14
Jan
Prenatal Occupational Pesticide Exposure in Mothers Leads to Neurodevelopmental Risks in Children
(Beyond Pesticides, January 14, 2026) Adverse neurodevelopmental outcomes in children 4–6 years old occur with reported maternal occupational exposure during pregnancy, as published in a study in PLOS One, according to research from Muhimbili University of Health and Allied Sciences in Tanzania and the Centre for International Health at the University of Bergen in Norway. “Our results show that self-reported maternal exposure to pesticides through direct spraying during pregnancy was associated with lower scores in social-emotional and executive function domains among children,†the authors state. Additionally, the authors note that they found an association between social-emotion scores in children and weeding practices of their mothers during pregnancy, as well as reduced overall neurodevelopmental scores following direct maternal pesticide exposure.
The study, conducted through self-reported pesticide exposure from the mothers of 432 mother–child pairs in three horticulture-intensive regions in Tanzania and development and learning assessments of their children, reflects the “concerns about maternal occupational exposure during pregnancy and its potential impact on child neurodevelopment,†the researchers describe. Current risk assessments fail to properly capture the disproportionate risks to farmers and farmworkers with various routes of exposure, “particularly in horticultural settings where women of reproductive age represent a substantial proportion of the workforce.†Common crops grown in Tanzania include maize (corn), rice, bananas, beans, coffee, and sweet potatoes.
Study Importance
As the authors state, “Global pesticide use has risen by about 80% in the last two decades, with Africa experiencing a staggering 175% increase, largely due to the growing population that put pressure on the agriculture sector to ensure sufficient yields in crop production.†Many of the agricultural workers, especially in low- and middle-income countries, are women. “In sub-Saharan Africa, they make up approximately 55% of the agricultural workforce, with Tanzania having the highest proportion at 81%,†the researchers point out. This burdens women with disproportionate health risks as a result of pesticide exposure through various activities, including planting, weeding, harvesting, and directly mixing and applying pesticides to crops. (See Catastrophic Harm to Women from Pesticides Drives Call for Their Elimination.)
“Literature shows that pesticides exposure can cause severe acute and chronic health effects in humans, including neurotoxicity, carcinogenicity, endocrine disruption, and respiratory issues, with agricultural workers and communities in developing countries facing disproportionate exposure,†the authors state. These health effects, and more, are catalogued in Beyond Pesticides’ Pesticide-Induced Diseases Database (PIDD) and extensively covered in Daily News articles. (See here, here, here, here, and here.)
Scientific literature shows that pesticide exposure during critical developmental windows can have long-lasting impacts, many of which are transgenerational. As the current study says: “Of particular concern is the potential for several of these pesticides to cross the placental barrier, leading to fetal exposure and adverse pregnancy or developmental outcomes. The fetus is especially vulnerable to pesticide toxicity due to underdeveloped detoxification mechanisms.†(See research here and here.)
In previous Daily News coverage, Beyond Pesticides reports on a study published in Environmental Research that finds an association between adverse neurodevelopment (brain function and development) among infants and exposure to the herbicide glyphosate during pregnancy that becomes more pronounced at 24 months. The increasing prevalence of neurodevelopmental disorders (NDDs) in both the United States and around the world raises concerns about the impact of toxic exposures on child development, prompting researchers to investigate the effects of gestational exposure. The results find a positive association between prenatal metabolite concentrations from the mother during pregnancy and impacted child communication at 12 months. At 24 months, researchers find that the glyphosate metabolite is associated with adaptive, personal-social, communication, and cognitive skill impairments.
Methodology and Results
In the current study, the researchers utilize a cross-sectional design with structured interviews to assess maternal exposure and the International Development and Early Learning Assessment (IDELA) to measure the children’s neurodevelopment. This includes motor skills, literacy, numeracy, social–emotional development, and executive function. “By using IDELA, the study ensures precise and consistent assessments across critical developmental domains, including cognitive, motor and social emotional skills,†the authors note. “Previous pesticide exposure studies used the Bayley Scales of Infant Development and the Cambridge Automated NeuroPsychological Battery, yielding consistent findings.â€
In total, 432 mother-child pairs, from three regions in Tanzania, participated. “The study was conducted among children born of women working in small-scale horticulture farms who had been working with pesticides before and during conception,†the researchers state. “Most mothers were aged 31–40 years (55.1%) and over half (55.3%) had six to ten years of experience in horticulture, but most (39.8%) have been living in the area for more than 20 years.â€
Statistical analyses within the study show:
- Children score significantly lower in social–emotional and executive function domains when mothers report spraying pesticides during pregnancy.
- Following maternal pesticide exposure, the lowest scores in children are in the categories of emergency literacy and executive function.
