Health Risk Assessment in Calcareous Agricultural Soils Contaminated by Metallic Mining Activity Under Mediterranean Climate

The agricultural lands surrounding the ancient mine site of Jebel Ressas (Tunisia) have been contaminated mainly due to the mining waste dumps left without environment protection measures. The metal contamination of agricultural soils and crops was studied to evaluate the local population health risk. The results show the soil Cd and Pb contamination over an area of 180 ha and up to 5 km distance from the dumps. The toxic metals contents in soil exceeded the maximum allowable Canadian limits for agricultural soils, reaching 231 and 20 100 mg kg(-1) for cadmium (Cd) and lead (Pb), respectively, but decreasing with the distance from the dumps. Although a low solubility and availability of metals could be expected within the calcareous soils of this area, metals appeared to be absorbed by edible plants (fruits and vegetables). High contents in parsley and mallow were recorded, reaching up to four times the allowable limits (EC 1881/2006) for Cd, and 26 times for Pb. Local population exposure to metals by both soil ingestion and consumption of contaminated plants has been estimated and the health risk has been confirmed for farmlands inhabitants, especially for children. The major source of risk for the local population is dietary. Soil dust contribution to health risk is at the most 3.4% for adults and at the most 13.1% for children.