Heavy Metals Contamination of Rice and Soil Samples in Nnatu St Azuuiyi Udene, Abakiliki, Ebonyi State, Nigeria

Abstract

Aim: Assess  the levels of heavy metals: arsenic (As), cadmium (Cd), copper (Cu), lead (Pb), and zinc (Zn) in three different sites of the major rice growing soils and determine  its accumulation in the rice grown on the same site in Nnatu St Azuuiyi Udene, Abakiliki, Ebonyi State. Study Design: Soil and rice samples were collected from three different farm locations into properly labeled plastic bags respectively using a 9mm soil Augerin Nnatu St AzuuiyiUdene, Abakiliki, Ebonyi State. Methodology: The collected samples were air-dried, ground, sieved and acid digested. The heavy metals in the samples were measured by atomic absorption spectrophotometer PG instrument AA500 FPC model. Results: The Mean ± SD (mg/kg) of heavy metals in rice were; As: 0.0013, Cd: 0.001, Pb: 0.002, Zn: 0.3620. Cu: 0.001 in site 1 whereas in Site 2; As: 0.0013, Cd:0.001, Pb:0.002, Zn:0.5040, Cu:0. 001. In site 3, the metals in rice were; As: 0.0013, Cd: 0.001, Pb: 0.002, Zn: 0.1950, and Cu: 0.040 respectively. The levels in the soil samples in site 1 were; As: 0.0013, Cd: 0.001, Pb: 0.002, Zn: 1.932. Cu: 0. 0267. In site 2, As: 0.0013, Cd: 0.001, Pb: 0.002, Zn: 1.597, Cu: 0.1550 and in site 3. As: 0.0013, Cd: 0.001, Pb: 0.002, Zn: 3.383, Cu: 0.0730 respectively. The mean values for arsenic, cadmium and lead in the soil and rice samples, respectively, were not significantly different (P > 0.05) in the three different sites whereas, for copper and zinc, the mean values were significantly different (P < 0.05) from each other at the different spots with an elevated concentration of copper and zinc in the soil samples than in the rice samples. However, these values were far lower than the values indicated by the World Health Organization as hazardous. Conclusion: The rice samples grown in Nnatu St AzuuiyiUdene, Abakiliki is safe for consumption.