“I’m sorry, but that’s not possible,” Melissa Bumstead said to another patient’s mother whom she met in a hospital hallway. “Childhood cancer is really rare. I don’t think it’s possible that we could live so close to each other.”

But the other mom had recognized Bumstead from a park where both their children played. They’d been moms at the park at the same time, and now they were moms of kids with rare cancers, in the same hospital, at the same time.

Chad and Melissa Bumstead with their son Luke, and their daughter Grace, who was diagnosed with a rare cancer at age 4 and is recovering.

In 2014, at age 4, Bumstead’s daughter was diagnosed with a rare leukemia called PH+ALL. After more than 100 days’ hospitalization, two years of treatments, including bone marrow transplant, chemotherapy, radiation — and then a relapse — she is now doing well.

But hers was not the only rare cancer in the neighborhood. A Simi Valley girl, Hazel, age 7, died in March 2018 of a brain tumor called neuroblastoma. Bailey, 2, also died of neuroblastoma, in 2015. Bumstead told the Ventura County Reporter that Bailey’s mother had lived in the area during the first trimester of her pregnancy. Another girl, whose mother also lived locally during her first trimester, died of neuroblastoma at age 4 in 2014. With 800 annual cases out of 73 million U.S. children, a child has a .001 percent chance of being diagnosed with neuroblastoma.

Bumstead said that a 9-year-old Simi Valley boy died of  a brain tumor called DIPG, or diffuse intrinsic pontine glioma, in 2016; a 16-year-old girl died of medullablastoma in 2013; and a 4-year-old boy died of hepatoblastoma in 2010. A 19-year-old woman who died of eye cancer lived on the same avenue Bumstead lived on. She said that one area baby now has Langerhans cell hystiocytosis, or LCH, which typically occurs in one out of 2 million children each year. A teenager has acute promyelocytic leukemia, or APL, which occurs at a rate of one in 250,000 people annually.

“Then there’s my daughter’s PH+ALL,” Bumstead said. “One in a million get it every year.”

When her daughter was bald due to undergoing treatment, people would approach Bumstead while she was out shopping. “They would see her and come up to me and say, ‘My child has cancer too,’ ” Bumstead said.

She began to wonder, “What is the statistical probability that all these cases would occur within miles of each other?”

Recent photo of Santa Susana Field Laboratory.

Bumstead said that she has since met many childhood-cancer families who all lived within a 20-mile radius of the Santa Susana Field Lab, a former rocket-testing site in Simi Valley. From 1949 until it was closed in the 1990s, the 2,860-acre hilltop site was home to rocket companies conducting thousands of fuel tests, including Rocketdyne, Atomics International, Boeing and Rockwell International; and federal agencies, including NASA and the Department of Energy.

A partial meltdown of a nuclear reactor happened at SSFL in 1959, causing radioactive chemicals to drift into the air, soil and water. Employees were directed not to tell anyone about the incident, and it was not publicly disclosed for 20 years, until 1979.

“I have found children with absurdly rare cancers,” Bumstead said, “all within 20 miles of the SSFL, and I mean absurdly rare, even in the rare world of childhood cancer.” She mapped out the cases she knew about, and saw what appeared to be pediatric cancers occurring within the 20-mile radius at above-national averages. She believes the actual numbers are higher because of privacy concerns; she believes that many families do not want to talk about childhood illnesses publicly. The 20-mile radius includes parts of Simi Valley, Bell Canyon and Thousand Oaks in Ventura County, and parts of West Hills, Chatsworth and nearby communities just over the county line.

Ewing-Sarcoma is diagnosed in about 200 children per year. That’s a .0003 percent chance of having it. Two area teens in the same high school were diagnosed with it.

Area map of Santa Susana Field Laboratory

Rhabdomyosarcoma accounts for 3 percent of all childhood cancers and is diagnosed in about 350 children per year — a .0004 percent chance of getting it. “We have two kids in our area with Rhabdomyosarcoma diagnosed,” Bumstead said.

