Low-Level Doses of Radiation Can Cause Big Problems

This is an expanded version of an article I wrote a couple of days ago.

When scientists speak of radiation, they speak not only of single doses but also of cumulative doses.

See for example, this research from the University of Iowa showing that “cumulative radon exposure is a significant risk factor for lung cancer in women”.

And see these studies on the health effects cumulative doses of radioactive cesium. (As I noted on March 29th, the radioactive cesium fallout from Japan already rivals Chernobyl. And the amount of radioactive fuel at Fukushima dwarfs Chernobyl).

Admittedly, the damage from huge single doses may be greater than the same cumulative dose from many small exposures. But the smaller doses can still add up.

Many studies have shown that repeated exposures to low levels of ionizing radiation from CT scans and x-rays can cause cancer. See this, this, this, this, this, this, this, this and this.

Remember, the radiation from CT scans and x-rays are external emitters – the radiation emanates from outside the body. In contract, internal emitters keep emitting their radiation inside the body. Therefore, the cumulative effect of multiple small doses of radiation from internal emitters could be even more dramatic, depending on the half life, metabolic pathways and other properties of the particular radioactive particle.

As the European Committee on Radiation Risk notes:

Cumulative impacts of chronic irradiation in low doses are … important for the comprehension, assessment and prognosis of the late effects of irradiation on human beings …

And see this.

One of the World’s Leading Experts on Radiation – Karl Morgan – Warned of Cumulative Low-Dose Exposures

American reporter Dahr Jamail reports today for Al Jazeera:

“The U.S. Department of Energy has testified that there is no level of radiation that is so low that it is without health risks,” Jacqueline Cabasso, the Executive Director of the Western States Legal Foundation, told Al Jazeera.

Her foundation monitors and analyzes U.S. nuclear weapons programs and policies and related high technology energy, with a focus on the national nuclear weapons laboratories.

Cabasso explained that natural background radiation exists, “But more than 2,000 nuclear tests have enhanced this background radiation level, so we are already living in an artificially radiated environment due to all the nuclear tests.”

“Karl Morgan, who worked on the Manhattan project, later came out against the nuclear industry when he understood the danger of low levels of ionizing radiation-and he said there is no safe dose of radiation exposure,” Cabasso continued, “That means all this talk about what a worker or the public can withstand on a yearly basis is bogus. There is no safe level of radiation exposure. These so-called safe levels are coming from within the nuclear establishment.”

Karl Morgan was an American physicist who was a founder of the field of radiation health physics. After a long career in the Manhattan Project and at the Oak Ridge National Laboratory, he became a critic of nuclear power and weapons. Morgan, who died in 1999, began to offer court testimony for people who said they had been harmed by the nuclear power industry.

“Nobody is talking about the fact that there is no safe dose of radiation,” Cabasso added, “One of the reasons Morgan said this is because doses are cumulative in the body.”

Indeed, Karl Morgan believed that the officially-defined “permissible levels” of radiation – which he helped to create on behalf of the government – are much higher than they should be.

As the Guardian wrote in Morgan’s obituary in 1999:

Karl Morgan … was a pioneer of health physics – the science of the effect of exposure to radiation on health. He was a member of the research group which laid the foundations for the Manhattan project and produced the first atomic bomb. However, after 30 years in the inner cabinet of the nuclear establishment, Morgan changed sides and testified in key radiation cases on behalf of those who claimed they had been harmed by nuclear weapons and the nuclear power industry.

The first signs of his change of view came in 1968, when he became an influential campaigner in obtaining a US law that required the medical profession to control excessive doses of radiation during X-rays.

After retirement in 1972 he became more active in drawing attention to the limitations of radiation protection measures.


He began his career as a physics professor but in 1943 was recruited to become a senior scientist in health physics to the top secret, atomic bomb project codenamed Manhattan Engineer District.

The following year, Morgan went to the newly-formed Oak Ridge national laboratory in Tennessee, where he became director of health physics from 1944 until his retirement. When told he would be in the health physics group, he was shocked and said it was a terrible mistake because he had never heard of health physics. The leaders of the research project said they had been in the same position. But they realised that since their attempts to build the first atomic pile, now known as a reactor, would create a source of intense radiation, they needed to understand how to protect people.


He wrote in his autobiography, The Angry Genie: One Man’s Walk Through The Nuclear Age, that he did not believe they had ever determined that it was safe. “We determined what we considered was acceptable.”

