In 1973, BBC Radio broadcast an interview with an elderly academic, Dr. Clothier, who discoursed on the government's efforts to stop the spread of Dutch Elm Disease, which had been infecting many of England's trees.
Dr. Clothier described some startling recent discoveries about the tree disease.
For instance, he referred to the research of Dr. Emily Lang of the London School of Pathological and Environmental Medicine who had found that exposure to Dutch Elm Disease immunized people to the common cold. Unfortunately, there was a side effect. Exposure to the disease also caused red hair to turn yellow. This was attributed to a similarity between the blood count of redheads and the soil conditions in which affected trees grew. Therefore, redheads were advised to stay away from forests for the foreseeable future.