Deaths from Pesticide Poisoning: Are we lacking a global response?

Abstract

Self-poisoning with pesticides accounts for around a third of all suicides worldwide. To tackle this problem, WHO announced a Global Public Health initiative in 2005. Planned approaches will range from Government regulatory action to the development of new treatments for pesticide poisoning. With broad-based support this strategy will have a major impact on the global burden of suicide.

Suicide is an important cause of premature mortality accounting for an estimated 849,000 deaths every year (WHO, 2002). In many agricultural communities of low- and middle-income countries pesticide self-poisoning accounts for many of these deaths (Gunnell &Eddleston, 2003). In 1985, based on data from Sri Lanka, Jeyaratnam estimated there were approximately 2.9 million cases of acute pesticide poisoning, resulting in around 220,000 deaths each year in the developing world (Jeyaratnam, 1985a). More recently, based on the finding that pesticide ingestion accounted for over 60% of suicides in many rural areas of China and South-East Asia, Gunnell & Eddleston (2003) estimated that there may be as many as 300,000 deaths each year from intentional poisoning (i.e. suicide by ingestion of pesticides) in these regions alone. This makes it likely that pesticide poisoning is the most frequently used method of suicide worldwide.

The research and policy attention pesticide poisoning has received has been relatively small in comparison to the magnitude of the problem (Buckley et al 2004; Gunnell & Eddleston 2003). Jeyaratnam (1985a) suggested that part of the reason pesticide poisoning had not received the global attention it deserved was the lack of scientific evidence concerning the extent of the problem. Even though a global estimate is still not possible today, due to the lack of large-scale, rigorous surveillance data, evidence is growing that the burden of pesticide poisoning has by no means been underestimated. Whilst data from low income countries in South America and Africa is less comprehensive than that from China and South East Asia, evidence is emerging that pesticide poisoning is equally important in such settings. In Brazil, for example, the high suicide rates in tobacco growing regions may be due to the wide use and availability of pesticides (Csillag, 1996). Furthermore, pesticides accounted for 18% of male and 7% of female hospital admissions for self-harm in Campinas, Brazil in 2002-4 (Fleischmann et al, 2005). In Southern Trinidad over 80% of suicides in one rural area were due to pesticide poisoning (Hutchinson et al, 1999). In Suriname a high proportion of both fatal (55%) and non-fatal (44%) episodes of suicidal behaviour involve pesticides (Graafsma et al, 2005). In Africa, data from Zimbabwe show rising levels of admissions for organophosphate self-poisoning: self-poisoning accounted for around three quarters of the approximately 200 admissions in one study (Dong & Simon, 2001). More recently data from Malawi implicated pesticide self-poisoning in almost 80% of suicides (Dzamalala et al, 2005).

Despite the problems in estimating the global burden of pesticide poisoning, we may safely assume that we are confronted with millions of cases of pesticide poisoning, hundreds of thousands of which result in deaths each year in low- and middle income countries. There is an urgent need for immediate action.

Approaches to suicide prevention

Two of the major components of current international suicide prevention strategies are the improved recognition and treatment of mental illness and restricting access to commonly used methods of suicide (WHO, 2004).

Mental disorders are found less frequently in suicides in Asian than in Western countries, possibly because a greater proportion of deaths in Asia result from the use of highly lethal pesticides in impulsive acts of self-harm. Nevertheless mental illness is present in a significant proportion of Asian suicides (Phillips et al, 2002) and is thought to play an important role in suicidal behaviours, underlining the role of mental health workers in these settings.

Epidemiological evidence demonstrates that restricting access to commonly used methods of suicide may lead to reductions in overall as well as method-specific suicide rates. The potential impact of changing the availability of pesticides on both pesticide poisoning and overall suicide numbers has been demonstrated in Western Samoa (Bowles, 1995). Furthermore, the benefits of restricting pesticide use to those least harmful to humans in self-poisoning is demonstrated by the widely differing case fatality rates associated with different pesticides - from >60% for paraquat (Hettiarachchi & Kodithuwakku, 1989) to <10% for several products (Eddleston et al, 2005;Eddleston, 2000). Likewise, just as the development and widespread use of N-acetyl cysteine had a dramatic effect on trends in paracetamol mortality in the England & Wales (Flanagan & Rooney, 2002) so too may the development of new antidotes to pesticide self-poisoning reduce suicides in low and middle income countries. International research in this area should be a global priority (Buckley et al, 2004). However, to date, the global response to the problem of self-poisoning with pesticides has been poor.

