21 Oct Study Evaluates Cancer Risk From Occupational Radiation Exposure
MedicalResearch.com Interview with:,
David Richardson PhD
Associate Professor Epidemiology
Gillings School of Global Public Health
Medical Research: What is the background for this study?
Dr. Richardson: The International Nuclear Workers Study (INWORKS) combines three cohorts from France, the United Kingdom, and the United States of America. INWORKS follows on from an earlier 15-Country Study but focuses on the three countries that provided the majority of the most informative data on early nuclear workers (1940’s onward). The use of data from just 3 countries, instead of 15, reduces the organisational requirements – and therefore financial burden – associated with the greater number of countries but the cohort selection (of the three main contributing countries) means that the power of the INWORKS study is not a concern. INWORKS uses information from the French, UK and US cohorts that has been updated since the 15-Country study was published.
The overall purpose of the study is to improve the understanding of health risks associated with protracted, low-level exposure to ionising radiation.
Medical Research: What are the main findings?
Dr. Richardson: There was statistically significant evidence of a positive association between external ionising radiation exposure and death from all cancers as a single group among the 300,000 nuclear workers.
The excess risk increased linearly with radiation dose. The ERR per Gray of absorbed dose to the colon was 0.51 with a 90% confidence interval of 0.23–0.82. The radiation-related risk of cancer varied little when lung cancers were excluded indicating the results were not influenced by workers smoking habits. The risks also remained stable but with greater uncertainty when workers with cumulative exposures above 100mSv were excluded indicating that the risks per unit dose at low doses were not different to those found at higher doses .
Medical Research: What should clinicians and patients take away from your report?
Dr. Richardson: The link between ionising radiation exposure and certain cancers is well known; however, much of our knowledge stems from studies of acutely exposed people, such as the Japanese atomic bomb survivors and radiation therapy patients. Questions remain about using information from these studies to describe risks under different (usually much lower but prolonged) exposure conditions, such as those experienced by nuclear workers. This study cannot determine if an individual’s cancer is related to workplace radiation exposure.
David Richardson PhD (2015). Study Evaluates Cancer Risk From Occupational Radiation Exposure