Arsenic groundwater content in rural areas from Mendoza, Argentina

PÉREZ CARRERA, A., E. ABRAHAM, M. SALOMON Y A. FERNÁNDEZ-CIRELLI

Valencia

Congreso; 2nd International Congress Arsenic in the Environment: from Nature to Humans; 2008

Red CYTED IBEROARSEN, CCIC

The Chaco Pampean Plain of central Argentina constitutes one of the largest regions of high arsenic groundwaters known, covering around 1x106 km2 (Smedley and Kinniburgh, 2002). High concentrations of arsenic have been documented from several densely populated provinces, where agriculture is one of the main activities. However, there are scarce data from other regions such as the arid area of central-west Argentina (provinces of Mendoza and San Juan). The high-As groundwaters in the pampean plains are from Quaternary deposits of loess (mainly silt) with intermixed rhyolitic or dacitic volcanic ash (Nicolli et al. 1989). It is well recognized that consumption of arsenic, even at low levels, leads to carcinogenesis. The aim of the present study was the determination of arsenic content in livestock drinking water from goat production systems located in the Lavalle department in the north of Mendoza province. Shallow groundwater samples were collected in 25 small farms located in an area characterized by disperses rural population where the main activity is goat production for subsistence. Manual wells are used to provide water both for human and animal consumption. Total arsenic in water was determined by inductively coupled plasma optical emission spectrometry, ICP-OES (Perkin Elmer, Optima 2000) according to norms APHA, 1993. Determinations were performed in duplicate with a relative error < 1.0% for all of them. Arsenic concentration ranged from < 10 to 584 mg/L (average: 103 mg/L and standard deviation: 125 mg/L). Only two samples were below the detection limit (10 mg/L). Arsenic concentrations in 92% of water samples were higher than the upper limit recommended by local regulations for human drinking water (10 mg/L). On the other hand, possibility of arsenic biotransference from water to animal tissues and milk is very low according to our previous experience (Pérez-Carrera and Fernández-Cirelli, 2005)