The Townsend Letter for Doctors & Patients wrote in 2002:

One of the original five ‘health physicists’ to set radiation safety standards was Karl Z. Morgan. Dr. Morgan served on the International Commission on Radiological Protection (ICRP), which set up most radiation standards. He also directed the Health Physics Division at Oak Ridge from 1944 until his retirement in 1972. In recent years, Dr. Morgan has publicly criticized the ICRP for failing to protect human health. In a 1994 article for the American Journal of Industrial Medicine, Dr. Morgan wrote: “The period of atmospheric testing of nuclear weapons by the United States, the United Kingdom, France and the USSR is a sad page in the history of civilized man. Without question, it was the cause of hundreds of thousands of cancer deaths. Yet there was complete silence on the part of the ICRP. During these years (1960-1965), most members of the ICRP either worked directly with the nuclear weapons industry or indirectly received most of their funding for their research from this industry.”

The ICRP’s alliance with the nuclear industry includes ties to the International Congress of Radiology. In his 1999 autobiography, The Angry Genie: One Man’s Walk Through the Nuclear Age (ISBN 0-8061-3122-5), Dr. Morgan related his concern about the ICRP’s refusal to address the danger of excessive X-ray exposure during diagnostic procedures and dentistry. Until the passage of the Radiation Control for Health and Safety Act of 1968, some X-ray equipment used in the 1950s and 1960s delivered 2 to 3 rem per X-ray. X-ray doses as low as 1.6 rem increase a woman’s chance of developing cancer, according to a 1974 study by Baruch Modan [Lancet (Feb. 23,1974), pp 277-279]. The Act did not address the cumulative effect of multiple, routine, and often unnecessary X-rays.

Other Top Radiation Experts Agree

By any measure, Dr. John Gofman was one of the greatest scientists of the 20th century. Gofman earned his doctorate in nuclear and physical chemistry, and was also a medical doctor. He worked on the Manhattan Project, co-discovered uranium-232 and -233 and proved their fissionability, helped discover how to extract plutonium and led the team that discovered and characterized lipoproteins in the causation of heart disease.

Dr. Arthur R. Tamplin was a doctor of biophysics, who was tasked – as a group leader in the Biomedical Division at Lawrence Livermore National Laboratories – with predicting the ultimate distribution within the biosphere and in humans of each radionuclide produced in the explosion of a nuclear device.

In 1963 the Atomic Energy Commission asked Gofman and Tamplin to undertake a series of long range studies on potential dangers that might arise from the “peaceful uses of the atom.” They told the truth, and the AEC launched a campaign of harassment in response.

What did they say, and why was the AEC so hostile?

Gofman and Tamplin documented that low levels of radiation can cause cancer and other diseases, and they argued that federal safety guidelines for low-level exposures should be reduced by 90 percent.

Ernest Sternglass (Emeritus Professor of Radiological Physics in the Department of Radiology, at the University of Pittsburgh School of Medicine), Dr. Alice Stewart (head of the Department of Preventive Medicine of Oxford University) and many other top scientists have also shown that low level radiation can cause cancer.

Military Commanders Told that Low-Level Radiation Increases the Risk of Cancer

A military briefing written by the U.S. Army for commanders in Iraq states:

Hazards from low level radiation are long-term, not acute effects… Every exposure increases risk of cancer.

(Military briefings for commanders often contain less propaganda than literature aimed at civilians, as the commanders have to know the basic facts to be able to assess risk to their soldiers.)

The briefing states that doses are cumulative, citing the following military studies and reports:

  • ACE Directive 80-63, ACE Policy for Defensive Measures against Low Level Radiological Hazards during Military Operations, 2 AUG 96
  • AR 11-9, The Army Radiation Program, 28 MAY 99
  • FM 4-02.283, Treatment of Nuclear and Radiological Casualties, 20 DEC 01
  • JP 3-11, Joint Doctrine for Operations in NBC Environments, 11 JUL 00
  • NATO STANAG 2473, Command Guidance on Low Level Radiation Exposure in Military Operations, 3 MAY 00
  • USACHPPM TG 244, The NBC Battle Book, AUG 02

Why was the military advising commanders on radiation in Iraq? Presumably because the American military used depleted uranium in Iraq (see this, this, this, this, this and this).