Multiple rare cancers appearing within the radius led Bumstead to wonder whether SSFL cancer-causing pollutants are still contaminating groundwater and drinking water, if they are migrating throughout the area, and if they render fruit and vegetables grown there too toxic to eat. She eventually joined Parents Against Santa Susana Field Lab Nuclear Disaster. She started a petition to force a thorough cleanup of the SSFL that has garnered more than 260,000 signatures.

“Children are the most vulnerable, with their immature systems constantly growing, and that’s why these pediatric cancers are so concerning,” Dr. Robert Dodge told the VCReporter. Dodge practices family medicine in Ventura and is a member of Physicians for Social Responsibility. “The incidence of these rare cancers certainly raises concerns.”

National Cancer Institute data show no unusually high rates of rare childhood cancers in Ventura County or the state of California. Nationally, NCI defines the rarity as less than 20 cases per 100,000 children, compared to 350 cases in 100,000 adults. Dr. Francisco Bracho is Medical Director of Ventura County Medical Center’s Pediatric Oncology Department, and he is also affiliated with Children’s Hospital Los Angeles. California does not have a higher incidence of childhood cancer, and Ventura county is similar,” Bracho wrote in an email to the Ventura County Reporter. “Rare cancers will not move the needle so no anomalous data would not be expected.”

Questions about contamination-linked cancers linger because the site has never been completely cleaned up and decontaminated. A half-century of government-mandated but incomplete cleanups, disputes about who is accountable for cleanup, medical claims and denials of claims has included legal cases initiated by area cancer patients and their families, including Rocketdyne employees who had fatal cancers.

A 1997 study found a 60 percent greater chance of cancers for area residents and former employees: “All available evidence indicates that occupational exposure to ionizing radiation among nuclear workers at Rocketdyne/AI has increased the risk of dying from cancers of the blood and lymph system.”

A 2007 EPA report concluded: “Multiple operations at the SSFL over the last six decades have resulted in the contamination of surface and subsurface environmental media by various hazardous substances. Extensive use of the most predominant hazardous substance at the site, trichloroethylene (TCE), has impacted the groundwater.”

One result of the ongoing debate is that scientists know a lot more about radiation than they did in the past. “We’re concerned about the science,” Dodge said. “The National Academy of Sciences has determined, there is no safe level of radiation contamination. None.”

“We’ve heard that this could still be a ‘normal’ anomaly,” Bumstead said, “and that if it were a ‘real’ cancer cluster that they would all be the same type of cancer. But the SSFL had dozens of different radioactive and chemical contaminants, so it makes sense to me that we’d see dozens of different cancers.”

Toxins identified as present in SSFL soil, in various reports, studies and tests over the years include cesium 137, perchlorate, plutonium-239, strontium-90, tritium and trichloroethylene, also called trichloroethene or TCE.

“Cesium-137 can remain hazardous for 600 years,” Dodge said. Radioactive cesium-137 burrows into muscle tissue to cause cancer, according to the U.S. Centers for Disease Control. One 2012 EPA survey found SSFL Cesium-137 contamination at levels up to 500 times higher than in uncontaminated soils.

Perchlorate was found at unsafe levels in 18 Simi Valley wells in 2002. A 2016 National Institutes of Health study shows how perchlorate affects the thyroid, brain, and metabolism. “Expanding evidence,” according to the study, suggests that children, pregnant women and fetuses may be especially susceptible.

Plutonium-239 is the deadliest substance on Earth,” Dodge said. plutonium is linked to lung cancer, liver cancer and bone sarcoma. Rocketdyne housed a plutonium fuel-fabrication facility and a nuclear waste processor where four or more nuclear reactors had partial meltdowns. A “half-life” of radioactive chemicals is the amount of time it takes for half of the chemicals to stop being radioactive: The half-life of plutonium-239 is 24,000 years.

