Oct. 9, 2013 at 4:55 PM ET
Officials at Malibu High School say they are moving students, running tests and questioning teachers about fears that some sort of chemical might be causing illness at the California school.
While most experts say such a cluster of illness is highly unlikely, the school officials say they are taking no chances. The case illustrates the heightened fears that exist around the idea of environmental contamination.
“Last month, our District was notified by a few members of the Malibu High School staff that they believed campus environmental conditions may be causing health issues. We took immediate action to engage a third party certified industrial hygienist to conduct the proper tests, and we moved the concerned teacher and closed off the room in question,” the Santa Monica-Malibu Unified school district superintendent said in a statement.
“Out of an abundance of caution and care for our students and staff, we are relocating all of our classes out of the Middle School Building,” the school says in a statement on its website.
It’s a big school, with 1,100 students in grades 6 to 12.
Some teachers there have said they fear soil removed from the school during recent projects was contaminated with polychlorinated biphenyls (PCBs), lead, and other chemicals. They’ve also mentioned potential mold problems in some classrooms.
Various local newspapers and television stations have reported that three teachers were recently diagnosed with thyroid cancer. School officials didn’t immediately confirm the reports.
County public health officials say they are helping in the inquiry and would review any findings from the environmental testing, which is being done by a commercial firm.
“Our assistance was requested. I wouldn’t call it an investigation,” said a spokesman for the Los Angeles public health department. Health officials are uncertain when test results will be available.
It’s not an uncommon situation, but rarely do fears truly pan out.
One problem is that cancer is a very common disease. It’s the No. 2 cause of death in the United States, and is diagnosed in 1.2 million people every year.
Cancer takes years and even decades to develop. The Centers for Disease Control and Prevention says a cancer cluster has to be carefully defined. Unless more than an expected number of people develop cancer – and it usually must be the same type of cancer in all of them – there’s little reason to suspect a cluster.
And the most common causes of cancer are ordinary and well known – smoking, obesity, a lack of exercise, and poor diet.
Polls show Americans are barely aware of this and are far more worried about chemicals and pollution, which cause fewer than 5 percent of cancer cases, according to Dr. Graham Colditz of the Washington University School of Medicine in St. Louis, an expert in the causes of cancer.
“Cancer clusters are reported often but very seldom do they turn out to be something definitive,” says Richard Clapp, an epidemiologist at Boston University.
Fears about cancer clusters are so common that the federal government devotes several websites to explaining why people fear them, why they are so commonly reported, and why there’s rarely a true cluster of cancer cases
“Because a variety of factors often work together to create the appearance of a cluster where nothing abnormal is occurring, most reports of suspected cancer clusters are not shown to be true clusters,” the National Cancer Institute says.
One even features a hypothetical school where seven staffers are diagnosed with various types of cancer.
“The distribution of types of cancer did not appear unusual given the age and gender of the employees,” the National Institute of Occupational Safety and Health says in one theoretical scenario.
There wasn’t evidence the teachers had been exposed to a known cancer-causing substance, such as benzene, and the building had only been in use for six years. Cancer usually takes longer than that to develop.
“Given this information, it was concluded that the cancers reported among these workers were unlikely to be the result of employment at the elementary school,” NIOSH notes in its scenario.
One of the best documented cancer clusters was during the 1960s, when a rare type of lung cancer called mesothelioma was linked to working with asbestos.
Thyroid cancer is a common cancer, with 60,000 new cases a year in the United States, according to the National Cancer Institute. It will affect 1 in every 92 people at some point in their lives. The only real known risk factor for thyroid cancer is radiation. Most cases are linked with inherited genetic mutations or are unexplained. It’s not linked to PCBs, says Clapp.
“PCBs have been well studied over the years. They are banned now,” he said.
As for mold, it can worsen allergies and asthma, and people who are sensitive to mold can suffer respiratory effects if they breathe in mold spores.
“It’s an annoyance and if it is true there is a severe enough problem of mold in the school, it might cause respiratory problems in people who are students there or teachers there,” Clapp says.