Chemistry question

Question

Which of the following is likely NOT a source of exposure to radiation?

1. medical sources
2. one's own body
3. consumer products
4. radon gas
5. the water we drink

Answer 1

All of these are potential sources of exposure to radiation, but at different degrees.

Radon gas by definition is a radioactive element, and it would be of a high concern.

Certain medical products use radioactive elements as the basis of how they work. Some examples are radioactively tagged drugs for treating cancer, and technicium-99 used for imaging.

There are also many consumer products that have used radioactive materials. The old mantles for Coleman gas lanterns used thorium because when when its electrons are excited they give off a very bright white light. Fiestware was a brand of plates and bowls that used uranium in the glaze. And smoke detectors use americium to detect particles in the air, but as long as the smoke detector is undamaged it presents no risk of exposure.

All plants and animals contain radioactive elements, such as carbon-14 and potassium-40. We all have approximately the same level of carbon-14 that is found throughout the biosphere because we continuously ingest it in the food we eat. Measuring how much remains and determining how much decayed is the basis of carbon-14 dating.

If by water, we think of pure water, then this would be the least likely source of exposure. Although tritium (hydrogen-3) is radioactive, it is also very rare in nature. However, the source of the water must also be considered because there can be radioactive elements dissolved in the water. Many gases dissolve in water, so there would be a certain amount of radioactive carbon, oxygen and nitrogen present from dissolved atmospheric gases, although the resulting radioactivity would be very low. However, as radon is also soluble in water, so in areas with high levels of radon in the soil this can be a considerable contributor to radioactivity in drinking water.

So there is a certain level of exposure to radioactivity from just about everything we come into contact with, but of the items listed, drinking water would present the lowest exposure for most people.