Assessment of Heavy Metals Accumulated in Wastewater Irrigated Soils and Lettuce ( Lactuca sativa ) in Kwadon, Gombe State Nigeria

摘要

Vegetables provide the human body with the essential bioavailable trace elements and a constant supply of these various elements is necessary for healthy daily life. However, high levels of these elements in soil and crop can have detrimental effects on soil fertility as well as crop yield and its consumers. Therefore, levels of some heavy metals (Fe, Zn, Cd, Cu, Pb and Cr) in soil and Lettuce were analyzed using atomic absorption spectrophotometer. The results showed that the levels of the heavy metals in the soil and Lettuce were below the threshold levels, but the concentrations were higher in the soil than in the vegetable. The results also revealed the trend in soil metals concentration as Fe > Zn > Cd > Pb > Cu > Cr and for the plant as Fe > Zn > Cd > Cu > Pb > Cr. Transfer factors (TF) decreased in the following order: Fe > Zn > Cu > Cd > Cr > Pb. Therefore the soil was healthy and the vegetable was safe for human consumption.