Extensive lead exposure in children living in an area with production of lead-glazed tiles in the Ecuadorian Andes

We have determined the concentrations of lead (Pb), cadmium (Cd), and mercury (Hg) in the blood of children living in two Andean villages in Ecuador with many family-owned cottage-type industries using Pb from discarded car batteries and occasionally, utility batteries containing Cd and Hg for the production of glazed tiles. The battery metals are ground together with water to a suspension, which is applied manually onto the tiles and then fused at about 1200°C in sawdust-fired kilns. Children aged 4-15 years were recruited from the schools with the assistance of the school-teachers. Children from homes with and without tile-glazing activities were to be included. Blood metal concentrations were determined by inductively coupled plasma mass spectrometry (ICP-MS). The children had extremely high blood lead concentrations (B-Pb), which ranged between 100 and 1100 μg/l (median 510 μg/l, n = 82). Children from families engaged in tile-glazing production had significantly higher B-Pb (median 600 μg/l) than those living in homes with no such activity (median 210 μg/l), although the B-Pb of the latter were nonetheless clearly elevated. B-Cd and B-Hg were low (medians 0.25 μg Cd/l and 1.6 μg Hg/l, respectively), indicating that the exposure from utility batteries containing Cd and Hg was low. The blood hemoglobin concentrations decreased significantly with rising B-Pb, indicating an effect on the heme synthesis. This was supported by a marked increase in the blood concentration of protoporphyrins with increasing B-Pb. It can be concluded that children from families with cottage industries producing glazed tiles are at risk for severe health effects due to high lead exposure.