Breast cancer risk from radiation lessened for modern X-ray technicians, study shows
Tuesday, June 18th 2002, 12:00 am
By: News On 6
WASHINGTON (AP) _ Female X-ray technicians today have a smaller risk of breast cancer than those who started work when radiation exposure limits were much higher, a study shows.
Researchers analyzed the health histories of 69,525 women who worked as X-ray technicians during the years 1926 through 1982 and found that breast cancer deaths were more common during the early years.
A report on the study appears Wednesday in the Journal of the National Cancer Institute.
After adjusting for other health factors, such as a family history of breast cancer, the authors found that women who worked as X-ray technicians before 1940 were nearly three times more likely to die of breast cancer than those first employed in 1960 or later.
For those working between 1940 and 1949, the risk of death from breast cancer was 2.5 times greater than those who started work after 1960.
``Our findings _ that breast cancer mortality was highest among technologists who first worked in the earlier calendar periods _ probably reflects changing exposures to radiation over time,'' the authors said.
Before 1934, the recommended exposure limit for medical radiation workers was 70 REMs a year. The recommended exposure limit was steadily reduced over the years and was set in 1958 at five REMs a year. A REM, for roentgen equivalent man, is a measure of absorbed ionizing radiation doses.
``The high risks of breast cancer mortality for women exposed to occupational radiation prior to 1950 and the subsequent decline in risk are consistent with the dramatic reduction in recommended radiation exposure limits over time,'' the authors said.
The study was compiled by 11 researchers representing the National Cancer Institute, the Food and Drug Administration, the University of Minnesota, Vanderbilt University Medical Center and Johns Hopkins Bloomberg School of Public Health.