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In a major victory for the people of south Memphis, a plant that uses carcinogenic ethylene oxide to sterilize medical equipment announced this fall that it is shutting down.

The decision by Sterilization Services of Tennessee follows more than a year of dogged organizing by residents and activists fed up with the industrial pollution that the company, and more than 20 others, releases into their community. Ethylene oxide, an odorless and colorless gas, has been linked to multiple forms of cancer.

“We’re relieved that the community will soon have one less polluting facility that they have to contend with,” Amanda Garcia, a senior attorney at the Southern Environmental Law Center, told Grist.

The facility opened in 1976 and is the flagship of Sterilization Services, which also has locations in Atlanta and Richmond, Virginia. In a letter to U.S. Representative Steve Cohen, a Democrat whose district includes Memphis, company attorneys said the facility will move, but did not disclose further details.

Community members and advocates told Grist that Sterilization Services’ facilities is just one of more than 20 sources of toxic pollution in south Memphis, where more than 98% of residents are Black. Among the most toxic are a refinery owned by Valero and a steel mill owned by Nucor. A 2020 study from the University of Memphis found that the life expectancy of local residents is 10 years lower than that of their neighbors just a few miles away. KeShaun Pearson, president of Memphis Community Against Pollution, called the elimination of a major polluter an “extreme victory,” but said there is more work to be done.

“Black people have been relegated to places that are overburdened with pollution and cancer-causing agents because of the zoning that has been approved for industry in those areas,” he said.

Cheryl Ballard, a lifelong resident of south Memphis, is happy to see the plant close, but wants to see air monitoring begin in the interim to ensure pollution levels do not exceed federal standards. Ethylene oxide is a colorless and odorless compound that, except in high concentrations, is difficult to detect without expensive equipment.

“Harm has already been done,” she said, noting that many residents have been exposed for 40 years.

Environmental regulators learned of the risks of medical equipment sterilization facilities in 2016, when the EPA found ethylene oxide to be 30 times more toxic to adults and 60 times more toxic to children than previously known. The finding was based on a series of studies in the early 2000s that linked ethylene oxide exposure to breast cancer in women and to lymphoma.

More than 50% of the nation’s medical equipment is sterilized with the chemical because it can fumigate heat-sensitive equipment without damage. In April, the EPA proposed revised regulations that it claims will reduce ethylene oxide emissions from these facilities by 80%. It will take more than a year for the new rule to go into effect.

According to the EPA, there are 86 medical sterilization facilities operating nationwide. In August 2022, regulators published the results of an analysis that found 23 of them, including the one in south Memphis, pose a cancer risk greater than 1 in 10,000 to nearby communities, a level that the agency considers unacceptable. That means that if 10,000 people were exposed to a certain level of the substance during their lives, one of them would be expected to develop cancer. According to a Grist analysis of agency data, the south Memphis plant is the seventh most toxic of its kind in the country.

In February, the Southern Environmental Law Center, on behalf of Memphis Community Against Pollution, asked the Shelby County Health Department to use its emergency powers under county and federal air pollution laws to address Sterilization Service’s carcinogenic emissions. According to Garcia, the agency argued it lacks the authority to compel the facility to address its emissions as long as it is in compliance with the federal Clean Air Act.

The situation highlights a recurring inconsistency in the nation’s air pollution laws: Companies can emit pollution at levels allowed by their permits yet generate cancer risk at levels that the federal government considers unacceptable. While environmental regulators have the authority to take emergency action against these emissions, they frequently do not. Historically, the EPA has largely used its emergency authority to address acute public health crises, such as a refinery in the Virgin Islands that rained oil on a nearby neighborhood.

Garcia said that the south Memphis case “highlighted serious concerns about the local air pollution-control program.” The Shelby County Department of Health did not respond to a request for comment.

The Food and Drug Administration has expressed concern that closing sterilization facilities could upset the medical device supply chain and lead to dangerous shortages in hospital equipment. In 2019, Norman Sharpless, the agency’s acting commissioner at the time, said in a statement that a shortage “can be a detriment to public health.”

The agency has said that it is researching alternatives to ethylene oxide sterilization, but that the development and approval of those methods could take many years.