Concentrations of arsenic, copper, cobalt, lead and zinc in cassava (Manihot esculenta Crantz) growing on uncontaminated and contaminated soils of the Zambian Copperbelt
Abstract
The concentrations of arsenic (As), copper (Cu), cobalt (Co), lead (Pb) and zinc (Zn) in washed leaves andwashed and peeled tubers of cassava (Manihot esculenta Crantz, Euphorbiaceae) growing on uncontaminatedand contaminated soils of the Zambian Copperbelt mining district have been analyzed. Even in strongly contaminated areas, the concentrations of copper in the leaves and tubers of cassavado not exceed the daily maximum tolerance limit of 0.5 mg kg[1]1/human body weight (HBW) established by the Joint FAO/WHO Expert Committee on Food Additives (JECFA).
The highest tolerable weekly ingestionof 0.025 mg kg[1]1/HBW for lead and the highest tolerable weekly ingestion of 0.015 mg kg[1]1/HBW for arsenic are exceeded predominantly in the vicinity of smelters.