Main findings
- Using pesticides in the home, having parents working with pesticides (especially in agriculture), and living near agricultural land were the exposures most frequently associated with childhood leukemia and brain tumors.
- The cancer risk was highest for those exposed to pesticides during pregnancy or early childhood, when children’s bodies and brains are still developing and are more sensitive to harmful chemicals.
- Studies have found that children exposed to these pesticides are nearly twice, and in some cases more than triple, likely to develop cancer, depending on the type, timing, and amount of exposure.
When Yessica Ramirez was pregnant, she spent her days mixing pesticides in giant tanks at an ornamental plant nursery in Florida. She was not given a mask or gloves and could not afford to buy her own protective gear. Even as the rash spread to her arms and hands, she pulled her shirt over her mouth to avoid inhaling the smoke.
“As a farm worker, the pay is very low, and you either have to buy protective equipment or feed your family,” Ramirez said. “I chose to support my family.”
At the time, she said, there was little talk about chemical exposure at her workplace. It wasn’t until a co-worker discovered a manual explaining the dangers of pesticides and the safety measures that employers should follow that she became aware of the risks.
A few months later, her daughter was born with craniosynostosis, a condition in which the bones in an infant’s skull fuse together prematurely. The baby also developed eczema and sleep apnea.
Ramirez has long suspected that the pesticides she handled during her pregnancy contributed to her daughter’s health problems. Her concerns reflect the results of numerous studies pointing to exposure to pesticides during pregnancy and childhood as a risk factor for childhood cancer, as well as recent research highlighting decades of evidence linking pesticide exposure to childhood leukemia and brain tumors, among others.
Critical periods of cancer risk: pregnancy and early childhood
Last month (May 2026) international cancer journalResearchers at the University of Nebraska-Lincoln analyzed the results of 88 epidemiological studies spanning more than 40 years. Agricultural states like Nebraska and Iowa have some of the highest rates of childhood cancer in the country, but pesticides are being detected across the country in both rural and urban areas.
The strongest and most consistent associations between pesticides and childhood cancer emerged during pregnancy and early childhood across studies. Cancer risks, particularly acute lymphoblastic leukemia (ALL), a rapidly growing blood cancer, ranged from about 1.5 times to more than 3 times higher, depending on the timing and type of exposure.
“Overall, exposure to both occupational and household pesticides is significantly associated with increased risk of leukemia and brain tumors in children, and risks for certain types of cancer appear to be associated with parental exposure during the prenatal period,” the authors write.
Decades of research reveals link between pesticides and childhood cancer
This study highlights growing evidence linking childhood cancer and environmental pollution. The case also comes amid heightened regulatory scrutiny of the health risks of pesticides, including lawsuits involving major manufacturers such as Bayer (and its subsidiary Monsanto) and Syngenta.
“This adds to the large body of literature identifying exposure to pesticides during pregnancy and childhood as a risk factor for childhood cancer,” said Mark Miller, Ph.D., a UCSF associate professor who directs the Pediatric Cancer and Environment Program (CCEP) of the National Pediatric Environmental Health Unit (PEHSU) Network. “Reducing children’s exposure to pesticides can help prevent the development of childhood cancer.”
Although pesticide residues occur in food and drinking water, this review focuses on exposures from agricultural debris, workplace exposures, and pesticide use in and around the home. Children often come into contact with residues on their parents’ clothing or brought home through contaminated household dust. Treating pets for fleas and ticks also exposes them to pesticides.
The authors said there is now evidence that precautions to reduce exposure are justified.
“The use of residential or agricultural pesticides in spaces where children spend most of their time poses significant risks to children’s health and physical development,” the researchers wrote.
Prenatal exposure to pesticides may worsen survival prospects
Leukemia is the most common childhood cancer, while brain tumors are the leading cause of cancer-related deaths in children. ALL accounts for approximately three-quarters of childhood leukemia cases.
Children are especially vulnerable to toxic chemicals because their brains and organs are still developing. Their bodies are also less able to process and eliminate pollutants. Some pesticides can cross the placenta and reach the fetus, and exposure may begin before birth.
A 2025 study of more than 800 children with ALL found that children exposed to household pesticides during pregnancy had a 60% higher risk of dying within five years of diagnosis. Prenatal exposure to rodenticides, which are primarily used to kill rats and mice, increased the risk by 91%.
