Risco de contaminação pela presença de disposição final de resíduos sólidos em bacias de captação superficial de água / Contamination risk due to the presence of an urban solid waste disposal site within the surface water catchment basins

RESUMO Modelos de vulnerabilidade são importantes ferramentas no estudo da contaminação da qualidade das águas. Esta pesquisa avaliou o risco de contaminação pela presença de disposição final de resíduos sólidos urbanos (DRS) em bacias de captação superficial de água (BCSs) no Estado de Goiás, Brasil. Foi realizada a identificação e caracterização das BCSs e das DRSs em um sistema de informações geográficas utilizando o software QGis 2.12.0 Lyon. A sobreposição das informações permitiu a identificação das BCSs com DRSs em suas delimitações, aplicando a elas o índice de susceptibilidade (IS), composto por características intrínsecas e extrínsecas das BCSs. Pelo cálculo da vulnerabilidade média foram selecionadas as BCSs com maior risco de contaminação, bem como as DRSs presentes, as quais foram analisadas por seis parâmetros técnicos. Dessa forma, foram identificadas 204 BCSs e 228 DRSs, sendo 93% classificadas como lixões. O IS foi calculado para as 43 BCSs com presença de 69 DRSs em suas áreas, selecionando as nove mais vulneráveis com a existência de 18 DRSs. A interdependência dos parâmetros avaliados possibilitou o cálculo do risco nessas DRSs. Conclui-se que a avaliação da vulnerabilidade se mostrou eficaz e de grande relevância para a identificação das BCSs mais susceptíveis à contaminação de suas águas, podendo ser aplicada a outras áreas de estudo. Em Goiás, a análise permitiu o cálculo do risco existente em 18 DRSs, sendo 4 delas classificadas como de risco alto, devendo ser consideradas prioritárias para adequação ou remediação de suas áreas.

ABSTRACT Vulnerability models are important in the study of water contamination by different soil usage activities. This research's goal is to evaluate the contamination risk by the presence of an urban solid waste disposal site (UWDS) within the surface water catchment basins (SWCB) used in the public water supply of Goiás, Brazil. Identification and characterization of SWCBs and UWDSs have been done in a geographical identification system using the QGis2.12.0 Lyon software. The information overlapping allowed the identification of SWCBs that had an UWDS within its limits, applying to them the Susceptibility Index (SI), composed by intrinsic and extrinsic SWCB characteristics. Calculating the average vulnerability, SWCBs, which presented the highest risk of water contamination, were selected and had their UWDSs analyzed by six technical parameters. This way, 204 SWCBs and 228 UWDSs were identified, out of which 93% were classified as irregular dumping sites. The SI was calculated for each SWCB that had the presence of UWDSs within their areas (43 SWCBs with 69 UWDSs), pointing the 9 most vulnerable ones, which had 18 UWDSs within its limits. The interdependence of the evaluated parameters allowed to calculate the risk in these UWDSs. In conclusion, the vulnerability evaluation has been proven effective and of great relevance in the identification of the SWCBs most susceptible to water contamination, and it can be applied to other studies. In Goiás, the analysis allowed the existing risk calculation for each of the 18 UWDSs, out of which 4 were found high-risk being in need of priority adequation and remediation.

Antioxidant activity evaluation of dried herbal extracts: an electroanalytical approach

