Answer to Question #484 Submitted to "Ask the Experts"

Q

Please let me know if high levels of radium in drinking water can harm an unborn fetus and/or nursing a newborn baby. I live in Plainfield, Illinois, where the levels are too high to be safe to drink . . . so says the back of our water bill each month! Please advise.

A

Thank you for providing additional information pertaining to the concentration of radium in your drinking water. The reported concentration of 6.4 picocuries per liter is most likely for the radionuclide radium-226 (²²⁶Ra). This is a naturally occurring radioactive material with a very long half-life (1,600 years) that is produced as natural uranium decays in soil and rock. Rock and soil in some locations have greater amounts of uranium (and therefore ²²⁶Ra) than rock and soil in other locations. Drinking water supplies from rock formations with higher amounts of radium will most likely have higher concentrations of ²²⁶Ra than other water sources. The reported concentration of 6.4 picocuries per liter for ²²⁶Ra in your water is less than the concentrations found in many other drinking water supplies in the United States. For example, there are several drinking water supplies in the Milwaukee, Wisconsin, area (and in other parts of the United States) that have ²²⁶Ra concentrations much higher than 6.4 picocuries per liter. Of course, the preceding information doesn't answer your question about potential health effects from the reported radium concentration in your water. Please let me continue with my answer. There is ²²⁶Ra in almost everything we eat or drink. The amounts vary from place to place and for different items that we eat and for the air that we breathe. Furthermore, ²²⁶Ra is only one source of the natural background radiation dose we receive each day. The radiation dose that the average U.S. resident receives each day from all background radiation sources combined has been determined by reputable organizations of scientists to be approximately 1 millirem. (The millirem is a unit of radiation dose just as the inch is a unit of length and a fluid ounce is a unit of volume.) A person living in Denver, Colorado, receives up to twice this average dose and a resident of the Gulf Coast region receives almost half of this average dose. These natural background doses are safe doses that have never been shown to produce any adverse health effects. In fact, radiation doses much higher than the average natural background radiation doses are also safe (that is, no adverse health effects have ever been shown to be produced by those doses). It is only those radiation doses that are many times the average natural background doses that may produce adverse health effects. I have calculated the radiation dose that you or your children could receive from drinking 64 fluid ounces (1.89 liters) of water each day having 6.4 picocuries of ²²⁶Ra per liter of water. (The calculation method I used is called "internal dosimetry" and is accepted in the United States and around the world as the correct way to perform such dose calculations.) The calculated daily radiation dose that you or your children would receive from drinking this water is a small fraction (a few percent or less) of the average daily natural background dose that you already receive. These doses are safe doses that will not produce any adverse health effects. Please be assured that I would not be concerned about drinking water containing ²²⁶Ra at 6.4 picocuries per liter nor would I have any concern for my family to drink such water. I hope that this information is useful. Genevieve S. Roessler, Ph.D.