“This study highlights that exposures in the home environment, even before a child is born, can have a lasting impact on survival after leukemia diagnosis,” said co-author Dr. Lena Winestone, a pediatric hematology-oncologist at UCSF Benioff Children’s Hospital.
Household pesticide use repeatedly linked to childhood cancer
Research has consistently identified household pesticide exposure as a risk factor for leukemia and brain cancer. Prenatal exposures appeared to be more strongly associated with risk than exposures later in childhood.
Examples of reviews include:
- Children who receive repeated prenatal and early childhood professional pest control treatments have higher rates of leukemia.
- Increased risk of brain cancer in children whose mothers used pet flea and tick products during pregnancy
- People whose fathers sprayed herbicides on their lawns and gardens had about twice the risk of brain cancer, but the risk decreased if they changed clothes or did laundry afterwards.
A large meta-analysis also found an increased risk of leukemia in mothers exposed to pesticides, especially insecticides, during pregnancy. Risk increased if both parents were exposed.
Another study found that receiving pest control treatment during pregnancy increased the risk of high-grade glioma (a rapidly growing brain tumor) by more than four times.
Living and working near farmland increases risk of childhood cancer
Some studies have reported that children in areas with high agricultural intensity are two to three times more likely to develop leukemia than children in less agricultural areas. Herbicides and pesticides showed the strongest association with leukemia, and all major pesticide classes were associated with brain tumors.
Parental occupational exposure also emerged as a risk factor. One study found that children who did not wear gloves when spraying pesticides had almost twice the risk of cancer.
This review highlights studies that show:
Another California study linked prenatal exposure to some pesticides sprayed near homes to an increased risk of ALL and acute myeloid leukemia (AML). Among the pesticides associated with increased risk is the herbicide diuron, which is still under review by the EPA.
Researchers believe that some children may be genetically more susceptible to pesticide-related cancers than others. Several studies have linked pesticide exposure to genes involved in chemical detoxification and DNA repair.
One small study found an increased risk of leukemia among children whose mothers were exposed to pesticides during pregnancy and carried genetic mutations involved in processing carcinogens. Risk was also increased among children with these characteristics exposed to indoor pesticides.
The researchers said pesticides can cause direct DNA damage or alter gene expression through epigenetic changes (changes in the way genes are expressed). They also raised concerns that pesticide-related genetic damage could accumulate across rural areas from generation to generation.
“Over generations, exposure to pesticides can cause changes in DNA,” the researchers wrote. “As the family grows, the cumulative damage over several generations becomes apparent.”
Drinking water and chemical mixtures increase cancer concerns
Few studies have directly investigated exposure to drinking water. In agricultural areas, nitrates from fertilizer runoff and animal waste often occur along with pesticides in groundwater, rivers, and streams. Some studies suggest that exposure in combination may pose a greater risk than individual pesticides, such as glyphosate, chlorothalonil, and paraquat, which were recently banned in Vermont.
A Maryland study found that childhood cancer rates were significantly higher when groundwater contained nitrates along with herbicides such as atrazine. A Nebraska study similarly linked mixed pesticides to higher rates of childhood cancers, including leukemia and brain tumors.
“The results of this study highlight the importance of evaluating pesticides in drinking water, individually and in mixtures, as potential risk factors for developing cancer in children,” the authors write.
Study reveals gaps in pesticide monitoring and cancer research
The researchers noted that many studies relied on indirect exposure measurements, such as proximity to agricultural land, rather than direct chemical tests. Data on private wells, long-term exposure histories, and household water treatment practices also remain limited.
Still, they said the evidence across studies is sufficient to warrant further research and stronger prevention efforts. Ramirez, who now works as general coordinator for the Florida Farm Workers Association, says she would like to turn back the clock if she wanted.
“The best thing to do is to go back to what we used to do, which is to grow plants without any chemicals and grow things organically,” she says. “But we’re a long way from where we are now.”
reference
VanDeSteeg GN, Russum AR, Sandbulte MR, Logan EG, Rhoades MG. Environmental pesticide exposure in the pathogenesis of childhood brain tumors and leukemia: A scoping survey of epidemiological studies. international cancer journal. Published online on May 26, 2026. doi:10.1002/ijc.70546