ABSTRACT The prevention of chronic and degenerative diseases, is a health concern deeply associated with oxidative stress. Such progressive phenomena can be avoided through exogenous antioxidant intake, which set up a reductant cascade, mopping up damaging free radicals. Medicinal herbs are commonly associated with high antioxidant potential, and hence their health benefits. The commerce of dried herbal extracts movements a big portion of developing countries economy. The determination of medicinal herbs the antioxidant activity capacity is of utmost importance. The assessment of antioxidant activity in phytotherapics is mostly achieved by spectrophotometric assays, however colored substances can produce interferences that do not occur in electroanalytical methods. Therefore, the aim of this paper is to compare spectrophotometric and voltammetric techniques to evaluate antioxidant activity in herbal drugs such as: Ginkgo biloba L., Camellia sinensis (L.) Kuntze, Theaceae; Hypericum perforatum L., Hypericaceae; Aesculus hippocastanum L., Sapindaceae; Rosmarinus officinalis L., Lamiaceae; Morinda citrifolia L., Rubiaceae; Centella asiatica (L.) Urb., Apiaceae; Trifolium pratense L., Fabaceae; Crataegus oxyacantha L., Rosaceae; and Vaccinium macrocarpon Aiton, Ericaceae. The spectrophotometric methods employed were DPPH (2,2-diphenyl-1-picrylhydrazyl), ABTS (2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) and the Folin-Ciocalteu assays. The electroanalytical method used was voltammetry and it was developed a phenoloxidase based biosensor. The redox behavior observed for each herbal sample resulted in distinguishable voltammetric profiles. The highest electrochemical indexes were found to G. biloba and H. perforatum, corroborating to traditional spectrophotometric methods. Thus, the electroanalysis of herbal drugs, may be a promising tool for antioxidant potential assessment.

Heterocontrole da fluoretação da água de abastecimento público em cidades do estado de Goiás, Brasil / External control of fluoridation in public water supply systems in the state of Goiás, Brazil

Resumo A adição do flúor na água é um método empregado na redução de cárie dentária. O controle da fluoretação é importante para manter a sua eficiência e, ao mesmo tempo, evitar o risco de ocorrência de fluorose, fruto do consumo de água com flúor em excesso. O objetivo deste trabalho foi avaliar a adequação dos níveis do fluoreto na água distribuída à população do estado de Goiás, Brasil. Foram analisadas 5.039 amostras de água coletadas em 225 municípios de Goiás, entre 2011 e 2013. Os resultados foram analisados por sazonalidade, tipo de manancial e localização geográfica. Ocorreu uma variação entre ausência e 2,5 mg F/L, com 28,2% das amostras entre 0,6 e 0,8 mg F/L e 39,1% entre 0,55 e 0,84 mg F/L. No período de chuva ocorreu um maior número de resultados atípicos e maiores valores quando comparados ao período da seca. Verificou-se que os sistemas abastecidos por água proveniente de mananciais subterrâneos possuem um menor controle de fluoreto quando comparados a sistemas provenientes de mananciais superficiais. Observou-se menores concentrações nas amostras coletadas no Norte e Leste goianos, com menos de 7,5% entre 0,6 e 0,8 mg F/L, para aquelas coletadas de sistemas de abastecimento que utilizam água de manancial subterrâneo com adição de fluoreto, existindo dificuldades na manutenção dos seus teores.

Abstract The addition of fluoride to the public water supply is a method used for reducing tooth decay. In this sense, the control of fluoridation is important for maintaining its efficiency and, at the same time, for avoiding the risk of fluorosis as a result of the consumption of water with excess of fluoride. The objective of this study was to evaluate the adequacy of fluoride levels in the water distributed to populations of the state of Goiás, Brazil. Towards this aim, 5,039 water samples collected between 2011 and 2013 in 225 municipalities of the state of Goiás were analyzed for fluoride level. The results were assessed with regard to season, type of water source and geographic location. Fluoride levels were found to vary between complete absence and 2.5 mg F/L, with 28.2% of the samples being between 0.6 and 0.8 mg F/L, and 39.1% between 0.55 and 0.84 mg F/L. The rainy season produced a greater number of atypical results and higher values than the dry period. The systems supplied by groundwater sources were shown to have a limited control of fluoride concentration compared to systems supplied by surface water sources. Lower concentrations of fluoride were found in samples collected in the North and East Mesoregions of Goiás, with less than 7.5% being between 0.6 and 0.8 mg F/L, which systems are mainly supplied by groundwater sources with fluoride addition .