LOS ANGELES — A study conducted by Honor Collegium students at UCLA under the supervision of Alison Lipman, Ph.D. found a “higher than average persistence of PCB-related diseases in individuals working at” PCB contaminated public schools in Malibu. The study may be seen at

–The study found a significantly higher prevalence of thyroid and Hashimoto’s disease at the Malibu schools compared to rates in the United States.

–The study also found significantly higher rates of thyroid disease, Hashimoto’s disease, and fertility issues compared with a control population at Oaks Christian School in Westlake Village.

“I am proud that these students conducted such a rigorous and well-researched study,” said Dr. Lipman. “I hope their work will be built upon in Malibu, and across the U.S. to protect teachers and students that are in PCB contaminated schools.”


The binomial test found a significantly higher prevalence of thyroid cancer and Hashimoto’s disease at Malibu schools, compared to published background rates in the US. The study reported five cases of thyroid cancer at Malibu schools, compared to less than one case expected (p = 3.175 x 10-14), and eight cases of Hashimoto’s disease at Malibu schools, compared to less than one case expected (p = 1.34 x 10-12). No significantly enriched diseases were found at OCS.

The Fisher’s exact test comparing disease rates between Malibu schools and OCS found significant enrichment at the Malibu schools, in thyroid disease (16 incidences at Malibu compared to zero incidences at OCS) (p = 2.110 x 10-4), Hashimoto’s disease (eight incidences at Malibu
compared to zero at OCS) (p = 0.0216), and fertility issues (seven incidences at Malibu compared to zero at OCS) (p = 0.0362); while thyroid cancer (five incidences at Malibu compared to zero at OCS) (p = 0.0983) showed marginal significance. No significance was found when comparing building location or length of exposure with disease occurrence.


The study tested whether the detected occurrence of PCBs at Malibu schools correlate with increased incidences of PCB-related diseases, and thus are putatively causing diseases in staff members working at the schools. It tested the hypothesis that there would be a higher than average persistence of PCB-related diseases in individuals working at these schools.

The study analyzed enrichments in the incidence of PCB-related diseases in staff members at the Malibu schools. In order to test our hypothesis, teachers at Juan Cabrillo Elementary School, Malibu Middle School and Malibu High School were administered an online survey (n =
146). The survey collected information on the prevalence and severity of PCB-related diseases, along with work hours, and work-site specific information, such as buildings that the teachers work in. In order to draw a comparison, teachers at Oaks Christian School in Westlake Village, built after the PCB ban, were administered the same survey as a negative control (n= 195). The study used binomial tests to assess increased prevalence of PCB-related diseases at the Malibu schools and Oaks Christian from responses (nMalibu= 41; nOaks= 23).  Then a Fisher’s exact test was used to identify enrichment in disease prevalence in Malibu schools compared to Oaks Christian disease rates.

Furthermore, calculated was the chance of having a PCB-related disease due to working in buildings with high levels of PCBs using odds ratio. Finally, a Fisher’s exact test was conducted to assess the relationship between exposure time and disease status.


Polychlorinated biphenyls (PCBs) are carcinogenic pollutants that have been banned nationally and have been found in state governed Malibu public schools Juan Cabrillo Elementary, Malibu Middle, and Malibu High School. Exposure to PCBs increases the risk of heart disease, thyroid disease, Hashimoto’s disease, and several forms of cancer.

The Malibu community became especially concerned about PCB exposure at its public schools after three teachers were diagnosed with thyroid cancer within months of each other in 2013. Since then, and outside of this study, approximately 50 illnesses have been reported by students,
teachers and alumni as potentially being linked to PCBs.

Subsequent testing in 2015 revealed classroom building materials within the campuses of Malibu High School and Juan Cabrillo Middle School with levels of PCBs thousands of times greater than the 50 parts per million threshold set by federal law. One sample tested at 570,000 parts per million, believed to be the highest ever found in an American school.

Controversially, the school district chose to halt testing and not pursue a PCB removal strategy, leading to federal litigation for an injunction to remove PCBs in compliance with Federal law and
continuing significant concern among parents, teachers, and students.

Research conducted by Dr. Robert F. Herrick at Harvard’s School of Public Health has found PCB contamination to be widespread in American schools, with up to 25,000 campuses affected and 20 million people exposed each school day.

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