Greater use of X-rays over the last 10 years, including a 140% increase in CT examinations, has raised the annual radiation dose that the UK public receives, health watchdog the Health Protection Agency has concluded.
Radiation scientists at the agency have estimated that about 46 million medical and dental X-ray examinations were carried out across the UK in 2008, an increase of 10% since 1997.
About two-thirds of the procedures were carried out in NHS hospitals while more than a quarter were performed by dentists.
The average annual radiation dose to each member of the public from all diagnostic X-rays has increased from 0.33 millisieverts (mSv) in 1997, the last time a detailed frequency survey was completed, to 0.4mSv, it added.
Most of this increase is because of the growth in the number of higher-dose CT examinations, warned the agency.
The NHS Breast Screening Programme accounted for 2.03 million X-ray examinations in 2008, an increase of 45% since 1997 when 1.4 million examinations were carried out, it added.
This increase was down to widening the age range for screening to cover women aged between 50 and 70, instead of those aged between 50 and 64.