Heavy Metals Accumulation In Cabbage Lettuce And Carrot Irrigated With Wastewater From Nagodi Mining Site In Ghana

Abstract- The heavy metal pollution is a major environmental problem especially in mining areas. The study was carried out to quantify heavy metal levels and compare their accumulation in the stems leaves and roots of Lactuca sativa lettuce Brassica oleracea L. var capitata cabbage and Daucus carrota var sativa carrot irrigated with wastewater from Nagodi mining site. Pot experiment was conducted using surface soil 0-20cm. Differential accumulation and translocation of copper Cu lead Pb iron Fe manganese Mn cadmium Cd and zinc Zn in the root stem and leaf of vegetables were investigated using atomic absorption spectrophotometer. Cd concentration in the various parts of D. carrota was in the range of 0.070 -0.090 mgKg. The highest concentration 17.30 mgKg of Mn was found in the stem of L. sativa. Fe was highly absorbed 139.6 mgKg by B. oleracea roots. The highest concentration 0.221 mgKg of Cu was found in D. carrota roots and the highest concentration 35.35 mgKg of Zn was found in the roots of Brassica. Cd accumulation in L. sativa and B. oleracea was below detection limit 0.002 mgKg. Pb absorbed by the three genotypes was below detection limit 0.005 mgKg. Though heavy metals were absorbed their concentrations were below WHOFAO recommended limits vegetables cultivated with such wastewater may be considered safe for consumption.