[Methodic aspects of the determination of threshold values for air hygiene on the basis of epidemiologic studies]

Longitudinal epidemiologic studies using descriptive and analytical techniques are suitable for deriving threshold values applicable to extreme emission cases once potential disturbing quantities have been systematically eliminated. Eliminating time responses and thus reducing the problem to the deviation of the related morbidities from the mean curve as a function of the agent concerned, is an essential element of the method. An approach varied according to this method makes it possible to utilize the entire information contained in epidemiologic and air protection data without having to use integrative techniques which would also reduce value and time resolution.