Allergic to the twenty-first century.

Journalist Jane Little has extreme reactions to all sorts of household domestic chemicals. She and her father became ill after they used disinfectant on their family farm in Cumbria during the foot and mouth disease outbreak of 2001. After recovering from the initial illness they have both been left with hypersensitivity to all chemicals. She speaks to Dr Judy Gianni, a leading Naturopathic doctor in Tucson, who specialises in treating chronic conditions and Susan Mulloy who suffers in a similar way to herself and who now lives in an isolated community in Arizona which has no chemicals at all as all the individuals living there are so intolerant to the modern world. Professor Claudia Miller from San Francisco attempts to explain why some people have multiple intolerances; she believes it is toxicants that cause the problems. Michael Sharp, Professor of Psychological Medicine at Oxford University specialises in diseases that don't have a clear explanation. He thinks it is far more common than one might think and is keen to avoid people thinking of unexplained diseases as being 'all in the mind.' Michael Depledge, Professor of Environment and Human Health at the University of Exeter discusses epigenetics.