Lead (Pb) is an environmental contaminant that presents a high risk for human health. We aimed to investigate the possible alterations triggered by the exposure to Pb acetate for a long period in motor performance and the possible relationship with biochemical, proteomic and morphological alterations in the cerebellum of rats. Male Wistar rats were exposed for 55 days, at 50 mg/Kg of Pb acetate, and the control animals received distilled water. Open field (OF) and rotarod tests; biochemistry parameters (MDA and nitrite); staining/immunostaining of Purkinje cells (PC), mature neurons (MN), myelin sheath (MS) and synaptic vesicles (SYN) and proteomic profile were analyzed. Pb deposition on the cerebellum area and this study drove to exploratory and locomotion deficits and a decrease in the number of PC, MN, SYN and MS staining/immunostaining. The levels of MDA and nitrite remained unchanged. The proteomic profile showed alterations in proteins responsible for neurotransmitters release, as well as receptor function and second messengers signaling, and also proteins involved in the process of apoptosis. Thus, we conclude that the long-term exposure to low Pb dose promoted locomotion and histological tracings, associated with alterations in the process of cell signaling, as well as death by apoptosis.

Lead (Pb) is an environmental and occupational neurotoxicant after long-term exposure. This study aimed to investigate the effects of systemic Pb exposure in rats from adolescence to adulthood, evaluating molecular, morphologic and functional aspects of hippocampus. For this, male Wistar rats were exposed to 50 mg/kg of Pb acetate or distilled water for 55 days by intragastric gavage. For the evaluation of short-term and long-term memories, object recognition and step-down inhibitory avoidance tests were performed. At the end of the behavioral tests, the animals were euthanized and the hippocampus dissected and processed to the evaluation of: Pb content levels in hippocampal parenchyma; Trolox equivalent antioxidant capacity (TEAC), glutathione (GSH) and malondialdehyde (MDA) levels as parameters of oxidative stress and antioxidant status; global proteomic profile and neuronal degeneration by anti-NeuN immunohistochemistry analysis. Our results show the increase of Pb levels in the hippocampus of adult rats exposed from adolescence, increased MDA and GSH levels, modulation of proteins related to neural structure and physiology and reduced density of neurons, hence a poor cognitive performance on short and long-term memories. Then, the long-term exposure to Pb in this period of life may impair several biologic organizational levels of the hippocampal structure associated with functional damages.

O objetivo deste trabalho foi investigar as concepções e hábitos dos estudantes, bem como, verificar as práticas educacionais abordadas por todos os sujeitos que compõe uma escola pública, sobre o subtema resíduos sólidos. A investigação foi realizada por meio de uma pesquisa-ação. Em um primeiro momento os alunos responderam a um questionário, os dados obtidos foram analisados e após a observação das dificuldades em relação ao conhecimento sobre resíduos sólidos, foi elaborado e executado uma palestra para a construção de um conhecimento, mudanças de hábitos e o enfrentamento da realidade escolar. Ao final os alunos refletiram sobre uma possível problemática no âmbito escolar relacionado ao subtema resíduos sólidos. As análises dos dados obtidos refletem que a maioria dos alunos possui conhecimentos e hábitos errôneos, bem como há a falta de abordagens e práticas educacionais sobre o tema Meio Ambiente e o subtema resíduos sólidos.

This study evaluated the water quality of artesian wells and effluents generated in cassava processing in a rural area of Bragança, Pará, with emphasis on physicochemical parameters, multielement composition, and cyanogenic compounds. The well water presented specific nonconformities, highlighting pH values below the recommended level and high concentrations of residual chlorine. Although cyanide was not detected in the groundwater, the effluents presented concentrations of total and free cyanide above legal limits, mainly in the pressing water and in the washing and fermentation tanks, indicating an environmental risk associated with the inadequate disposal of these residues. Regarding the multielement analysis, boron and copper enrichment was observed in the well water, and high concentrations of manganese and nickel were found in the effluents, exceeding the limits established by Brazilian environmental legislation. The multivariate analysis revealed distinct physicochemical profiles between the well water and the effluents, with temperature, dissolved oxygen, and pH being the main factors responsible for the differentiation between the matrices. The results indicate the need for improvements in the management and treatment systems of cassava processing effluents, aiming at protecting water resources and reducing potential environmental and human health risks.