Radiation—the word itself can bring shivers to even the most hardy individuals, but it shouldn't. As Mark Twain said, “It isn't what we don't know that causes the problems, it's what we think we know that just isn't so.” The fear of radiation comes from the many doomsayers that have used an unwitting press and public to their advantage for decades.
Radiation exposure extends lifespan. There is no question that high amounts of radiation are harmful, but low amounts are beneficial to humans and animals. This is the concept of hormesis which applies throughout nature. Hormesis means that high and low doses produce opposite effects, with low doses providing beneficial effects and high doses the opposite.
The average American gets a dose of around 360 millirems of radiation per year—roughly the equivalent of 36 X-rays. About 200 millirems of that comes from radon gas, a colorless, odorless
by-product of natural uranium, found in trace amounts almost everywhere. Medical X-rays come in second place, dosing a person with 53 millirems a year on average. (1)
About 40 millirems of our annual dose is internal, generated from the decay of isotopes incorporated into the molecules of our being: a potassium-40 atom in the brain firing off a gamma ray here, a carbon-14 in the liver spitting out a beta particle there. Enough radiation escapes our bodies that sleeping nightly with another person adds 1 millirem to our annual dose.
Important trivia fact! Since the concentration of potassium is higher in muscular tissue, the amounts in men tend to be somewhat higher. So, if you find yourself in a crowded room and want to keep your dose rate to a minimum, you should always stand close to a woman to avoid receiving an unnecessary high dose from K-40. (2)
Radiation from cosmic rays comes next, at 27 millirems per year. This means that living in Denver will expose you to more radiation than living in a sea-level city like New Orleans. For every hundred feet of altitude, the annual dose from radiation increases by 1 millirem per year. A five hour airplane flight provides exposure of 2.5 to 5.0 millirems. Yet, the postulated danger of receiving an extra 10 millirems per year from living at the border of a radioactive waste site has received vastly more attention from the press and public. (3)
Radiation exposure varies around the world. Grand Central Station in New York = 0.53 rem/yr, while St. Peter's Square in Rome = 0.80 rem/yr, Morro Do Ferro in Brazil = 7-14 rem/yr and Ramsar, Iran = 48 rem/yr. Note that the rules that are applied in the decommissioning of US nuclear power plants would require the stone structures of St. Peter's Square in Rome and the Grand Central Station in New York to be dismantled and buried because of radioactivity. (4)
Other sources or radiation are pretty much everything around us, contributing around 20 millirems per year. The food we eat, the clothes we wear, even the paper of a magazine—all are naturally laced with tiny amounts of unstable isotopes, radioactive cousins of normal atoms. For example, all living things require potassium and one out of every 8,550 potassium atoms is radioactive containing potassium-40, meaning that food emits a little bit of radiation. Since bananas happen to be high in potassium, they are actually one of the most radioactive foods. Eating 600 bananas is about the equivalent of having one chest X-ray. (1)
Have you heard?
Low levels of radiation are beneficial to humans.
Mice exposed to low levels of radiation lived longer than mice that were not.
Fish exposed to low levels of radiation grew faster than fish that weren't.
Low levels of radiation increase fertility and embryo viability and decrease sterility and mutations.
Chernobyl and Three Mile Island
It's more likely you've heard about Chernobyl and Three Mile Island. When radioactivity from the Chernobyl accident reached the West Coast, the press warned about the dangers of possible fallout, speaking of the number of picocuries of radioactivity detected in high clouds without ever explaining that a picocurie is one part per trillion. Nor did the press mention that you would have to drink 63,000 gallons of that radioactive rain water to ingest one picocurie of radioactivity. (5)
In more recent times there has been Fukushima. A magnitude 9.0 earthquake at Japan's Sendai nuclear power plant just offshore from Northern Honshu, Japan, was one of the strongest earthquakes in recorded history. The resulting tsunami was one of the worst ever recorded. The earthquake and tsunami extensively damaged six 33 to 40 year old nuclear generating units at the Fukishima Daiichi nuclear power plant. More than 10,000 people died in the earthquake and tsunami. Not a single person died or was made seriously ill by damage to the nuclear power plant. (6)
While some people in residential ares near Fukushima were wearing cumbersome radiation-blocking suits, filtered gas masks, gloves, and booties, there are many people living carefree in Brazil, India, Iran, Norway and other places where folks have lived normal lives for countless generations with radiation levels as much as 100 times greater than forbidden areas of the Fukushima homes. (7)
All this leads to the case of the linear no-threshold (LNT) model of radiation.
Governments and advisory boards have based regulatory policy for 70 years on the LNT model of radiation induced cancer. High dose radiation can cause cancer, but no such correlation has ever unequivocally been shown at low doses in the range of X-ray and computed tomography (CT) examinations, or in the vicinity of nuclear power plants.
The proven consequence of high doses of radiation has simply been assumed to apply even at doses near zero, and no threshold has been given below which it is harmless. Consequently, all doses have been predicted to cause cancer. But as many studies prove, the body responds differently to radiation at high and low doses. At low doses, the body eliminates the damage through various protective mechanisms that have evolved in humans from eons of living in a world bathed in low dose rate but sometimes high dose natural radiation, reports Jeffrey Siegel and colleagues. (8)
Even data from atomic bomb survivors, the gold standard of dose response information, do not support the LNT model; adaptive protections mitigate radiation induced damage at low doses and low dose rates. No epidemiological studies have ever demonstrated a casual relationship between low dose radiation exposure and carcinogenesis.
Many people, though they admit the absence of evidence, nevertheless believe that 'precautions' derived from the LNT model save lives. But misguided applications of the LNT model to regulation and policy have caused death and psychological damage from unnecessary mass evacuations and have created adverse health consequences from patients' fear-driven rejection of potentially life-saving X-rays, and CTs. Additionally, hundreds of billions of dollars are wasted on unnecessary precautionary measures due to unwarranted fear of low dose radiation.
Siegel and his colleagues sum this up well in their recent paper: “Science must finally arrive at summary judgment that the LNT model is fallacious and thereby alleviate suffering and abate needless, paralyzing public fear. A linear threshold model with no low-dose harm can free people from the grip of groundless phobias. No harm, No fear.” (8)
References
Stephen Cass, “Everything emits radiation—even you,” discovermagazine.com, June 4, 2007
B. L. Cohen and D. W. Moeller, Issues in the Environment, American Council on Science and Health, pp62 and 66, 1992
J. P. Young and R. S. Yalow, Editors, Radiation and Public Perception: Benefits and Risks, American Chemical Society, Washington, DC, 1995
M. M. Hart, “Radiation: what is important?” Lawrence Livermore Laboratory, Livermore, CA, May 2, 1998
Dixy Lee Ray, “Radiation around us,” in Rational Readings on Environmental Concerns, Jay H. Lehr, Editor, (New York, Van Nostrand Reinhold, 1992), 589
Jay Lehr and Alan Lloyd, “With time and reflection, Fukushima lessons taking shape,” Environment & Climate News, February 2012
Jay Lehr, “Nuclear fears trumping reality in wake of Fukushima,” Environment & Climate News, July 2012
Jeffrey A. Siegel et al., “Low-dose radiation exposure should not be feared,” Physics Today, 69 (1), 12, 2016
Jack Dini is author of Challenging Environmental Mythology. He has also written for American Council on Science and Health, Environment & Climate News, and Hawaii Reporter.
