The World Health Organisation recognises that pesticide self-poisoning is one of the most important global means of suicide, killing around 150,000 people every year.
Highly hazardous pesticides (or HHPs), responsible for these deaths, are sold with few restrictions or control in many parts of the world. Small-scale farmers who use HHPs often do not have facilities for their storage - so pesticides are left around the house, tucked up on high shelves, or hidden in the garden or fields. At moments of stress or anger, they are easily accessible and often drunk with little forethought.
Ingestion of HHPs often results in the person's death. By contrast, drinking other pesticides that are not very toxic to humans causes only mild to moderate poisoning. The toxicity of the pesticides stored in people's houses determines whether the act of self-harm results in death or a mild poisoning with a brief visit to the hospital.
Our work in Sri Lanka has shown that government action to reduce the availability of HHPs in farming communities can dramatically reduce pesticide suicides. After the introduction of HHPs into rural communities in the 1960s, the national Sri Lankan suicide rate increased from around 8/100,000 people over 8 years old in 1960 to 57/100,000 in 1989. Pesticides were responsible for more than 80% of all suicides . More people did not suddenly want to die - simply the poisons now at hand were so toxic and dangerous that there was a massive rise in suicides.Remarkably, pesticide regulation by the Department of Agriculture - identifying the most problematic pesticides one after another and then replacing them in agriculture with alternative pesticides - resulted in a rapid fall in total (not only pesticide) suicides. The rate is now 17/100,000 and continues to fall (see the Sri Lankan case study) [1, 2]. Between 1995 and 2015, pesticide regulation saved an estimated 93,000 lives at a cost of 1.3 US dollars per disability adjusted life year (DALY - a year of good life lost to disability or death). Importantly, these pesticide bans had no apparent effect on the cost of agricultural inputs or outputs .
One of the key barriers to pesticide suicide reduction in low-income countries is a lack of capacity for effective pesticide regulation, such as gathering data on the specific HHPs most commonly used for suicide in the country and drafting the necessary legislation. An absence of systems for surveillance of pesticide poisoning constitutes a further barrier to decision-making. Since countries may register different pesticide formulations that are imported or produced locally under different names, each country needs to conduct its own assessment of what HHPs lead to most harm.
Because the overwhelming majority of pesticide suicides are impulsive (in one study, 47.6% of non-fatal suicide attempts occurred after less than ten minutes thought about the act ), means substitution is rare, and people rarely attempt suicide using other means. With the removal of HHPs from agricultural practice, pesticide suicides globally should fall from 150,000 per year to less than 50,000. We estimate that this will take between 5 and 10 years. Taking the more conservative time period, and a steady reduction over this time, a mean of 75,000 lives per year will be saved over 10 years.
There are other benefits from stopping pesticide poisoning. There are immense emotional and financial burdens for families after pesticide suicides. Preventing deaths, and allowing distressed people the time and space to find help, will markedly reduce these burdens. Fewer children will find themselves suddenly without a parent, with benefits for their development and education.
The reduced availability of HHPs will also reduce the number of cases of people getting poisoned by pesticides while working, either spraying the pesticides or working in sprayed films. There will be less contamination of both food and environment, again offering marked benefits for children growing up in these communities. There will also be fewer cases of accidental poisoning of children as happens in communities using HHPs - for example, the 21 children who died in Bihar from a contaminated school lunch in 2013 .
The usefulness of pesticide regulation has recently been emphasised by the WHO who used the country example of South Korea to report its success. See page 43 in the 2017 World Health Statistics report, cited below.
1. Gunnell D, Fernando R, Hewagama M, Priyangika WDD, Konradsen F, Eddleston M. The impact of pesticide regulations on suicide in Sri Lanka. Int J Epidemiol 2007; 36: 1235-42. https://www.ncbi.nlm.nih.gov/pubmed/17726039
2. Knipe DW, Metcalfe C, Fernando R, Pearson M, Konradsen F, Eddleston M, Gunnell D. Suicide in Sri Lanka 1975-2012: age, period and cohort analysis of police and hospital data. BMC Public Health 2014; 14: 839. https://www.ncbi.nlm.nih.gov/pubmed/25118074
3. Manuweera G, Eddleston M, Egodage S, Buckley NA. Do targeted bans of insecticides to prevent deaths from self-poisoning result in reduced agricultural output? Environ Health Perspect 2008; 116: 492-95. https://www.ncbi.nlm.nih.gov/pubmed/18414632
4. Deisenhammer EA, Ing CM, Strauss R, Kemmler G, Hinterhuber H, Weiss E. The duration of the suicidal process: how much time is left for intervention between consideration and accomplishment of a suicide attempt? J Clin Psychiatry 2009; 70:1. https://www.ncbi.nlm.nih.gov/pubmed/19026258
6. World Health Statistics 2017 report. South Korea success story. Section 3.5, page 43.