Accumulation of lead and arsenic in Malabar spinach (Basella alba L.) and sweet potato (Ipomoea batatas L.) leaves grown on urban and orchard soils

ABSTRACT

Ethnic vegetable crops are increasingly being grown in the United States and may accumulate heavy metals when grown on urban soils. This study evaluated accumulation of lead (Pb) and arsenic (As) in tissues of Malabar spinach (Basella alba L.) and sweet potato (Ipomoea batatas L.) grown on an urban and an orchard soil with Pb concentrations of 1,120 and 272 mg kg⁻¹, respectively, and As concentrations of 6.92 and 90 mg kg⁻¹, respectively. Tissue Pb was higher in both crops grown on both contaminated soils compared with an uncontaminated soil, while tissue As was higher on the orchard soil only. Malabar spinach did not accumulate Pb or As in its shoot, but concentrations of both metals were higher in sweet potato stems compared to leaves or tubers. Consumption of sweet potato stems should be avoided when sweet potato leaves are grown as a vegetable on soils with elevated levels of Pb and As.

KEYWORDS:

• heavy metals
• leafy vegetables
• tropical crops
• urban
• vegetable crops

Abbreviations

As	=	arsenic
BLA	=	broiler litter ash
Pb	=	lead
SP	=	super phosphate

Acknowledgments

The authors appreciate the assistance of Ms. Gesese in conducting the experiment.