SCIENCE New Facts on the Strontium Peril

By J. H. Bradley A RECENT article in Nature gives an account of the official experiments on the uptake of Strontium-90 fallout by plants—experiments whose meaning and ominous results no British newspaper has seen fit to mention.

Rigorous safety precautions were used, and the work was done with Strontium-89. which is safer but has exactly the same chemical behaviour.

The work, though very far from satisfactory, was more systematic and scientific than suggested by the official account given in the House of Commons.

It is interesting to note that higher strontium-calcium ratios are found in roots than in leaves and shoots. a result which is rather surprising and of great theoretical importance.

Even a little Strontium is dangerous The very small amounts of strontium needed for these experiment do not appreciably influence the uptake of calcium. It is calcium which strontium replaces: very little strontium is enough to be dangerous.

Different plants show different degrees of uptake, which can be due in part to the different structures and levels of their roots. A fuller table of the uptakes as related to root structure and depth of ploughing could easily have been included. but perhaps would have made the question uncomfortably clear for some politicians.

It is urgently necessary to extend the trials beyond sugar beet. tye grass, and barley. to include important crops such as potatoes, green vegetables, lettuce. tomatoes, and wheat.

Indeed, one wonders why no crop for human food was chosen for these trials—sugar is, after all, the most carefully purified article of human diet!

Nor do the investigators put forward any reason for their choice based on the classification of plants.

lt was shown that stubble led to 25 per cent greater uptake than fallow—a result of great scientific significance, which in itself can lead to extensive work and a good deal of elucidation of obscure questions in the uptake of minerals by plants.

Uptake after using a rotary cultivator was 0.388 per cent: after ploughing to a depth of seven inches 0.526 per cent: after seven-inch and twelve-inch ploughing. 0.442 per cent.

The seven-inch ploughing simply brought the strontium down to the roots, while the figures given show that twelve-inch ploughing brought 70 per cent of it back to the surface. with the obvious result.

In addition, we are told that the ‘hard subsoil’ (chalk!) was at nine inches depth. so that twelve-inch ploughing brought an extra 25 per cent chalk into the topsoil. i.e., about 300 tons per acre.

It is not then surprising to learn that liming at half a ton an acre had no effect, even allowing for the very bad mixing in ploughing.

The ploughing trials are interesting as showing that in a heavily contaminated area after an H-bomb explosion, harrowing might be the best treatment to give. Fall-out should be buried as far as possible. to cut down direct radiation dangers.

The complete unrealism of so-called Civil Defence in Britain will probably mean that this very important question of the best method of disposal will be completely ignored.

Again, we are told that fall-out is ‘relatively soluble’ but not relative to what. Maybe it really was “much as when washed down by rain’, but every scientist wants very good evidence before believing that.

It has solved no problems This investigation has raised many problems, and solved none; which is not surprising. in view of the choice of those high-calcium conditions which any schoolboy can understand are bound to give the most favourable of all possible results for the Government.

Perhaps this why the strontium-calcium ratios are given for the plants, but not for the soil. Rough calculations suggest that the two figures are not greatly different if the soil has about one per cent chalk in the top 10 inches.

Unfortunately this figure is much too low, and the conclusion is that there is a strong preferential uptake of strontium —the very fact the Government wishes most to conceal.

Trials on the calcium-deficient Welsh mountains will tell a much worse story again.