tradicionais”. Um dos pontos mais diferenciadores é a sua interdisciplinaridade, a qual se encontra refletida na estrutura curricular do curso. A substituição do conhecimento fragmentado, apresentado nos modelos tradicionais em diferentes Unidades Curriculares (UC), pelo estudo de problemas reais em Saúde Ambiental que permitem envolver e relacionar várias áreas de conhecimento, promove não só uma melhor integração dos conteúdos curriculares, mas também potencia a aprendizagem, de uma forma contextual. Neste modelo pedagógico o docente deixa de ser visto como um meio para expor a matéria, passando a ser considerado pelo estudante como um especialista com quem poderá esclarecer as suas questões ao longo das sessões de recurso (equivalente às aulas teóricas). Adicionalmente, existe a necessidade da figura de um tutor, o qual acompanhará o grupo ao longo do estudo do problema nas sessões de orientação tutorial. Este trabalho em grupo promove o desenvolvimento de competências transversais. Foi realizada uma análise comparativa do desempenho dos estudantes entre os dois planos de estudos. Numa primeira fase, foram determinadas as notas equivalentes às novas UC dos 1º e 2º anos considerando a classificação obtida pelos estudantes em 16/17 e de acordo com o plano de acreditação do ciclo de estudos. Posteriormente, estes resultados foram comparados com as notas obtidas pelos estudantes nas novas UC em 2017/18. Os dados denotaram uma melhoria nos resultados de aprendizagem, enfatizando a pertinência do PBL na Licenciatura em Saúde Ambiental.
- Practices of receiving fish products and the sensory perception of its quality by food operators: the importance of training programsPublication . Morais, Rita; Gomes, Sara; Freitas, MarisaFood safety is an important issue worldwide, once foodborne diseases are a significant cause of morbidity and mortality. The selection of reliable suppliers and inspection of incoming raw materials/ingredients are crucial to guarantee the safety of food. Regarding to the freshness of fish products it can be perceived in sensory terms by sight, touch, smell and taste. Food operators should therefore be effectively trained to ensure that inspection procedures are adequately performed.
- Impacts of microcystins on morphological and physiological parameters of agricultural plants: a reviewPublication . Campos, Alexandre; Redouane, El Mahdi; Freitas, Marisa; Amaral, Samuel; Azevedo, Tomé; Loss, Letícia; Máthé, Csaba; Mohamed, Zakaria A.; Oudra, Brahim; Vasconcelos, VítorCyanobacteria are a group of photosynthetic prokaryotes that pose a great concern in the aquatic environments related to contamination and poisoning of wild life and humans. Some species of cyanobacteria produce potent toxins such as microcystins (MCs), which are extremely aggressive to several organisms, including animals and humans. In order to protect human health and prevent human exposure to this type of organisms and toxins, regulatory limits for MCs in drinking water have been established in most countries. In this regard, the World Health Organization (WHO) proposed 1 µg MCs/L as the highest acceptable concentration in drinking water. However, regulatory limits were not defined in waters used in other applications/activities, constituting a potential threat to the environment and to human health. Indeed, water contaminated with MCs or other cyanotoxins is recurrently used in agriculture and for crop and food production. Several deleterious effects of MCs including a decrease in growth, tissue necrosis, inhibition of photosynthesis and metabolic changes have been reported in plants leading to the impairment of crop productivity and economic loss. Studies have also revealed significant accumulation of MCs in edible tissues and plant organs, which raise concerns related to food safety. This work aims to systematize and analyze the information generated by previous scientific studies, namely on the phytotoxicity and the impact of MCs especially on growth, photosynthesis and productivity of agricultural plants. Morphological and physiological parameters of agronomic interest are overviewed in detail in this work, with the aim to evaluate the putative impact of MCs under field conditions. Finally, concentration-dependent effects are highlighted, as these can assist in future guidelines for irrigation waters and establish regulatory limits for MCs
