Ruminations on Radiation:  How cultural fears of radiation emanate

By Jonathan Tiemann, August 2019

In 1984, Gordon Matthew Sumner, better known by his stage name, Sting, broke away from his New Age band, The Police, and began to perform and record on his own. His first solo album, released in mid-1985, was the fancifully-named The Dream of the Blue Turtles. The album included a song called “We Work the Black Seam,” a lament over the loss of coal mining jobs, presumably in the north of England. Sting may well have intended the piece as an updated homage to the old miners’ union hymns. But unlike “The Blackleg Miner,” which advocated violence against strikebreakers, Sting’s piece fingers nuclear power as the cause of the loss of coal mining jobs. The song’s refrain complains

One day in a nuclear age
They may understand our rage
They build machines that they can’t control
And bury the waste in a great big hole
Power was to become cheap and clean
Grimy faces were never seen…

The refrain then ends with a curious non sequitur:

Deadly for twelve thousand years is carbon-fourteen

Sting’s throwaway line about C-14 owed its impact to a carefully-cultivated cultural feature of the decade between the Three Mile Island incident in 1979 and the fall of the Berlin Wall in 1989 — a reflexive fear of radiation.

Carbon-14 is radioactive, but the claim that it is “deadly for twelve thousand years” is arbitrary and incorrect, even allowing Sting artistic license to make it. The half-life of C-14 is in the neighborhood of 5730 years, so 12,000 years is about two half-lives, or the time over which approximately three-fourths of a sample of C-14 would decay. Carbon-14 decays by emitting a beta particle (an electron), effectively converting one of the neutrons in its nucleus to a proton, and leaving behind Nitrogen-14, a stable isotope of the most common element in the atmosphere. Since Carbon-14 is a naturally-occuring isotope, this is a process that takes place around us all the time, and natural C-14 decay makes a small contribution to the background radiation that always surrounds us.

Sting, of course, was not making a scientific claim. The amount of C-14 necessary to produce a deadly dose of radiation would be huge. He was appealing to the old Cold War fear of radiation to make a political point. By 1985 that fear had become a shared cultural assumption, reinforced by means ranging from James Bond movies to Rocky and Bullwinkle cartoons to duck-and-cover drills. It is a cultural assumption that remains with us today and hampers our ability to think rationally about nuclear energy.

Radiation can be dangerous. So can heat. Or water. But it is not inherently so. In fact, radiation, like visible light or heating by infra-red, is indispensible to life. But to talk seriously about the dangers, real or exaggerated, of radiation, we should really focus on ionizing radiation, those forms energetic enough to displace electrons from their atomic orbits, turning atoms into ions.

Ionizing Radiation

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We denote the three most important forms of ionizing radiation by the first three letters of the Greek alphabet, alpha, beta, and gamma. Alpha particles are essentially helium nuclei (two protons and two neutrons), produced by radioactive decay of certain elements. These can be quite energetic, but they cannot penetrate human skin, so they are only dangerous to a person that has ingested their sources. Beta particles are fast-moving electrons. These can penetrate skin, but a few millimeters of wood or aluminum offer sufficient shielding to block them. Gamma rays are electromagnetic rays like their cousins visible light, ultraviolet light, and x-rays, but gamma rays are more energetic. We all constantly receive background doses of gamma rays, but large doses of this form of ionizing radiation can be dangerous.

Three factors complicate the measurement of the health effects of ionizing radiation. First, while very large doses of ionizing radiation have effects that are large, dangerous, and sometimes fatal, the long-term effects of smaller doses are difficult to measure. Second, different forms of radiation have different biological effects. Alpha particles can be more damaging at the same level of energy than beta particles or gamma rays, but, as noted, alpha particles are only damaging to health if they originate from within the body. And third, the effect on a person’s body of receiving a particular quantity of radiation depends in part on the time span over which the dose occurs. An intense dose, received over a span of minutes, can be far more damaging than the same quantity of radiation received over, say, a year.

The standard approach to assessing dosages of ionizing radiation is to measure their energy, and then make an adjustment according to the type of radiation. The basic unit of ionizing radiation is the Gray (Gy), equal to the absorption of one joule of energy per kilogram of tissue. We convert Grays to another unit, Sieverts (Sv), to adjust for differences in biologial effects of different forms of radiation. One Gy of beta or gamma radiation delivers a radiation dose of 1 Sv, whereas 1 Gy of alpha radiation delivers 20 Sv. A Sievert is actually quite a large unit when it comes to radiation, so we usually speak in terms of millisieverts (mSv). Since mSv are units of quantity, to express rates of exposure we speak in terms of mSv/hr or mSv/yr.

Berkeley Radiation Lab

Very large doses of radiation can have immediate, or short-term, harmful effects. Large enough doses can be fatal. For example, the UN Scientific Commission on the Effects of Atomic Radiation considers a 1000 mSv dose in a short period the threshold for causing radiation sickness in the form of Acute Radiation Syndrome. Symptoms of this syndrome include nausea and decreased white blood cell count, but not death. Above this, the severity of illness increases with dose. The same group also assumes that a population receiving such a dose would see a five percentage-point increase in the incidence of fatal cancers. UNSCEAR also estimates that a short-term, full-body dose (as opposed to a focused, therapeutic dose) of 5000 mSv would be fatal within a month to about half those that received it, and nearly anyone receiving 10,000 mSv would die within a few weeks.

Very few people receive radiation doses even remotely close to the acute and fatal ranges. Rates of background radiation vary widely across the world. According to the World Nuclear Organization,[1] the average background radiation dose across the world is 2.4 mSv/yr. However, depending on elevation, climate, and geology, that background dose can range from about 1 to about 40 mSv/yr. Intriguingly, those differences in background doses do not seem correlated to the incidence of cancers. 146 of the emergency workers controlling the 2011 Fukushima accident received short-term doses of over 100 mSv, and six received more than 250 mSv. Authorities are monitoring this population for adverse health effects; otherwise, according to a May 2013 UNSCEAR report, “Radiation exposure following the nuclear accident at Fukushima Daiichi did not cause any immediate health effects. It is unlikely to be able to attribute any health effects in the future among the general public and the vast majority of workers.”[2]

{Chart by Randall Munroe, with help from Ellen, Senior Reactor Operator at Reed Research Reactor.)

MMM

For the general population, the two most important sources of radiation exposure are natural background radiation and medical applications like x-rays and CAT scans. Even major events like the Fukushima disaster resulted in meaningful exposures to only a small population of emergency workers. For the rest of us, fears of radiation from anything related to nuclear fission — short of the detonation of an atomic bomb — are nothing more than a cultural canard.

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[1] World Nuclear Association, “Nuclear Radiation and Health Effects,” https://www.world-nuclear.org/information-library/safety-and-security/radiation-and-health/nuclear-radiation-and-health-effects.aspx

[2] Ibid.