So why is arsenic in rice?
The plant apparently has an affinity for arsenic, a toxic element that occurs naturally in soil and groundwater. "It turns out that rice needs to take up silica," Jackson explained, "and in paddy conditions, arsenic is chemically very similar to silica."
Arsenic in drinking water has been studied for a long time; it's a big problem in Bangladesh, and also can be an issue in the United States. Exposure can cause thickening and discoloration of the skin, stomach pain, numbness in hands and feet, partial paralysis and blindness, according to the Environmental Protection Agency. Arsenic also increases the risk of bladder cancer and other cancers.