Heavy Metals Contents in the Edible Parts of Some Vegetables Grown in Candi Kuning, Bali and Their Predicted Pollution in the Cultivated Soil

Abstract

Vegetables are important for human diet due to their contents including mineral, vitamin, carbohydrate, protein and fibers, but they often associate with poison such as heavy metals derived from lands where the vegetables are grown. This brings us to investigate the contents of some heavy metals, namely Pb, Cu, Cr, and Zn, in edible parts of 10 species vegetables cultivated in Candi Kuning, Bali and to predict the level of pollution in the cultivated soils. Wet digestion method was involved to prepare the samples before determination of the metals using Atomic Absorption Spectrometer (AAS). The concentrations of heavy metals in the edible parts of the vegetables were found vary depended on the species and types of the edible parts. The heavy metals contained in edible parts of the ten species of vegetables were approximately in the range of 11.11 to 374.55 mg/kg for Pb; 4.34 to 150.15 mg/kg for Cu; ND (not detectable) to152.82 mg/kg for Cr; and 5.12 to 90.69 mg/kg for Zn. Most of those levels are higher than the permissible-maximum limit regulated by FAO/WHO. Therefore, the agricultural soils in Candi Kuning which is one of the vegetable production centers in Bedugul area of Bali for cultivation of the vegetables could be predicted that were generally polluted by the metals. Lead and chromium were the metals that cause high level of pollution, while copper and zinc were less polluted in the soil.

Keywords: heavy metals, vegetables, agricultural soils, pollution