Abstract
The composition of water can be influenced by the input of elemental constituents from natural and anthropogenic sources. Elevated levels of vanadium, arsenic, fluoride and other trace elements in water (ground, surface and tap) from various provinces in Argentina (including La Pampa, south east Buenos Aires, Río Negro and Neuquén), were analysed by inductively coupled plasma mass spectrometry (ICP-MS) and ion selective electrode (for fluoride). Vanadium species were determined in water by a newly developed solid phase extraction method (SPE). Vanadate (VV) was found to be the predominant species in water samples. The correlation between vanadium and arsenic species, and total elemental levels are presented. Vanadate (VV) correlates strongly with total arsenic, vanadium, fluoride and also the inorganic arsenic species compared to the vanadyl ion (VIV). However, vanadyl (VIV) had stronger Spearman correlations with the organosenical species. The levels of vanadium, arsenic and other trace elements were analysed in hair and nail samples and in water to evaluate exposure levels. The elemental exposure via drinking water increased in the following order: La Pampa (General San Martin-GSM and Eduardo Castex-EC) > Buenos Aires (Moron-MO) > Río Negro (General Roca-GR). In La Pampa (GSM and EC) and Buenos Aires (South east-SE) many sites showed vanadium, arsenic and fluoride levels exceeded the international regulatory limits for drinking water. La Pampa residents had the widest distribution of vanadium and arsenic in hair, fingernails and toenails compared to other populations in this study. A significant Spearman correlation (P < 0.0001) exists between the levels of vanadium and arsenic in groundwater from La Pampa and hair or nail values. The rural farms in La Pampa have no access to treated water. An electrocoagulation method using aluminium and iron electrodes showed a high level of efficiency in removing vanadium, arsenic and fluoride from groundwater. This may offer clean, and safe drinking water for farmers living in these areas of Argentina.