Assessment of Heavy Metal Contamination Risk in Rice Field and Rice Plant in Brantas Watershed, Jombang Regency

Abstract

Risk assessment of heavy metal contamination of Pb, Cd, Fe, Cr, Cu, Co, Mn, and Zn was carried out on in four wetland areas in Jombang Regency. The study also aimed at determining potential non-carcinogenic and carcinogenic risks to the community. The soil and rice samples from the four rice field zones were destructed by wet ashing method and measured by AAS. The concentration of heavy metals in the soil was in the order of Fe> Mn> Zn> Cu> Pb> Co> Cr> Cd. The concentration of heavy metals in the rice was in the order of Fe> Mn> Zn> Cu> Cr> Co> Pb> Cd. The ability of rice plant to transfer heavy metals from soil was in the order of Zn> Mn> Cr> Co> Pb> Fe> Cu> Cd, respectively. The daily intakes of heavy metals through rice consumption were Pb (0.003), Cd (0), Fe (0,165), Cr (0.011), Cu (0.013), Co (0.008), Mn (0.072), and Zn (0.074) in mg kg-1day -1. Hazard Quotient of Pb value was greater than 1, while CR (Cancer Risk) for Cr was greater than 10-4. The potential for total non-carcinogenic risk ranged from 1.82 to 3.79, while the potential carcinogenic risk ranged from 4,5.10-3 to 6,4.10-3. Long term exposure to heavy metals through rice consumption may pose a potential carcinogenic and carcinogenic health risk to local people.