Exposure to radiation in the U.S. on the rise

For the average person in the U.S., exposure to radiation from medical devices has gone up by six times compared to levels detected during the 1980’s, according to data supplied by the National Council on Radiation Protection & Measurements (NCRP).

A recent large-scale study found that radiation exposure since 1989 indicates the annual per capita radiation dose increased 5.9 times, from 0.54 millisieverts in 1980 to 3.2 millisieverts in 2006. For the entire population, the collective medical radiation dose rose by 7.5 times during the same period, growing from a total of 124,000 sieverts to 930,000 sieverts.

The preliminary findings of the study were presented at the NCRP’s annual meeting in Arlington, Va. by Dr. Fred A. Mettler, Jr., a member of the NCRP subgroup responsible for the study, and Professor Emeritus in the Department of Radiology at the University of New Mexico School of Medicine. Mettler focused only on levels of ionizing radiation exposure. The findings did not include recommendations or risks versus benefits assessments of medical radiation. However, the study may include recommendations and risk assessments when it is completed in 2008.

The researchers believe that the rise in exposure can be attributed to the proliferation of CT scans and nuclear medicine procedures. The data Mettler presented show the number of CT scans done in this country has grown each of the past 14 years, from 18.3 million scans in 1993 to 62 million scans in 2006.

In 2006, CT scans made up 12 percent of all medical radiation procedures done in the U.S. but accounted for 45 percent of the population’s collective medical radiation dose, NCRP said.

Mettler said the doses of radiation from these tests can be significantly reduced without reducing diagnostic accuracy. He also said that many are not educated enough on the magnitude of risk associated with increased medical radiation.