Every year, roughly 385 million cases of unintentional acute pesticide poisoning are reported worldwide, according to the Pesticide Action Network, an umbrella group of more than 600 NGOs in 90 countries campaigning to reduce chemical pesticide use. Behind that figure stand people whose bodies absorb the cost of modern agriculture: the men and women who pick, prune and pack the food a nation eats. In South Africa, that burden falls heavily on farmworkers, many of them women, and on children living beside sprayed vineyards and orchards.
Colette Solomon, co-director of Women on Farms Project, an organization advocating for farmworkers and farm dwellers, says pesticides are often sprayed while female workers are harvesting crops. In many cases these workers are not given gloves or other protective equipment, because hand protection is seen as impractical for handling delicate fruit such as grapes.
“[The workers] are not provided with PPE, such as hand protection, or they’re not practical for the delicate types of work they do, leaving them to handle contaminated vines barehanded, as well as breathing in these chemicals,” Solomon told Mongabay.
Even when agrochemicals are not sprayed while women are working, they must often re-enter vineyards soon after spraying, she added in an email interview. And because farmworkers’ homes frequently sit next to vineyards, pesticides can drift into their houses.
The exposure is not limited to adults. A team led by environmental epidemiologist Regina Molomo collected urine samples from 9-15-year-olds in one South African fruit-growing area between 2017 and 2019 and analyzed them for biomarkers of pesticide exposure. Sixty percent of those tested showed signs of recent exposure to various pesticides. Forty percent of the surveyed children lived on farms, and 80% had at least one family member working on a farm.
The children, interviewed by the researchers, reported seeing pesticide spray drift from farms onto their homes in Grabouw, Piketberg and the Hex River Valley, as well as regular use of household pesticides by their families. The study also found that children from households using open water sources had higher levels of pesticide biomarkers than those relying on taps, boreholes or other closed sources.
Against this backdrop, the question of what should replace hazardous agricultural chemicals has become urgent, and it extends beyond farmworker health to the safety of the food on everyone’s table. Testing commissioned by the African Centre for Biodiversity (ACB), which has campaigned against genetically-engineered organisms in Africa since 2003, found pesticide residue in 86% of common South African food items, including bread, maize meal, fruit and vegetables, and infant foods. In 2024, the country was shaken by the deaths of six children who ate snacks accidentally contaminated with the highly toxic pesticide Terbufos.
A recent seminar organized by the ACB put a spotlight on two potential alternatives: biopesticides and genetically-engineered pesticides. Biopesticides use plant extracts or organisms such as bacteria and fungi to kill pests. Mariam Mayet, the ACB’s executive director, told Mongabay that farmers worldwide have long used biopesticides including extracts from the neem tree (Azadirachta indica) and pyrethrum, made from chrysanthemum flowers. “They’re quite distinct from genetically-engineered or gene-silencing pesticides,” she said.
Genetically-engineered pesticides, by contrast, use technologies their proponents say precisely target only specific pests. They include RNAi (ribonucleic interference) sprays, which contain modified RNA molecules that interfere with how a pest’s cells carry out instructions stored in its DNA. Other GE methods use CRISPR technology to change or disable a specific gene or trait; researchers can, for instance, breed and introduce genetically-edited sterile insects into a population to hinder reproduction. These approaches, which would release living, genetically-modified organisms into farm landscapes, remain in development and testing, though some RNAi pesticides have already been deployed.
How well their safety is understood is contested. Sarah Zanon Agapito-Tenfen, a plant geneticist and biosafety researcher at the Norwegian Research Centre (NORCE), was part of an international task force of about 20 scientists that reviewed more than 40 years of studies on GE pesticides. Speaking at the ACB webinar, she said that of 700 research papers examined, just 23 looked at effects beyond target species, and half of those lacked controls. Of the dozen studies the task force deemed sound, all on RNAi sprays, 11 detected effects on non-target organisms. Missing information remains, for example, on how RNAi pesticides might affect fungi that help plant roots absorb water and nutrients, or pollinators like bees. “This is not a large literature with gaps. This is a very small literature. Whole parts of the picture are missing,” she said.
Gudrun Dittrich-Schröder, who researches genetic pest control at the Forestry and Agricultural Biotechnology Institute at the University of Pretoria, takes a different view, though she acknowledges more research is needed. RNAi sprays, she told Mongabay by email, could reinforce a broader integrated pest management strategy, offering farmers a way to control pests that have developed resistance to conventional techniques. The sprays will need assessment for toxicity and environmental effects; she was aware of only one RNAi study in Southern Africa, a lab test of genetically-altered RNA on mealybugs published earlier this year. Organisms intended for release require deeper ecological and genetic assessment, especially when modifications are designed to spread, as with gene drives. “Releasing a living, reproducing organism raises different questions from spraying a product,” she said. “Important research gaps remain. Research gaps show that data are lacking; they do not by themselves demonstrate harm.”
For Anna Shevel, network coordinator of UnPoison, a South African nonprofit campaigning to end highly hazardous pesticides, biopesticides offer farmers a faster, safer route. South Africa already has “great” guidelines requiring biopesticide manufacturers to identify all ingredients, set out risks to crops, wild plants and pollinators, and provide safe-use instructions. But approval sometimes stalls in the registrar’s office of the Department of Agriculture, which lacks the capacity to evaluate these products, leaving them on the same pathway as synthetic agrochemicals. “It’s like trying to put a dugout canoe through a bullet train [of] health and safety trials and testing,” she said.
Some biopesticides already work here. Dittrich-Schröder cited a naturally occurring insect virus, Cryptophlebia leucotreta granulovirus, used for years against false codling moth, whose larvae feed on citrus fruit. “It was at least as effective as the chemical alternatives tested,” she said, and harmless to key beneficial insects.
Africa accounts for a small share of global pesticide use, Mayet notes, but producers see African markets as untapped ground as worldwide use has risen sharply over 30 years. She argues the most effective alternatives are not simply “safer pesticides” but farming systems using intercropping, agroforestry and natural pest predators. “The safest pesticide is the one farmers do not need to use because the farming system itself is healthy, diverse and resilient,” she said. “Pesticides treat symptoms. Agroecology addresses the conditions that make crops vulnerable to pests in the first place.”
The women who pick fruit and vegetables by hand for minimum wage, in South Africa the equivalent of less than $2 an hour, want an end to chemical-dependent, capital and water intensive monoculture, Solomon says. “Driven by profit maximization rather than workers’ rights, working conditions and health, we don’t imagine that these ‘alternatives’ [genetically-engineered pesticides] can be the solution,” she said.
Whether regulators can build the capacity to evaluate safer options, and whether the research gaps on genetically-engineered pesticides can be closed before they reach South Africa’s farms, may determine how soon the country’s farmworkers and consumers stop paying the price of chemical-dependent agriculture.