DSA - Capítulos (ou partes) de livros
Permanent URI for this collection
Browse
Browsing DSA - Capítulos (ou partes) de livros by Issue Date
Now showing 1 - 10 of 19
Results Per Page
Sort Options
- Qualidade do Ar InteriorPublication . Proença, Maria do Carmo; Cano, ManuelaUma vez que 80-90% da nossa vida é passada no interior, nas últimas décadas tem-se verificado uma crescente preocupação da comunidade científica com a Qualidade do Ar Interior (QAI), devido aos efeitos que a mesma pode exercer sobre a saúde dos seres humanos. Com o intuito de melhorar a eficiência energética, os edifícios actuais são mais estanques favorecendo a acumulação de contaminantes gerados no interior quando a ventilação é insuficiente. Em Portugal, na sequência da Directiva 2002/91/CE foi revista a legislação e, em 2006, foi publicado o RSECE - eficiência energética de edifícios com sistemas de AVAC e que, entre outros, estabelece requisitos para a Qualidade do Ar Interior. Este artigo refere os principais contaminantes do ar interior, suas principais fontes e efeitos na saúde. Descreve a metodologia de avaliação da QAI bem como os valores de referência adoptados. São descritos alguns casos de estudo, suas principais conclusões e recomendações.
- Risk Assessment of Cyanobacteria and Cyanotoxins, the Particularities and Challenges of Planktothrix spp. MonitoringPublication . Churro, Catarina; Dias, Elsa; Valério, Elisabete
- Occurrence of Estradiol in Environmental Waters. Estradiol: Synthesis, Health Effects and Drug InteractionsPublication . Domingues, Valentina F.; Fernandes, Virgínia C.; Correia-Sá, Luísa; Catarina, MansilhaNatural estrogens are a group of steroid hormones that include the main active hormones, 17ß-estradiol (E2), estrone and estriol. Among these compounds, E2 is recognized to be the most active estrogen synthesized in female ovaries. Environmental problems due to estrogenic compounds are mainly related to aquatic environments. Indeed, numerous studies confirmed the occurrence of these substances at concentrations of toxicological concern (e.g., the feminization of fish in large rivers and toxicological effects on wildlife). Generally, the main sources of estrogens are recognized as treated and untreated municipal and industrial effluents, as well as livestock wastes from agricultural practices, as sewage and manure often used as fertilizers. Moreover the steroid hormones found in the urine of mammals are largely present as inactive conjugates, however the behavior of these forms will deconjugate to rapidly release the free hormones in the environment. As a consequence, large quantities of estrogens are spread in environmental waters, where they may sorb to sediments and persist for relatively long periods. Recently, the development of new analytical equipment, namely tandem mass spectrometers coupled to LC and GC systems, allowed improvements in the sensitivity, selectivity, and speed of analysis. Such improvements in sensitivity and selectivity could also be accomplished by innovative sample preparation techniques, most of them with the added benefit to be easy to execute, cost effective, and environmental friendly. Concerning the evaluation of the biological effects of estradiol, several methods have recently been developed: on whole organisms (vitellogenine assay), cells (cell proliferation), yeast estrogen screen, ER CALUX and molecular assays. In this chapter, various aspects of the estradiol presence in environmental waters are discussed. An overview of the current legislation related to water quality is given. The work then focuses on the health and environmental impacts and evaluation methods. Then, finally, the example case studies illustrate the health effects of estradiol and its environmental impact.
- The Kidney Vero-E6 Cell Line: a Suitable Model to Study the Toxicity of MicrocystinsPublication . Menezes, Carina; Valério, Elisabete; Dias, ElsaMicrocystins (MCs) are toxins produced by cyanobacteria from water environments that can induce acute and chronic effects on humans and animals, after ingestion/contact with contaminated water. This group of cyclic heptapeptides comprises approximately 80 variants, being microcystin-LR (MCLR) the most frequent and toxic variant. The studies of MCs effects on cell lines often lead to contradictory results, given the fact that distinct MC toxicity endpoints (mainly cytotoxicity and genotoxicity) have been studied in diverse cell lines (and cell clones) under distinct exposure conditions (different doses-ranges, time of exposure, MCs variants, etc). In our work with Vero-E6 cells we tested MCLR (both pure toxin and from cyanobacterial extracts of M. aeruginosa) within a wide range of concentrations (1 nM- 200 μM), using several endpoints and methodologies (cytotoxicity, morphology, genotoxicity, protein expression). In this chapter we will summarize our results and discuss the utility of Vero-E6 cell line to evaluate the toxicological properties of MCLR.
