15
Jun
Review of 88 Epidemiologic Studies Links Pesticides to Pediatric Brain Tumors and Leukemia
(Beyond Pesticides, June 16, 2026) If there is one take-home message regarding reducing risk of childhood leukemias and brain cancers, it is to avoid exposure to pesticides during pregnancy—especially indoor insecticides such as flea and tick products, including DEET, household plant and commercial pesticide treatments, and proximity to pesticide applications in agriculture. A review by researchers at the University of Nebraska Medical Center and School of Natural Resources in Omaha considered 88 epidemiological papers published between 1980 and 2022 on pediatric cancer and environmental pesticide exposure and found elevated rates of pediatric cancers associated with pesticide exposure. The reviewers assessed the known associations between the risk of childhood leukemia and brain tumors and their or their parents’ exposure to pesticides, pesticide breakdown products and mixtures. They asked how important known exposures in drinking water were to the children’s risk, and whether genetics is a primary influence on cancer development.
The researchers found that the risk of childhood brain tumors increased 1.5 times if pest control products were applied during the entire year before conception. High-grade glioma risk was four times higher when pesticides were applied during pregnancy. Prenatal exposure to flea and tick products raised risk, especially for children diagnosed under the age of five, and risk doubled if the mothers directly handled the flea and tick products. The number of pets treated magnified the risk, as did the number of applications. In one reviewed study, exposure to insecticides was more closely correlated with (acute lymphocytic leukemia) ALL if the exposure occurred during pregnancy than when the child was three years old.
Pediatric cancer is the second leading cause of death in children five to nine years old and third leading cause from ages 10-14. One case of childhood cancer can cost nearly a million dollars in medical expenses and lost parental income, the authors write. Brain cancer is the second most common childhood cancer, and the leading cause of child mortality. Of childhood cancers, leukemia is the most common among children 0-14, and ALL accounts for 25-35% of all childhood cancers.
The latency period for these childhood cancers is clearly short, suggesting that prenatal influences, including intense environmental exposures, and particular genetic susceptibilities may be factors. Most blood and brain cancers occur in children under 10, with a sharp peak in children two to five, whose ability to surmount the challenge is hampered by their weaker capacity for detoxifying chemicals and the vulnerability of rapidly developing organs targeted by the diseases. Moreover, young children, especially those under five, are far more directly exposed to all kinds of contaminants in their homes than older children and adults, and this includes various insecticides—the authors cite the fungicide sulfuryl fluoride, the multi-target compound methyl bromide, and the insecticide classes pyrethroids, organophosphates, and carbamates in particular.
Pesticide exposures of pregnant women are of extreme concern. They not only harm the mother, but pesticides can cross the placental barrier and directly affect the fetus as well. The prenatal exposures and even preconception exposures may be the most critical for risk of brain cancers and leukemias.
With respect to drinking water exposures, the reviewers analyzed a study of pesticides in Maryland groundwater that found that a mixture of nitrates (fertilizer components) and the herbicides atrazine and metolachlor produced nearly 7.5 times the risk of leukemia, brain and spinal cord, non-Hodgkin lymphoma and bone cancer in exposed children than in unexposed children. Although there is little specific research on prenatal pesticide exposures in drinking water, a 2025 Italian rat study found that in three groups treated with different dosages of glyphosate, there was a dose-related increase in the incidence of both benign tumors and malignancies, including leukemia, in both sexes, with early-life onset and premature death. Forty percent of the leukemia deaths occurred within the rats’ first year of life.
The genetic connection to leukemias and brain cancers is less clear than the environmental exposures. An estimated 10-20% of pediatric cancers are attributable to alterations in the parental germ cells, but only about 5% of ALL cases are thought to be genetically related—and of these, most result from “genetic damage induced by environmental exposures,” according to the authors of the current review. Over the last 40 years, childhood leukemia incidence has increased by about 35%, especially among Latino children, according to a 2021 National Institute of Environmental Health Sciences/EPA report on children’s environmental health. This suggests that environmental factors must play a much bigger role in childhood cancer incidence than strict genetic inheritance. But such factors, including pesticides, can damage DNA by scrambling chromosomes during replication, activating cancer-related genes or inactivating tumor suppressor genes. So even mechanisms that appear to be genetic can have their source in toxic chemical exposures.
This review echoes a previous one by the National Institute of Pediatrics and National Polytechnic Institute analyzed by Beyond Pesticides in 2024. That meta-analysis of 174 studies found that “more than 80% of the epidemiological studies show positive associations [with forms of childhood cancer] and pesticide exposure,” and, of those, about a third found positive associations of pre- and post-natal pesticide exposure with leukemia and neuroblastoma, a childhood cancer of immature sympathetic nervous system cells. Of the studies in that meta-analysis focusing on pesticides, more than half involved parental and prenatal exposures, reinforcing the evidence that the preconception and prenatal periods of reproduction are the most vulnerable phases of life for both parent and child. Anybody who is worried about reproductive success and children’s thriving must consider the ubiquity of pesticides in homes, water, air, and food. Eliminating them from the environment would be an efficient way to sharply reduce the stress, heartbreak and expense of childhood cancers.
See Beyond Pesticides’ explainer “Pesticides and Children Don’t Mix” for further information. See also resources on less toxic methods of controlling fleas and ticks.
All unattributed positions and opinions in this piece are those of Beyond Pesticides.
Sources:
Environmental Pesticide Exposure in the Etiology of Pediatric Brain Tumors and Leukemia: A Scoping Review of Epidemiological Studies
VanDeSteeg et al.
International Journal of Cancer 2026
https://onlinelibrary.wiley.com/doi/10.1002/ijc.70546
Ten Years of Scientific Studies Find Association Between Childhood Cancer and Pesticide Exposure
Beyond Pesticides, April 4, 2024
https://beyondpesticides.org/dailynewsblog/2024/04/ten-years-of-scientific-studies-find-association-between-childhood-cancer-and-pesticide-exposure/
Dire Pediatric Cancer Risk Linked to Pesticide Mixtures, Laws To Protect Children Found To Be Lax
Beyond Pesticides, December 3, 2025
https://beyondpesticides.org/dailynewsblog/2025/12/dire-pediatric-cancer-risk-linked-to-pesticide-mixtures-laws-to-protect-children-found-to-be-lax/
In Utero Origins of Acute Leukemia in Children
De Smith and Spector
Biomedicines 2024
https://www.mdpi.com/2227-9059/12/1/236
