Maria Paula Casagrande Marimon

Anomalous fluoride concentration in groundwater - is it natural or pollution? A stable isotope approach.

Fluoride anomalies (up to 11 mg/l) have been detected in groundwater of the central region of Rio Grande do Sul State, Southern Brazil, in an area where fluorosis is endemic. Two hypotheses are investigated concerning the fluoride origin: lithochemical affiliation from regional rock or contamination by fertilisers application. These hypotheses are discussed based on the stable isotope data of water, nitrate, and sulphate, which indicates that the local precipitation is the main groundwater recharge source. The isotopic composition of groundwater sulphate is similar to that of fertiliser sulphate. However, a conclusive assignment of groundwater sulphate to fertiliser origin is not indicated because further possible sulphate sources fall into the same isotopic range. In contrast, the isotopic composition of dissolved nitrate suggests that there is no direct relationship to the use of NPK fertilisers. Hence, an origin of the high fluoride content in groundwater related to long-term rock–water interactions seems likely.

Fluoride in the Serra Geral Aquifer System: Source Evaluation Using Stable Isotopes and Principal Component Analysis

Groundwater with anomalous fluoride content and water mixture patterns were studied in the fractured Serra Geral Aquifer System, a basaltic to rhyolitic geological unit, using a principal component analysis interpretation of groundwater chemical data from 309 deep wells distributed in the Rio Grande do Sul State, Southern Brazil. A four-component model that explains 81% of the total variance in the Principal Component Analysis is suggested. Six hydrochemical groups were identified. δ18O and δ2H were analyzed in 28 Serra Geral Aquifer System samples in order to identify stable isotopes patterns and make comparisons with data from the Guarani Aquifer System and meteoric waters. The results demonstrated a complex water mixture between the Serra Geral Aquifer System and the Guarani Aquifer System, with meteoric recharge and ascending water infiltration through an intensive tectonic fracturing.

Considerações sobre a proposta de planejamento regional no extremo sul de Santa Catarina: Projeto geoparque caminhos dos cânions do sul

O objetivo do presente artigo, que apresenta reflexoes dedicadas para a dissertacao de mestrado desenvolvida no Programa de Pos-Graduacao em Planejamento Territorial e Desenvolvimento Socioambiental da UDESC, consiste em apresentar algumas questoes sobre o Projeto Geoparque Caminhos dos Cânions do Sul. Neste territorio, em que a proposta do Geoparque esta inserida, existem os Parques Nacionais de Aparados da Serra (PARNAS) e o Parque Nacional da Serra Geral (PNSG), sitios arqueologicos e paleontologicos e vinte Geossitios atestados pelo Servico Geologico do Brasil (CPRM), entre outras potencialidades. Um Geoparque tem o proposito de desenvolver uma regiao no seu aspecto cultural, economico e ambiental, tornando-se possibilidade de efetivacao de um planejamento regional para alcancar o desenvolvimento socioambiental. A SDR e a AMESC, alem de outras instituicoes, estao integradas em torno do objetivo de obter o titulo de Geoparque para o Extremo Sul Catarinense.

Origin of high fluoride contents in groundwater of the Santa Maria Formation, Guarany Aquifer System, southern Brazil

A comprehensive assessment of man-made impact on the environment is much kept behind because of missing unified systems of environmental monitoring. They represent sources of reliable information on the current status of the environment, as well as the absence of approaches to assess the impact of chemical pollution by different anthropogenic sources. Vegetation, being the component of environmental systems, is very sensitive to atmospheric man-made load. However, permissible concentrations of elements in plants, causing deflection in their development are differently estimated in different regions and vegetation species. As to the Baikal region, it is commonly the sanitary state of woods, that is primarily assessed. Coniferous trees, in particular pine, represent the main tree species in the region. In the Olkhon region we investigated the trace element compositions in pine needles to obtain the background contents of toxic metals. This region of the National park lies 300 km away from the industrial sources of pollutants, beyond the zone of wind effect, and has no industry. The research was made on the healthy (green) and dried up (red) pine needles. The elements like Zn, A1, Mn, Fe, Cr, Cu, Co, Ni, Sr, Cd, Pb, Li, Rb, Sb and As were measured by atomic absorption and flame emission photometry. The samples were decomposed in autoclaves with the mixture of nitric acid and hydrogen peroxide. Distinct differences were found in a series of elements contained in the green and dried needles. The red needles are characterized by higher contents of Zn, A1, Cu and low Mn, Fe, Pb with similar contents of other elements. It is proposed to use the ratio Fe/Mn for evaluating the ecological status and characterization of the damage to trees. In the study region in the green needles Fe/Mn=0.5, in red ones it is 0.7 (for comparison the ratio Fe/Mn in the zone of industry influence the ratio is 1.1-2.0). The obtained values of metal concentrations in the green pine needles can be accepted as background in the assessment of the sanitary state of the Prebaikalian woods, and reddening of the needles most likely reflects the natural serial level of tree stands.