SCIENCE How fall-out kills

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•We were going to get a fallout shelter, but we thought THE long-term -effects of nuclear war are caused by radio-active fall-out (particles of dust made radio-active and thrown into the air by a nuclear explosion).

Most fall-out comes down locally - in our example of a one-megaton bomb on the centre of London, with a stiff breeze towards Manchester, heavy deposits of fall-out occured as far away as Glasgow. Up to one-fifth of the fall-out around the earth by the prevailing winds, most staying in the northern hemisphere (where it was produced!

Long-term

Most will descend in a belt around the world over the next four weeks. The longer it stays in the air the less radioactivity it will contain as this gradually breaks down.

Only the longer-lived radioactive elements (Caesium-137, Carbon-14 and Strontium-90) will be left.

Cancer

• But what are the long term effects on humans of radiation? There are two types of long-term effects -one is on those who have survived immediate exposure to fall-out, the other is on people who may be thousands of miles away.

In the first case there is a greater risk of cancers -in our example, 5-10% of the survivors of an LD50 dose of 450 rads* (Derby area, would develop cancers.

Even in Glasgow, something like 1,000 cancers will be caused - from a bomb in London!

A similar number of genetic (i.e. inherited) handicaps will also be caused. Other long term effects suffered by some of the victims of immediate fall-out will be cataracts, leukaemia, retarded development of unborn children and infertility of War. ›ut shelter, a bomb would be safer." be safer." men lasting for years.

There will also be an increase in stillbirths and mental retardation of some newborn children.

Now what about delayed fall-out? This will pose a risk to anyone in the world -more so in the north. For example, there was a small increase (about 5%) in leukaemia cases, when atom bomb tests were taking place in the atmosphere. An all-out nuclear war would pose a far greater threat.

The long-lived elements mentioned previously are easily absorbed by plant life which will eventually be eaten by various animals including us. Strontium-90 is very similar to calcium and goes straight to the bones where it can cause leukaemia while Caesium-137 and Carbon-14 will go to all parts of the body where they can cause other types of cancer.

*The LD50 dose is the amount of radiation that will kill 50% of people who receive it.

Heath, United Kingdom Heat

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