Ionising Radiation Exposure of the UK Population
Sources of ionising radiation can be found all around us in the natural environment, in soils, air and water. We are therefore exposed every day through the food we eat, water we drink, and the air we breathe. Additionally, humans have harnessed radiation for use in industry, electricity generation, communications, medicine and even the home. The largest sources of exposure are inhalation of products derived from radon and thoron, intake of other naturally occurring radionuclides via food, cosmic radiation, terrestrial gamma radiation and diagnostic medical exposures. Minor sources are occupational exposure, discharges into the environment, historical nuclear weapons testing fallout and consumer products containing radioactivity.
The UK Health Security Agency( UKHSA) and its predecessor organisations have calculated the exposure of the UK population from naturally occurring and artificial sources of ionising radiation periodically since 1974. These reviews make estimates of total exposure of the UK population, giving a collective dose, measured in man Sv, from each source of radiation. The total collective dose to the population is the sum of these doses. Once the total collective dose has been estimated, the average( sometimes called“ per caput”) dose to an individual, in mSv, is estimated by dividing the total collective dose by the UK population size.
UKHSA ' s last review, published in 2016, provided data from 2010. This is now a bit old but is the best complete set of data currently available. The chart shows how the total collective dose( and hence the per caput dose) is distributed between the main sources of radiation exposure. The vast majority of exposure comes from natural radiation, which contributed 84 % of the average dose in 2010. Almost all of the remaining 16 % came from diagnostic medical exposures, with just 0.23 % arising from nuclear weapons fallout, occupational exposures( other than to radon or cosmic radiation) and discharges into the environment.
Breakdown of the per caput dose to the UK population in 2010 by source of exposure
The next review is expected from UKHSA later this year, but updated data for the inhalation of radon / thoron and diagnostic medical exposures, which are the largest contributors, are not going to be available on this timescale. The 2025 updated figures will therefore be very similar to those published in 2016, as the natural sources of radiation will not have changed significantly over time, although exposure scenarios such as the number of people travelling at altitude, or the level of occupational exposures, will be a little different. The format in which the data is presented is changing, however. Rather than a printed report, where individual parts cannot be updated without reprinting the entire document, UKHSA is moving to a webbased format. This will allow future updates to be made more easily as and when data become available for a given section. This should help keep the chart more up to date in the future.
Can we predict what the 2025 chart would look like, if updated data for diagnostic medical exposures and inhalation of
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