Review of Radiation by Robert Gale and Eric Lax - and why we should probably build more nuclear power plants.

Since the nuclear meltdown at Fukushima radiation has achieved an even worse reputation than it had previously. To what extent is this reputation deserved? Speaking more broadly, how great a risk does radition pose to us, and in what ways does it help us?

Robert Gale and Eric Lac, the authors of Radition, starts by stating a few facts that everyone should know but which many people probably do not know. First, radiation is present everywhere. It is in the ground, in the air, in the food that we eat, and in ourselves. There is no way you can avoid radiation (this holds true for non-ionizing as well as ionizing radiation). Second, raditation can kill you. Depending on the type of radiation and the dose received radiation may cause a cell to turn into a cancer cell if mutations occur to an “unlucky” set of genes. If a higher dose is received radiation can kill cells and induce radiation sickness. The powers of radioactive material can also be used to cause substantial explosions as with the atom and hydrogen bombs. What I suspect many people don’t know is that radiation can also save you. Radiation therapy have saved millions of people, and emergency exit signs which shine even when there is no electricity have save many more people still. CT scans allows us to detect cancers and other things inside the human body which helps doctors enormously.

Radiation is generally categorized as either ionizing or non-ionizing. Ionizing radiation have enough energy to rip away charged particles or molecules. If that molecule happens to be in the DNA in one of our cells, that cell may become a cancer cell. Non-ionizing radiation, such as microwaves form cell phones, or the visual part of the spectrum that we can actually detect with our eyes, cannot cause this type of damage to cells. Ultraviolet is right on the border between these two, with some ultraviolet rays containing enough energy to rip apart molecules which is why you can get skin cancer from overexposure to the sun. This also means that there is no plausible scientific theory explaning how microwave radiation, which has less energy than ultraviolet rays, from cell phones cause cancer. Togehter with the fact that brain cancer has not increased since cell phones came into use is why I have no problem with letting my children use cell phones. The authors however, focus mostly on ionizing radiation

Gale and Lax starts with the basics, desrcibing what alpha, beta, and gamma radiaiton is and then going into depth about the amount of radation that an average person receives and the interesting discussion on whether exposure to small amount of radiaiton is bad, neutral or even good for you (hormesis). Regarding exposure the authors note that people are quite inconsistent in their fears. For instance, taking a CT scan which many people even demand will give you the same does of radiation as being 6km from ground zero in Hiroshima. Also people tend to be skeptical about being scanned with x-rays on airports, forgetting that they will receive much more radiation during the upcoming flight...

But what do the authors say about the hot topic of nuclear energy. In short they say, while there are of course safety issues, it is better than coal generated power in pretty much every aspect. Renewable sources (sun, wind, water) also have problems associated with them, mainly that they are expensive and that they cannot provide a steady stream of electricity without which our economy cannot function.

What about nuclear accidents though? Lets start with the most recent accident, Fukushima. It is certainly interesting to note that, though some people did receive a large dosis of radiation not a single person have died from radiation expsure till this day. According to wikipedia, the predicted number of Fukushima related cancers range from 0-100, many of which will be possible to treat. The tsunami on the other hand killed approximately 20.000 people. The media coverage often suggets that the Fukushima accident was the big news. This simply reaffirms that people (and the media) have substantial biases in their fears. It is of course more or less impossible to tell people to stop being afraid of shark attacks or flying or anything that has radiation in its name, but lets not base public policy on irrational fears...

Wait you say, what about the Thernobyl accident? Well partly because that reactor exploded (due to a clear design flaw), 10 times more radioactivity was released compared to Fukushima. However, this should also be copared with atmospheric atom bomb tests which releases 200 times more radioactivity than the Thernobyl accident did. These are now banned, however, prior nuclear tests have caused high levels of radioactivity in the environment on a global level.

Estimates of the number of casualties following Thernobyl vary widely and largely depends on whether one thinks that exposure to low doses of radiation increases cancer risks, which is a controversial topic. We are also dealing with a very high basal rate of cancers. Since 38% percent of all women and 45% of all men will be diagnosed with cancer sometime in their life, even say a 0.5 percent increase mean thousands, or millions of people... Bottom line, Thernobyl was a bad accident, and similar mistakes should of course be avoided in the future, however, should we abandon a cheap energy source that almost zero pollution because of one poorly designed reactor and one reactor which was only almost able to survive a major natural disaster?

