Exposição ao praguicida glifosato e a ocorrência do transtorno do espectro autista: existe associação? / Exposure to the pesticide glyphosate and the occurrence of autistic spectrum disorder: is there an association?

O presente estudo teve como objetivo estudar a associação entre a exposição ao glifosato e a ocorrência do Transtorno do Espectro Autista (TEA). Trata-se de um estudo documental com busca de dados acerca da prevalência do TEA (Centers of Disease Control and Prevention) e de um levantamento para verificar o princípio ativo do praguicida mais usado no Brasil (Instituto Brasileiro do Meio Ambiente e dos Recursos Naturais Renováveis) e no mundo (United States Evironmental Prevention Agency). Os resultados mostraram que a prevalência do TEA aumentou ao longo dos anos. Do mesmo modo, o uso e a compra de praguicidas também aumentaram, sendo o glifosato o princípio ativo mais usado. Ainda que os resultados apontem a existência de uma relação entre a exposição ao glifosato e a ocorrência de autismo, são necessários mais estudos para afirmar o potencial neurotóxico do glifosato e sua associação com o nascimento de crianças autistas.

The present study aimed to study the association between exposure to glyphosate and the occurrence of Autistic Spectrum Disorder (ASD). This is a documental study with search for data about the prevalence of ASD (Centers of Disease Control and Prevention) and a survey to verify the active principle of the most used pesticide in Brazil (Brazilian Institute of Environment and Renewable Natural Resources) and worldwide (United States Environmental Prevention Agency). The results showed that the prevalence of ASD increased over the years. Likewise, the use and purchase of pesticides have also increased, with glyphosate being the most widely used active ingredient in the world. Although the results point to the existence of a relationship between exposure to glyphosate and the occurrence of autism, further studies are needed to confirm the neurotoxic potential of glyphosate and its association with the birth of autistic children.

Efeitos tóxicos à saúde humana e ao ambiente causados pelo derramamento de rejeitos de minério da barragem de Fundão / Toxic effects to human health and the environment caused by the spillage of ore tailings from the Fundão dam

Objetivo: analisar as evidências científicas existentes até o presente momento que descrevem os efeitos tóxicos causados à saúde humana e ao ambiente, devido à liberação dos rejeitos de minério, decorrentes do rompimento da barragem de Fundão em Mariana - MG. Métodos: a revisão narrativa da literatura baseou-se na busca de artigos em quatro bases de dados: PubMed, SciELO, Science Direct e LILACS, utilizando os descritores "Dam", "Fundão" e "Mariana" junto com o operador booleano "AND". Resultados: trinta e quatro das oitenta e cinco publicações encontradas atenderam aos critérios de inclusão e foram utilizadas para compor a presente revisão. Foram observados os seguintes efeitos tóxicos: contaminação da água e do solo, principalmente, por metais pesados, potencial genotóxico, citotóxico e mutagênico da água, diminuição da diversidade microbiana, contaminação de peixes, perda da vegetação e prejuízos ao metabolismo de crescimento de plantas. Entre esses metais, foi relatado aumento na concentração de ferro, manganês, cobre, cádmio, chumbo, arsênio, cromo, magnésio, alumínio, mercúrio, cobalto, bário, níquel e selênio. Além disso, o desastre promoveu o aumento no número de casos de doenças humanas, como dengue, doenças respiratórias, dermatológicas, intestinais, psicológicas e comportamentais. Conclusão: todas as evidências científicas expostas na presente revisão sugerem que houve a contaminação ambiental, bem como da população local, por agentes tóxicos presentes nos rejeitos de minério, em especial metais pesados, liberados após o rompimento da barragem de Fundão. Assim, torna-se essencial a realização de mais estudos que visem esclarecer os efeitos tóxicos crônicos decorrentes dos rejeitos de minério liberados ao ambiente.

Objective: to analyze the scientific evidence existing to date that describes the toxic effects caused to human and the environmental health, due to the release of ore tailings, resulting from the rupture of the Fundão dam in Mariana-MG. Methods: the narrative literature review was based on a search for articles in four databases: PubMed, SciELO, Science Direct and LILACS, using the descriptors "Dam", "Fundão" and "Mariana" together with the Boolean operator "AND". Results: thirty-four, of the eighty-five publications found, met the inclusion criteria and were used to compose the present review. The following toxic effects were observed: contamination of water and soil mainly by heavy metals, genotoxic, cytotoxic and mutagenic potential of water, decrease in microbial diversity, contamination of fish, loss of vegetation, and impairment of plant growth metabolism. Among these metals, increased concentrations of iron, manganese, copper, cadmium, lead, arsenic, chromium, magnesium, aluminum, mercury, cobalt, barium, nickel and selenium were reported. In addition, the disaster promoted an increase in the number of cases of human diseases, such as dengue, respiratory, dermatological, intestinal, psychological and behavioral diseases. Conclusion: all the scientific evidence exposed in the present review that there was environmental contamination, as well as of the local population, by toxic agents present in the ore tailings, especially heavy metals, released after the collapse of the Fundão dam. Thus, further studies aimed at clarifying the chronic toxic effects resulting from the ore tailings released into the environment are essential.

