Methods for survey and diagnosis

This contribution is an overview of current epidemiologic methods used in evaluating organic dust-containing environments for evidence of adverse pulmonary effects. Potential problems include vague diagnostic criteria of "disease" and inadequate tools for definitive diagnosis, as illustrated by asthma and hypersensitivity pneumonitis. The enthusiastic investigator may consider trivial changes indicative of real or potential disease, and add the studied environment to a growing list of menaces of the workplace or of everyday life. Attention to scientific principles is needed lest epidemiology becomes scare-mongering made respectable by sophisticated statistics.