- Assessment of cyanobacterial biomass as sustainable agricultural fertilizer: soil experiment with plants in Pot †Publication . Massa, Anabella; Azevedo, Joana; Azevedo, Rui; Pinto, Edgar; Costa, Anabela; Vasconcelos, Vitor; Campos, Alexandre; Freitas, MarisaProviding food to the growing human population in a sustainable way is one of the greatest challenges of modern society. In this context, cyanobacterial biomass (CB) can function as a source of macronutrients to increase soil productivity. These organisms can be collected from the environment in considerable amounts, since they tend to grow in large blooms. However, some of these cyanobacterial strains produce toxins that need to be carefully monitored to avoid food accumulation. The objective of this work was to evaluate the possible use of toxic and non-toxic strains of CB as fertilizer supplement in the growth of economically relevant vegetables. One-month old Raphanus sativus (radish) and Spinacia oleracea (spinach) plants were grown in pots in indoor controlled conditions. Six experimental conditions were set: (1) a control with no nutrient addition, (2) a recommended dose of a NK commercial fertilizer (CF), 0.6g of lyophilized CB of (3) a non-toxic strain of Cylindrospermopsis raciborskii, (4) a toxin-producing strain of C. raciborskii, (5) Microcystis aeruginosa, and (6) Anabaena sp. Several variables were estimated: in CB, this included the NPK dose addition, and in plants, the height, dry weight (dw) of the shoot and root, and the mineral content of plant edible parts. The mineral content in CB was estimated and compared with the recommended dose of CF, according to the information given by the fabricant label. We found no significative differences in N composition; nevertheless, there was a significative higher content in P and significative lower content in K in the CB. In the plants, we found no significative statistical differences between the treatments for the dw of radish root and spinach height. In spinach, the dw of the shoot in the M. aeruginosa treatment was significantly lower than the control, CF, and both the toxic and non-toxic C. raciborskii biomass. Additionally, in radish, the plant height and dw of the shoot M. aeruginosa treatment were significantly lower than in the toxic strain of C. raciborskii treatment. When analyzing mineral content in edible parts, we found that spinach treated with control and CF showed a higher content of Ca, Mo, N, P, and K, while in radish, the same two treatments plus the C. raciborskii toxic had higher Co and Fe content. M. aeruginosa amendment seems to impair shoot growth in both plant species. On the contrary, the toxic C. raciborskii CB seems to have a beneficial effect on growth and in mineral uptake on radish plants.
- Lichens as bio indicators of atmospheric pollution in Porto, PortugalPublication . Freitas, Marisa; Costa, Natália; Rodrigues, Matilde; Marques, Joana; Vieira Da Silva, ManuelaThe emission of air pollutants mainly from anthropogenic sources has led to the degradation of air quality. These pollutants determine the occurrence or worsening of respiratory disorders. Biomonitoring provides information on the quality of the environment or its modifications, having been used as an alternative to monitoring of chemical pollutants. The variation of the biodiversity of lichens can be used as a warning to check if other biological systems are being affected by atmospheric pollution. Lichens have been used as bioindicators, since they have differential sensitivity to air pollution. The purpose of this study was to assess the diversity and abundance of lichens in different zones of the Porto (North Portugal) with respect to the rates of atmospheric pollutants. Three zones were selected for sampling, represented by urban, suburban and rural zones. LDV was calculated for each zone. The average concentrations of CO, CO2, SO2, NO2, O3 and PM10 were also measured. The most sensitive lichens were present in the area with the highest LDV. In places where there were higher concentrations of pollutants, namely NO2 and SO2 a lower LDV. This study suggests that lichens can be used as prevention systems to protect public health, in particular diseases related to air pollution and as a potential alternative or complement to expensive chemical monitoring equipment.
