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The Chacopampean plain is one of the most arsenic affected areas in Argentina, especially in groundwater, used both for animal drinking and forage irrigation. The main objective of this study was to determine the effect of arsenic (As) present in irrigation water on the germination parameters of red clover (Trifolium pratense L.), white clover (Trifolium repens L.), and alfalfa (Medicago sativa L.) seeds exposed to different concentrations of As(V). The germination and viability parameters of seeds from the three species were not affected by elevated concentrations of As. However, As significantly reduced the radicle and hypocotyl lengths of the three forage specimens. The inhibition level of the plants increased with the increase in the  concentration of As. Regarding to hypocotyl length/radicle length ratio, the results evidenced that both the hypocotyl and radicle of clover species are affected in the same degree, while alfalfa radicles seemed more affected than hypocotyls at higher concentrations of As. Our results showed that irrigation with solutions containing As affect seedling growth parameters differently in the three species, and the effect of As is mostly evidenced when in high concentrations.(AU)

A planície de Chacopampeana é uma das áreas mais afetadas pelo arsênico na Argentina, principalmente em águas subterrâneas, usada tanto para água potável animal quanto para irrigação forrageira. O principal objetivo deste estudo é determinar o efeito do arsênio (As) presente na água de irrigação sobre os parâmetros de germinação de sementes forrageiras: trevo vermelho (Trifolium pratense L.), trevo branco (Trifolium repens L.) e alfafa (Medicago sativa L.) expostos a diferentes concentrações de As (V). Verificou-se que os parâmetros de germinação e viabilidade das sementes das três espécies não foram afetados pelas concentrações elevadas de As. No entanto, reduziu significativamente o comprimento da radícula e o comprimento do hipocótilo das três mudas de forragem, e seu nível de inibição é maior com o aumento da concentração de As. Quanto à relação comprimento de hipocótilo/comprimento da radícula, os resultados evidenciaram que nas espécies de trevo tanto o hipocótilo quanto a radícula são afetados no mesmo grau, enquanto as radículas de alfafa pareceram mais afetadas do que os hipocótilos em concentrações maiores de As. Nossos resultados mostraram que a irrigação com soluções contém Afetar os parâmetros de crescimento de plântulas de maneira diferente nas três espécies, e foi demonstrado que o efeito do As é principalmente evidenciado em altas concentrações.(AU)

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The Chacopampean plain is one of the most arsenic affected areas in Argentina, especially in groundwater, used both for animal drinking and forage irrigation. The main objective of this study was to determine the effect of arsenic (As) present in irrigation water on the germination parameters of red clover (Trifolium pratense L.), white clover (Trifolium repens L.), and alfalfa (Medicago sativa L.) seeds exposed to different concentrations of As(V). The germination and viability parameters of seeds from the three species were not affected by elevated concentrations of As. However, As significantly reduced the radicle and hypocotyl lengths of the three forage specimens. The inhibition level of the plants increased with the increase in the  concentration of As. Regarding to hypocotyl length/radicle length ratio, the results evidenced that both the hypocotyl and radicle of clover species are affected in the same degree, while alfalfa radicles seemed more affected than hypocotyls at higher concentrations of As. Our results showed that irrigation with solutions containing As affect seedling growth parameters differently in the three species, and the effect of As is mostly evidenced when in high concentrations.

A planície de Chacopampeana é uma das áreas mais afetadas pelo arsênico na Argentina, principalmente em águas subterrâneas, usada tanto para água potável animal quanto para irrigação forrageira. O principal objetivo deste estudo é determinar o efeito do arsênio (As) presente na água de irrigação sobre os parâmetros de germinação de sementes forrageiras: trevo vermelho (Trifolium pratense L.), trevo branco (Trifolium repens L.) e alfafa (Medicago sativa L.) expostos a diferentes concentrações de As (V). Verificou-se que os parâmetros de germinação e viabilidade das sementes das três espécies não foram afetados pelas concentrações elevadas de As. No entanto, reduziu significativamente o comprimento da radícula e o comprimento do hipocótilo das três mudas de forragem, e seu nível de inibição é maior com o aumento da concentração de As. Quanto à relação comprimento de hipocótilo/comprimento da radícula, os resultados evidenciaram que nas espécies de trevo tanto o hipocótilo quanto a radícula são afetados no mesmo grau, enquanto as radículas de alfafa pareceram mais afetadas do que os hipocótilos em concentrações maiores de As. Nossos resultados mostraram que a irrigação com soluções contém Afetar os parâmetros de crescimento de plântulas de maneira diferente nas três espécies, e foi demonstrado que o efeito do As é principalmente evidenciado em altas concentrações.

