Background: Acute poisoning, especially deliberate self-poisoning with agricultural pesticides, is an emerging global public health problem, but reliable incidence estimates are lacking. Only a few previous studies have assessed the impact of regulatory or other preventive measures.
Objective: To estimate trends in incidence and causes of acute poisoning over time in rural Sri Lanka, and to assess the possible impact of policies that aimed to restrict availability of highly toxic pesticides.
Methods: Time series of incidence of acute poisoning based on retrospective in-patient records of six government hospitals in southern Sri Lanka from 1990 to 2002.
Results: Data of 8,110 admissions for acute poisoning were available for analysis. Most cases were young adults, who deliberately self-poisoned themselves with pesticides, males outnumbering females. Average incidence rate of acute poisoning over the study period was 318 per 100,000 (95% confidence interval [CI], 311 to 325). Incidence of all poisoning showed an increase over the period of study. However, this increase was lower for pesticide poisoning, and the mortality rate and case fatality ratio of pesticides went down towards the end of the 1990s. The decline in mortality was attributed to regulatory controls for the group of highly hazardous organophosphorus compounds implemented in 1995 and for the organochlorine endosulfan in 1998.
Conclusions: Regulatory control of highly toxic pesticides provides important health benefits, especially in terms of lower number of deaths from self-poisoning. However, despite the positive effect of these bans, many deaths from pesticide self-poisoning still occur after ingestion of agricultural pesticides classified as only moderately poisonous.