by Ahimsa Porter Sumchai, MD
“There appears to be no threshold below which exposure can be viewed as harmless. ” – Professor Emeritus Herbert L. Abrams, “Biological Effects of Ionizing Radiation (BEIR) VII”
It is easy to be lulled into the false belief a little radiation can’t hurt you. After all, you are starting to hear it a lot these days. Fact is, even low exposure to x-rays and gamma rays increases your risk of cancer. That was the finding of Stanford and Harvard Professor Emeritus Herbert Abrams and 16 international experts on the National Research Council.
Abrams was a Stanford physician who sat on a committee of 16 international experts in fields spanning physics, radiology, genetics and biology to develop risk estimates for the seventh in a series of reports issued in the wake of the July 1945 atomic bombings of Hiroshima and Nagasaki investigating the effects of low level radiation exposure. The committee reviewed new data on atomic bomb survivors and their offspring along with 1,300 research studies on the impacts of radiation exposures in humans and animals and at the cellular level.
The Biological Effects of Ionizing Radiation (BEIR) VII is the seventh in a series of reports commissioned by the U.S. Nuclear Regulatory Commission and Departments of Defense, Energy and Homeland Security to provide health agencies and policymakers with authoritative risk estimates.
The BEIR VII report confirms doses of radiation as low as “near zero up to about 100 milliSieverts” at progressive exposure causes DNA damage and correlates to increased risk of a variety of cancers in humans. The report offers estimates for leukemia and cancer using risk models based on age and gender in a distribution matching U.S. population demographics. Additionally, it estimates the excess lifetime risks for 12 categories of cancer.
The principle findings of BEIR VII are alarming:
- Radiation exposure in the first year of life increases lifetime risk of cancer up to four times for boys and for female infants the risk doubles.
- For women exposed to radiation, the risk of developing cancer was 37.5 percent higher than for men. The risks for developing solid tumors such as breast and lung cancer were almost 50 percent higher than for men.
- For men exposed to ionizing radiation, the radiation induced risk for developing specific cancers including leukemia were much higher than for women.
According to the American Cancer Society, x-rays and gamma rays are known human cancer causing agents, or carcinogens. Research conducted in the last decade indicates it is actually the secondary low energy electrons generated by the primary radiation that cause single and double strand breaks in DNA that lead to cell mutations, cancers and subsequent death.
SF Bay View Health and Environmental Science Editor Ahimsa Porter Sumchai, M.D., founding chair of the Hunters Point Naval Shipyard Restoration Advisory Board’s Radiological Subcommittee and contributor to the 2005 Draft Historical Radiological Assessment, can be reached at firstname.lastname@example.org. Dr. Sumchai is also president and medical director of Golden State MD Health & Wellness, an author and a UCSF and Stanford trained researcher. This story first appeared on Medium.