- “Women who reported to engage in pesticides spray activity during pregnancy had children with significantly lower mean emergent numeracy and lower fine and gross motor domain scores compared to those who reported to not spray during pregnancy. Similar outcomes were observed in children of women who reported washing clothes used for pesticides spray/handling activities.â€
- In the children of pregnant women who engaged in weeding activities within 24 hours of pesticide spraying, mean emergent numeracy domain scores are also significantly lower.
- A multiple linear regression analysis “showed a borderline relationship between engaging in spray work during pregnancy and low total test scores… It was also shown that spraying pesticides during pregnancy was significantly associated with lower social-emotional scores and executive function scores.â€
- Sensitivity analyses to determine sex-specific trends finds “that the significant negative association between spraying pesticides and the observed decrease in social-emotional and executive function scores is driven primarily by boys. Boys of mothers who reported spraying pesticides during pregnancy had significantly lower social emotional, executive function and total IDELA scores.â€
The study findings show that maternal occupational exposure through pesticide-related activities, particularly directly spraying crops, leads to lower neurodevelopment scores. This primarily affects the social-emotional, executive function, and overall domains of their children, notably in boys.
Previous Research
There is a wide body of science documenting the hazards of pesticide exposure to infants and children, particularly with perinatal and prenatal exposure. (See Beyond Pesticides’ resources on Hazards of Pesticides for Children’s Health and Children and Pesticides Don’t Mix for more information). In previous Daily News, entitled Prenatal, Childhood Exposure to Toxic Pesticides Linked to Neurodevelopment Issues, a study published in Environmental Research finds that early life organophosphate pesticide exposure is linked to poorer neurodevelopment.
Additional Daily News regarding a California-based population study published in BMC Public Health finds that “7.5 [percent] of all pregnant people in California who gave birth in 2021 lived within 1 km [kilometer] of agricultural fields where OP pesticides [organophosphates] had been used during their pregnancy.†This study highlights the significant disparities that occur with elevated exposure to pesticides in rural areas and adds to the existing scientific literature on perinatal and maternal pesticide exposure associated with adverse long-term health effects for children and mothers.
Cited within the current study is additional research that adds to this body of science, including:
- A study of children from smallholder tomato farmers in southern Tanzania reports “delayed neurodevelopment in children associated with maternal engagement in agricultural work.â€
- An assessment of 355 one-year-old infants in Costa Rica, with “mothers living within 5 km of banana plantations with frequent aerial mancozeb (a fungicide) spraying,†reveals lower social-emotional scores with higher urinary metabolite concentrations. (See here.)
- Another study incorporating 618 urine samples from women in South Africa shows that maternal urinary metabolites of pyrethroids are associated with lower social-emotional scores in one-year-old infants.
- “In a U.S birth cohort involving 162 mother-child pairs found that prenatal exposure to pyrethroids, as indicated by its urinary metabolites 3-PBA and cis-DCCA, was associated with poorer performance in executive function in children aged 4–9 years.†(See study here.)
- A similar study of a cohort study of 363 mother-child pairs finds “higher gestational concentrations of organophosphate metabolites, as measured by maternal urine levels of dialkyl phosphate, were associated with significantly lower executive functioning in children aged between 7 and 12 years.â€
The Organic Solution
To protect mothers and their children, as well as all individuals, wildlife, and the environment, Beyond Pesticides advocates ending all exposure routes to toxic pesticides with the adoption of organic practices. Both women and men working in agriculture, as well as those living nearby, should not face disproportionate risks to their health, and their families, due to their occupation. Anyone who consumes crops should also not face health threats from hazardous chemical residues. The only way to ensure safe agricultural production that does not create acute and chronic health threats to future generations is to remove petrochemical pesticides and synthetic fertilizers from the equation and utilize organic methods.
Beyond Pesticides and organic advocates believe that a transition away from chemical-intensive agriculture and land management is the most viable solution to avoid adverse health impacts and end reliance on toxic chemicals throughout all households and communities. Beyond Pesticides’ program of science, policy, and action takes on the existential threats from fossil fuel-based pesticides and fertilizers—widespread illness, biodiversity collapse, and the climate crisis.
Support the organic solution by buying and growing organic products, as well as taking action each week to have your voice heard on governmental actions that are harmful to the environment and public and worker health, increase overall pesticide use, or undermine the advancement of organic, sustainable, and regenerative practices and policies through Action of the Week. Without your engagement and incredible generosity, it would not be possible to lead the transition to a world free of toxic pesticides. Learn more about Beyond Pesticides’ programs and resources here.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Source:
Mwakalasya, W. et al. (2025) Neurodevelopment in children born to women exposed to pesticides during pregnancy, PLOS One. Available at: https://journals.plos.org/plosone/article?id=10.1371%2Fjournal.pone.0326007.
