Pesticide poisonings hit 400 million cases a year — 400 times WHO's 1990 estimate

More than 400 million cases of pesticide poisoning occur worldwide each year, according to a new estimate — counting only accidental exposures during farm work, not intentional self-harm. Annual deaths from such poisonings were put at around 11,000.

The findings were published recently in the international journal Frontiers in Public Health by Wolfgang Boedeker and Meriel Watts of the Pesticide Action Network (PAN), an international civil society organization.

The research team compiled 214 studies published between 2006 and 2023, along with WHO mortality statistics, to synthesize data from 139 countries.

The studies reviewed by the research team directly reported 369,632 cases. Applying weighted extrapolations to the agricultural populations of each country, the team estimated the global scale of pesticide harm at between 402 million and 433 million cases per year. Against a global agricultural workforce of about 934 million, that figure represents roughly 46 percent — though the case count can exceed the number of individuals affected, since one person may be poisoned more than once in a year.

By country, an average of 42.3 percent of farmers experienced at least one pesticide poisoning in a given year. Burkina Faso recorded the highest rate at 83.8 percent, followed by India at 73.6 percent, while the United States stood at 0.04 percent.

WHO's 1990 estimate put annual pesticide exposure harm at 1 million cases and 20,000 deaths. The new research suggests the figure has risen roughly 400-fold over the past three decades. However, the 1990 estimate counted only cases severe enough to require treatment, while the current study also included surveys that classified even a single headache as a poisoning.

Global pesticide use more than doubled over the same period, rising from 1.8 million tons in 1990 to 3.8 million tons in 2023.

The same research team had published a similar paper in 2020, in which a survey question asking farmers whether they had ever fallen ill due to pesticides yielded an estimate of 385 million pesticide poisoning cases per year.

The journal that published that paper retracted it, citing a flaw in the survey question: respondents could interpret it as referring only to the past year or to their entire lifetime, making the responses unreliable.

In the revised study, the team drew on national mortality statistics to identify deaths attributed to pesticide poisoning, and surveyed farmers directly to capture cases of illness or treatment linked to pesticide exposure.

In surveys that classified even a single headache as poisoning, an average of 50 percent of respondents reported falling ill. By contrast, surveys requiring two or more concurrent symptoms dropped that figure to 20 percent.

Small-scale surveys with 132 or fewer respondents found an average of 60 percent reporting poisoning, while larger surveys of more than 332 participants put the figure at 36 percent.

The research team also factored in experimental findings on whether farmers' self-reported symptoms can be taken at face value. A prior study conducted in Nepal, which the team incorporated, divided farmers into two groups — one sprayed with insecticide and the other with neem oil, a non-pesticide substance.

Both groups reported pesticide poisoning symptoms, and blood enzyme levels — which typically change upon pesticide exposure — showed no difference between the two. A significant number of participants even reported symptoms during periods when no pesticides were used at all.

On the other hand, the research team found that official hospital and government records severely undercount pesticide poisoning. WHO mortality data submitted by national governments recorded only 722 pesticide poisoning deaths per year across 110 countries combined.

India's government reported 7,805 pesticide-related deaths in 2021 in its own internal report but did not submit that figure to WHO.

By region, South Asia had the highest recorded burden at about 214 million cases, followed by Southeast Asia at about 60.76 million and East Africa at about 49.34 million.

The research team concluded that even accounting for the possibility that farmers over-report poisoning symptoms, the volume of cases absent from hospital and government records is likely far greater, and estimated that roughly 400 million pesticide poisonings occur globally each year.

However, the team acknowledged that data availability was limited.

Non-fatal poisoning cases could be estimated at the national level for only 49 countries. Central Asia was excluded entirely due to a lack of data, while Eastern Europe was extrapolated from figures from Hungary alone, and central and southern Africa from Cameroon alone.

The team also noted that surveys conducted in areas of heavy pesticide use, when scaled up to represent an entire country, could produce figures higher than the actual national average.

DOI: 10.3389/fpubh.2026.1825899

Boedeker W, Watts M, Clausing P and Marquez E (2026) Worldwide unintentional acute pesticide poisonings: reassessing the occupational and non-occupational burden. Front. Public Health 14:1825899.