Infants Are Most at Risk

Infants are, apparently, most vulnerable to low level radiation exposure.

As Brian Moench, MD, notes:

Administration spokespeople continuously claim “no threat” from the radiation reaching the US from Japan, just as they did with oil hemorrhaging into the Gulf. Perhaps we should all whistle “Don’t worry, be happy” in unison. A thorough review of the science, however, begs a second opinion.

That the radiation is being released 5,000 miles away isn’t as comforting as it seems…. Every day, the jet stream carries pollution from Asian smoke stacks and dust from the Gobi Desert to our West Coast, contributing 10 to 60 percent of the total pollution breathed by Californians, depending on the time of year. Mercury is probably the second most toxic substance known after plutonium. Half the mercury in the atmosphere over the entire US originates in China. It, too, is 5,000 miles away. A week after a nuclear weapons test in China, iodine 131 could be detected in the thyroid glands of deer in Colorado, although it could not be detected in the air or in nearby vegetation.

The idea that a threshold exists or there is a safe level of radiation for human exposure began unraveling in the 1950s when research showed one pelvic x-ray in a pregnant woman could double the rate of childhood leukemia in an exposed baby. Furthermore, the risk was ten times higher if it occurred in the first three months of pregnancy than near the end. This became the stepping-stone to the understanding that the timing of exposure was even more critical than the dose. The earlier in embryonic development it occurred, the greater the risk.

A new medical concept has emerged, increasingly supported by the latest research, called “fetal origins of disease,” that centers on the evidence that a multitude of chronic diseases, including cancer, often have their origins in the first few weeks after conception by environmental insults disturbing normal embryonic development. It is now established medical advice that pregnant women should avoid any exposure to x-rays, medicines or chemicals when not absolutely necessary, no matter how small the dose, especially in the first three months.

“Epigenetics” is a term integral to fetal origins of disease, referring to chemical attachments to genes that turn them on or off inappropriately and have impacts functionally similar to broken genetic bonds. Epigenetic changes can be caused by unimaginably small doses – parts per trillion – be it chemicals, air pollution, cigarette smoke or radiation. Furthermore, these epigenetic changes can occur within minutes after exposure and may be passed on to subsequent generations.

The Endocrine Society, 14,000 researchers and medical specialists in more than 100 countries, warned that “even infinitesimally low levels of exposure to endocrine-disrupting chemicals, indeed, any level of exposure at all, may cause endocrine or reproductive abnormalities, particularly if exposure occurs during a critical developmental window. Surprisingly, low doses may even exert more potent effects than higher doses.” If hormone-mimicking chemicals at any level are not safe for a fetus, then the concept is likely to be equally true of the even more intensely toxic radioactive elements drifting over from Japan, some of which may also act as endocrine disruptors.

Many epidemiologic studies show that extremely low doses of radiation increase the incidence of childhood cancers, low birth-weight babies, premature births, infant mortality, birth defects and even diminished intelligence. Just two abdominal x-rays delivered to a male can slightly increase the chance of his future children developing leukemia. By damaging proteins anywhere in a living cell, radiation can accelerate the aging process and diminish the function of any organ. Cells can repair themselves, but the rapidly growing cells in a fetus may divide before repair can occur, negating the body’s defense mechanism and replicating the damage.

Comforting statements about the safety of low radiation are not even accurate for adults. Small increases in risk per individual have immense consequences in the aggregate. When low risk is accepted for billions of people, there will still be millions of victims. New research on risks of x-rays illustrate the point.

Radiation from CT coronary scans is considered low, but, statistically, it causes cancer in one of every 270 40-year-old women who receive the scan. Twenty year olds will have double that rate. Annually, 29,000 cancers are caused by the 70 million CT scans done in the US. Common, low-dose dental x-rays more than double the rate of thyroid cancer. Those exposed to repeated dental x-rays have an even higher risk of thyroid cancer.


Beginning with Madam Curie, the story of nuclear power is one where key players have consistently miscalculated or misrepresented the risks of radiation. The victims include many of those who worked on the original Manhattan Project, the 200,000 soldiers who were assigned to eye witness our nuclear tests, the residents of the Western US who absorbed the lion’s share of fallout from our nuclear testing in Nevada, the thousands of forgotten victims of Three Mile Island or the likely hundreds of thousands of casualties of Chernobyl. This could be the latest chapter in that long and tragic story when, once again, we were told not to worry.

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