KSHB 41 reporter Fernanda Silva covers stories in the Northland, including Liberty. She also focuses on issues surrounding immigration. Share your story idea with Fernanda.
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A federal agency has completed its review of cancer cases among staff and employees at an elementary school in Liberty, finding no evidence of an unusual pattern of cancer.
The National Institute for Occupational Safety and Health (NIOSH) released findings last month addressing cancer concerns among employees at Warren Hills Elementary School in Liberty, Missouri.
"There is no evidence of an excess or unusual pattern of cancer among school employees," the agency said in its February report.
Last week, Warren Hills Elementary School families received an email from the school’s principal stating that the school “continues to be a safe and healthy environment for our students and staff.”
According to the report, between 2013 and 2025, 11 of the school’s 294 employees reported 12 cancer diagnoses — three of which were breast cancer. NIOSH stated that this does not exceed expectations for the general population.
The agency acknowledged limitations in the data about the number of cases: The survey was voluntary, not distributed to former employees who left before 2022, and records only date back to 2013 — not to the school’s opening in 2006.
The report found no evidence of “employee overexposure to a cancer-causing chemical or hazard at the school.”
Environmental sampling showed that levels of radon, carbon dioxide, carbon monoxide, nitrogen dioxide, ammonia, volatile organic compounds, ozone, chlorine, and particulate matter in the air were "below occupational exposure limits."
Another concern raised by parents and school staff was the cell tower located on school property.
NIOSH states they reviewed a 2023 compliance report and found that radiofrequency (RF) radiation levels for the general public were "less than 5% of the Federal Communications Commission’s maximum permissible exposure limit."
NIOSH concluded that RF levels from the cell tower were "well below" regulatory limits.
The report stated that NIOSH reviewed the results of multiple air, surface, building material, water, and soil samples collected and tested by consultants in the school or on school grounds between 2015 and 2025. "The chemicals tested were not found at levels exceeding occupational exposure limits (for chemicals that have such limits)," the report read.
The report looked into soil samples collected at two walkways near school entrances and one location near the playground. Lead and arsenic levels in soil on school grounds were above state target levels — "but the levels were consistent with levels naturally found in soil throughout the state," the document stated.
Polycyclic aromatic hydrocarbons (PAHs) were also found at levels above state targets. NIOSH determined that the elevated PAH levels were “likely due to rainwater runoff from adjacent blacktop paving” and that "these levels are unlikely to represent a substantial occupational exposure."
NIOSH recommended establishing a multidisciplinary occupational safety and health committee at the school. The agency also encouraged employees to “learn more about known risk factors and ways to reduce the risk of cancers.”
For months, we've been amplifying the voices of concerned parents about the cancer cases at the school.
The email from the principal to the school’s community, sent last week, says the school had already received “positive reports" from the Clay County Public Health Center and the Missouri Department of Health and Senior Services.
"There are no health or safety concerns within our building," read the email. “All three groups looked at the building separately and came to the same conclusion: Warren Hills Elementary is a safe and healthy place for students and staff."
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