Phenoxy acid herbicides and contaminants: description of the IARC International Register of Workers. IARC Working Group.

An International Register of Persons Exposed to Phenoxy Herbicides and Contaminants was established in 1984 by the International Agency for Research on Cancer in collaboration with the National Institute of Environmental Health Sciences (U.S.A.). The purpose of this Register is to investigate the long-term hazards associated with exposure to these herbicides and to serve as a system of scientific collaboration at the international level. Presently, 18,972 workers from 19 cohorts in 10 countries are enrolled in this Register. Fifteen cohorts are from companies that manufacture and formulate phenoxy acids or chlorophenols, and four cohorts are sprayers of phenoxy herbicides. Cancer incidence and mortality are the main outcomes of interest, and vital status for members of the Register has periodically been updated. The great advantage of this Register is its large size, facilitating the detection of hazardous effects of exposure.