The dietary intake of mercury from rice and human health risk in artisanal small-scale gold mining area, Indonesia

Artisanal and Small Scale Gold Mining (ASGM) contributes as the biggest source of mercury (Hg) emission in Southeast Asian countries including Indonesia. Rice paddies are the most impacted agriculture area caused by Hg emission from ASGM sewage water. It may pose to health risk effect to humans due to the consumption of the rice as the staple food. This study was aimed to evaluate the Hg accumulation in rice and health effect to residents in Lebaksitu ASGM area by analysis of total mercury (THg) and methylmercury (MeHg) in hair. Two villages were selected in this study, Hg hotspot village (Lebak-1) and low Hg exposure village (Lebak-2). The THg concentration in rice ranged from 9.1-115 µg/kg with an average of 32.2 µg/kg. MeHg concentration in rice constituted 14.7-81.8% of the THg. Rice in Lebak-1 had higher THg and MeHg concentrations than those in Lebak-2. The mean THg and MeHg concentration in hair were 3.2 mg/kg and 1.78 mg/kg, respectively. Residents in Lebak-1 had significantly higher THg and MeHg in hair than those collected from Lebak-2. The MeHg ratio to THg in hair varied widely ranged from 15.68-92.43%. There was a significant correlation between high intake of MeHg from rice and the accumulation of MeHg in the hair. It was concluded that rice is the potential source of MeHg exposure to humans through daily consumption in rice consumer countries.