June 28, 2005 -- People who work in nuclear power plants may have a slightly higher risk of developing cancer, according to the largest study ever conducted of nuclear industry workers.
The researchers show that people who are consistently exposed to low doses of radiation -- such as those who work in nuclear plants -- have about a 10% higher risk of death due to all cancers except leukemia. The risk of death due to leukemia was found to be 19% higher.
Based on those estimates, researchers say about 1%-2% of all deaths among nuclear industry workers may be attributed to radiation exposure.
However, researchers say many of the more than 400,000 nuclear workers who participated in the study worked in the early days of the nuclear industry and were exposed to much higher doses of radiation than under current standards.
The results appear in today's online edition of the British Medical Journal.
Low-Dose Radiation Linked to Cancer
Researchers say current radiation-protection recommendations call for limiting occupational exposure to low-dose radiation to less than 100 millisieverts over five years and under 1 millisievert per year for the public.
Those recommendations are based largely on information from the survivors of the atomic bomb in Japan. But researchers say extrapolating radiation-related cancer risk estimates for nuclear industry workers and the general public is controversial.
In the study, researchers monitored 407,391 nuclear industry workers from 15 countries, including the U.S., for an average of about 13 years.
All of the workers were exposed to low-dose radiation as part of their work in the production of nuclear power, manufacture of nuclear weapons, processing of nuclear fuel, or nuclear reactor or weapons research.
Researchers say the radiation-related cancer risk estimates are two to three times higher than those based on Japanese atomic bomb survivors.
But they say their cancer risk estimates are consistent with current radiation-protection standards.
In addition, researchers say that in this study, less than 5% of nuclear industry workers received the maximum 100 millisieverts cumulative dose of radiation over their entire career, and most of those doses were received in the early days of the nuclear industry when radiation protection standards were less stringent.