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The Chaco Pampean Plain of central Argentina represents one of the largest regions with high levels of arsenic (As) in groundwater. The aim of this study was the assessment of a biotransference factor (BTF) as a tool for the estimation of As concentration in cow's milk from As drinking water concentration. Total As content in livestock drinking water, soil, forage, and milk was determined in farms located in an area of high As groundwater, in order to analyze the relation between As uptake and its transfer to milk. The concentrations of As in milk ranged from 0.5 to 8.0 µg/L. From the results obtained, drinking water may be considered the main source of exposure to As, and the biotransference factor for milk ranges from 1.5 × 10(-5) to 4.3 × 10(-4). Therefore, BTF provides a simple tool for the estimation of arsenic levels in milk through the As livestock drinking water content.

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Economic studies are essential in evaluating the potential external investment support and/or internal tariffs available to improve drinking water quality. Cost-benefit analysis (CBA) is a useful tool to assess the economic feasibility of such interventions, i.e. to take some form of action to improve the drinking water quality. CBA should involve the market and non-market effects associated with the intervention. An economic framework was proposed in this study, which estimated the health avoided costs and the environmental benefits for the net present value of reducing the pollutant concentrations in drinking water. We conducted an empirical application to assess the economic feasibility of removing arsenic from water in a rural area of Argentina. Four small-scale methods were evaluated in our study. The results indicated that the inclusion of non-market benefits was integral to supporting investment projects. In addition, the application of the proposed framework will provide water authorities with more complete information for the decision-making process.

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Arsenic (As) may occur in surface freshwater ecosystems as a consequence of both natural contamination and anthropogenic activities. In this paper, As concentrations in muscle samples of 10 fish species, sediments and surface water from three naturally contaminated rivers in a central region of Argentina are reported. The study area is one of the largest regions in the world with high As concentrations in groundwater. However, information of As in freshwater ecosystems and associated biota is scarce. An extensive spatial variability of As concentrations in water and sediments of sampled ecosystems was observed. Geochemical indices indicated that sediments ranged from mostly unpolluted to strongly polluted. The concentration of As in sediments averaged 6.58 µg/g ranging from 0.23 to 59.53 µg/g. Arsenic in sediments barely followed (r = 0.361; p = 0.118) the level of contamination of water. All rivers showed high concentrations of As in surface waters, ranging from 55 to 195 µg/L. The average concentration of As in fish was 1.76 µg/g. The level of contamination with As differed significantly between species. Moreover, the level of bioaccumulation of As in fish species related to the concentration of As in water and sediments also differed between species. Whilst some fish species seemed to be able to regulate the uptake of this metalloid, the concentration of As in the large catfish Rhamdia quelen mostly followed the concentration of As in abiotic compartments. The erratic pattern of As concentrations in fish and sediments regardless of the invariable high levels in surface waters suggests the existence of complex biogeochemical processes behind the distribution patterns of As in these naturally contaminated ecosystems.

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Small-scale and household low-cost technologies to provide water free of arsenic for drinking purposes, suitable for isolated rural and periurban areas not connected to water networks in Latin America are described. Some of them are merely adaptation of conventional technologies already used at large and medium scale, but others are environmentally friendly emerging procedures that use local materials and resources of the affected zone. The technologies require simple and low-cost equipment that can be easily handled and maintained by the local population. The methods are based on the following processes: combination of coagulation/flocculation with adsorption, adsorption with geological and other low-cost natural materials, electrochemical technologies, biological methods including phytoremediation, use of zerovalent iron and photochemical processes. Examples of relevant research studies and developments in the region are given. In some cases, processes have been tested only at the laboratory level and there is not enough information about the costs. However, it is considered that the presented technologies constitute potential alternatives for arsenic removal in isolated rural and periurban localities of Latin America. Generation, handling and adequate disposal of residues should be taken into account in all cases.

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The Chaco Pampean Plain of central Argentina constitutes one of the largest regions of high arsenic (As) groundwaters known, covering around 1 x 10(6) km2 (Smedley & Kinniburg, 2002; Farías et al. 2004). The high-As groundwaters are from Quaternary deposits of loess (mainly silt) with intermixed rhyolitic or dacitic volcanic ash (Nicolli et al. 1989, Smedley et al. 1998,2002). Early in the last century an endemic disease due to contamination of drinking water with arsenic was recognised. This disease is called HACRE (Hidroarsenicismo Crónico Regional Endémico, Chronic Endemic Regional Hydroarsenism) and is connected with a particular type of skin cancer (Astolfi et al. 1981). One of the most affected region is the province of Cordoba, where Nicolli et al. (1989) reported As concentrations that exceed the maximun level permitted for drinking water of 50 microg/l for 82% of the groundwater samples (n=60) of a study area comprising approximately 10000 km2. The southeast of Cordoba is an important milk production zone in Argentina, where dairy product consumption is up to 192 equivalent milk l/inhabitant/year. As a secretion of the mammary gland, milk can carry numerous xenobiotic substances, which constitute a technological risk factor for dairy products and above all for the health of the consumer (Licata et al. 2004). Nevertheless no studies on the incidence of high-As livestock drinking water in livestock health and its transfer to milk have been performed in Argentina. The aim of the present study was the determination of arsenic content in livestock drinking water and milk from dairy farms located in an area of high-As groundwaters, to analyse the relation between As uptake through water and its transfer to milk.

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