Total arsenic, lead, cadmium, copper, and zinc in some salt rivers in the northern Andes of Antofagasta, Chile

The pre-Andes water in the region of Antofagasta is the main drinking and irrigation water source for approximately 3000 Atacame˜na indigenous. people. The concentration for soluble elements filtration in field through a 0.45-mm filter. was: Cd-0.1 ngrml; Pb-0.5 ngrml; and Zn and Cu between 1 and 10 ngrml. In particulate material the concentrations were: for Cd-0.1 ngrml; for Pb-0.3 ngrml; and for Zn and Cu less than 1 ngrml. The total content of these elements is far below the international recommendations WHO. and the national standards N. Ch. 1333 mod. 1987 and 409-1 of 1984.. On the other hand, in some rivers a very high arsenic concentration was found up to 3000 ngrml. which exceed more than 50 times the national standard. In order to verify the analytical results, inter-laboratory and comparison with different determination methods have been done.