High risk for neural tube defects; the role of arsenic in drinking water and rice in Asia

Background: Neural tube defects (NTDs) affect > 300,000 children annually worldwide. The incidence of NTDs in Northern India (7.7/1000), is tenfold higher than in the US (0.7/1000). Higher rates were previously reported in Northern China. The causes of these trends have not been elucidated. Arsenic is a teratogen shown in animals to induce NTDs. The main potential sources for environmental arsenic exposure, groundwater and rice as a staple food, are high in India and China. Objectives: To discuss the possible association between high environmental arsenic exposure through drinking water and rice with the high NTDs rates in these regions. Discussion: Arsenic contamination of groundwater is the main source of environmental arsenic exposure. The locations of toxic arsenic regions in China and India correspond in most cases to the northern regions where the NTDs rates were high. Rice, the staple food in India and China, can absorb up to 10 times more arsenic than other crops, such as wheat and might further increase arsenic exposure. Conclusions: We hypothesize that this NTD-arsenic in drinking water and rice association may explain why these areas in the northern regions of both countries have the highest incidence of NTDs. If proven true, this has major public health implications.