Epidemiology of atrazine.

Chronically exposed workers in chemical plants have revealed no increased incidence of benign or malignant disease attributable to atrazine. Some case-control studies showed a slight increase of non-Hodgkin's lymphoma (NHL) incidence while others were negative. Weighted evidence supports no causal association of malignant changes in farming populations with atrazine. Two studies on a rural population suggested an increase of ovarian tumors in exposed women. Neither statistics nor exposure data are satisfactory, however, and no other studies present supporting evidence. New studies under clearly defined conditions are desirable. Very high doses of atrazine ingested in suicidal attempts had no acute clinical effect, suggesting that atrazine is virtually innocuous to humans. Sporadic reports on suspected acute poisoning leave too many questions open to be convincing: they reflect coincidence rather than causality. The tolerance of ruminants to triazine is limited. Severe poisoning in case of accidental intake of concentrated products is to be expected. Poisoning through ingestion has been controlled with activated charcoal. Adsorption on fodder enhances tolerability of triazines. Suspected poisoning through spray-contaminated fodder requires differential diagnosis to avoid confusion with other pasture toxins, electrolyte problems, or gastrointestinal infection.