Hygiene - Development and change of a term

Being a term of technical language originally, nowadays hygiene is widespread in everyday language. The linguistic law governing such transitions has been well described in philology. Consequently the change of a term from technical to standard language is characterized by the loss of its denotation, its exact and specific meaning, while its connotation is increasing. Initially hygiene was used in the sense of 'maintenance and improvement of health', relating to the private as well as public and working area. As all kinds of dirt and pollution have been recognized as a risk to health, hygiene more and more became a synonym of cleanliness and sterility. This sense of word has soon been widened by 'free of something that does nor belong'. Therefore a metaphorical use of the term became possible, the meaning of which may differ completely from the technical sense. It is the question, in what way the conception of the field gets influenced by these facts of the matter.