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Rare Cancer Cluster in Ladera Ranch Prompts Environmental Testing
ReRare Cancer Cluster in Ladera Ranch Prompts Environmental Testing
At least six children in Ladera Ranch, California, have been diagnosed with Ewing sarcoma, a rare bone cancer. Families are demanding answers as state and local agencies launch environmental investigations into possible causes, including pesticide exposure.
A cluster of rare cancer diagnoses in Ladera Ranch, California, has prompted environmental testing and demands for answers from families, though state health officials say no specific cause has been identified. At least six children in the Orange County community have been diagnosed with Ewing sarcoma, an exceptionally rare cancer that forms in bone or nearby soft tissue and primarily affects adolescents and young adults, according to federal officials and local reporting.
Concerns intensified following the March 2026 death of 17-year-old Brody Matteson, who died from complications of treatment for Ewing sarcoma. After his death, more families began speaking publicly about rare cancer diagnoses in the community. Some residents, including Matteson's father, Dustin Matteson, have suggested the illnesses could be linked to the community's use of herbicides and pesticides, prompting calls for a broader environmental investigation.
«We don't have a clear line of evidence for pesticides, but it is one of the things that concerns us,» Matteson told NBC Los Angeles in July. «Knowing that this is a very rare cancer diagnosis amplifies the concerns,» said Dr. Janet Yoon, a pediatric oncologist and sarcoma specialist at City of Hope in Los Angeles. «Anytime you hear of cases in a geographic location, it does raise some concerns... I can completely understand why further investigation is being done.»
In 2024, prompted by residents' concerns, the California Department of Public Health conducted a county-level review to determine whether pesticide use could have played a role in the development of certain cancer types. «That analysis did not find an unusual pattern at the county level, but the data available at the time was limited,» the CDPH stated on its website. The agency is now conducting a second review of cancer incidence data for the Ladera Ranch area, with an estimated completion in fall 2026, though the timeline may change based on the scope and complexity of the review.
«At this time, our colleagues at CalEPA and its boards, departments and offices have not identified any immediate environmental hazards,» the CDPH stated. The agency also noted that it is not yet known whether diagnoses of Ewing sarcoma and other cancer types are higher than expected in the community, or whether environmental factors can increase the risk.
In July 2026, First Assistant U.S. Attorney Bill Essayli asked the Environmental Protection Agency to investigate possible environmental factors that could have contributed to multiple pediatric cancer cases. Over the summer, hundreds of residents gathered at community meetings. The Ladera Ranch Maintenance Corporation (LARMAC), the master homeowners association for the planned community, temporarily paused its use of certain landscape chemicals and formed an advisory committee to review its landscaping practices.
As the investigation has continued, some residents have also publicly reported diagnoses of other cancers, including glioblastoma, although the current state review has not established whether those cases are related. On Sept. 14, California State Fullerton researchers began collecting soil and water samples from local parks as part of the environmental investigation. Jennifer Piazza, Ph.D., professor in the Department of Public Health at Cal State Fullerton, assembled a team of researchers to help address the environmental concerns stemming from the pediatric cancer cases.
«Environmental sampling is the first step of our larger, ongoing scientific investigation,» she said. «We are collecting soil and water samples across Ladera Ranch. They are being analyzed for heavy metals, such as arsenic and lead, as well as pesticides.» The team expects to have results by the end of the year, Piazza said. «I also want to emphasize that whatever we find does not imply causality in terms of the pediatric cancer cases in Ladera Ranch,» she added.
LARMAC released a statement extending its «heartfelt compassion to the families who have been affected by these devastating illnesses.» The organization said it takes the concerns seriously and will continue to cooperate with public health agencies. «At this time, we are not aware of any determination by those agencies identifying a specific environmental cause or linking the Association's landscape management practices to these illnesses,» the statement read. LARMAC also noted that it has reduced the use of synthetic pesticides and switched to organic pesticides.
Medical experts caution that no confirmed genetic or environmental cause of Ewing sarcoma has been identified. «With Ewing sarcoma, there is no confirmed genetic or environmental cause that we know of,» Yoon said. «We have not found any confirmed genetic or environmental factor that increases the likelihood of developing Ewing sarcoma.» Some studies have linked occupational or high-level exposure to certain pesticides with an increased risk of several cancers, though the evidence varies by chemical and cancer type, according to the American Cancer Society. The ACS states that no known lifestyle-related or environmental cause of Ewing sarcoma has been identified.