- Comet AssayPublication . Costa, Solange; Teixeira, João PauloComet Assay is a simple and sensitive approach to assess genotoxic damage in different cell types, using only a small number of cells. Over the last decades it has gained wide acceptance as an important tool in fundamental DNA damage and repair studies with applications ranging from molecular epidemiology to genetic toxicology. In short, after alkaline DNA unwinding, subsequent electrophoresis causes the relaxed and broken fragments of DNA to move toward the anode away from the nucleoid core, appearing like a ‘comet.’ The distribution of DNA within the comet relates to the extent of DNA damage present in the cells.
- BiomonitoringPublication . Costa, C.; Teixeira, João PauloBiomonitoring concerns the systematic measurement of compounds and/or detection of cell or cell molecules alterations in living organisms with the purpose of identifying or assessing potential hazardous exposure and effects to chemicals. Biomonitoring presents a wide range of advantages over environmental monitoring and has been considered to be a valuable tool for both ecological and human health surveillance. Cautious interpretation of data is one of the most sensitive issues on this matter. Still, the development and application of biomonitoring lead to improved knowledge of the effects of chemicals on living organisms and at the same time to increased protection of public health and environment.
- Sick Building SyndromePublication . Mendes, A.; Teixeira, João PauloSick Building Syndrome (SBS) is recognized by the World Health Organization as a group of symptoms that have no clear etiology and are attributable to exposure to building variables (indoor air quality, lighting, noise, psychological effects). SBS symptoms may occur singly or in combination with each other increasing in severity over the working shift and resolving rapidly when leaving the building in the evening, improving over the weekend and usually disappearing on holiday. The symptoms of SBS include eye, nose, and throat irritation; sensation of dry mucous membranes; dry, itching, and red skin; headaches and mental fatigue; nausea and dizziness.
- Biomarkers, Human HealthPublication . Coelho, P.; Teixeira, João PauloHuman health is constantly affected by a multitude of agents present in the surrounding environment. Biomarkers are key factors, both in clinical health risk assessment and in environmental risk assessment. Traditionally, they are classified in three different classes: exposure, effect, and susceptibility. Their main usefulness relies on their ability to link hazard exposure to the pathogenesis of human disease. The development and validation of biomarkers as early predictors of clinical disease is a top priority, improving health risk assessment and contributing to new disease prevention policies in environmental and occupational settings.
- ToxicologyPublication . Costa, Solange; Teixeira, João PauloToxicology is the study of the adverse effects of xenobiotic agents on living organisms. It encompasses the detection, occurrence, properties, effects, and regulation of toxicants. In addition, toxicology plays an active role in society by advising how to mitigate, control, or prevent deleterious effects of toxicants. As a multidisciplinary science, toxicology continues to expand and evolve. Not many disciplines can achieve the perfect balance between production of science and direct applications, toxicology may be unique in this regard.
- CarcinogenesisPublication . Botelho, M.; Teixeira, João PauloCancer, or neoplasia, is a complex disease with multiple causes. Many intrinsic and extrinsic factors influence the development of cancer. Intrinsic or host factors include age, sex, genetic constitution, immune system function, metabolism, hormone levels, and nutritional status. Extrinsic factors include substances eaten, drunk, or smoked; workplace and environmental (air, water, and soil) exposures; natural and medical radiation exposure; sexual behavior; and elements of lifestyle such as social and cultural environment, personal behavior, and habits. Intrinsic and extrinsic factors can interact with one another to influence the development of cancer. In this article, we will discuss all the varied aspects of research that will ultimately lead to the prevention of cancer in man.