Arsenic intake and urine as biomarker of exposure in two endemic arsenic areas in Chile: Phytoremediation as a strategy for the recovery of contaminated soils

Abstract

The aim of this chapter was to study the distribution of total arsenic (t-As) and inorganic arsenic (i-As) in drinking water and foods (raw and cooked) consumed in arsenic-endemic areas. Inorganic arsenic intake from both drinking water and foods was estimated using samples collected from two arsenic endemic areas in the Antofagasta Region of Chile. The t-As contents in drinking water varied in the range 265 ± 13-572 ± 21 ug L-1 and 0.10 ± 0.10-0.25 ± 0.01 ug i-As g-1 ww in foods. In both arsenic endemic area considered, majority of the participants interviewed exceeded the FAO/OMS reference intake (149.8 ug i-As/day). In this chapter it used urine as arsenic (As)-biomarker of exposure. Detection of As in these biological samples is indicative of systemic absorption after exposure to it. Several samples of urine collected from subjects interviewed in one of the As-endemic area, showed high levels of t-As in the urine that fluctuated between 78-459 ng mL-1. It is known that this situation implies a very high risk for human health and then, it is important to carried out some economic and environmentally strategies for reducing the high levels of As in drinking water and foods. Studies done in arid zones have suggested that collecting plants species on contaminated soils may be effective for selecting potential plants to be used in phytoremediation. The ability to accumulate As from certain plants has generated interest for using them in phytoremediation and/or revegetation for the recovery of contaminated soils. This chapter have showed the potential of four plants collected in the contaminated soils of Antofagasta Region of Chile: Atriplex atacamensis, Atriplex halimus, Lupinus microcarpus and Pluchea absinthioides. Populations in certain regions, including those in the Second Region in Chile, may present a relatively high intake of i-As, derived first from drinking water and second from high consumption of vegetables and cereals. Excessive exposure to i-As in drinking water and foods can lead elevated urinary-As levels, showing that the toxicological risk to which the inhabitants of small towns of the Antofagasta Region, Chile, have been substantial.