The route of transfer to the human population of lead from contaminated soil close to a smelter in Bulgaria

Past emissions from a non-ferrous smelter at Kuklen, near Plovdiv, in Bulgaria have resulted in very high concentrations of heavy metals, in particular Cd and Pb, in agricultural soils close to the plant. An interdisciplinary research project, initiated under the auspices of the EU INCO-Copernicus programme, has included investigation of the principal processes by which the heavy metals are being transferred from the contaminated soils to the children of the village who have abnormally high Cd and Pb blood concentrations. The primary source of Pb in blood is the land close to the smelter which has elevated concentrations of Pb and which is used to grow food and fodder for livestock. Fodder with Pb concentrations as high as 48 mg/kg is consumed directly by the animals resulting in high Ph concentrations in livers and kidneys. These are then consumed by the human population. The evidence clearly indicates this to be one route of transfer through the food chain. Other, more direct, routes, e.g the use of flour prepared from locally produced grain or the direct ingestion of dust from school playgrounds, the street and homes, may also play an important role.