“Oceans are the primary source of naturally occurring iodine. Iodides in the sea accumulate in seafish, shellfish, and seaweed. From the seas, iodine enters the environment in the form of sea spray or gases. Once airborne, iodine can be deposited on land and on nearby agricultural crops. Once in the soil, iodine readily binds with organic material, resulting in a long soil residence time. Iodine also enters the air from burning fossil fuels as a fuel source, but this source contributes far less to the environment than the oceans do. In foods, iodine is present as iodide and non-elemental forms.”