Most childhood cancers cannot be prevented the way adult cancers can. Only about 5% are caused by inherited genetic mutations, and the majority arise from spontaneous changes in a child’s DNA that no one can predict or control. Still, an estimated 15% of childhood cancers may be linked to preventable environmental exposures, and there are concrete steps parents can take during pregnancy and early childhood to lower risk where the science supports it.
In the United States, roughly 18 out of every 100,000 children under 20 are diagnosed with cancer each year. That number rose slowly between 2001 and 2016, then began declining through 2022. The overall rarity of these cancers makes prevention research difficult, but several risk factors have emerged clearly enough to act on.
Prenatal Nutrition and Folic Acid
Taking folic acid during pregnancy is one of the most well-supported steps for reducing a child’s cancer risk. A large international study found that mothers who took folic acid supplements during pregnancy had roughly an 18% lower risk of their child developing acute lymphoblastic leukemia (ALL), the most common childhood cancer. The protective effect was even stronger for acute myeloid leukemia (AML), where folic acid use was associated with a 48% reduction in risk.
Folic acid is already recommended during pregnancy to prevent neural tube defects, so this cancer-protective benefit comes at no extra cost or effort. Most prenatal vitamins contain adequate amounts.
Reducing Pesticide Exposure
Children who live near areas with heavy pesticide use face elevated risks for brain and central nervous system tumors. Research tracking residential proximity to agricultural pesticide applications found that several common fungicides and insecticides were linked to roughly 60% to 150% increased odds of specific brain tumors in children. These associations held up across multiple statistical models.
You don’t need to memorize chemical names to act on this. The practical takeaways: if you live in an agricultural area, keep windows closed during spraying seasons and check local pesticide application schedules when available. For household use, minimize chemical pest control indoors, especially during pregnancy and early childhood. Choose mechanical traps or least-toxic alternatives when possible. Wash produce thoroughly, and consider peeling fruits and vegetables that carry higher pesticide residues.
Air Quality and Benzene
Benzene, a chemical released by vehicle exhaust and industrial sources, is one of the strongest environmental predictors of childhood leukemia. A meta-analysis pooling data from multiple studies found that benzene exposure more than doubled the odds of AML in children. Neighborhoods near major roadways and airports showed consistently higher rates.
Benzene damages blood-forming cells through its breakdown products, which can cause the kind of DNA breaks that lead to leukemia. If you’re choosing where to live or where your child spends time, proximity to heavy traffic corridors matters. Keeping car windows up in congested traffic, using air purifiers with activated carbon filters at home, and avoiding idling vehicles near schools or play areas are small steps that reduce cumulative exposure. Tobacco smoke is another significant indoor source of benzene, making a smoke-free home doubly important.
Diet During Pregnancy
Cured and processed meats (hot dogs, bacon, deli meats, sausages) contain compounds called nitrites that can form cancer-promoting chemicals in the body. Some research suggests that frequent consumption during pregnancy may increase brain tumor risk in offspring, particularly in children who inherit certain genetic profiles that make them less efficient at neutralizing these chemicals. In those genetically susceptible children, each additional serving per week was associated with a 29% to 61% increase in risk.
Since parents can’t know their child’s genetic profile in advance, limiting processed meat during pregnancy is a reasonable precaution. Fresh, unprocessed protein sources are a straightforward swap.
Vaccination Against Cancer-Causing Viruses
Hepatitis B vaccination is one of the clearest success stories in childhood cancer prevention. A 30-year follow-up study found that infants vaccinated at birth had 84% lower rates of primary liver cancer compared to unvaccinated children. The protection persisted into young adulthood.
The hepatitis B vaccine is part of the standard infant immunization schedule in most countries. HPV vaccination, typically given in the preteen years, protects against cancers that develop later in life but originates from infections that can begin in childhood. Keeping children current on recommended vaccines is one of the most effective and well-proven cancer prevention tools available.
Medical Imaging and Radiation
CT scans deliver significantly more radiation than standard X-rays, and children are more sensitive to radiation’s effects because their cells divide rapidly. The National Cancer Institute recommends several principles for minimizing this risk. CT scans should only be performed when genuinely necessary, and the settings should be adjusted for a child’s smaller body size. Lower-resolution scans are often sufficient for diagnosis. When possible, ultrasound or MRI, which use no ionizing radiation, should be used instead.
As a parent, you can ask two questions before any scan: “Is this CT necessary, or would another type of imaging work?” and “Will the settings be adjusted for my child’s size?” Pediatric hospitals and radiology centers following the “Image Gently” guidelines routinely make these adjustments, but it’s worth confirming, especially in emergency departments where protocols may be less standardized.
When Genetics Play a Role
A small but important subset of childhood cancers stems from inherited predisposition syndromes. Pediatric oncology guidelines recommend genetic evaluation when a child shows any of five warning signs: a family history of similar or related cancers, bilateral or multiple tumors, cancer diagnosed at an unusually young age, physical features associated with a known syndrome, or a tumor type that frequently occurs alongside genetic predisposition.
For families identified as high-risk, surveillance programs can make a significant difference. Children with Li-Fraumeni syndrome, one of the most well-studied predisposition conditions, had a five-year survival rate of 89% when enrolled in a structured screening program compared to 60% among those who were not screened. Experts generally recommend surveillance when a child’s risk of developing cancer before age 20 exceeds 5%.
These screening programs typically involve regular imaging and blood work on a set schedule, tailored to the specific syndrome. If childhood cancer runs in your family or your child has been diagnosed with a rare tumor type, a referral to a cancer predisposition program can clarify whether genetic testing and ongoing monitoring are warranted.
Putting Risk in Perspective
California researchers estimated that about 15% of childhood cancers in the state were attributable to environmental hazards, with leukemia carrying the highest environmental fraction at roughly 21%. The remaining cases largely result from random DNA copying errors that happen as a child grows, which no lifestyle change can prevent.
This means that parents who do everything right can still have a child who develops cancer, and that reality is important to acknowledge. Prevention in childhood cancer is not about eliminating risk. It’s about reducing the exposures you can control: taking prenatal vitamins with folic acid, minimizing pesticide and air pollution exposure, limiting processed meats during pregnancy, staying current on vaccines, and being thoughtful about medical radiation. These steps won’t guarantee anything, but they shift the odds in your child’s favor where the science says it’s possible.