Earlier this month, the Air Force found polychlorinated biphenyls (PCBs) carcinogens at certain underground military locations in Montana.
The findings came after nine officers—who’d worked at the locations up to 25 years ago—were diagnosed with non-Hodgkin's lymphoma. One has died.
PCBs were banned in 1979 but are still found in the environment.
Earlier this month, the Air Force found “potentially hazardous” levels of polychlorinated biphenyls (PCBs)—a group of man-made organic chemicals the Environmental Protection Agency calls probable human carcinogens—at two Air Force facilities in Montana. The PCBs may be linked to several cases of cancer in officers working at the base.
The PCBs were detected as part of the Air Force Global Strike Command’s Missile Community Cancer Study, according to an August 7 Air Force Global Strike Command press release.
How did it happen
The two facilities in question are located at Malmstrom Air Force Base, where military officers work in underground bunkers reached by elevators that go deep into the earth. At times, the officers remain in the concrete and steel-enclosed bunkers for several days at a time, according to the Associated Press (AP).
The discovery of PCBs comes after “an extensive sampling of active US intercontinental ballistic missile bases to address specific cancer concerns raised by missile community members,” the Air Force Global Strike Command said in the release.
Nine officers who worked at the base up to 25 years ago were diagnosed with non-Hodgkin’s lymphoma—a blood cancer affecting the lymphatic system, according to the AP. One of the officers has died. Military briefings obtained by the AP noted that the cancer could be linked to their time on the base.
The Air Force Global Strike Command says that the cancer study’s results showed “PCB levels above the cleanup threshold designated by law in two of our facilities,” and that they are taking “immediate measures to clean up and mitigate” the PCBs. Results for other locations are currently pending.
But the issue doesn’t stop there. The AP reports that data from the Torchlight Initiative, a grassroots group of former missile launch officers, found that at least 268 officers (or their family members, if they’d died) self-reported cancer diagnoses, blood diseases, or other health conditions. They found of 217 cases of cancer, and 33 were non-Hodgkin’s lymphoma.
The bunker where these officers worked may play a role in their diagnosis, as they were built over 60 years ago—well before the ban on PCBs. “Missileers have raised health concerns multiple times over the years about ventilation, water quality and potential toxins they cannot avoid as they spend 24 to 48 hours on duty underground,” the AP reports.
A closer look at PCBs
Nicole Deziel, PhD, a member of the Yale Cancer Center and associate professor of epidemiology at Yale School of Public Health, tells MDLinx that PCBs are a group of synthetic chemicals that were frequently used in many commercial and industrial products—such as electrical equipment, fluorescent lighting, plasticizers, adhesives, or caulk—until their eventual ban in 1979.
Despite the ban, inadvertent PCBs are still present. “Due to their widespread use and improper disposal over the years, they remain in our buildings and in our environment and our food chain,” Deziel says. “They were banned due to concerns over their toxicity and carcinogenicity as well as their persistence in the environment. They do not break down easily.”
The journal Toxics found that PCBs move through the environment via several routes. For example, they may be ingested through foods (like seafood or dairy products) or they can be inhaled indoors and outside.
The EPA explains that PCBs found in fish and other animals may also be the most carcinogenic. “As a result, people who ingest PCB-contaminated fish or other animal products and contact PCB-contaminated sediment may be exposed to PCB mixtures that are even more toxic than the PCB mixtures contacted by workers and released into the environment,” they report. This is because PCB mixtures transform when they are released into the environment.
Patients should be warned against eating fish or wildlife from PCB-contaminated locations, per recommendations from the Agency for Toxic Substances and Disease Registry (ATSDR). Patients can follow up with state advisories to learn about these locations.
Beyond ingesting fish, patients who handle waste or recycling may also be more susceptible to PCB contamination, Deziel says. According to the International Journal of Environmental Research and Public Health,“Severe PCB contamination levels have been reported in e-waste recycling areas…notably in urban and industrial areas…from extensive PCB use and intensive human activity.”
Exposure time seems to play a role in how PCBs affect human health. “Although PCBs exposure does not necessarily entail clinically relevant consequences in the short term, recent studies suggest that their bioaccumulation can reduce fertility with transgenerational effects,” according to the journal Toxics.
Unsurprisingly, the journal found that people with the highest blood concentration of PCBs are those working over a long period of time in PCB-contaminated workplaces.
Deziel explains that PCBs can lead to cancer in different ways—depending on the structure and properties of each chemical. Some, she says, can cause direct damage to DNA, while others act through a molecule called the aryl hydrocarbon receptor, a protein that mediates toxicity. Others cause endocrine disruption.
“Hormone levels are critical for normal growth and development, and alterations in thyroid hormone levels may have significant health implications, including cancers,” Deziel says.
In addition to the potential blood cancer linked to PCBs, The EPA says that patients have also been diagnosed with rare liver cancers and malignant melanoma.
Treating PCB exposure
The ATSDR says there is no specific medication for patients exposed to PCBs, so treatment is supportive. The ATSDR recommends patients avoid further exposure as well as other hepatotoxic substances.
For acute exposure of the skin or eyes, patients should flush with water, remove contaminated clothing, and clean the skin thoroughly. Patients who inhale PCBs should be monitored for signs of toxicity.
“In the rare event of ingestion of PCBs, emesis would be contraindicated because of the high risk of aspiration. The value of administering activated charcoal after ingestion is unknown. Unless a patient has an intact or protected airway, administering charcoal is contraindicated,” the ATSDR recommends. Patients who’ve been exposed to PCBs should be examined regularly, with “particular attention to hepatic function and dermal lesions.”