The research team, led by Charity Kanyika-Mbewe of Mzuzu University together with collaborators at Makerere University and other institutions, surveyed 339 rice farmers selected through systematic random sampling from three Extension Planning Areas: Kaporo North, Kaporo South, and Vinthukutu. Participants, 54.6 percent of them male and 45.4 percent female, ranged in age from 16 to over 55 years, and nearly all had received some formal education. Using a semi-structured questionnaire translated into the local language, Tumbuka, the researchers collected data on sociodemographic profiles, pesticide handling and application practices, safety measures, knowledge of pesticide toxicity, self-reported health effects, and environmental awareness. The instrument was pretested before deployment, and the analysis was carried out in STATA using descriptive statistics, chi-square tests, and multivariable logistic regression models fitted at a significance level of 0.05.

What the survey uncovered was a chemical landscape dominated by moderately hazardous compounds. Farmers reported using ten different active ingredients belonging to five chemical classes, with five herbicides led by 2,4-Dichlorophenoxyacetic acid and six insecticides led by cypermethrin. Organophosphate-based products accounted for 33.70 percent of all chemicals in use. Under the World Health Organization’s hazard classification, most of these fell into class II, meaning moderate toxicity, but a troubling 6.20 percent belonged to class Ia, extremely hazardous, or Ib, highly hazardous. These are the kinds of compounds, including agents such as carbofuran methyl and parathion at the extreme end of the spectrum, for which exposure can cause acute poisoning, respiratory distress, and serious skin and eye damage. Some farmers also turned to natural repellents such as neem tree extracts, a small but noteworthy counterpoint to the synthetic chemical reliance.

The human toll emerged clearly in farmers’ self-reported symptoms. Approximately 54 percent of respondents said they had experienced at least one acute symptom after handling pesticides, with headaches reported by 16.38 percent, respiratory disorders by 14.66 percent, and eye irritation with tearing by 12.07 percent. These symptoms align with what toxicologists expect from exposure to class II compounds such as 2,4-D, profenofos, chlorpyrifos, and cypermethrin, which can produce nausea, dizziness, and irritation of the skin, eyes, and airways. The study’s authors note that such presentations are consistent with findings from earlier research in Ethiopia, Nigeria, and Ghana, suggesting that the pattern of exposure and harm among African smallholders is not unique to Malawi but part of a broader regional problem.

Protection, where it existed at all, was fragmentary. Fully 41 percent of farmers used no personal protective equipment whatsoever during mixing or application, and among those who did use some form of protection, only 5.72 percent wore complete coveralls. The reasons appear to be a tangle of access, cost, and perception: some farmers considered pieces of equipment unimportant, others simply could not obtain them, and previous research has documented complaints that protective gear designs hinder physical flexibility in hot field conditions. Chemical mixing itself is a major exposure pathway, and the study found considerable direct contact with concentrated products at precisely the stage when risk is highest. The disconnect between knowing that pesticides are dangerous and actually protecting against them was one of the starkest patterns in the data.

Storage and disposal practices amplified the hazard. A striking 86.22 percent of farmers stored pesticides inside the houses where they lived, with smaller fractions using basements, sheds, or verandas, placing toxic chemicals in close proximity to food, water, and family members. Meanwhile, 73.45 percent took no precautionary measures when disposing of empty chemical bottles before or after spraying. Improperly discarded containers can leach residues into soil and water, disrupting ecosystems and creating secondary exposure routes for people and livestock. The authors contrast this with better practice documented elsewhere, such as in Nepal’s Chitwan district, where pesticides were more often kept in separate storage away from dwellings, underscoring that the Karonga situation reflects a knowledge and infrastructure deficit rather than an inevitability.

