Heavy metal(loid)s contamination assessment in jhum soil-rice system, Arunachal Pradesh, Northeast India

Abstract

The metal(loid)s accumulation in rice grain poses a significant global concern, particularly because rice is widely consumed food in the world. In this study, concentration of lead (Pb), cadmium (Cd), iron (Fe), nickel (Ni), and arsenic (As) was assessed in paddy soil and four different local rice varieties under Jhum Farming (JF) system in the then Lower Subansiri (now Keyi Panyor) district of Arunachal Pradesh, northeast India. Nemerow’s Pollution Index (PI_N) in Jhum farming (JF) soils ranges from 0.9 to 1.9, with an average of 1.4, indicating 'clean' to 'slight' pollution. Except for two sites, others were classified as pollution-free based on PLI (Pollution Load index). The mean hazard quotient (HQ) for non-carcinogenic risks from heavy metals through rice intake was within safe limit (HQ<1) for all local rice varieties (Amo, Baede, Lemeh and Riyu). Overall, no significant non-carcinogenic health risks due to studied metals including arsenic under traditional Jhum Farming (JF) system. Regular monitoring of heavy metal(loid)s in soil-rice system is important to ensure the safety of rice production and take suitable management options.