4.2 a beta-emitting radioactive isotope called iodine-131 is often released into the air during nuclear
accidents. it can settle on skin and clothing and can be inhaled or ingested. iodine is absorbed in
the body by the thyroid gland, where it is used to make molecules that travel throughout the body.
when the thyroid gland has enough iodine, any excess iodine is removed by the body. if a nuclear
accident occurs at a power plant, workers are asked to ingest potassium iodide tablets which
contain a stable isotope of iodine. explain how this minimises the risk of damage to their bodies.