Strontium-90 can concentrate in bone, make its way into teeth, and is linked to bone cancer and lymphomas, according to the American Cancer Society. The 2012 EPA survey found strontium-90 at levels 284 times higher than in uncontaminated soil.

TCE is the focus of current research: Findings of a 2018 study in the Journal of Applied Toxicology link TCE to human liver DNA damage. A 2017 Science Direct report suggests that the developing central nervous system and immune system are susceptible to TCE damage. Studies from 2015 and 2016 describe how TCE impacts heart growth in fetuses. The National Institutes of Health reports that TCE is carcinogenic to humans and a hazard to the central nervous system, kidneys, liver, immune system, male reproductive system and the developing embryo/fetus. The presence of TCE in groundwater was one of the topics covered at the California Department of Toxic Substances Control’s (DTSC)  April 2018 Community Biannual Update.

Tritium has been found at unsafe levels in the SSFL area. A new 2018 study in the Journal of Radiological Protection highlighted chromosome irregularities — alterations of genes — in people exposed to tritium.

No definite link between cancer and SSFL has been established because 1990s researchers could not assess other factors that cause cancer — such as smoking, a family history of cancer, poor diet or alcohol misuse. The 1997 study showed a 60 percent greater chance of cancers for area residents, but doctors at that time had no way to measure family histories or smoking behaviors of Rocketdyne employees, so they could not point to SSFL radiation as the sole cause of their cancers.

Boeing, as well as NASA and the Department of Energy, are each legally accountable for cleaning up different portions of the site, and all cleanup is being overseen by the DTSC. The DOE has decontaminated the portion that it is responsible for, according to DOE representative John B. Jones, who wrote to the VCReporter in a May email that there is no evidence that chemicals are migrating offsite from the two portions DOE is responsible for: “The 2017 sampling results are consistent with previous findings. The main chemical contaminants of concern in Area IV and the Northern Buffer Zone are non-radioactive chemicals trichloroethene (TCE) and tetrachloroethene (PERC). Samples from offsite wells are below drinking water standards, demonstrating that these chemicals are not migrating offsite and do not present health risk to surrounding communities.”

DTSC representative Russ Edmondson wrote to the VCR in a June email that SSFL’s groundwater is not used for drinking water. The drinking water for local communities is mostly imported from other sources, including Golden State Water Company and Simi Valley Waterworks District No. 8 in Simi Valley; Las Virgenes Municipal Water District in L.A. County; and Los Angeles Department of Water and Power in L.A. city areas such as Chatsworth and West Hills. “The majority of imported water comes from the State Water Project (the California Aqueduct) supplied by the Metropolitan Water District of Southern California,” Edmondson wrote.

The cleanup has been perennially steeped in disagreement and lawsuits. Boeing has no plans to decontaminate its portion to a level safe enough for residential building, but rather to a level just safe enough to host hiking trails. In 2009, Boeing successfully sued to overturn one of the cleanup mandates that had been ordered, claiming that it imposed “uniquely onerous cleanup rules that apply nowhere else in California.”

Daniel Hirsch, President of Committee to Bridge the Gap and retired Director of UC Santa Cruz’s Program on Environmental and Nuclear Policy, wrote to the VCReporter in an email that commitments were made that all contamination would be cleaned up by 2017: “It is now 2018 and the cleanup has not only not been completed, it has not even begun. The state toxics agency is now estimating cleanup by 2034. At the same time, the parties responsible for the pollution are pushing to break out of their cleanup agreements and leave the great majority of the contamination not cleaned up at all.”

Hirsch noted SSFL’s hilltop geography. “It sits on hills, below which live half a million people within 10 miles. The pollutants are carcinogens, which by definition cause cancer, and they ‘want’ to migrate downhill, to where the people are.”

Hirsch wrote that the only way to protect people from further injury is to clean up the source: “And it is precisely the promise to do that which is being broken by the state toxics agency and the polluters responsible for the contamination.”