If the medical community is a caregiving army, then nurses are the enlisted corps. They’re the in-the-trenches troops with the cloth chevrons of the sergeant or the corporal sewn on their sleeves, not the more rarefied officers—like doctors, administrators, and government policymakers—with bars or stars pinned to their shoulders. It was Clara Barton who founded the American Red Cross, in 1881. It was Sojourner Truth, a nurse, who battled for abolition and advocated for nursing education for African American women. It was Florence Nightingale who tended to soldiers during the Crimean War in the 1850s and, during peacetime, helped introduce modern sanitation practices to hospitals.

In the twenty-first century, the nurses are mobilizing again. This time they’re on the march for a decidedly modern cause: cleaning up the environment. Leading the effort is the Alliance of Nurses for Healthy Environments (ANHE), a 7,000-strong international organization that aims to do for the planet what nurses have done for patients since the dawn of the profession—serve as bringers of health.

“We were established to help lead the nursing discipline,” says Katie Huffling, a registered nurse and midwife, and the executive director of ANHE. “Our goal is to be a guiding voice in environmental health. I think having nurses engage in policy can be incredibly effective.” ANHE’s goal is actually two goals: both to reduce the environmental impact of the health care industry, and to address the environmental issues such as climate change and particulate pollution that harm our health.

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The nursing profession first tumbled to the importance of that work in 2008. That was the year the University of Maryland Environmental Health Education Center convened a meeting of 50 nurses in Oracle, Ariz., to write a document and plan an agenda for what the group dubbed “environmental health nursing.” It was a much-needed new approach. The medical sector is responsible for 8% of U.S. greenhouse gas emissions each year, according to Huffling. American health care facilities generate 14,000 tons of waste daily, 25% of which is plastic. All by itself, the UCLA Health network of hospitals was going through 2.6 million disposable gowns per year before switching to washable garments in 2012.

The Oracle attendees came up with four broad categories of action they would take to address these and other problems: education—or folding studies of environmental reforms into the nursing school curriculum; research—conducting basic studies of how to make the industry and the broader economy greener; policy—developing new programs and reforms to implement those measures; and advocacy—fighting for those improvements.

“There were a whole bunch of us in the room and there was a lot that bubbled up,” says Tom Engle, a registered nurse and the leader of ANHE’s steering committee. “Ultimately, these were the four things that we said we wanted to do.”

ANHE takes a range of approaches to conduct that work. Twice a year, they hold what they call “Hill days,” in which members of the organization troop up to Capitol Hill and meet with lawmakers to push for legislation and regulations that would codify their policies and proposals. ANHE members are also regular attendees when the Environmental Protection Agency (EPA) holds comment periods—during which the agency conducts public hearings on proposed new policies. In the past year alone, five to 10 ANHE-affiliated nurses at a time have made presentations to the EPA on a range of issues from vehicle emission standards, to cleaning up lead pollution, to regulating toxic PFAS chemicals to reducing methane output from landfills and the petrochemical industry. In this regard, the pandemic proved to be something of an unlikely boon, with ANHE members no longer required to appear before the hearings personally, but rather attending virtually.

“It’s really helped us expand the number of nurses who provide testimony since they don’t have to fly into D.C.,” Huffling says.

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Some of the job the organization does involves not so much engaging with government as with the health care providers themselves—working with individual hospitals and giant healthcare systems like Providence Health & Services and Kaiser Permanente to reduce their carbon footprint. That’s not so easy. “Hospitals run 24/7 and within a very narrow temperature continuum,” says Engle. “They use a lot of stuff that is plastic too.”

Facilities in some parts of the country have a leg-up on others, especially in states like Oregon, where Engle is based, that have a lot of wind, solar, and hydropower online already. “Our hospitals can participate in systems that allow them to get renewable energy,” he says. “In other areas that’s a lot harder.”

All health care providers, however, can try to practice the green doctrine of reduce, reuse, and recycle. UCLA Health eliminated 230 tons of landfill waste a year when it switched to reusable gowns, for example. In this area too, the pandemic played an unexpectedly salutary role. “The University of Maryland Medical Center had already switched to washable gowns,” says Heffling. “During COVID there was a huge shortage of [single-use] gowns, but Maryland could say ‘We’re fine with what we have.’” That experience helped ANHE push out the message to other hospitals that have not yet adopted the reusable policy.

“I was trained in the 1970s,” adds Engle. “Back then most things were cleaned up and sterilized. We’ve migrated away from cleaning to using plastics, but there are probably some steps back we can take.”

Read more: Tackling Climate Change Can Save Hospitals Money

In other cases, the nurses rely not on the soft power of persuasion but the hard power of litigation. In 2022, ANHE joined with Earthjustice and others to file Alliance of Nurses for Healthy Environments vs. Regan, to compel the EPA to enforce its own ozone standards in three test venues—Detroit; Las Vegas; and Bexar County, Texas—where levels had drifted above maximum concentrations established in 2015. Before the trial could begin, the EPA acceded to the plaintiffs’ demands and the suit was dropped.

Other big wins ANHE has helped notch include pushing for a successful ban on fracking—which harms health by releasing particles into the air and chemicals into groundwater—in Maryland, in 2017; and the 2016 passage of the Frank R. Lautenberg Chemical Safety Act, which helps tighten safety rules on such toxic substances as lead, mercury, PFAS, and asbestos.

In 2024 and beyond, the group will increasingly be training its guns on climate change—the overarching crisis that is making the planet as a whole increasingly sickly. “It has such profound impacts on human health,” says Huffling, “and when strong climate action is taken it [provides] the greatest opportunity for disease prevention.”

Close to a generation after that first gathering in Oracle, ANHE continues to take the fight to the forces dirtying the planet and bringing illness to the people who live on it. On the hospital ward, nurses administer their care one case, one patient, one person at a time. In the wider world, they are working to look after all eight billion of us.

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Write to Jeffrey Kluger at jeffrey.kluger@time.com and Andrew D. Johnson at andrew.johnson@time.com.

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