Assessment of the Toxicological Effects of Pesticides and Detergent Mixtures on Zebrafish Gills: a Histological Study

Abstract Pesticides, as Temephos and Roundup, and surfactants, like Sodium Dodecyl Sulfate (SDS), when discharged into the environment, are harmful to non-target wildlife, especially fish. To evaluate the effects of those chemicals alone and their binary combinations, we assessed the histological alterations in Danio rerio gills after 15 days of exposure to Temephos (1ppm), Roundup (10ppm), SDS (2ppm), SDS plus Temephos (2ppm+1ppm), SDS plus Roundup (2ppm+10ppm) and Temephos plus Roundup (1ppm+10ppm). Hyperplasia, a regressive change, was significant in all exposed groups. The progressive change, complete fusion of lamellae, was significantly intensive in Roundup plus Temephos group. Regarding circulatory disturbances, vascular congestion was significant intensive in SDS group, while severe aneurysm was observed in Roundup group. Although xenobiotics in the blend are biologically complex, mainly for long periods, combinatorial exposure incremented only complete fusion of lamellae. Our results reinforce the rationalization of indiscriminate use of those compounds alone or in combination.

Primary culture macrophages from fish as potential experimental model in toxicity studies with multiwalled carbon nanotubes

Multiwalled carbon nanotube (MWCNT) has been broadly used in several sectors of society. This material when exposed to the environment might reach the aquatic animals and cause toxic effects. Here, it was evaluated the MWCNTs toxicity in melanomacrophages primary culture that was submitted to 1 µ gm L-1 MWCNTs for 24 hours. After exposition to MWCNT, 48 and 59% liver and spleen melanomacrophages were healthy, respectively. The control group presented 85% viability. Phagocytosis activity of melanomacrophages was observed by presence of black inclusions in cytoplasm. The findings indicate MWCNT was cytotoxic to melanomacrophages, where its release and effect into aquatic environment must be more studied. Finally, the melanomacrophages present large potential as experimental model for evaluation of carbon-based nanomaterial toxicity.

Immunohistochemical Analysis of P-gp, LC3-II, and Cathepsin-D Associated with Histological Changes in Fish Liver: from the Impacted Environment to Clean Water

Abstract Herein we evaluated the histopathological alterations and expression patterns of multixenobiotic resistence (MXR) and autophagic proteins in liver samples of fish chronically exposed to anthropogenic contaminants in a highly polluted river, and then again after they had been transferred to good quality water. Two groups were established: euthanized on the day of capture (0 h), and maintained for 30 days in a tank (30 d). The fish of 0 h presented liver with vacuolated and hypertrophic hepatocytes. Also, it was observed strong immunostaining of cathepsin-D, LC3-II and P-gp. Necrosis and apoptosis were also observed throughout the liver. Conversely, the second group (30 d) showed recovery of the liver normal histology and weak immunoreaction of the studied proteins. So, our results indicated that there was a hepatic recovery in the fish kept in good quality water, as showed by the decreased expression of cathepsin-D, LC3-II, and the MXR (P-gp). Therefore, the alterations here observed could be proposed as potential biomarkers to be tested for following the impacts of remediation or mitigation measures to environmental impacts.

Length-weight relationship and reproductive activity of the Leporinus piau Fowler, 1941 captured in a small deactivated hydropower plant / Relação peso-comprimento e atividade reprodutiva do Leporinus piau Fowler, 1941, capturados em uma pequena usina hidrelétrica desativada

Reproductive activity of 'piau gordura' Leporinus piau was studied using biometric, macroscopic and microscopic analysis. A total of 74 specimens of L. piau were collected quarterly from January to December 2005 in a small deactivated hydropower plant located at Jorge Pequeno Stream and preserved in a fixative solution until analysis. The alterations after fixation were evaluated. The stages of gonadal maturation were determined by histology and gonadosomatic index (GSI). The females and males in the spawning capable and regressing stage were registered from October to December. L. piau is total spawning and the HSI (hepatossomatic index), SRI (stomach repletion index) and CFI (coelomic fat index) of females and males did not showed a statistical difference. However they were numerically different between the stages of maturation. For both sexes, the smallest specimens captured during the reproductive activity have measured around 8.3 cm in total standard. The length-weight relationship observed for the parameter 'b' was 3.01 and the parameter 'a' was 0.02. This study demonstrates the importance of Jorge Pequeno Stream in the reproductive activity of migratory fish in the upper São Francisco river.

A atividade reprodutiva do 'piau-gordura' Leporinus piau foi estudada, utilizando análises biométricas, macroscópicas e microscópicas. Um total de 74 exemplares de L. piau foram capturados trimestralmente de janeiro a dezembro de 2005 em uma pequena usina hidrelétrica desativada localizada no Ribeirão Jorge Pequeno e fixados até as análises biométricas e histológicas. As alterações após fixação foram avaliadas. Os estádios de maturação gonadal foram determinados por histologia e índice gonadossomático (IGS). As fêmeas e os machos capazes de desovar foram registrados de outubro a dezembro. L. piau possui desova total e os índices IHS (índice hepatossomático), IRS (índice de repleção estomacal) e IGC (índice de gordura celômica) de fêmeas e machos não apresentaram diferença estatística apesar de numericamente serem diferentes entre os estádios de maturação. Os menores exemplares capturados em atividade reprodutiva mediram 8,3 cm de comprimento total para ambos os sexos. Na análise da relação peso-comprimento, o parâmetro 'b' foi 3,01 e o parâmetro 'a' foi de 0,02. Este estudo fornece importantes informações sobre L. piau e sugere o papel do Ribeirão Jorge Pequeno na atividade reprodutiva de peixes na região do alto rio São Francisco.