Answer to Question #417 Submitted to "Ask the Experts"

Q

What are the specific results of a pregnant woman drinking well water contaminated with high levels of naturally occuring uranium and ²²⁸Ra? How would the fetus be affected?

A

I would like to start with a few general comments that may temper my response and place it in proper context. This is an important question and I am aware that potential exposures of pregnant women to unfamiliar materials are apt to raise concern. Most authorities note that roughly one in 20 children are born with an abnormality that can be detected on medical examination although most of these are minor and do not have a meaningful or persistent effect. There is usually not a detectable cause for these effects even though we can identify inheritance or other possible factors in a fraction of cases. I must be somewhat general in my answer because "high levels" can be defined in several different ways. However, there are few studies of human populations and these have not detected significant developmental effects, even with concentrations of uranium or radium much greater than those that are commonly associated with natural sources of drinking water, or even with sources that have been contaminated. Statistical studies that evaluated the outcome of later pregnancies in women who worked as "radium dial painters" and consumed large quantities of radium or related elements detected only a possibility of minimal effects. Likewise, studies of populations living near "uranium mill tailings" have not detected an increased incidence of developmental effects. Therefore, most of our information about developmental effects from these elements comes from experiments with laboratory animals that were injected with very large amounts. These types of experiments usually involve increasing the amounts until effects are obtained so that the scientist can relate the amount and the effect. The amounts required to produce observable effects have been thousands of times greater than those allowed in public drinking water, or in any source of well water that I have read about. My direct response to your questions, as stated, is that I would expect NO specific results of a woman drinking contaminated well water and that there should be no effects on the fetus. I hope that this provides an adequate response to your question. Please feel free to contact our website editors if there is any further detail that you wish to ask about. Melvin R. Sikov, Ph.D.