This chapter contains sections titled: Scope of Epidemiology Epidemiological Studies on Dioxin-Exposed Populations Clinical Observations Case–Control Studies Cohort Studies on Producers and Users of Dioxin Contaminated Chemicals Cohort Studies on the General Public After Accidents Cohort Studies of Pulp and Paper Mill Workers Environmental Exposure through Pollution Other Organochlorines and Organobromines General Conclusions References