Investigation of heavy metals contaminantion level in the locally cultivated rice using Atomic Absorption Spectroscopy (AAS)

Abstract

Rice (Oryza sativa) is a stable food in many countries in the world including Africa. The present of heavy metals in the environment which  are toxics affect the nutritional value of the rice. The accumulation of heavy metals in the body may lead to different health problems  such as cancer, diabetes, liver and kidney failure. The study was conducted to access the presence of some selected heavy metals (Pb, Cu,  Cd, As, Ni, Zn) in rice sample using atomic absorption spectroscopy technique. Five sample of rice (EXCHINA, CP, WHEETER-4,  ROBBER, and YERMALINTA) which were cultivated in Damashewa village of Kirikasamma local government area were collected. Wet  digestion method was used to destroy organic matter in the sample. The result of analysis showed that the concentration of Zinc( Zn) in  all the four sample of rice range from (16.50-36.02mg/kg) and that of Cadmium Cd ( 0.05-0.18mg/kg) and that of copper Cu  (7.02-22.20mg/kg) which is far below the safety limit of 50-100mg/kg for zinc and 0.4mg/kg for cadmium, and copper is 73.3mg/kg set up  by the FAO/WHO (2001), this could lead to anaemia, renal damage, bones disorder and cancer of the lungs. While the concentration of  lead Pb (3.57- 16.24mg/kg), nickel Ni (2.50-11.24mg/kg) and that of Arsenic As (0.98-4.33mg/kg) is also above the set safety limit of  0.3mg/kg for lead. Based on this research all rice sample were highly contaminated with lead, arsenic and nickel as a pollutant. Thus, the need for physical examination of the consumers and inhabitants within the study area.