Pesticide Suicides: What More Evidence is needed to Ban Highly Hazardous Pesticides?

Globally, but particularly in low-income and middle-income countries (LMICs), pesticide ingestion is used as a means of self-harm and poisoning. Epidemiological research during the past 20 years has presented much evidence of the concerns, problems, and solutions, as well as how agricultural pesticide suicides contribute to the global burden of disease. Of particular concern are pesticides that fall into one of the eight criteria from the UN Food and Agricultural Organization and WHO 2008 Joint Meeting on Pesticide Management, which resulted in classification criteria for highly hazardous pesticides. 

Many of the pesticides used for suicide fall into the first seven criteria, which are based on a hazard classification from their inherent toxicity, or they are listed on an international convention. Criterion eight, however, is more nuanced, such that evidence is needed to illustrate that the active ingredients and formulations of the pesticide have shown a high incidence of severe or irreversible adverse effects on human health or the environment, such as suicide data. Yet these data are not globally recognised or used as evidence of a pesticide leading to a negative health outcome. 

Evidence has been mounting for global action to eliminate highly hazardous pesticides. In The Lancet Global Health, Y Y Lee and colleagues aptly illustrate the cost-effectiveness of national banning of highly hazardous pesticides linked to suicides, using the methods of WHO-choosing interventions that are cost-effective (ie, WHO-CHOICE). Lee and colleagues highlight two key strategies for preventing pesticide suicides, which are to invest in mental health treatments or to remove access to highly hazardous pesticides. Their study clearly shows that the estimated cost of and time for an effect to be realised through mental health interventions is not as justifiable as the national elimination of highly hazardous pesticides.

It should be noted that banning highly hazardous pesticides is not anticipated to completely prevent pesticide suicides, but rather, as Lee and colleagues rightly state, to induce a shift to less fatal suicide attempts with less toxic pesticides. This in turn allows longer-term mental health interventions to be accessed. The article contributes another angle to the increasing evidence that removing access to highly hazardous pesticides is key for protecting the health of vulnerable populations such as children, workers, and people with suicidal thoughts, ideation, or plans. This research also raises the question of whether we really need any more evidence to trigger the banning of highly hazardous pesticides. 

Oddly, because of the history of chemical regulation and the initial absence of their regulation for health effects, pesticides have been generally viewed as innocent until proven guilty. The burden of proving ill-health effects has rested with academic researchers and non-governmental organisations conducting epidemiological studies with limited funding, as well as with regulators. Although there is a shift in high-income countries, such as within the EU, to move this burden to pesticide-producing corporations—with a focus more on the hazard classification than risk assessment—this is less the case with regulatory bodies in LMICs. Furthermore, industry does not have to include data implicating a potential health risk or risk factor of a pesticide linked to self-harm. There is ample existing data on pesticide poisonings globally, the health effects associated with pesticides, and the costs of these effects. Yet, these findings are not always a catalyst for implementing stricter regulations or bans. 

In international pesticide management, pesticide suicide data have been side-lined as evidence for managing a particular pesticide because of the tendency to classify this use as “misuse” of pesticides, which places blame on the end user and not on regulation, labelling or easy access. This trend is evidenced by suicide data not being permitted for use when a country submits risk assessment data to advocate for listing a pesticide under the Rotterdam Convention. A listed pesticide triggers a process of prior informed consent, whereby an importing country must be informed of the exporting country's regulatory status for the pesticide in question. There needs to be a move away from this separation of unintentional and intentional pesticide exposures and poisoning data, towards using both as evidence for decision making. The result of this separation has been to exclude poisoning and mortuary data linked to pesticide suicides from regulatory and policy decision making. Furthermore, research has indicated that pesticide exposures could have a role in depression leading to pesticide self-harm. The work of Lee and colleagues, and others, suggests that suicide data should be used for evidence-based policy making, particularly for poor and marginalised communities in LMICs exposed to highly hazardous pesticides. 

Self-harm using pesticides is less of a problem in high-income countries, where stringent legislation and regulation prevent easy access. Lee and colleagues’ findings highlight an urgent need in LMICs to ban highly hazardous pesticides and to include suicides in all pesticide poisoning data that are used in decision making. 

As Donely observes, banning a pesticide takes on different formats in each country, given the complexity of national legal structures and push-back by industry, and the concept of banning should therefore be viewed as referring to eliminating any access to the pesticide. Crucially, as Lee and colleagues emphasises, all access to highly hazardous pesticides should be eliminated with urgency, whether this is achieved legally through a ban, withdrawal of registration, or non-renewal of registration of a pesticide, or whether a company is urged voluntarily to withdraw a product. 

Globally, there is a move within chemical research—including costing health effects and prevention interventions—to highlight the economic effect on a country of inaction, rather than only action. Whereas Lee and colleagues show the cost effectiveness of taking action by eliminating highly hazardous pesticides, another question to be asked is what the cost of inaction will be to countries, communities, and families. Despite the limitations of studies, it is time that regulators and the international chemicals management community include pesticide suicide data as part of decision making.