How pesticide poisoning became a global health problem

To mark World Health Day 2024, Ellie Roger explores the causes of pesticide poisoning – one of the world’s major, yet often overlooked, health challenges.

*Warning: This article discusses self-harm and suicidal behaviour. If you have questions on self-harm or feel suicidal, use this link to find an international helpline.*

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There is little doubt that pesticide poisoning is a significant public health problem. Every year, 385 million people (that’s 44% of the world’s farming population) are poisoned in the course of their work, with an estimated 11,000 people sadly losing their lives.

Even more significantly, more than 100,000 people die yearly from intentional (self-harm) poisoning with pesticides. Pesticide poisoning is one of the most common methods of suicide worldwide, responsible for at least 14 million deaths since the 1960s.

This is a problem that is disproportionately affecting vulnerable people living in low and middle-income countries. These are countries that generally rely heavily on agriculture, with much of their population employed in small-scale farming in rural communities.

There are also the chronic effects of pesticide poisoning, from long-term pesticide exposure of those applying pesticides, as well as their families and children who live, work and play in the fields. This has been linked to the development of Parkinson’s disease, asthma, depression and anxiety, attention deficit and hyperactivity disorder (ADHD), and cancer.

How did we get here? What has caused this issue? And why has so little action been taken?

The Green Revolution and widespread use of pesticides

The root of the problem can be traced back to the Green Revolution – a period in the mid-twentieth century when the spread of new agricultural technologies dramatically increased global food production.

Alongside the introduction of new plant strains, fertilizers and irrigation systems, pesticide use quickly became widespread in new parts of the world.

This huge influx in (often unregulated) pesticides meant that a wide variety of products became readily available. They were sold in local shops with few restrictions. They were then taken home to farming villages, where they were kept in homes and gardens.

Farmers were led to believe that pesticides could do nothing but good. Pesticides were thought to be ‘medicine’ for their crops – essential for successful farming. They had little knowledge about toxicity, or safe usage and disposal.

However, as the world celebrated an increase in food production, far less attention was given to the significant, growing number of people who were dying from pesticide poisoning.

The graph below illustrates the impact of the Green Revolution on suicide rates alone in Sri Lanka, as pesticide poisoning became a common method of self-harm.  The suicide rate more than quadrupled between 1950 and 1984, before falling rapidly following a series of pesticide bans.

Deadly pesticides with high toxicity

What farmers do not always understand is that this ‘medicine’ can be just as lethal to humans as it is to pests.

All pesticides are toxic. They are substances that have specifically been designed to kill insects, rodents, and other organisms that may damage crops. The suffix ‘cide’ can be directly translated from Latin to mean ‘killer’.

However, not all pesticides are particularly harmful to humans. Some have a very low toxicity and pose little or no threat to human health. There are others though – classed as highly hazardous pesticides – that can be acutely toxic and deadly to humans.

Even a small amount of a deadly pesticide can be enough to kill a person. Pesticide exposure may come from food contamination, accidental poisoning, or intentional self-harm (where frequently there is low intent to die but a desire to communicate mental distress to others). In these circumstances, there is very little a doctor can do to save their life, especially in resource-poor settings. Many people die before even reaching a hospital.

Meanwhile, pesticide manufacturers continue to claim that their products are safe, if used correctly. Therefore, when someone is poisoned, it is put down to ‘misuse’. This shifts the blame on to the vulnerable people who use them rather than the agricultural systems in which they live.

In reality, there is little that can be done to remove the threat to life from acutely toxic pesticides. Farmers are often unable to understand the labels on pesticide bottles, and personal protective equipment (PPE) is rarely available and can be expensive and impractical in hot weather conditions.

The most effective way to prevent deaths is to is to prevent or eliminate the danger altogether, banning the use of deadly pesticides. This is demonstrated in the hierarchy of control for chemical risk management, shown below.

Global inequalities in pesticide regulation

Banning pesticides is not a new concept. Almost every country now has pesticide regulators, whose job it is to register and license pesticides for use. If a certain pesticide is deemed to be too dangerous, new regulation can be brought into force.

However, as with many things, there is global inequality.

In high-income countries, it is normal to have a large team of regulators who evaluate pesticides for safety and effectiveness. A 2013 survey by the Food and Agriculture Organization (FAO) of the United Nations found that the United Kingdom had a team of around 150, the Netherlands 120, and the USA over 700. These have probably grown further over the last ten years.

Consequently, pesticides that pose a real danger to health or the environment are likely to have been banned for use or severely, and importantly, effectively restricted in high-income countries. There is therefore little threat to citizens in these countries, who are unable to access them.

In comparison, the same 2013 survey found that responsibility for pesticide regulation fell to just one or two individuals in 77% of low and middle-income countries. These pesticide regulators tend to have very limited resources, in addition to low capacity, making effective evaluations of pesticides rarely possible.

As a result, many dangerous pesticides that have already been controlled in high-income countries remain readily available in countries that are home to some of the world’s most vulnerable people.

Economic interests outweighing health impacts of pesticide poisoning

Recently, we have seen calls for increased action on highly hazardous pesticides through international conventions. However, time and time again, there has been strong opposition from the pesticide industry and pesticide producing countries, who have managed to divert, slow, or block international negotiations.

It is becoming clear that industry and national economic interests are, at times, outweighing the threat to public health. Pesticide producing countries know that if they were to stop manufacturing and exporting a certain pesticide, the opportunity would be seized by another country. No country wants to transfer their economic profits.

There are also disturbing double standards in pesticide trade. Some pesticides that are banned for use in high-income countries continue to be manufactured there before being exported to low and middle-income countries.

It seems illogical that a product deemed too dangerous for use in a country with good healthcare and education can be shipped and sold to vulnerable communities in resource poor countries. The argument that countries need these dangerous chemicals in their food, water, and households is not supported by any data.

Preventing deaths from pesticide poisoning

However, I remain optimistic that one day we can end this global health problem. Progress is already being made.

We already know that, despite claims from the pesticide industry, acutely toxic pesticides are not needed for food security. On the contrary, there is strong evidence that chemical pesticides damage the soil, kill beneficial natural predators of pests, and lead to pesticide resistance.

There are many examples of deadly pesticides being replaced with less toxic alternatives, with no adverse impact on agriculture. Instead, what we have seen is an almost immediate fall in the number of people dying from pesticide poisoning.

By taking careful action to regulate and ban dangerous, unnecessary pesticides, deaths from pesticide poisoning will become a thing of the past.

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Related articles and publications

Can we really blame farmers for pesticide ‘misuse’?

Is the EU about to end the toxic trade of pesticides?

Are self-interests and inequalities threatening to undermine the SAICM process?

Five things I have learnt about pesticide suicide in the last year