Allergic to the 20th century.

An investigation of the various causes of asthma, beginning with the medical detective work that tracked down the cause of a severe outbreak of asthma in Barcelona in 1981. Finds a complexity of environmental, chemical and physical causes, including the human body's ancient immunological defence against parasitic worms, no longer required but capable of being activated by otherwise harmless airborne substances. There is a report on an antenatal asthma prevention research project conducted by Dr. David Hide (Allergy Unit, St. Mary's Hospital, London), and on research into occupational asthma and the effects of exposure to allergens during the first year of life.