Lead and Cadmium Accumulation in African Spinach (Amaranthus cruentus L.) Grown on Soil from a Dumpsite

Abstract

In this study, a nursery experiment was set up to assess the Lead (Pb) and Cadmium (Cd) accumulation in Amaranthus cruentus seedlings grown on contaminated soil. Amaranthus seeds were broadcast on the nursery bed and allowed to germinate for one week before sprouted seedlings were pricked and transplanted into polypots containing soil from a dumpsite, topsoil and sandy soil (5 kg each). The seedlings were arranged in a completely randomize design with 5 replicates per treatment. The physico-chemical properties, Lead and Cadmium concentrations in all soil types were determined before planting, while data were collected for eight weeks after planting. Weekly measurements of plant height, collar diameter, and number of leaves were done, while Lead and Cadmium concentrations in the plants were determined after harvest. Lead and Cadmium were detected in the dumpsite soil and Amaranthus cruentus grown on the dumpsite soil. Highest height, collar diameter and number of leaves occurred in the contaminated seedlings. Amaranthus cruentus absorbed Lead (7.66 mg/kg) and Cadmium (0.54 mg/kg), which were higher than the recommended safe limits for vegetables (0.3 mg/kg and 0.2 mg/kg, respectively). In addition, transfer factors for Lead (0.53 mg/kg) and Cadmium (0.51 mg/kg) indicated high bio-accumulation of the metals by the vegetables. Hence, vegetables produced from dumpsite soil may not be safe for consumption.