Radiation Hormesis

The word “hormesis” is derived from the Greek word “hormaein” meaning: “to excite,” which is the origin of the word “hormone.” In 1902, the English physiologist, E. Starling, discovered that an acid extract from the human duodenum contained a substance designated as secretin that, when discharged into the bloodstream, stimulated the pancreas to release its secretions when food has passed through the stomach. In 1904, Starling coined the word "hormone" to designate any substance that is produced by the body in small amounts and carried in the bloodstream to affect the function of other organs. Biochemistry during the 1920’s was called physiological chemistry and developed around the study of vitamins and hormones, both low dose substances. C. Southam and J. Erlich noticed that large concentrations of oak bark extract inhibited fungal growth, but in low doses they lead to the paradoxical effect of stimulating fungal growth. Publishing their results in the journal Phytopathology in 1943, they modified Starling's word to "hormesis" which describes stimulation by low doses of agents that are harmful or lethal at high doses. Hormesis came to refer to any stimulatory or beneficial effect induced by low doses of an agent that cannot be predicted from extrapolation of its detrimental or lethal effects when administered at high doses. When considered from the perspective of ionizing radiation, the topic raises heated debates from a majority of health physicists that vehemently opposes the concept calling it a pseudo-science and a minority of radiation biologists supporting it, leading to an unsettled controversy.