Japan’s nuclear crisis and some people’s radiating ignorance about radiation

It’s funny that in this age of Google, there are still presidents of universities like Dante Guevarra who will declare a school holiday on fear of a nuclear fall-out.
The other day, Guevarra sent home PUP students, apparently after receiving calls from irate parents who have inquired why their sons and daughters are still in school when the rest of the world was on edge over the earthquake- and tsunami-hit Fukushima Daiichi nuclear power facility in northeast Japan.

The furious calls were apparently fueled by a hoax SMS message saying that the Philippines is going to be annihilated by radiation from Japan’s damaged nuclear facility, or words to that effect. Ugh.

There were only two ways to react to this ignorant overreaction. One is to ask for Dante Guevarra’s resignation for, yes, ignorance and replace him with a more somber official.

The other is to die laughing and, after passing out harmless, irradiated gas generated by the laughter, to Google, learn, and find out.

I did the last, as the investigator instinct in me dictated. I browsed the Internet about radiation. Here’s what I learned:

Radiation, according to the American Nuclear Society (ANS), are of two types: electromagnetic radiation and atomic and subatomic particle radiation. Electromagnetic radiation, which travels at the speed of light, includes visible light, radio waves, microwaves, x-rays, gamma rays, and infrared and ultraviolet radiation.

On the other hand, atomic and subatomic particle radiation includes alpha and beta particles, neutrons, protons and heavy ions, and its speed and energy depends upon the source of radiation and on any subsequent interaction of the radiating particle with other matter.

Radiation can be both harmful and harmless. Excessive radiation can kill, while controlled radiation can be generated to diagnose and treat ailments, eliminate or reduce harmful micro-organisms to enhance the safety of medical equipment and the food supply, cook food, transmit information (radio, television, cellular phones, etc.), and many other applications.

Says the ANS: “Unstable atoms that exist in nature are said to be naturally radioactive. Examples of radioactive atoms found in nature are carbon-14, potassium-42, radon-222, uranium-235, uranium-238 and thorium-232. In addition to naturally occurring radioactive materials, radioactive atoms can be produced when the nucleus of an atom is made to interact with a particle or electromagnetic radiation to form an unstable nucleus; this is typically done in nuclear reactors and particle accelerators.”

The latter is what is happening to Japan’s nuclear reactors. So, are we in imminent danger of annihilation by radiation as the hoax text messages warn and as Dante Guevarra ignorantly feared?

No.

Japan is very far from the Philippines. Whatever radiation may be released in the atmosphere even if all of the four Fukushima Daiichi nuclear power plants erupt (heaven forbid) will not wipe the Philippine archipelago off the map. Surely, there might be health hazards, but these will not kill whole populations.
I say this bravely because if officials of the Tokyo Electric Power Company, International Atomic Energy Agency, and some nuclear scientists who are in the know of what’s happening in Japan are to be believed, the radioactive fallout from the damaged nuclear power plants can still be minimized and controlled. No need, thus, to panic.

Which brings us to the question, “What radiation level is deemed life-threatening?

The answer depends on the source of the radiation.

There is cosmic radiation, which is from outer space, primarily the sun, which is partly blocked by the earth's atmosphere. It follows that the higher the altitude, the less air there is to block it and, therefore, the higher the radiation levels.

Then there is terrestrial radiation, from uranium, thorium, and other radioactive materials in the soil.

The food we eat can be radioactive, as they naturally contain Carbon-14 and potassium. And because we eat, then we, humans, can be radioactive, too. Kissing and other forms of human contact transmit radiation.

The one that humans, including Guevarra, fear most is radiation from nuclear matters and activity, such as nuclear weapons use. Comparing the radiation levels from any of these sources is in order to clear the air.

But to do it, let’s measure radiation first.

There are many types of radiation measurement, how it is stored in objects, how it affects tissues, and how it affects humans.

One measurement is the curie, named after scientist Marie Curie. A curie is a measure of how fast atoms disintegrate per second. A curie is about 37 billion disintegrations per second. All objects have a certain amount of curies.

Another measurement is the Roentgen, a radiation unit that indicates how much radiation is present in the air of a specific environment. A roentgen show how much radiation may be absorbed by standing in a particular place for a certain amount of time.

A more common type of measurement is the rad, or ‘radiation absorbed dose’, and the rem, or ‘roentgen equivalent man’.

These two can measure any type of radiation, including alpha, beta, neutron, gamma and "X," and deal with how much radiation is absorbed by objects. One rad is equivalent to 100 ergs (an energy unit) absorbed by 1 g of material.

Used to define limits of exposure for people who work in nuclear power plants, rem is a biological measurement divided into millirems and assigned a length of time, such as millirems (mrem) per hour.

“Technically, rad and rem measurements have been replaced by gray and sievert, which are metric measures. Gray is a precise measurement of how much energy the ionizing radiation gives to the tissue it passes through, while sievert takes into account the type of radiation and produces a biological measurement of how dangerous the absorbed radiation is to the body.”

For our purpose, let’s use rem.

If you ride an airplane, you get a radiation dose of 0.5 mrem per hour. How “high” you live varies the radiation you get from the sun. At sea level, you get around 25 mrem to around 50 mrem a year if you live at an altitude of 1.6 kilometers. At 3 km, that would be about 100 mrem a year.

On terra firma, we get about 30 mrem a year, although this can be much less along the coasts. There are places on earth where radiation is higher, like in some villages in India and Brazil that have high levels of thorium in local sands. We inhale radon which is present in the air and that’s an estimated 200 mrem a year.

Porcelain false teeth or crowns are radioactive; so is watching television. These give us around 0.1 mrem every year.

The ANS says medical tests radiate the following typical dose levels: extremity (arm, leg, etc.) X-ray, 1 mrem; dental X-ray, 1 mrem; chest X-ray, 6 mrem; nuclear medicine (thyroid scan), 14 mrem; neck/skull X-ray, 20 mrem; pelvis/hip X-ray, 65 mrem; CAT Scan, 110 mrem; upper GI X-ray, 245 mrem; and barium enema, 405 mrem.

Nuclear weapons fallout is estimated to be less than 1 mrem a year. There is a slight increase in radiation doses when one lives close to a nuclear power plant due to the release of uranium and other chemicals.

Granting you get radiation from all of the above sources every year, you will probably get over 35o mrem, much less than the estimated 250,000 mrem that can kill you. This means, on the average, 3,000 mrem a year for, say, 80 years before you get the chance of dying from cancer. 450,000 mrem can produce instant death.

So, the risks from radiation are very low, even if you ride airplanes everyday, replace your porcelain teeth every year, or watch TV till you get eye sore, or have nuclear medicine procedures until your money runs out. I think the risk of dying from getting hit by a speeding bus on Commonwealth avenue is greater than the risk posed by Japan’s nuclear disaster. Was this why Energy secretary Mario Montejo bats for the operation of the Bataan Nuclear Power Plant? I guess so.

So, Mr. Guevarra, you can cry now because you were had by the hoaxers. If only you googled.