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2015 Feb 9
To The Editor,
The Flin Flon Reminder:
I wish to respond to questions about radiation raised by readers following my speaking engagement in Creighton on January 22.
My message was that radiation is natural and all around us. In fact each one of us is bombarded by roughly 100,000 particles of radiation every second of our lives (approximately 10% of this from our own bodies); this is enough to hit every cell in an adult body, on average, about once per year.
The fact that we (and other living things) thrive in this sea of radiation is a strong suggestion that nature takes care of us: i.e., as with many other natural challenges in our environment, our bodies have protection mechanisms. The fact that some of us develop cancer or other diseases suggests that this protection isn't perfect.
For radiation, the dose below which we don't see evidence of a negative health effect is about 100 mSv, or roughly 50 times our annual natural dose. Any "man-made" radiation that citizens are likely to encounter due to nuclear spent fuel repositories and transportation, will be at most a fraction of one per cent of our natural dose (and more likely zero).
In terms of health risk, there is no difference between natural radiation and "man-made" radiation. The two can differ in quantity of course, and each can potentially be harmful (e.g. high exposures to radon). Interestingly, we probably know more about radiation than any other agent in the environment, and it is also the easiest to track (as I demonstrated in Creighton). In fact a growing body of evidence suggests that environmental levels of radiation might even be good for us - a concept known in the chemical world as hormesis, whereby small amounts of exposure are beneficial, but large amounts are harmful.
As a species that evolved amongst much higher radiation levels than we see now on the planet, it wouldn't be surprising if we depended similarly upon it for good health (the prevailing theory being that it stimulates our immune systems, better preparing us against the onslaught of other chemical agents out there). Some readers challenged this view by bringing up examples of people getting sick when exposed to relatively high levels of radiation (e.g. extended exposure to radon, or polonium in cigarettes) - these are good examples of my point here: low levels are safe; high levels are not.
This should not be confused with how radiation is regulated, which in Canada (following international standards) takes a precautionary approach by assuming a proportional risk right down to the smallest background doses. This has often led to misunderstanding, so it is important not to confuse regulatory best-practices with evidence of a health effect.
This is the science of radiation today - which is what I was asked to represent at the Creighton CLC public meeting. At least one reader chose to challenge my ethics - claiming that I'd lie about the effects of radiation since I work in the nuclear field. I live near Canada's largest nuclear research site, so to such people I would ask: Would you take money to endanger your children, and countless others? Why, I wonder, do you think I would?
Dr. Jeremy Whitlock,
Deep River, ON
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