UNINTENTIONAL FATAL PARAQUAT POISONINGS AMONG AGRICULTURAL-WORKERS INCOSTA-RICA - REPORT OF 15 CASES

This study analyzes the exposure circumstances of 15 fatal occupationa l paraquat poisonings. To evaluate the potential danger of dermal abso rption and the amount needed to produce a fatal outcome in the event o f oral intake, we reviewed the medical records and autopsy protocols a nd interviewed relatives. Five fatalities were due to ingestion of a m outhful of paraquat concentrate, and five to intake of a smaller amoun t, three cases were associated with dermal exposure, and in two, there was no evidence of either oral or dermal exposure. Several cases conc erned diluted paraquat spray The clinical and pathomorphological findi ngs, including a ''blinded'' evaluation of lung slides, were consisten t with paraquat poisoning in all cases. Difficulties in establishing t he diagnosis and recognizing the exposure were identified, as well as classification of unintentional poisonings as suicides at autopsy. The findings suggest that paraquat may cause fatal poisonings by ingestio n of small amounts, by dermal absorption of diluted paraquat, and poss ibly by inhalation. More conclusive studies are warranted. (C) 1997 Wi ley-Liss, Inc.