[Release of lead and other metals from piping into drinking water in the Basque Country (Spain)].

OBJECTIVES To evaluate exposure to lead and other metals from drinking water as a result of the materials used for pipes in the supply areas of the Basque Country (Spain). METHOD Random sampling of properties in the supply areas was carried out. A total of 3,295 samples were taken in 154 areas, which together represented 87% of the properties supplied in our region. A method known as random day time sampling was used. Each sample was tested for lead, and samples from larger areas were also tested for nickel, copper and chromium. Testing for iron was optional. RESULTS A total of 1.75% (0.85-2.64) of the properties in the supply areas exceeded the reference value for lead (10 μg/L), 2.21% (0.97-3.46) exceeded that for iron (200 μg/L) and 0.33% (0.11-0.55) exceeded that for nickel (20 μg/L). None of the samples exceeded the reference values for copper and chromium (2 mg/L and 50 μg/L, respectively). CONCLUSIONS The problem of metals release from piping in the properties of the areas studied in the Basque Country is residual. For most of the properties, metal levels in water are below reference values and general measures are not required. Suppliers must identify the presence of lead piping and the risk due to this type of piping as part of the control and management program for each individual supply area and, in particular, in those areas not included or not fully analyzed in this study.