No one who disputes that nuclear power is associated with some risks. However, what are the alternatives? It is striking how many people simply ignores this question. I often hear environmentalist say that they want the entire society to be based on renewable energy. I fully share that ambition, however it is currently not a feasible alternative which means that we have to chose between nuclear energy and burning of fossil fuels to get sufficient energy. If we don't use nuclear then we have to generate or buy fossil fuels. Yet no one talks about what type of pollutants are released from fossil fuel burning power plants. The authors convincingly show that pollutants from coal burning power plants induce much more harm than waste from nuclear power plants. In one year one coal burning power plant releases 720 tons of carbon monoxide, a toxic gas, 50kg of lead which is poisonous to us as well as to the fish in the lakes where a lot of smoke lands, 80kg of mercury, 10.000 tons of sulfur dioxide which results in acid rain, and 3.7 million tons of CO2. This waste is released directly out into the environment, not burried in a mountain like nuclear fuel. In addition, coal plant workers as well as coal miners develop lethal lung cancer much more often than other people.

 

To sum up the argument for building more nuclear power plants; Yes, there are risks associated with nuclear power but taking into account energy costs and the waste produced nuclear power is currently the best feasible alternative available.

The authors also discusses another controversial issue, namely whether or not we should radiate food to kill of pathogens. In a single year there are 2 billion cases of food poisoning in the world, mainly in the developing world. This number could be drastically reduced by radiating the food which would kill of the bacteria. Yes, some nutrients would be lost but food lose more nutrients when you cook it and that is not controversial. The bottom line is that radiating food can save many lives, particularly in the developing world and there seem top be no rational argument against doing this, if there is I hope that someone will enlighten me.

All in all, radiation is a great and accessible introduction to the field of radiation, a field associated with a substantial lack of knowledge and as a result many irrational fears among the public.

Radiation exposure

Some forms of radiation is dangerous to you and some forms are not dangerous to you. Sunlight, which is a form of electromagnetic radiation, is good for you in moderate doses (it causes your skin to make D-vitamin), but not in large doses (can lead to skin cancer). As a general rule, high energy radiation (waves with a short wavelength) is dangerous to you whereas low energy radiation is bad for you. Radio waves for instance, are so low energy that they cannot do anything to you. At the other end of the scale you have cosmic rays that come in from deep space and hits the earth. Cosmic rays have a lot of energy and when they shoot through your body they may rip up a few DNA molecules, potentially causing the cell to become a cancer cell. Luckily the earths magnetic field protects us from cosmic rays and we generally do not have to worry about them (astronauts do however).

In between radio waves and cosmic rays you find microwaves. These waves have the special property of causing H2O molecules to jiggle. Now jiggling a molecule is the same as heating it up, that is why microwaves are great for heating foods which always contains a fair amount of water. For the same reason you do not want to stick your head in the microwave oven (your brain contains a lot of water to). Mobile phones also communicate using microwaves and when you are using a mobile phone will heat your head a little bit. I want to emphasize little because it is a minuscule amount of heating compared to other sources, and there is no scientific reason to assume that the heating would cause any adverse effects whatsoever.

What about radioactivity? Radioactivity is the high energy radiation that is generated when larger atoms fall apart. In general radioactivity is bad for you because just like cosmic rays it can destroy DNA molecules, however, some forms of radioactivity (alpha particles) are only dangerous if you first eat them (this is because, unlike gamma radiation, they cannot penetrate the skin). For this reason you want to avoid radioactivity as much as possible. Having said that, there is no way that you can avoid radioactivity completely because atoms are falling apart all around us all the time. This informative chart shows how much radioactivity you get from various things you are more or less likely to encounter in your life. For example tonight, when I sleep next to my wife, a certain number of atoms in her body will break, radioactivity will be emitted, and I will receive 0.05 micro sieverts of radiation. You get a hundred times more (5 micro sieverts) if you visit the dentist and get a teeth x-ray, that is why the dentist leaves the room when the picture is taken. If this sounds bad though, consider that a transatlantic flight will give you a full 40 micro sievert, four times as much as a dental x-ray!

