Nearly half of cotton farmers and farm workers in Tanzania have said they often became seriously ill within 24 hours after using harmful pesticides.
The findings, published in Toxics, found that of the 1,074 cotton farmers and farm workers who were surveyed, 48 per cent became ill within 24 hours of being exposed to harmful pesticides over the past year while they were working on farms.
Only six per cent of these farmers sought medical treatment at a clinic or hospital, indicating that pesticide poisoning is likely under-reported in official medical records.
Professor Michael Eddleston, Director at the Centre for Pesticide Suicide Prevention (CPSP), who was involved the study along with Dr Keith Tyrell, CPSP’s Head of Global Strategy, said: “This study clearly shows how harmful toxic pesticides are and the damage they can do to the health of farmers and farm workers.
“The scale of the problem is likely to be much larger as the cases often go unreported.
“We would like to encourage Tanzania’s government to phase out highly toxic pesticides and make safer alternatives available for farmers producing cotton and supporting them to access them.”
Dr Keith Tyrell, Head of Global Strategy at CPSP, added: “Like many cotton-producing countries, the Government of Tanzania is closely involved in the cotton sector.
“The Tanzania Cotton Board, which is a statutory body, procures and distributes pesticides to farmers at a subsidised price.
“It is hoped that the study will provide a basis for the adoption of safer and more sustainable methods of cotton production.”
Professor Deodatus Kakoko, Dean of the School of Public Health and Social Sciences at Muhimbili University of Health and Allied Sciences (MUHAS) in Tanzania said: “This robust study reveals a significant problem of pesticide poisoning in Tanzania.
“It is a very welcome addition to the body of scientific evidence on this neglected topic.
“More routine surveillance is needed to detect such problems in future.”
Raphael John Mwezi, Head of the Toxicology Unit at Tanzania Plant Health and Pesticides Authority said: “The large-scale study provides important new evidence of the impact of hazardous pesticide use on the health of farmers and workers in Tanzania.
“The large numbers of farmers reporting pesticide poisoning is alarming and warrants swift action, particularly in relation to the few pesticides that were associated with most of the incidents.”
Professor Andrea Rother, Head of Environmental Health Division and Associate Professor in the School of Public Health and Family Medicine, University of Cape Town said: “Promoting personal protective equipment (PPE) is widely seen as sufficient to protect people from pesticide exposure. The study shows that this is not the case.
“Although training on PPE use can play a limited role in reducing pesticide exposure, it does not address gendered and climatic conditions in Africa, and access to inappropriate PPE.
“Thus, as the study highlights, PPE use does not significantly reduce Unintentional Acute Pesticide Poisoning (UAPP).”
More than 80 per cent of the reported cases were linked to exposure to four pesticides: profenofos, lambda-cyhalothrin, and combinations of chlorpyrifos and cypermethrin. Profenofos and chlorpyrifos are both organophosphorus insecticides that have adverse effects on the nervous system.
Each of them is already banned in at least 39 countries.
The more severe health effects reported in the current study include extreme agitation, loss of consciousness and seizures.
Chlorpyrifos is currently under consideration for listing under both the Stockholm and Rotterdam conventions due to its persistence and its harmful effects on health and the environment. Children are particularly vulnerable to its effects on brain development.
Lambda cyhalothrin has different effects on the body, with skin and eye irritation and respiratory effects being widely reported.
PPE can never be seen as a solution to allow use of highly toxic pesticides.
Safer alternatives already exist in Tanzania that will protect farmers’ health and profits.
For example, the food spray method attracts predatory insects into the cotton crop foliage, while biopesticides and botanical pesticides that have been shown to be effective against key cotton pests.
Drawing on evidence from Tanzania’s growing organic cotton sector, the study highlights the potential for cotton cultivation free of Highly Hazardous Pesticides (HHPs).
Over half-a-million farming households in Tanzania rely on cotton as their main source of income. Cotton is an important export crop for the country and there are ambitious plans to scale up production.
The study was led by Pesticide Action Network (PAN) UK and Muhimbili University in Tanzania.