Friday, April 12, 2013

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.

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