3 of 18

Write now Article Tools

LOW-LEVEL RADIATION

Our bodies are subject to all sorts of chemical and physical insults from the food we eat to thermal changes that occur. These insults' to our body, as they are called, cause breaks in the strands of our DNA at very high rates: 8,000 per body cell per hour. Any one of these can result in cancer. The lifetime damage is immense: 5 x 1019 breaks in 75 years so it would seem that it's almost certain we will have cancer.

Fortunately, most of this damage is bypassed by cell reproduction (the damaged ones reproduce less often) or they are repaired. We have a wonderful body.

But anti-nuclear activists teach us that any radiation can cause cancer. How might that happen?

If we add radiation to our normal cancerous background about 100 more breaks are added to the 8,000 per cell per radiation unit (10 mGy.) This is true if we are irradiated instantaneously and receive all the radiation in one dose. However, if we get that radiation unit spread out over a year as an increased background dose we add about one break per cell. That compares to 200,000 breaks from oxidative and thermal insults from food and our environment. Such a low increase in harm (1 in 200,000) is negligible in adding to the risk of cancer.

However, there are important benefits because this low level radiation enhances the repair mechanism for the other potential cancers and it makes our risk of cancer lower.

The effects have been well demonstrated in epidemiological studies (studies of effects) of large populations. Low-level radiation effects are difficult to study because, by definition, the effects are small and take a long time to develop. So, we study them through studies of large populations that experience the same radiation conditions for a long time. We also have to remove confounding effects such a smoking, poverty, bad diet and so on.

Long-term studies have been performed with stable populations up to 80,000 people, in places where the people can be tracked. Chinese peasants, for example, do not move around like Americans so it's easy to track large populations for decades. A large population that lives in a high background radiation area is compared to a similarly sized population in a low background radiation area.

These studies have been done in China, in India, in Brazil, and in the USA, among groups subjected to weapons testing, in populations whose work is with nuclear materials, in patients of low-dose radiation therapies, and in survivors at Nagasaki and Hiroshima. It

• 1
• 2
• 3
• next page >>

Add your voice

Know something about The issues around nuclear power?
We want to hear your view. Write now!