An intersectoral global public health initiative

In collaboration with other relevant UN agencies, governments, academic institutions, non-governmental organizations and interested parties, WHO has announced an intersectoral global public health initiative with the overall goal of reducing morbidity and mortality related to pesticide poisoning, adhering to a strategy of concerted action at various levels. The five objectives of the programme are:

• Review and recommend improved pesticide regulatory policies;

• Implement sustainable epidemiological surveillance and monitoring of pesticide poisoning in clinical settings and communities;

• Improve the medical management and mental health care of people with pesticide poisoning in health care facilities at different levels;

• Provide training in the safe handling, identification and management of pesticide poisoning at different sectors and levels;

• Develop or strengthen community programmes that minimize risks of intentional and unintentional pesticide poisoning.

There are three components to WHO’s strategy. First, to establish sentinel projects in selected countries with a high burden of intentional and unintentional pesticide poisoning. Second, to establish regional centres, associated with the sentinel project sites, for the prevention and management of pesticide poisoning, and for enhanced surveillance, training, and community action. Third, to disseminate information to governments, decision makers and the public at large about insights, experience, and lessons learnt from research, formulated as recommendations to guide global policy and local action for the prevention and management of pesticide poisoning.

When suicidal behaviour plays an important role in non-fatal and fatal self-poisoning by pesticides, it is key that relevant preventive measures are anchored in national suicide prevention programmes; these, unfortunately, mostly do not exist as yet in low- and middle income countries. To this end, WHO has started to work with governments worldwide to raise awareness of the importance and magnitude of suicidal behaviours and to provide technical assistance in the development and implementation of national strategies for suicide prevention.

It is crucial that governments ratify and enforce the Hazardous Chemicals and Wastes Conventions, i.e. the Basel, Rotterdam, and Stockholm Conventions. The majority of countries where pesticide poisoning is a major problem have not done so (Konradsen et al, 2005). Together, these Conventions cover key elements of the management of hazardous chemicals, most comprehensively in the case of Persistent Organic Pollutants (POPs), which are covered by all three treaties (www.basel.int; www.pic.int; www.pops.int; last accessed on 21 February 2006).

Closing remarks

The available data suggest that acute pesticide poisoning has been a major problem in developing countries for many years and that it should be a major public health concern today. Jeyaratnam (1985b) argued 20 years ago that most research studies and publications on the impact of pesticides on health concentrated on aspects relevant to the industrialized world and that the industrialized countries have in fact been able to successfully control pesticide poisoning.

Although little has been done in developing countries, there is encouraging work in progress. Pilot studies are underway in some areas of China and Sri Lanka to assess the effect on suicide and suicide attempts in rural areas of the adoption by farmers of a double locked box where pesticides are stored. In Sri Lanka the Non-Governmental Organisation (NGO) Sumithrayo and other groups are active in evaluating interventions of this sort. Early results from one group working on the feasibility of locked boxes in Sri Lanka suggest that this is a practical approach to pursue, if developed in collaboration with local communities, signalling the importance of large scale evaluations (personal communication: Flemming Konradsen). With creativity, willingness and appropriate funds much can be done to prevent this unnecessary loss life.

Considerable work is still required to determine the appropriate balance between public health approaches to reduce pesticide poisoning and the need for crop protection products by the agricultural sector.

Action has to be effective at least in the areas of pesticide policy, pesticide information, mental health care, clinical management of pesticide intoxication and restricting hazardous exposure to pesticides. In view of the complexity and novelty of many of these areas, a solid yet feasible research programme has to back them. This will only succeed if a broad intersectoral and financial support is made available, involving the governmental and the private sector, including relevant NGOs and agencies of the UN System.