Evaluation of Some Trace Metals from the Leaves of Some Economic Trees Grown in Kudenda Industrial Area of Kaduna State-Nigeria

Chromium, zinc and cadmium were quantitatively estimated from the leaves of mango, guava and cashew trees cultivated in Kudenda Industrial Area of Kaduna using Atomic Absorption Spectrometry. The results of the analysis indicated higher concentration of chromium in guava and mango leaves (0.087 and 0.083 mg/kg) respectively, with lower level in that of cashew (0.033 mg/kg). Zinc was found to be low at 0.54 and cadmium just at the maximum permissible mark of 0.05 mg/kg in cashew leaves and very low values of 0.024 and 0.003mg/kg, respectively in mango and guava. The chromium levels in guava, cashew and mango leaves were above the allowable limits in the range of 0.05-0.18 mg/kg whereas zinc concentration in the cashew leaves was also below the Food and Agriculture Organization/ World Health Organization ( FAO/WHO) set limits of 0.05 mg/kg and 60 mg/kg, respectively. The results revealed that, with continuous industrial activities, pollution due to the studied heavy metals is likely accumulate to dangerous levels if appropriate measures are not taken.