[Levels of lead, cadmium, zinc and arsenic in the water in the province of Salamanca. Multidepartmental coordinated project of investigation supported by the Junta of Castilla Leon in 1884]. / Estudio de los niveles de plomo, cadmio, zinc y arsénico, en aguas de la provincia de Salamanca. Proyecto de Investigación Coordinado Multidepartamental subvencionado por la Junta de Castilla León n.o 1884.

BACKGROUND: To establish the degree of contamination by lead, cadmium, zinc and arsenic in the water in Salamanca province and its relationship with the provenance of the samples and their collection point. METHODS: Transverse, observational, descriptive epidemiological study. Province of Salamanca. RESULTS: Water from water pipes, fountains, springs, wells, rivers, streams and lakes in the province of Salamanca were studied, analyzing the lead, cadmium, zinc and arsenic contents of 180 samples using Atomic Absorption Spectroscopy. Results indicated that 56% of samples analyzed showed toxic levels of cadmium, and 28% of samples gave toxic levels of lead, but showed tolerable levels of zinc and arsenic. No major differences were observed in the degree of contamination by the four elements between the four provincial district areas. Levels of contamination by the four elements were compared for water from the water supply, and samples from wells, fountains, springs and surface water, showing similar contents of the elements studied. CONCLUSIONS: Findings suggest that the water in the province of Salamanca shows "naturally" high cadmium and lead content, probably due to the geological characteristics of the terrain.