The Unseen Cost of Farming: Millions Face Acute Pesticide Poisoning Worldwide

The researchers estimate that between 402 million and 433 million cases of unintentional acute pesticide poisoning occur worldwide every year, alongside approximately 11,000 deaths.

A new global study suggests that accidental pesticide poisoning is affecting hundreds of millions of people each year, with farmers and agricultural workers carrying a particularly heavy share of the harm. The research paper, titled 'Worldwide Unintentional Acute Pesticide Poisonings: Reassessing the Occupational and Non-Occupational Burden,' was written by Wolfgang Boedeker, Meriel Watts, Peter Clausing and Emily Marquez and published in the journal Frontiers in Public Health.

The researchers estimate that between 402 million and 433 million cases of unintentional acute pesticide poisoning occur worldwide every year, alongside approximately 11,000 deaths. These figures cover poisoning that happens without deliberate self-harm, including incidents during pesticide mixing, spraying, storage, transport or accidental contact at home and in the community. The findings draw attention to a health burden that is often hidden because many affected people never reach a hospital, receive a formal diagnosis or appear in national statistics.

Nearly Half of the World's Farmers May Experience Poisoning Each Year

The study estimates that the global farming and agricultural workforce includes around 934 million people, with roughly 46% potentially experiencing acute pesticide poisoning every year. That proportion translates into an immense number of people living with headaches, nausea, skin irritation, breathing difficulties, dizziness, eye problems, weakness and other symptoms associated with recent pesticide exposure.

Non-fatal poisoning was most heavily concentrated in Southern Asia, where researchers estimated nearly 214 million annual cases among farmers and agricultural workers. South-eastern Asia followed with about 61 million cases, while Eastern Africa accounted for an estimated 49 million. India produced the largest national estimate, with approximately 169 million cases, based on an average poisoning prevalence of about 74% across 11 publications and a farming population of roughly 230 million.

Estimated poisoning prevalence among farming and occupational populations ranged from 0.04% in the United States to 84% in Burkina Faso. Very low figures in countries such as the United States and Australia may reflect weaknesses in reporting rather than safer working conditions alone, since their estimates relied heavily on registers and poison-centre records instead of direct surveys among farmworkers.

Researchers Combined Hundreds of Studies With Global Mortality Records

The research team reviewed scientific literature covering the years 2006 to 2023, searching PubMed, EMBASE and Web of Science while also checking reference lists and the authors' own collections. Studies focused only on intentional pesticide poisoning, suicide, chronic diseases without acute poisoning data, treatment outcomes or poorly defined populations were excluded.

A total of 214 articles covering 62 countries were included, while WHO mortality records broadened the overall analysis to 139 countries. After repeated yearly register entries were removed, the publications documented 369,632 cases, consisting of 360,450 non-fatal poisonings and 9,182 deaths. The researchers then created country-level estimates and applied them to regional farming and population figures supplied mainly by the World Bank and United Nations sources.

Most evidence about farmers came from surveys carried out in specific agricultural districts. National registers, hospitals and poison-control centres supplied much of the information for the general population. Around 85% of occupational studies relied on workers reporting symptoms themselves; smaller numbers used diagnoses made by researchers or official medical codes. The wide variation in case identification, sample sizes and reporting periods made global calculation difficult, yet the researchers' sensitivity analysis produced a stable range of 402 million to 433 million annual cases, even when lower-quality evidence or studies using lifetime exposure questions were excluded.

Official Records Capture Only a Fraction of the Human Cost

Many poisoned workers do not seek medical care because treatment is unaffordable, clinics are far away, transport is unavailable or taking time away from work could mean losing income. Symptoms such as nausea, headaches and tiredness can be mistaken for heat stress, infection or other illnesses, because some doctors lack training in recognising pesticide exposure. Countries may also have no mandatory reporting system, no central database or limited coordination between hospitals, poison centres and mortality registers.

The study describes how a small number of recorded deaths can sit at the top of a much larger pyramid of harm. Research from an agricultural area in Ecuador previously found that four pesticide-related deaths were associated with an estimated ten hospitalisations, 40 poisonings that reached medical care, 400 possible cases without clinical treatment and 4,000 instances of subclinical nervous-system effects. Such patterns suggest that hospital data alone cannot reveal the real scale of pesticide-related illness.

Some researchers counted a person as poisoned after one reported symptom, while stricter studies required two, three or more symptoms and sometimes excluded existing health conditions. A strict definition requiring at least two symptoms produced an average prevalence of 20%, compared with about 50% in studies accepting one symptom. More than two-thirds of the reviewed studies failed to specify how soon symptoms had to appear after exposure, and over half of occupational surveys did not clearly identify the period during which exposure could have occurred.

Safer Farming Requires Stronger Rules, Training and Better Surveillance

Global pesticide consumption doubled from approximately 1.8 million tonnes in 1990 to 3.8 million tonnes in 2023, increasing the number and frequency of potential exposures. The researchers argue that the true burden may be even higher because standard employment figures can exclude informal labourers, unpaid family workers and people involved in subsistence farming.

The authors acknowledge that some regions were represented by only one country, small studies or limited population coverage. Grey literature and local poison-centre reports may have been missed, national surveillance remains fragmented, and differences in farming systems prevented estimates based on specific pesticide-use patterns. Deaths caused by pesticides in contaminated food were not calculated. Fatal occupational poisoning is also likely to be undercounted because many mortality systems do not identify whether a victim was a farmer or worker.

The paper calls for shared definitions, stronger national monitoring, mandatory reporting and clearer separation of cases involving farmers, workers and children. Researchers recommend prospective studies that follow poisoned people over time, since acute exposure may offer an early warning of chronic health damage. Governments are urged to expand training and certification for pesticide users, require employers to provide suitable protective equipment and ensure that protective measures are affordable and practical in hot working environments.

The most important recommendation is the progressive removal of highly hazardous pesticides, especially substances classified by WHO as extremely or highly dangerous. The authors support the Food and Agriculture Organization's call to phase out these chemicals and the Global Framework on Chemicals target to end their agricultural use by 2035 where risks cannot be managed. Less hazardous products and agroecological farming practices could reduce poisoning without necessarily lowering agricultural productivity, offering farmers protection that does not depend solely on avoiding exposure to chemicals that may be too dangerous to use safely.