The environmental dimension of the problem was equally concerning. Most farmers were unaware that pesticides can contaminate water and air or kill fish, frogs, and birds, and 77.29 percent did not know how long they should wait after application before harvesting any organisms from the farm environment for consumption. Yet 72.86 percent admitted eating organisms harvested from the farms’ surroundings, a pathway for pesticide residues to enter the human food chain. Water sources add another layer of risk: 76.70 percent of farmers relied on boreholes for drinking water, and 61.60 percent mixed or applied pesticides within less than 50 to 100 meters of drinking water sources, with only 24.19 percent using sources more than 100 meters away. Pesticide residues in surface and groundwater threaten aquatic species and soil microorganisms, and some compounds, such as DDT, can persist for years and bioaccumulate up food chains, though the study found no reports of restricted chemicals like DDT being used in Karonga’s rice fields.

The statistical analysis revealed who was most and least likely to handle chemicals responsibly. Farmers aged 55 and above were 0.42 times less likely to adhere to better pesticide handling practices compared with those aged 36 to 45, an adjusted odds ratio of 0.042 with a 95 percent confidence interval of 0.17 to 0.97, even though older farmers showed greater awareness of water contamination effects, likely reflecting accumulated experience. Education emerged as the strongest protective factor: farmers with secondary education or higher were 2.37 times more likely to handle pesticides well and to understand environmental degradation, with a 95 percent confidence interval of 1.41 to 3.97. Chi-square tests confirmed significant associations between education level and both safe pesticide use and personal protective equipment use, and between gender and appropriate dosing. Sex, however, did not significantly influence understanding of environmental effects, and neither gender, age, nor education shaped overall attitudes toward pesticide use, suggesting that attitude change may require interventions beyond schooling alone.

Underlying these statistics are structural realities. Malawi faces widespread illiteracy of 33.75 percent and poverty affecting 58.8 percent of the population, and farming remains overwhelmingly subsistence-based, conditions under which safety guidelines, however well-intentioned, rarely take hold. The country’s pesticide application has climbed steadily from 0.07 kilograms per hectare in 2000 to 0.62 kilograms per hectare by 2020, mirroring a global trend that saw 3.54 million tons of pesticides applied worldwide in 2021. As rice demand is projected to surpass 550 million tons by 2050, pressure on smallholders to intensify chemical use will only grow, making the safety gap identified in Karonga a question of global food system design rather than a local anomaly.

The study’s recommendations are correspondingly practical. The authors call for structured training programs on the health and environmental impacts of pesticide exposure, improved access to personal protective equipment, and promotion of less toxic or biological pesticides to reduce risk at the source. They also urge that pesticide retailers, who function as farmers’ primary source of information, be trained in safety and proper usage themselves, and that policymakers integrate pest management strategies grounded in the One Health concept, which links human, animal, and environmental health. Without such interventions, the researchers warn, the acute symptoms already documented, headaches, respiratory disorders, eye irritation, nausea, blurred vision, and even seizures, may be only the visible edge of a deeper chronic burden. For the farmers of Karonga, and the millions like them across rice-growing Africa, the harvest now depends not only on controlling pests but on closing a knowledge gap that has grown as fast as the chemicals have spread.

Subject of Research: Pesticide handling practices and associated ecotoxicological and human health risks among rice farmers in Karonga district, Malawi

Article Title: Pesticide handling practices and associated ecotoxicological and human health risks among rice farmers in Karonga district, Malawi

Article References: Kanyika-Mbewe, C., Kaonga, C., Chidya, R., Wanda, E., Odong, R., Kubiriza, G. K., & Akoll, P. (2025). Pesticide handling practices and associated ecotoxicological and human health risks among rice farmers in Karonga district, Malawi. BMC Environmental Science, 2(1), Article 6. https://doi.org/10.1186/s44329-025-00019-5

Image Credits: AI Generated

DOI: 10.1186/s44329-025-00019-5

Keywords: pesticides, rice farming, Malawi, farmer health, personal protective equipment, ecotoxicology, water contamination, WHO toxicity classification, smallholder agriculture, pesticide storage, environmental degradation, One Health