Impact case study database

Pathway to impact

In 2017, Eddleston established the Centre for Pesticide Suicide Prevention (CPSP; www.centrepsp.org) at UoE with a USD1,300,000 (GBP947,210; 01-21) Incubator Grant from the Open Philanthropy Project Fund. The CPSP uses the research in rural Asia to influence global pesticide policy and promote pesticide regulation for suicide prevention. Its initial work has focused on global policy with the WHO and FAO, and on national projects in Nepal, India, and Sri Lanka, leading to significant international and national policy and practice change.

Impact on policy and guidelines

In 2016, the 3^rd edition of Disease Control Priorities (DCP-3), published by the University of Washington, identified pesticide regulation as a probable highly effective approach to reduce non-communicable diseases, based on UoE research (see panel 2, p.1680, [5.1]). However, at this point, ‘safe storage and use’ of pesticides, based on industry-funded work and pilot studies, continued to also be encouraged as a life-saving alternative to pesticide bans [5.2].

The UoE-led randomised controlled trial [3.5], which definitively showed a lack of effect from ‘safe storage’, led to a major switch in WHO focus, from ‘safe storage’ to pesticide regulation. In 2019, the WHO Mental Health Unit collaborated with the FAO to publish a guideline for pesticide registrars and regulators on how they could prevent suicides through effective regulation [5.3]. The Head of the WHO Unit states: “ *Research work led by Professors Eddleston (Edinburgh) and Gunnell (Bristol) has been seminal in helping WHO formulate its strategy to attain the suicide reduction target within the United Nations Sustainable Development Goals (UN SDGs). Their empirical findings and systematic review concerning the effectiveness of national pesticide regulations in preventing suicide, and the relative ineffectiveness of lockable storage devices in pesticide suicide prevention, informed us to produce the booklet “WHO/FAO Preventing suicide: a resource for pesticide registrars and regulators (Geneva 2019)*”. This booklet concludes, citing paper [3.1]: “For suicides by pesticide poisoning, regulations to ban the most toxic products are the most effective approach to reducing deaths” [p. 20; 5.3].

Impact on WHO’s Menu of Cost-Effective Interventions for Mental Health

Building on this work, in 2019, the WHO assessed the cost-effectiveness of bans of several HHPs as a means of suicide prevention in 14 countries. Eddleston contributed technical expertise and data to this modelling exercise [5.4a] and was a co-author on the report [5.5]. The assessment found that banning HHPs could result in up to 28,000 fewer suicide deaths each year across the 14 countries at an annual cost of USD0.007 per capita. The report concluded that national bans are cost-effective in countries where pesticide self-poisoning accounts for a high proportion of suicides, and are among the most cost-effective mental health interventions evaluated [5.4a; 5.5].

The Head of the WHO Mental Health Unit confirms [5.4a] that this cost-effectiveness analysis informed the WHO’s first draft of the Menu of Cost-Effective Interventions for Mental Health [5.4b], such that regulatory bans on the use of HHPs were included as one of 3 population-wide interventions that could contribute to preventing suicides. The draft Menu was approved by the WHO Executive Board in December 2019 [5.4c], and subsequently formally accepted at the World Health Assembly in November 2020 [5.4a]. Thus, directly informed by UoE research, pesticide regulation now forms an integral part of the WHO’s plan to reduce suicides worldwide.

Of note, bans of HHPs do not mean that farmers cannot use any pesticides: Eddleston’s earlier proposal for a minimum pesticides list (Eddleston et al 2002 Lancet 360: 1163–67) has directly informed an influential analysis, funded by agricultural non-governmental organisations, the US Department of Agriculture, the US Agency for International Development, and the FAO (amongst others). Published in 2020, this proposes, for the first time, a systematic method to implement a minimum pesticide list and outlines lower-risk candidate compounds that could be used instead of HHPs to protect crops while reducing risks to human bystanders, aquatic and terrestrial wildlife and pollinators [5.6].

Impact on practice: national bans in Nepal, India and Sri Lanka

In Nepal, discussion with the CPSP and provision of clinical data from UoE on HHPs being used for suicides in Nepal resulted in bans of 5 organophosphorus and carbamate pesticides in 2019. The Chief of the Plant Quarantine and Pesticide Management Centre (Nepalese Ministry of Agriculture and Livestock Development) testified: “ In part due to these conversations, the Pesticide board took the decision in February 2019 to ban 5 highly hazardous pesticides, including dichlorvos, from agricultural use. These represent all the WHO Class I pesticides that were still being use [sic] in Nepal. We believe that these bans will reduce suicides and episodes of severe occupational poisoning in the country.” [5.7].

They further state: “ Further discussions with the Centre for Pesticide Suicide Prevention informed us that a marked reduction in suicides from aluminium phosphide had occurred in India after the standard 56% pure 3g tablets were banned and replaced by a lower concentration powder. After review of data […] a decision was made to ban these 3g tablets in Nepal. Again, we believe that we will see a marked reduction in suicides as a result of this decision” [5.7].

In April 2018, the Indian Supreme Court instructed the Department of Agriculture to decide whether to ban 18 HHPs following public interest litigation put forward by the Indian non-governmental organisation Alliance for Sustainable & Holistic Agriculture. CPSP was then invited by the Alliance to prepare a submission to the Department of Agriculture on the benefits of such bans for suicide prevention [5.8a]. In August 2018, the Department of Agriculture banned 12 HHPs with immediate effect and a further 6 with effect in 2020 [5.8b]. Several of these pesticides had been shown by UoE research to be extremely toxic and key for pesticide suicides in India and responsible for hundreds of thousands of deaths in the country (paragraphs 26–43 of [5.8a]).

A report to the Sri Lankan government of the 2 key pesticides responsible for suicide in rural areas (carbosulfan and profenofos, as identified in [3.6]) resulted in a request from the Ministry of Defence to the Department of Agriculture to ban these pesticides [5.9a]. Such as ban was also supported by the Sri Lanka Medical Association Expert Committee on Suicide Prevention, which in December 2019 published a policy document recommending bans for carbosufan and profenofos, citing papers [3.2] and [3.4], the WHO/FAO guideline [5.3] and data provided by Eddleston as a special adviser [5.9b].

Impact on health and welfare

Limiting easy access to lethal means by banning HHPs means that the self-harm that does occur is much less likely to result in death, allowing people to survive their transient suicidal impulse and obtain the support they need from family, community and mental health services. UoE’s body of research since 2002 has proven that banning HHPs and thus restricting access to highly lethal means for suicide prevents suicides. Continued global regulation of pesticides to remove HHPs from poor smallholder farms in low-and-middle-income countries will further and rapidly reduce pesticide suicide and, where pesticide poisoning is common, total suicide rates.

In Sri Lanka, the ban on 3 pesticides in 2008–2011, reported in REF2014, was estimated to save an estimated 900 lives per year by 2015 [5.10]. The Indian and Nepalese bans are only now being implemented and their effects will start being seen in the next few years. Approximately 1,200 and 72,000 pesticide suicides occur annually in Nepal and India, respectively. These national bans are predicted to reduce pesticide suicide rates by 40% and 25–30%, respectively, conservatively resulting in an overall reduction of approximately 20,000 deaths per year.

Removal of HHPs from agricultural practice following the new WHO and FAO advice, will, based on the Sri Lankan experience [3.2], result in pesticide suicides globally falling by more than two-thirds each year, from 150,000 per year to fewer than 50,000. Over 10 years, this reduction will save an estimated mean of 75,000 lives per year.