The increasing use of paraquat as a suicidal agent.

Paraquat, the most important of the bipyridyl group of herbicides, has proved a most effective weedkiller and is now in world-wide use. When used as intended, the compound is quite safe, but misuse has led to a significant number of deaths. If taken orally in significant amounts a fatal outcome is likely and there is as yet no effective antidote. Deaths from paraquat poisoning have been proportionately higher in Ireland than elsewhere. The present paper analyses 26 fatal and 7 non-fatal poisonings occurring in Northern Ireland during the period 1967-1975. The history, clinical features, length of survival and pathological findings are discussed. Extensive toxicological analyses have been performed on samples taken during life, and on a wide range of body fluids and tissues obtained at autopsy. These data are presented and show the progressive but slow fall-off in paraquat recovery after ingestion, with detectable levels still present for up to 21 days. The increasing incidence of suicidal, as opposed to accidental, paraquat poisoning is stressed. The decline in accidental poisoning suggests that the measures taken to prevent accidental ingestion are proving successful. The swing from accident to suicide is reflected in the shorter survival times, differing autopsy findings and significantly higher tissue and body fluid levels encountered in suicidal poisonings.