The problematic of arsenic in Argentina: investigation at La Matanza district, Buenos Aires, Argentina

VAZQUEZ, CRISTINA; RODRÍGUEZ CASTRO, M. CAROLINA; PALACIOS, OSCAR; BOEYKENS, SUSANA

Conferencia; 9th Conference on sustainable development of energy, wáter and environment systems; 2014

The environmental situation in the Buenos Aires Metropolitan Area (AMBA) is characterized by a marked deterioration of urban ecosystems. This deterioration in life quality is caused by non controlled anthropogenic pollutant discharges. Surface water, groundwater as well as soils and sediments have been widely polluted by industrial and municipal wastewaters, household wastes, and agricultural activities over the past several decades. At the same time, due to population growth in urbanized areas, the risk of exposition to polluted waters through drinking water has grown. La Matanza district, located in the Buenos Aires Province, with an area of 325.71 km2 and a population of 1,249,958 inhabitants is divided into 15 villages. Among them, Virrey del Pino, with an area of 116.520Km2 and a population of 90.382 inhabitants (2001 census INDEC). In our study, we focused the investigation in this neighborhood which is affected by industrial activity in the area and a lack of monitoring. The neighborhood is classified as residential, but lacks the most essential public services such as tap drinking water, natural gas and sewers. Population has to get water by particular pumping wells drilling from 14 to 40 m depth to reach the aquifer. There are not paved access roads complicating the access of neighbors in rainy days and aggravating the situation of urban hygiene. The industries of the area, in most cases, lack of treatment plants for waste generated, originating bulbs with high degree of chemical and biological contamination that strongly alter the environment. In addition to this situation, La Matanza district is located inside the area of Argentina affected by HACRE (Chronic Regional Endemic Hydroarsenicism, ?hidroarsenicismo crónico regional endémico?, in Spanish). HACRE is produced by the chronic consumption of water with high levels of arsenic. The presence of this element in the water constitutes a serious world health concern due to its toxicity. Depending on the intensity and duration of exposure, this element can be acutely lethal or may have a wide range of health effects in humans and animals. Argentina´s concern with arsenic and its influence on human health dates back to the previous century. The origin of arsenic is mainly natural, and related to different geological processes that affected the region. During the Quaternary period, accumulation of eolic and fluvial materials was produced in arid environmental conditions. In this region, volcanic material is an important component of loessic and sandy eolic deposits. The physical and chemical characteristics of the hydrogeological system are mainly determined by the form of accumulation of materials and the nature of loessic deposits. Thus, the need for development of new tools to monitor arsenic is compelling . Biomonitoring gives a fullview of an internal or absorbed dose of a chemical in an organism and it can be the most reliable exposure assessment methodology as it considers all routes of uptake and all sources of contamination. Also, it reveals exposure history to a contaminant that might not be detected in water samples because of an intermittent source of contamination, making it an ideal instrument for risk assessment and risk management.Dog (Canis lupus familiaris) has long been an important research model and a promising tool as a target and bioindicator for metal contamination. This is due to the fact that dogs share the same environment as humans [1]. Blood and hair particularly appear as interesting monitoring tools for exposure risk assessment.In order to establish a full view of arsenic exposure in the area, several matrices and targets were analyzed. As matrices, water and soil samples were analyzed; as targets, canine and human hair samples were selected. The aim of this study was to investigate acute and chronically exposure to arsenic at Virrey del Pino inhabitants. The analytical techniques used in this study were selected considering available amount of sample, sensitivity, accuracy, reproducibility and detection limits of the method.In this sense, total reflection X-ray fluorescence spectrometry (TXRF) was used for the direct analysis of water samples and dog hair samples after an in situ domestic microwave digestion in this later case [2]. Wavelength dispersive X ray spectrometry was selected for the analysis of soil after dried and pressed the samples. Finally, hydride generation atomic absorption spectrometry was used for the analysis of human hair.