Arsenic used to be added to chicken feed, to change the color of the meat. The chickens’ arsenic droppings were used to fertilize rice fields. Rice concentrates arsenic out of the soil. I think the rice from Arkansas and other southern states are the most contaminated with arsenic. Whoops.
There are cooking methods to remove arsenic from rice. Simplest method is to use a coffee percolator to run fresh hot water through the rice. The other way is to boil the rice in lots of water for five minutes, discard the water, then add fresh water and cook until completed.