Oppenheimer, the Christopher Nolan film up for several Academy Awards this weekend, tells the story of how J Robert Oppenheimer developed the world’s first atomic bombs. Set in a secret laboratory in Los Alamos, on northern New Mexico’s Pajarito plateau, the film pays scant attention to the Indigenous communities who inhabited the land before the Manhattan Project and the illnesses they endured after nuclear tests.

Now, nearly 80 years later, Los Alamos is once again booming as the US modernizes its nuclear arsenal. Scientists at Los Alamos National Laboratory (LANL), the only facility in the country currently producing plutonium cores of nuclear weapons, aim to ramp up production from zero to 30 pits per year over the next two years. The lab has hired some 4,000 new employees in the last two years, bringing the staff population up to nearly 16,000 people.

Locals worry about what the expansion will mean for their health.

“We know that every single family in our communities, especially those that are in closest proximity to [Los Alamos National Laboratory], have a handful of family members that suffer from different types of cancer and autoimmune disease,” said Marissa Naranjo, who is from Santa Clara, Kewa and Cochiti Pueblos. An activist with Honoring Our Pueblo Existence (Hope), Naranjo lives in Albuquerque but grew up on tribal land less than 20 miles from the lab.

In the years after Oppenheimer and his team experimented with radioactive plutonium, residents of surrounding communities began reporting heightened rates of cancer, autoimmune disease, and reproductive health issues – not unlike residents of north-western New Mexico, who lived near uranium mines that began supplying the lab, or their neighbors to the south, who lived downwind from the site where scientists first detonated the atomic bomb.

Studies and investigations found heightened rates of esophageal, bone, lung, kidney and brain cancer among former lab employees. But there were few formal efforts to study the lab’s impact on the pueblos, or local tribal communities.

“There’s a lack of epidemiological studies on these populations that have been, most likely, most heavily affected,” said Dylan Spaulding, a senior scientist at the Union of Concerned Scientists. The pueblos “have not been in a position to do their own studies and yet the burden of proof is often on them”.

Scientists at Los Alamos conducted a few early experiments in the 1940s on the impacts of plutonium on the human body, including by injecting 18 subjects, at least five of whom were civilians, with the substance. They found that plutonium collected in subjects’ livers, lungs, bones and lymph nodes, and that exposure to radiation predisposed people to thyroid and breast cancers.

A later, controversial study that analyzed the remains of 271 employees and 1,825 civilians indicates the impact the lab’s activities carried over the general population. Of the more than 2,000 tested subjects, the one with the highest concentration of plutonium was the body of a 91-year-old woman who lived 30 miles north of the facility. She had lived with her son-in-law, a janitor at the lab. “The plutonium concentration in her liver was 60 times higher than that of the average New Mexico resident,” according to a report on CDC findings published in December in Searchlight New Mexico, a local outlet.

As the lab expands, with plans to store as much as twice as much radioactive waste on site, locals are concerned. Plutonium, the radioactive material at the core of nuclear weapons, is most dangerous when inhaled. It can accumulate in the bones, disrupt cell development, and has been linked to sterility and cancer.

“I think LANL is used to being able to dump and manage waste very recklessly because they have the shield of being a militarized area,” said Kayleigh Warren, the environmental justice project coordinator at the non-profit Tewa Women United, and a member of the Santa Clara and Isleta Pueblos. She added: “They’re not in the practice of consulting with the community.”

Warren said that local distrust of the facility goes back to its foundation. Los Alamos’s plutonium facility and radioactive waste disposal areas were built atop nearly 2,000 cultural sites – including ceremonial kivas, petroglyphs and ancestral prayer sites – adjacent to the modern-day boundaries of the Santa Clara, San Ildefonso, Cochiti and Jemez Pueblos. From 1956 to 1972, the lab released chromium-contaminated water from its cooling towers into a nearby canyon, creating a large plume that seeped into local groundwater that the energy department is still cleaning.

Local wariness only grew as communities suffered illnesses they attributed to the lab; Warren said her community has a prevalence of breast and prostate cancers. “Another thing that I’m really concerned about is unexplained infertility,” she said. “There are a lot of healthy young women in my community who are infertile, who have recurrent miscarriages, who cannot carry pregnancies to term or who cannot conceive at all.”

As it ramps up warhead core production, the lab is making room for the new waste that it will generate. Although most of the lab’s waste has been moved to a waste disposal facility in southern New Mexico, it stores some legacy waste and containers that officials say are too unstable for transport on site. That includes four containers of cold war-era waste that lab employees believe have accumulated radioactive hydrogen, called tritium, inside. To safely transport those containers, the lab says it needs to release the gas that has built up inside them. Tritium, though rarely released in quantities high enough to cause health impacts, has been linked to cancer and birth defects.

The lab first announced its plans to vent the containers in March 2020 – a few weeks into the Covid-19 pandemic when many surrounding pueblo communities were preparing for outdoor spring ceremonies. The All-Pueblo Council of Governors issued a statement of concern and Tewa Women United collected more than 3,000 signatures on a petition, delaying the planned release. Earlier this year, the lab postponed those plans again, after Tewa Women United collected another 2,000 signatures and petitioned the Environmental Protection Agency and New Mexico environmental department to withhold the permits the lab required.

Steve Horak, a public affairs specialist at the lab, says that all decisions at the lab, including tritium venting, follow state and national environmental laws, like the Clean Air Act. “The Clean Air Act limits are set at levels that are protective of even the most vulnerable members of the population, including pregnant women, children, and the elderly,” he said in an emailed statement. By following the act, the venting “will be safe for all residents of the nearby communities”.

Warren, meanwhile, says: “The United States has really been lax in its regulation of tritium” and that pueblo activists are “very concerned about exposure” because it bonds to hydrogen – including in food and water.

In 2015, the Department of Energy launched an environmental management field office in Los Alamos, tasked with cleaning up legacy contamination from the Manhattan Project and Cold War eras. Since 2016 that work has been guided by a consent order from the New Mexico environment department, which has prioritized investigating spills and soil surrounding landfill leaks in nearby watersheds and canyons. The field office is also responsible for disposing of and transporting radioactive waste.

Most recently, in 2022, the field office began hosting listening sessions with “a diverse group of stakeholders, pueblos, non-governmental organizations and the public” to develop a long-term strategic vision. According to the field office’s website (the Department of Energy did not provide comment for this article), it “has met with approximately 170 participants who represent 20 stakeholder and pueblo groups, and has received nearly 2,000 comments”.