- Investigação em Saúde e Ambiente: avaliação de risco e estratégias de adaptação à proliferação de cianobactérias tóxicasPublication . Freitas, Marisa; Campos, Alexandre; Mohamed, Zakaria; Brahim, Oudra; Ranilla, Cesar; Uro, Victor; Almeida, Marisa; Vasconcelos, VítorA proliferação progressiva de cianobactérias tóxicas nos sistemas de água doce é atualmente reconhecida como uma consequência da eutrofização e das alterações climáticas. Neste contexto e face às potenciais implicações económicas e para a saúde, torna-se fundamental desenvolver estratégias de prevenção e adaptação aos efeitos negativos destas florescências, reduzindo a vulnerabilidade dos sistemas de produção primária, nomeadamente a produção agrícola.
- Relevância do parasita Anisakis simplex em peixe fresco no mercado português: potencial risco para o consumidor?Publication . Vieira Da Silva, Manuela; Machado, Mónica; Silva, Ana; Freitas, MarisaPortugal é considerado o maior consumidor de peixe por habitante da União Europeia e o terceiro maior do mundo. O consumo de peixe em Portugal (55,6 kg / per capita / ano) é mais do que o dobro do consumo médio na Europa. Os principais riscos biológicos estão associados à presença de bactérias, vírus, biotoxinas, histamina e parasitas. Anisakis simplex é um parasita cujas larvas no terceiro estágio infetam o peixe. Com a morte do hospedeiro, as larvas migram para o tecido muscular, sendo nesta fase infeciosas para os seres humanos.
- Exposure of Mytilus galloprovencialis to diarrhetic shellfish poisoning toxin: food safety implicationsPublication . Silva, M.; Campos, A.; Pérez, D.; Azevedo, C.; Costa, P. Reis; Martins, J. C.; Vasconcelos, V.; Freitas, MarisaThroughout the world, toxins produced by algae are responsible for approximately 60000 human food poisonings yearly. Shellfish toxins cause damage to wildlife and have a negative economic impact on recreation, tourism and shellfish industry, being almost a worldwide phenomenon. Dinoflagelates such as Dynophysis and Prorocentrum lima are considered a primary producer of diarhetic shellfish toxins, such as Okadaic Acid (OA) and Dinophysistoxins (DTXs), which can be accumulated in the tissues of the bivalves. Bioaccumulation process could increase the concentration of OA and DTXs at risky level, making bivalves unsafe for human consumption.
- Seasonal dynamics of microcystis spp. and their toxigenicity as assessed by qPCR in a temperate reservoirPublication . Martins, António; Moreira, Cristiana; Vale, Micaela; Freitas, Marisa; Regueiras, Ana; Antunes, Agostinho; Vasconcelos, VítorBlooms of toxic cyanobacteria are becoming increasingly frequent, mainly due to water quality degradation. This work applied qPCR as a tool for early warning of microcystin(MC)-producer cyanobacteria and risk assessment of water supplies. Specific marker genes for cyanobacteria, Microcystis and MC-producing Microcystis, were quantified to determine the genotypic composition of the natural Microcystis population. Correlations between limnological parameters, pH, water temperature, dissolved oxygen and conductivity and MC concentrations as well as Microcystis abundance were assessed. A negative significant correlation was observed between toxic (with mcy genes) to non-toxic (without mcy genes) genotypes ratio and the overall Microcystis density. The highest proportions of toxic Microcystis genotypes were found 4-6 weeks before and 8-10 weeks after the peak of the bloom, with the lowest being observed at its peak. These results suggest positive selection of non-toxic genotypes under favorable environmental growth conditions. Significant positive correlations could be found between quantity of toxic genotypes and MC concentration, suggesting that the method applied can be useful to predict potential MC toxicity risk. No significant correlation was found between the limnological parameters measured and MC concentrations or toxic genotypes proportions indicating that other abiotic and biotic factors should be governing MC production and toxic genotypes dynamics. The qPCR method here applied is useful to rapidly estimate the potential toxicity of environmental samples and so, it may contribute to the more efficient management of water use in eutrophic systems.