During the period from 1980-1988, a large and comprehensive study was conducted to determine the risks of occupational exposure to low levels of radiation. A summary of the study’s final report, which was completed in 1991 but not widely released, has been published under the title of Nuclear shipyard worker study (1980–1988): a large cohort exposed to low-dose-rate gamma radiation.
Here is the paper’s abstract:
This paper is a summary of the 1991 Final Report of the Nuclear Shipyard Worker Study (NSWS), a very comprehensive study of occupational radiation exposure in the US. The NSWS compared three cohorts: a high-dose cohort of 27,872 nuclear workers, a low dose cohort of 10,348 workers, and a control cohort of 32,510 unexposed shipyard workers. The cohorts were matched by ages and job categories. Although the NSWS was designed to search for adverse effects of occupational low dose-rate gamma radiation, few risks were found. The high-dose workers demonstrated significantly lower circulatory, respiratory, and all-cause mortality than did unexposed workers. Mortality from all cancers combined was also lower in the exposed cohort. The NSWS results are compared to a study of British radiologists. We recommend extension of NSWS data from 1981 to 2001 to get a more complete picture of the health effects of 60Co radiation to the high-dose cohort compared to the controls.
I have known about this study for a number of years, but have never quite understood why its publication was delayed. Billions of dollars of additional costs are imposed annually on taxpayers and utility rate payers in order to follow the ALARA (as low as reasonably achievable) principle.
ALARA rules force Nuclear Regulatory Commission license holders to reduce exposures to levels far below the occupational levels received by the shipyard workers in the reported study. Based on the information discovered in the study, those rules have no positive effect on worker health. I can only come up with one logical, but disturbing, explanation for why the study results were not used as the basis for writing new rules to govern occupational and general population radiation exposures – “One man’s COST is another man’s REVENUE.”
You can obtain a PDF copy of the summary report at http://www.inderscience.com/storage/f124751110836129.pdf.
One of the authors, Dr. John Cameron, spent a good deal of time during the last 15 years of his life trying to ensure that the information found during the Nuclear Shipyard Workers Study did not get lost or removed from our knowledge base. He passed away in March 2005. He deserves our thanks for his stubborn refusal to let this information disappear. You can learn more about Dr. Cameron at http://www.inderscience.com/editorials/f971012452118613.pdf