Key agricultural pesticides responsible for acute pesticide poisoning in rural Sri Lanka - data to guide policy decisions.

Abstract

Introduction: Acute pesticide poisoning is a major public health problem among agricultural communities in low-and middle-income countries. Using recent surveillance data, this analysis identifies key pesticides responsible for acute poisoning in Sri Lanka to inform timely, evidence-based policy interventions, with relevance to similar agricultural settings.

Methods: We analyzed interim data from two prospective studies in rural Sri Lanka: 1) a suicide surveillance system (Oct 2023-Apr 2025) and 2) a community-based cohort of 1,200 pesticide sprayers (Jan-Dec 2024). Self-poisoning deaths were identified through police, coroner, and household follow-up data, while occupational poisoning was monitored through bimonthly cohort follow-up. Descriptive analyses were identified the pesticides and active ingredients responsible for poisoning events.

Results: Of 1,040 suicides identified, 236 (22.7%) involved pesticide ingestion; a single pesticide was confirmed in 184 (78.0%) of deaths. Insecticides accounted for 165/184 (89.7%) deaths, predominantly the carbamate carbosulfan (120/184, 65.2%; 95% Confidence Intervals (CI) 58.3-72.1) and organophosphorus profenofos (20/184, 10.9%; 95% CI 6.4-15.4), with a small proportion involving illegal pesticides (13/184, 7.1%) or herbicides (19/184, 10.3%). Pesticide sprayers reported 1,311 incidents of acute occupational pesticide poisoning, with 856 events occurring after use of a single identified pesticide. Insecticides were the most frequently implicated, led by profenofos (167/856, 19.5%; 95% CI 16.9-22.1), followed by herbicides, including pretilachlor (125/856, 14.6%; 95% CI 12.2-17.0) and glyphosate (81/856, 9.5%; 95% CI 7.5-11.5).

Discussion: These findings show that most pesticide poisoning is concentrated in two insecticides: carbosulfan and profenofos. Their continued prominence despite earlier regulatory actions suggests ongoing pesticide substitution and highlights the need for strengthened surveillance and targeted regulation.

Conclusion: Carbosulfan and profenofos now account for most pesticide suicides in Sri Lanka, while profenofos is also the leading cause of acute occupational pesticide poisoning. These findings highlight the need for ongoing surveillance and timely regulatory review.