Concentrações de randônio nas águas subterrâneas, rochas e solos de Porto Alegre, RS

AUTOR(ES)

Ana Clara Butelli Fianco

FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

2011

RESUMO

Many water-supply systems in Brazil utilize groundwaters at least as part of their networks. This is the case of Porto Alegre, capital of Rio Grande do Sul State, whose population is about 1.4 million inhabitants. However, there is little present knowledge in Brazil of the factors affecting Rn presence in the water supplied for end-users, despite the economic importance of groundwaters. 222Rn analyzes groundwater and soil samples were performed at several sites in Porto Alegre, Brazil, with the aim of investigating the major factors affecting its presence in solution. Analysis for 226Ra (eU, equivalent Uranium) activity concentration was also performed in selected rock samples in order to obtain information on the 222Rn generation by the aquifer rock matrices. Several samples exhibited dissolved 222Rn activity concentration exceeding the World Health Organization maximum limit of 100 Bq/L. The dissolved radon content in groundwaters providing from the Fractured Pre-Cambrian Aquifer System exhibited direct significant correlation with the equivalent uranium in the rock matrices, as a typical result of water-rock interactions. Aeration was confirmed as an important factor for Rn release, as expected due to its gaseous nature. This process was responsible for the lack of relationship between radon produced by rocks and its presence in soils. Thus, despite the calcic-alkaline to alkaline Pre-Cambrian granitoid rocks of the area studied are important reservoirs for underground resources, they can release high amounts of the gas radon to the liquid phase, claiming the attention of the local authorities responsible by the management of the hydrological resources as much attention has been paid to Rn in waters since it is considered a constituent that may be responsible for fatal cancers when continuously ingested in drinking water or confined in closed environments.

ASSUNTO(S)

Águas subterrâneas porto alegre (rs) geoquímica

Documentos Relacionados

• Caracterização e classificação de solos de várzea na região metropolitana de Porto Alegre, RS
• Fungos anemófilos em Porto Alegre, RS.
• Avaliação da diversidade e do perfil de susceptibilidade a antimicrobianos de Enterococcus sp. isolados nas águas do Arroio Dilúvio-Porto Alegre, RS
• Atributos espaciais e valorização imobiliária em Porto Alegre, RS
• Plantas alimentícias não-convencionais da região metropolitana de Porto Alegre, RS