Q: How can you protect yourself from radiation poisoning? A: The only way to avoid all harmful effects of radiation is to avoid exposure to radiation. Of course, complete avoidance is impossible. Everything on earth receives continuous exposure to low-level radiation from three sources: cosmic radiation from outer space, radioactive materials around us, and radioactive materials within our bodies. Virtually all of this occurs naturally; it has been with us since the beginning of time. A small portion is man-made. Most of this is medical, from which we derive great benefit. It would not be prudent to refuse a medical x-ray exposure that could be lifesaving on the grounds that there may be a miniscule chance of a harmful effect later.Once we are exposed to radiation there is no treatment available that will prevent its effects. Thus we should take steps to avoid unnecessary exposure from which we receive no benefit. The major example of this is nuclear war.A great deal of attention lately has been devoted to potassium iodide to prevent radiation effects. This refers to the thyroid gland. One of the major products of a nuclear explosion is radioactive iodine. The thyroid gland concentrates iodine and uses it to make thyroid hormone. Accumulation of radioactive iodine in the gland can lead to thyroid cancer. A large dose of non-radioactive iodine if given in time can "load" the thyroid gland to capacity, preventing accumulation of radioactive iodine. It must be emphasized that thyroid cancer is only one of many risks of radiation exposure. Potassium iodide does nothing to protect against any other radiation effect. We must avoid a false sense of security from its use.S. Julian Gibbs, DDS
