University of Delaware (UD) researchers have discovered a soil microbe that mobilizes an “iron shield” to block the uptake of toxic arsenic in rice. Arsenic occurs naturally in rocks and soils, air and water, plants and animals. It’s used in a variety of industrial products and practices, from wood preservatives, pesticides and fertilizers, to copper smelting. Chronic exposure to arsenic has been linked to cancer, heart disease and diabetes. The UD finding gives hope that a natural, low-cost solution–a probiotic for rice plants–may be in sight to protect this global food source from accumulating harmful levels of one of the deadliest poisons on the planet. Rice currently is a staple in the diet of more than half the world’s population.