Allergies.

Alex Kirby investigates allergies. More than half the UK population suffer from allergies. Prevention would be best, but Dr Sarah Myhill says pharmaceutical companies have a vested interest in developing drugs to suppress symptoms over years, but never really finding causes. Unchecked allergies may become systemic, and Dr Myhill believes, can cause Chronic Fatigue Syndrome. Prof. Jean Golding is running 'Children of the 90s', a study of 14,000 children to examine allergies which could be absorbed through the skin. Dr Seif Shaheen is testing how a pregnant woman's diet affects her children, and advises mothers against smoking. Industrial pollution worries Dick Van Steenis. Jonathan Rostov explores the idea that too much hygiene is weakening immunity. Tony Frew is experimenting with a DNA vaccine. Sarah Myhill suggests a link between silenium or zinc deficiency and asthma .