The Environmental Protection Agency proposed a series of major reforms this past week to slash toxic air pollution at chemical plants and facilities that sterilize medical equipment, nearly 18 months after ProPublica reported how an estimated 74 million Americans were exposed to elevated cancer risk from these businesses.

The first set of rules place stricter limits on roughly 80 air pollutants, according to EPA Administrator Michael S. Regan. The list includes potent cancer-causing chemicals such as ethylene oxide, which is used to sterilize medical equipment, and chloroprene, an ingredient in synthetic rubber. The proposal, which would affect more than 200 manufacturers, requires routine air monitoring around these chemical plants, something local communities have long requested.

Regan announced the first wave of changes last Thursday at a press conference in St. John the Baptist Parish, Louisiana. The area falls within an 85-mile stretch along the Mississippi River known as “Cancer Alley” due to its concentration of industrial polluters, many of which are located near communities of color.

“For generations, our most vulnerable communities have unjustly borne the burden of breathing unsafe, polluted air,” Regan said in a statement. “Every child in this country deserves clean air to breathe, and EPA will use every available tool to make that vision a reality.”

The EPA declined to make any agency employees available for an interview.

Environmental experts said the proposal is a huge step forward. The updated rules impose stricter health standards for emissions of chloroprene and ethylene oxide to reduce the risk of cancer residents face when they breathe pollution from chemical plants. The proposal also would require facilities to fix leaks and install devices to limit emissions from smokestacks, storage tanks and other equipment. If the new rules are adopted, the number of residents near these facilities who would be exposed to unacceptable cancer risk ultimately would drop by 96%, the EPA said.

“This is a very big announcement” that targets the largest and most hazardous chemical manufacturers, said Adam Kron, an attorney at Earthjustice. The group sued the EPA years ago to force them to update these rules in a more timely manner.

Beverly Wright, executive director of the Deep South Center for Environmental Justice, said in a statement that this was “the most significant rule I have seen in my 30 years of experience working in Cancer Alley.”

The American Chemistry Council, an industry trade group, said that it was reviewing the proposed new rules but signaled it was concerned about aspects related to ethylene oxide. “Overly conservative regulations on ethylene oxide could threaten access to products ranging from electric vehicle batteries to sterilized medical equipment,” the group wrote on its website. “We support strong, science-based regulations for our industry. But we are concerned that EPA may be rushing its work on significant rulemaking packages,” it added. “We will be engaging closely throughout the comment and review process.”

In 2021, ProPublica published a unique analysis of cumulative cancer risk from industrial air pollution nationwide. Using emissions data reported by the companies, we found that in some parts of Louisiana’s Cancer Alley, the added lifetime cancer risk from these chemicals was up to 47 times what the EPA considers acceptable. Many residents who live near multiple facilities face unacceptable cancer risks from combined emissions, yet the EPA rarely considers cumulative risk. Out of all the pollutants that the EPA regulates, ProPublica's analysis found, ethylene oxide is the most toxic, contributing to the majority of the excess cancer risk created by industrial air pollution in the United States.

Our work spurred reform, including additional air monitoring, two state cancer studies and the EPA’s rejection of a less stringent health standard for ethylene oxide. Weeks after we published our series, Regan said the agency would conduct a series of unannounced EPA inspections of major polluters. The EPA’s new proposed rules, though, go even further.

The agency’s proposal also requires many facilities to conduct air monitoring and make the resulting data publicly available. On top of limiting emissions of 80 pollutants, chemical plants for the first time would monitor for six chemicals — benzene, ethylene oxide, chloroprene, vinyl chloride, ethylene dichloride and 1,3-butadiene — at the fence line, or perimeter, of their facilities. If annual averages exceeded EPA guidelines, the companies would need to find and repair any leaks that were likely to have caused the excessive emissions.

Scott Throwe, a former EPA air pollution expert who now works as a consultant, said the EPA could have gone further by requiring direct, continuous monitoring of toxic air pollutants at the vents, smokestacks and other outlets where emissions are released.

Fence line monitoring only tells you that something is leaking, he said, and doesn’t help you identify the exact piece of equipment responsible. These facilities are so large that each plant may have thousands of potential leaky spots. “They’re not going to find it in five minutes and slap some Silly Putty on the leak and call it a day,” he said. If the EPA required direct monitoring at the source, he added, it would be much easier to pinpoint the culprit.