All of this pales in comparison to a regular CT scan, a standard technique in medicine that gives you a full 2 milli sieverts, that is 2000 micro sieverts. A chest scan (which I have taken) will give you 7 milli sieverts. Still even at 7 milli sieverts there is no proved risk of adverse effects, although it is not clear that there is no risk either. The lowest dose that has been clearly linked to cancer is 100 milli sieverts. To get radiation poisoning you need 400 milli sieverts and if you get 4 sieverts (4000 milli sieverts), it is usually fatal...

Watch this if you are afraid of mobile phones or microwave ovens

I have previously written about microwaves here and here. However, the fact is that even though I write about it sometimes there really isn't much to say except, fantastic technology, keep it coming. There are NO dangers associated with mobile phones or with microwave ovens (unless you stick your head in one and somehow manages to turn it on. Neither is there any reason to expect that these technologies could be dangerous.

If you want to hear this from a real expert there is a terrific lecture available on youtube which I admit, I found on the fantastic blog Bad Astronomy.

Here is the first part of the lecture.

The rest you can find here: part 2, part 3, part 4, part 5.

One statement that stuck with me was that the radiation you get from base stations (which many people worry about) is approximately equal to the radiation you get from the planet Venus (and as you know the radiation you get from venus is merely reflected sunlight).

Dangers of radiation in the home

The best Swedish site for news on technology, in my opinion, is www.idg.se. Today they have an article on radiation in the home. The article is based on an interview with Maria Feychting professor in epidemiology at Karolinska Institutet. The article discusses the danger of the radiation associated with products that are becomming increasingly common in ordinary homes. I am speaking of mobile phones, routers, wireless keyboards and mice, bluetooth headsets and dect phones.

The conclusion of the article, briefly put, is that there are no scientific evidence that this radiation causes any harm. It is a fact that studies showing potential dangers of radiation get much more attention than studies which show zero effects, even though the latter type are much more common. Furthermore, most of the studies which have shown slight biological effects of radiation have subsequently been replicated with contrasting results i.e. the latter studies did not find any effects.

I think that one of the reasons why some people are so afraid of these things is the fact that they radiate, and we all know that radiation is bad right? No, not necessarily so. Radiation can be your friend to. If it were not for the radiation from the sun we would not be alive. Similarly, seeing involves the capture of radiation by photoreceptors in the back of your retina. In fact we are all rich sources of radiation which you can see for yourself if you have a camera that pick up infrared wavelength.


But isn't that different? Sure some sorts of radiation are more dangerous than others. Cosmic rays which arive from outer space are extremely rich in energy, and alot of that type of radiation would be bad for you. Similarly, X-rays will slightly increase the risk of cancers because it is rich in energy. But what about the radiation from all those home devices? This radiation is lower in energy than normal visual light, so you are very unlikely to get cancer from this type of radiation. These devices actually emit microwaves, just like your microwave oven. The difference is that the radiation is not contained within a box, and also the power is 10,000 smaller than in an ordinary microwave oven (for a dect phone it is 100,000 times smaller). If you want a different point of view on these issues, you can visit this page.

The article also gives some quick answers to the following questions:

1. Does radiation from mobile phones cause cancer: False

2. Will using a bluetooth headset reduce the amount of radiation you are exposed to: True (because a bluetooth headset has a much lower effect than the mobile phone)

3. A dect phone emits more radiation than a mobile phone: False

4. A 3G phone radiates more than a GSM mobile phone: False

5. More wireless devices in the home will make it more dangerous: False

6. A new router radiates more than an old router: False

7. It is dangerous to have your mobile lying next to you when you are sleeping: False

8. The mobile will emit less radiation if you hold your hand over it: False (actually it will radiate more becuase that is necessary in order to communicate the station.

9. Even the good old cable hardware emits radiation: True (anything with a current in it, a cable for instance, will generate a magnetic field which is also basically a form of radiation.


I want to end with a personal reflection on an issue which I think is highly relevant yet often forgotten. Mobile phones, which as mentioned is the device which has the highest effect and thus the highest radiation, has been around for about two decades now. In spite of their popularity, there has not been any increase in cancers in this timeperiod. This "natural experiment" shows that if mobile phones have any effect at all on the human body, that effect have to be very subtle. Pretend for a moment that there has been a slight increase in some obscure form of cancer, or other type of disease, that is a result of mobile phone radiation. Even such a necessarily slight effect would pale in comparison to the enourmous benefits of being able to call ambulances, fire fighters and the police from almost anywhere on this planet. Hurray for mobile phones!