Bioaccumulation of Pb, Cd and As by Euphorbia prostrata growing in sites having different contamination levels

Abstract

ABSTRACT Many rural people in developing countries rely on herbal remedies, but these derive from plants which may be subject to heavy metal pollutants. Lead, cadmium and arsenic are confirmed carcinogens and may produce toxic effects if present above the recommended levels in medicinal herbs. The study assessed the uptake and associated health risk of Pb, Cd and As by Euphorbia prostrata exposed to different contaminating sources. The levels of Pb were within safe limits of the World Health Organization both in soil (200 mg/kg) and plant (10 mg/kg). Cadmium concentration in soil from all sites exceeded the allowable range (0.6 mg/kg), exceeding the safe permissible limit of 0.3 mg/kg in plants growing in contaminated sites. E. prostrata and other medicinal herbs growing in polluted sites should not be used therapeutically.