Answer to Question #1713 Submitted to "Ask the Experts"
The following question was answered by an expert in the appropriate field:
Information comparing doses received from various sources of ionizing radiation can be found in many publications. A common reference is the Health Effects of Exposure to Low Levels of Ionizing Radiation: BEIR V (1990). The pie chart on page 16 is frequently used to demonstrate the percentage effective dose equivalent (EDE) from various sources. The average EDE from medical sources is 0.39 mSv, or 11 percent of the average EDE of 3.60 mSv in the United States.
Probably the most accessible, extensive report on radiation exposures can be found in the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) 2000 Report. In Volume I, Sources, Annex D provides expansive tables on the uses and exposures received from the various sources of ionizing radiation in medicine. From Table 36, a comparison can be found of estimated doses from medical and dental x-ray examinations. For populations that have a high level of medical care, like the United States, the annual per caput effective dose is 1.2 mSv from diagnostic medical sources, compared with 0.01 mSv from dental sources. The annual caput effective dose is given as 2.8 mSv in the first section, Report to the General Assembly, of Volume I. The obvious differences in average annual and medical doses is due to more recent studies, more data, and data from different sources. However, I would consider it reasonable to conclude that 10 percent of medical exposures are from dental procedures.
John Jacobus, MS
Certified Health Physicist