UNSCEAR 2008 Report, Volume I Published
The United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) has published Volume I of their 2008 report on the Sources and Effects of Ionizing Radiation. Volume I addresses the Sources of ionizing radiation, and includes two scientific Annexes:
Annex A: Medical radiation exposures (202 pages)
Annex B: Exposures of the public and workers from various sources of radiation (245 pages)
The report points to the use of radiation in medicine as the major source of human exposure to ionizing radiation other than from nature. A summary of the report to the UN General Assembly says that "Medical exposures account for 98 per cent of the contribution from all artificial sources and are now the second largest contributor to the population dose worldwide, representing approximately 20 per cent of the total.".
The findings from 1997 - 2007, reported that about 3.6 billion x-ray examinations were performed each year, an increase of more than 40 per cent, or 1.1 billion, from the previous decade. Most of the population dose from the procedures occurred in countries with high levels of health care where average exposure from medical uses is now equal to about 80 per cent of that from natural sources. In the United States medical exposure, from 1980 - 2006, grew to be comparable with natural background exposure, the report says.
Computed tomography (CT) scans were the major contributor, with other contributions from diagnostic X-rays, interventional procedures, nuclear medicine and others, the report said. One of the most striking changes over the past decade or so has been the sharp increase in medical exposures owing, for example, to the rapid expansion in the use of CT scanning, the report said. "In several countries this has meant that medical exposure has displaced exposure due to natural sources of radiation as the largest overall component," it said.
The report defines four levels of health care. In the highest, level one, based on the number of physicians per capita in the population, medical X-ray examinations are 65 times more frequent than in level three and four countries with the lowest ratio of physicians per capita. Nevertheless, as techniques develop and their use widens, said the report, medical uses of radiation continue to increase irrespective of the level of health care being delivered.
The findings are contained in the first of the two volumes of supporting evidence underpinning the UNSCEAR report for 2008 covering medical radiation exposures; the second covers exposures of the public and workers from various sources of radiation. A second volume with three more annexes to the 2008 report is scheduled to be published before the end of 2010. In total the five annexes to the report amount to more than one thousand pages.
In future the UN secretariat envisages publishing the detailed supporting evidence for the Committee's findings in electronic format, and on a more frequent basis. Data collection is expected to draw on national reporting by UN Member States, and conducted in coordination with other organizations such as the World Health Organization (WHO) and the International Atomic Energy Agency (IAEA).
For more information on the 2008 Report, go to the UNSCEAR web site: http://www.unscear.org/unscear/en/media.html