Methylmercury Bioaccumulation In Rice And Health Effects: A Systematic Review

Methylmercury (MeHg) is highly toxic. Rice can accumulate high levels of MeHg. Rice is the staple food of more than half of the world's population; therefore, MeHg exposure via rice consumption has become a global emerging issue. This article reviews the rice Hg concentration in the world, the bioaccumulation mechanism of MeHg in rice, the human Hg exposure from rice consumption, and health effects. It is found that rice Hg concentrations from non-contaminated areas around the world are generally within the safe intake range. Most MeHg in rice is found in edible white rice since MeHg in rice plants can form the MeHg-Cys complex (MeHg-cysteine), which can be transferred into rice grain during maturation of rice. Exposure to MeHg through rice consumption can reduce antioxidant activity and damage the nervous system in rats and may cause children's intelligence decline.