Nobody knows if Malibu High School is making people sick. But last October, Los Angeles media reported a possible cancer cluster involving three teachers allegedly diagnosed with thyroid cancer. The ensuing controversy was met with missteps by the Santa Monica-Malibu Unified School District — and silence from the teachers union.

Six months later, dozens of parents and teachers have formed a group demanding answers, and a federal Environmental Protection Agency analyst has openly criticized Malibu school officials for failing to promptly resolve potential health threats or address community fears.

The district has spent half a million dollars on soil and other tests, as well as legal advice, to quell the controversy. But in January, a dozen teachers refused to return to their classrooms inside a Malibu High School building, although California EPA Region 9 officials insist it's safe.

EPA senior policy analyst Hugh Kaufman in Washington, D.C., says the district is largely to blame for the uproar. He says district officials have tried to “evade and avoid comprehensive assessment. They've spent half a million dollars dodging and covering up. We still don't know what the problem is, or what the magnitude of the problem is, because the school district refuses to do what they have to do to find out.”

Underlying the drama is the fact that scientists say it's all but impossible for thyroid cancer to be caused by the contaminants found during the Malibu High tests: common, if undesirable, toxins in the soil and PCBs in old window putty.

Thyroid cancer is widely believed to be largely hereditary. According to the National Cancer Institute, its only known environmental cause is radiation. There is, to date, no evidence of a radiation source at Malibu High School.

Marcia Brose, director of the Thyroid Cancer Therapeutics Program at the University of Pennsylvania, says thyroid cancer is so common that “it's not surprising that you might discover some people who have had thyroid cancer, and they might know somebody [who has it] nearby. Unless there's really clear radiation risks in the area, I don't think that there's any evidence for thinking that their thyroid cancer is caused by an environmental toxin, particularly.”

But the controversy has unnerved some Malibu parents and teachers, who are reporting such illnesses as asthma and rashes, with some pointing to the high school as the possible cause.

Santa Monica-Malibu Unified School District chief financial officer Janece Maez says the district has spent nearly $500,000 responding to the controversy, but critics accuse officials of foot-dragging.

EPA's Kaufman says, “I've done environmental assessments for over 40 years, and it would probably cost about $200,000 to do a substantive environmental assessment, taking about one or two months.”

Brigette Leonard, a Malibu High School theater teacher, who says she was diagnosed with thyroid cancer in April 2013, tells L.A. Weekly, “We just wanted the truth. We wanted testing to occur to prove that we are in a safe environment or to prove that we are not — and remediate and help the situation.”

She says, “We were told to 'shut up' from our union rep, from the superintendent and from our principal. So, at first, the teachers did. We believed, 'Oh, OK, look at this media frenzy. This was not what we wanted.' ”

Public Employees for Environmental Responsibility (PEER), a nationwide activist group, has stepped in, suggesting on its website that contaminants such as PCBs (polychlorinated biphenyls) could be tied to old materials used in 1963 to construct the school.

PEER also alleges — apparently inaccurately — that WWII coastal defense operations were conducted on the high school land. Jay Field, spokesman for the U.S. Army Corps of Engineers, tells the Weekly that Malibu High is miles from the old Department of Defense sites, saying in an email, “The closest sites we have are in the Santa Monica Mountains National Recreation Area.”

The war of words began in 2010 after routine soil testing at Malibu High — required before it launched its “campus modernization project” — revealed toxins including PCBs, which the EPA has listed as “probable human carcinogens,” in addition to chlordane, lead, DDT and arsenic.

At an Aug. 30, 2010, meeting, the school district's Measure BB Advisory Committee discussed whether disturbing the soil could send toxins into the air. Committee member David Reznick, the influential president of Malibu Bay Company, one of the largest landowners in Malibu, asked “if there were areas that are going to be disturbed” or “current health hazards to the students,” according to the minutes.

District officials promised that if the tainted soil needed to be disturbed and removed, it would be done in the summer of 2011, when few students were around. That summer a contractor, Arcadis, removed 1,158 tons of contaminated soil.

Some parents and teachers say they were in the dark about this major cleanup until last October. But it was approved at a public meeting in 2010, and the documents apparently were made available online.

Hope Edelman, whose two children attend Malibu High, says of the soil-remediation controversy: “No real effort was made to inform parents that there were contaminants in the soil that was moved. The words 'toxins, PCBs, pesticides, contaminants' — I didn't hear any of those words until October of 2013.”

Last August, district crews dug trenches under some high school classrooms — a routine project to install utility fire alarms.

Apparently as a courtesy, Malibu High School principal Jerry Block called theater teacher Leonard, who was being treated for thyroid cancer, and suggested she stay home until the digging project was done.

Leonard tells the Weekly that Block “told me to not come to school anytime soon … and I said, 'Well, I technically can't because I'm radioactive — because I was home having my radiation treatment. I can't get out of bed, I can't come to school — why?' He said, 'Just don't, because it will make you really upset.' ”

Leonard, who was a student at Malibu High School and then taught for more than a decade in the same classroom, says she is “pretty much the definition of what long-term exposure would look like.”

Teachers began to discuss their health issues with one another. Two months later, in October, 20 teachers wrote to the district, alleging that three teachers had thyroid cancer and that others suffered illnesses including thyroid problems, rashes, hair loss and migraines. They questioned whether toxins were to blame.

The L.A. media swooped in. Only a few outlets correctly reported that the only known environmental cause of thyroid cancer is radiation.

In response to the teachers, the district performed preliminary air testing and “wipe testing” of surfaces in 13 classrooms and other rooms, cleaned them and deemed the buildings safe — a finding backed by EPA Region 9 officials.

When classes resumed on Jan. 7, several worried educators were allowed to use classrooms next door at Juan Cabrillo Elementary School. Twelve teachers asked the district to conduct an extensive re-evaluation for the presence of PCBs and other chemicals.

So what, if anything, is wrong at Malibu High?

Jennifer deNicola, a parent who serves on the district's Malibu Schools Environmental Task Force, has launched the group Malibu Unites for Healthy Schools, which is seeking comprehensive toxin testing of both campuses. After that, she says, “We can sit down collaboratively with the parents and the teachers and the district and figure out the best solution for our school.”

Meanwhile, the EPA and the state Department of Toxic Substances Control are overseeing a plan in which private contractor Environ will create a “best management practices” approach for the coastal school district. District Superintendent Sandra Lyon says, “We're moving along, getting Environ on board so we can start implementing best management practices.”

Leonard says, “All we want is to prove that this is all just absolutely a coincidence and that people just get sick, that we just happen to be people with the same [disease]. I would absolutely love it if we're all wrong. Don't just tell us that we're wrong.”

Principal Block and the district's risk management specialist, Gary Bradbury, would not comment, referring the Weekly to Lyons' office.

The EPA's Kaufman thinks district officials brought this distrust upon themselves. “All they needed to do was do some low-cost environmental testing in all the classrooms and in the soil and get an environmental profile,” he says, “and they'd have answers within a month or two of what kind of exposure the students and teachers have.”