Hospitals are zapping X-ray patients with levels higher than necessary.

A survey published by the Consumers' Association shows that many hospitals don't follow guidelines to keep radiation doses to an absolute minimum.

These guidelines stipulate that before X-rays are taken, staff ask whether X-rays of the body part to be filmed have been done before and check earlier hospital records.

Just over half of those surveyed said they were not asked if the relevant body part had been X-rayed before, and nearly three quarters were asked on the day of the procedure, when it might be too late to locate the earlier X-ray films.

Furthermore, nearly three out of l0 women of childbearing age had not been asked whether they might be pregnant before given an abdominal or pelvic X-ray.

Forty per cent of the men were given no genital shielding, to guard against damage to sperm.

According to the British Medical Journal, these findings are similar to ones published in September by the Royal College of Radiologists which estimated that unnecessary radiation from X-rays might be responsible for between l00 and 250 of the l60,000 deaths from cancer in Britain each year.

If you face X-ray tests now or in the future, the Consumers Association suggests that you (l) tell your doctor about any previous X-rays, (2) question the need for pre employment chest X-rays or, if you are under 50, female and have no history of breast cancer, routine mammograms, (3) insist on gonadal shielding and (4) tell your doctor if there's any possibility that you are pregnant.