Arsenic contamination in rice and drinking water: An insight on human cognitive function
Noraini Abu Bakar, Wan Norhamidah Wan Ibrahim, Siti Munirah Mohd Faudzi
Abstract
• Highly risk area: Bangladesh, India and Indonesia (As >0.2 mg/kg in rice). • Similar risk: Arsenic in rice from Vietnam, Malaysia, Myanmar, and Thailand. • Groundwater arsenic (>10 μg/L) linked to cognitive decline. • Long term of arsenic impacts on cognition are underexplored in Southeast Asia. Arsenic, a prevalent environmental contaminant in drinking water and rice, poses significant health risks, especially in Southeast Asia. Emerging evidence suggests that even low-level arsenic exposure may contribute to neurodevelopmental disorders such as autism spectrum disorder (ASD). However, evidence linking low-level arsenic exposure in water and rice to neurobehavioral dysfunctions are often underestimated, neglecting the risks to children. This review aims to explores arsenic contamination in rice and drinking water across Southeast Asia, comparing it with Bangladesh, India, and China—three of the world's largest rice producers and consumers. It focuses on prenatal and postnatal exposure, exploring potential impacts on cognitive function related to ASD traits. Bangladesh, India, and Indonesia consistently report arsenic levels in rice above the 0.2 mg/kg safety threshold, while Malaysia, Vietnam, Myanmar, and Thailand generally remain below this limit. Seven studies reported noncarcinogenic risks (HQ > 1), while nine studies found carcinogenic risks (CR > 1 × 10 −4 ) associated with rice consumption, highlighting potential health concerns in the Southeast Asian region. Additionally, six studies with unspecified risks. In Vietnam, Bangladesh, India, and Cambodia, arsenic contamination in groundwater has been associated with arsenicosis and elevated cancer risks. Although a positive correlation between low-level arsenic exposure (below 50 µg/L) and cognitive decline has been observed in the Asian countries, this link remains underexplored in Southeast Asia. Further research is needed to investigate arsenic exposure during critical developmental periods and its impact on neurobehavioral outcomes in vulnerable populations.