Monday, 21 April 2014

Linear no-threshold, LNT, evidence, contra-evidence and links

Nuclear power gives the lowest cost, non-carbon, electricity we can get in quantity. It is far safer than generally assumed. Nuclear power is the safest form of energy available.

Accidents in nuclear plants [ref 1] - measured by lost time due to injuries are:

  • ⅒ that of general industry
  • ¼ that of the average office
Mortality rates, compared to the general population, are:
  • 35% lower cancer rates
  • 66% lower for non-cancers
  • 60% lower for all-causes of death
(Based on a sample size of 53,698 employees)

The fear of nuclear power is based on a misrepresentation of radiation harm promoted by the scientific community starting back in 1956 : LNT. LNT, linear, no-threshold, extrapolated to zero. It assumes a linear relationship between harm and radiation at all doses. This linear relationship is valid a high radiation levels. There was never any unambiguous data to suggest such a relationship at low levels of radiation. Notwithstanding, the linear relationship was extrapolated to zero far beyond any data gathered. Even back in 1956, data contradicting LNT at low doses was available but was suppressed. By accepting LNT at low doses we sign up to a model that says:

  • any tiny amount of radiation can kill you :- there is no safe level.
  • very small exposure doses accumulate the likely harm over time. E.g. A single 1000 mSv dose is equal to 100 doses of 10 mSv.
Scientists working to block testing seized on the geneticists’ suggestion that all radiation doses, even the tiny ones being caused by weapons testing-related fallout, could cause harm. They officially accepted that idea in 1958 and began a heavy promotional campaign to spread fallout fears. A search of the New York Times article archive on the word “fallout” returned 964 instances during the period from Jan 1, 1958 through Jan 1, 1964.

- Healthy doses of radiation

Scientists promoted LNT as their only political tool to stop atomic bomb tests during the cold war. LNT later became a tool to oppose nuclear power too. It wasn't always the same scientists. For example. The early fire at Britain's Windscale reactor in 1957 was later used by scientists, employing LNT, to prove that 240 people died. No one can point to actual people who died but the theory says 240 did so the theory must be right. A 2010 study of workers directly involved in the Windscale fire cleanup found no significant long term health effects from their involvement. These were the people exposed to the highest radiation doses! By the 1960s LNT was mainstream. Anyone denying it - demanding evidence - would've been in for a hard time from his/her peers. It was taught to me in physics class as Gospel. It became dogma based on a better safe than sorry mentality (aka ALARA).

In recent years scientists have began to break ranks with LNT dogma. Everyone agrees that high doses of radiation are harmful. The vast majority of radiation leaks and contamination (including so-called deadly Fukushima radiation) occur at low levels - very close to naturally found radiation levels. The deadly nature of such low doses has been disproved by a number of studies. When LNT models were used to project fatalities, thousands of deaths are predicted (such as the initial WHO models for Chernobyl predicting 4000+ fatalities). There were about 60 fatalities due to radiation Chernobyl. Actual scientists looking at the harmful effects from Chernobyl, e.g. UNSCEAR, consistently failed to match the models to reality. Despite their findings entirely contradicting LNT models, recent UNSCEAR reports still can't put their head above the parapet to say LNT extrapolated to zero is rubbish. The PC-police in the radiation scare industry prevent them speaking out. Many scientists prefer to keep their jobs, and avoid controversy.

In 2006 the United Nations Chernobyl Forum and in 2008 the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR) showed in comparison to the Russian general population, a 15% to 30% lower mortality from solid tumors among the Russian Chernobyl emergency workers and a 5% lower average solid tumor incidence among the heavily radiated population of the Bryansk district. In the most exposed group of these people with an estimated average radiation dose of 40 mSv, a 17 % decrease in the incidence of solid tumors of all kinds was found. [ref 10]
There are no human data to support the LNT model for short-term low doses below approximately 0.2 Sv, which is the equivalent of 2 centuries of natural background irradiation to the whole body or 200 mammograms to breast tissue.

Cost of Chernobyl

There were a total of 56 fatalities from Chernobyl as at 2004. Apart from these high-dose cases, large numbers received low doses from contamination of the environment by radioactive isotopes from Chernobyl, but there has been no evidence of any increase in leukaemia or other cancers and no increase in hereditary diseases in this large population. Unfortunately, because of widespread radiation phobia, there were an estimated 1250 suicides and between 100,000 and 200,000 elective abortions in Western Europe. The great tragedy of Chernobyl was that so much harm was done – not by the effects of radiation – but by the irrational fear of it.[ref 11]

Cost of LNT

Current estimates of the cost incurred in preventing one death by implementing the current radiation protection regulations based on the LNT hypothesis is approximately $2.5bn.[ref 11]
  1. Per Peterson : Energy from Nuclear Fission
  2. There are 30,000 or so scientific papers detailing radiation research. Some research has found contra-evidence specifically refuting LNT. No evidence has ever supported LNT, although there is plenty of evidence of harm, it is harm at high radiation doses.
  3. Disreputable origins of LNT - Ed Calabrese – Researching Dose Response: Link | 1½ hour podcast
  4. Compare a map of cancer incidence in the USA against natural radiation levels. No correlation.
  5. Compare the incidence of cancer in those exposed to quite high levels of radiation (aircraft crews, flight pilots, people living in areas of high radiation). There is no additional risk.
  6. In 1982, more than 20,000 tons of steel was accidentally contaminated with cobalt-60, much of this radioactive steel was used to build apartments and exposed thousands of Taiwanese to gamma radiation levels of up to > 1000 times background (ave. 47.7 mSv, max. 2360 mSv excess cumulative dose)[1]. This was discovered in 1992. A study by Chen et al[2] found a lower cancer incidence with time, the opposite of what LNT predicted. Taiwanese cobalt-60 contamination puzzle
  7. The predicted harm from the Chernobyl accident was based on LNT. The predictions were entirely contradicted by facts. Some 200,000 Soviet women were pressurized into having abortions. All for nought. No additional risk justified it: Nuclear Nightmares, BBC Horizon 2006
  8. Low dose radiation doesn’t cause cancer, it helps prevent it
  9. Video: Wade Allison interviewed by Helen Tunnicliffe
  10. Spirited debate about BEIR VII and Linear No Threshold (LNT) Dose Assumption - Atomic Insights
  11. Radiation: Facts, fallacies and phobias, DR Wigg, Australasian Radiology (2007) 51, 21–25
  12. Is radiation as dangerous as they say? (Video/DVD), Cameron JR. Medical Physics Publishing, Madison, WI, 2001. Available from URL:
  • [1] 1 mSv per year is the public dose limit for exposure in the USA. Natural background radiation in the USA varies from 1 mSv to 6 mSv per year.
  • [2] Chen et al, 2006. Cancer risks in a population with prolonged low dose-rate gamma-radiation exposure in radio-contaminated buildings, 1983–2002". International Journal of Radiation Biology 82(12): 849–58.

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