The average American now receives more than five times as much radiation from medical procedures as in the early 1980s. The medical sector now accounts for almost half of an average person's dose.
The effective radiation dose for an average US citizen was 6.2 mSv during 2006, the National Council for Radiation Protection reported, up from 3.6 mSv in the early 1980s. The figures were released last week during the NCRP's annual conference.
The main sources of radiation to an individual can be grouped as coming from background and medical procedures (green and blue respectively). In the USA each now accounts for around half of effective individual exposure.
The impact of nuclear power on the effective dose per individual (in the darkest Industrial and Occupational sector) is almost invisible at less than 0.1%.
Background radiation from the ground, outer space and people's own bodies remained steady at 3.11 mSv. Meanwhile, the rise of nuclear medicine imaging techniques - especially computed X-ray tomography (CT) scans - meant that doses from medicine went from 0.53 mSv to 3.00 mSv.
Radiation emissions from nuclear power, nuclear research and uranium activities were included in an industrial category which accounted for 0.003 mSv per year - less than 0.1% of overall exposure.
Some 67 million CT scans were carried out in the USA during 2006, as well as 18 million other nuclear medicine procedures, according to an NCRP estimate.
In response to the rise of medical exposure to account for 48% of effective dose, the NCRP said it was working with other organizations to ensure that referrals for CT scans are based on "objective, medically relevant criteria.