Despite the drawbacks, fence line monitoring could give regulators a new, straightforward tool to crack down on polluters. A neoprene manufacturer in LaPlace, Louisiana, has faced years of enforcement action from state and federal agencies, yet continues to emit high levels of chloroprene. The chemical can cause liver or lung cancer. Local emissions are so high that the EPA urged state regulators to evacuate students from the nearby Fifth Ward Elementary School last fall. The students have not been moved.

The plant, owned by Denka Performance Elastomer, already has chloroprene monitors at more than 20 locations along its perimeter. The new EPA proposal would regulate chloroprene concentrations at the fence line for the first time, using 0.3 micrograms per cubic meter as a limit. When annual concentrations exceed that, companies would need to reduce their emissions.

The data around the Denka plant from January 2022 to January 2023 shows that nearly all of the monitors exceeded this new proposed threshold. Monitors close to the school showed levels up to five times the limit. Denka didn’t respond to a request for comment. In February, the U.S. Department of Justice sued the company on behalf of the EPA to compel Denka to cut chloroprene emissions. Denka has denied many of the allegations and in a counterclaim said the EPA’s conclusions about the high cancer risks posed by chloroprene are “dead wrong.”

The new EPA rules don’t just apply to facilities that make chemicals. A second EPA proposal, announced Tuesday, would require 86 facilities across the country that use ethylene oxide for sterilizing medical supplies or fumigating spices to install equipment to reduce emissions of the cancer-causing gas. The EPA estimated the rule would reduce ethylene oxide emissions from the facilities by 80%. Both EPA proposals are open for public comment and could be finalized by next year.

Tuesday’s proposal is based on the latest EPA science on ethylene oxide. In 2016, the agency concluded the chemical was 30 times more carcinogenic to people who continuously inhale it as adults and 50 times more carcinogenic for those who are exposed since birth than the agency previously thought. Industry representatives have described the EPA’s conclusion as extreme and overly protective.

The prior regulations for sterilizing facilities were based on outdated scientific studies. The agency was supposed to review the rule for possible revision in 2014 and 2022, but missed both deadlines. A coalition of environmental groups, including the Laredo, Texas-based Rio Grande International Study Center, sued the EPA in December to speed up the timeline. The lawsuit is still pending. Laredo, a border city of 250,000, has been home to the most toxic commercial sterilizer in the country, according to the 2021 ProPublica analysis.

“Today, residents of Laredo are a step closer to breathing cleaner air,” said Laredo City Council member Vanessa Perez, who co-founded the Clean Air Laredo Coalition in 2021. “It’s the EPA’s mission to ensure our air is safe to breathe. We are relying on the EPA’s ruling to move the country in the right direction for environmental protection and justice.”

Owned by Missouri-based Midwest Sterilization Corporation, the Laredo plant released far more ethylene oxide on average than any plant of its kind in the country during the five-year period covered by ProPublica’s analysis.

In a statement, Midwest Sterilization said the company “sterilizes life-saving medical devices used in everyday medical procedures and surgeries.” The company said it “has been anticipating the proposed EPA rule and working hard to make changes ahead of its release to the public.” It added: “It’s important to note that most of the changes proposed by the EPA, have already been achieved by Midwest, or are currently being implemented.”

Environmental groups celebrated the release of the long-overdue proposal but also said it should be strengthened before it is finalized. They want the EPA to require fence line monitoring of ethylene oxide at sterilizing facilities (like the agency is proposing for chemical plants) and to expand the rule to cover emissions from off-site warehouses that also are a significant source of emissions. They also called for the EPA to phase out the use of ethylene oxide.

Last year, studies published by the Texas Department of State Health Services found that rates of three types of cancer associated with ethylene oxide exposure — breast cancer, all-age acute lymphocytic leukemia and extranodal non-Hodgkin lymphoma — were “significantly greater than expected” in Laredo given the population.

The ProPublica analysis found that the Laredo facility elevates the estimated lifetime cancer risk for nearly half of the city’s residents, including 37,000 children, to a level experts say is not sufficiently protective of public health. Among them is Yaneli Ortiz, who was diagnosed with acute lymphocytic leukemia in 2019. She had just turned 13 years old. Ethylene oxide should not be ruled out as a factor in Yaneli’s diagnosis given her proximity to the facility and its history of emissions, environmental health experts said, but it is impossible to definitively say whether exposure to the chemical caused her cancer.

After Yaneli underwent years of treatment that included a harrowing near-death experience, doctors recently told her and her parents that there are no signs of cancer in her body.

Still, Yaneli is dealing with the fallout from the side effects of her treatment, particularly from the havoc that the steroids wreaked on her hips, shoulders and knees. She underwent replacement surgery for her hip and left shoulder. Recently, her right shoulder has been hurting so much that the pain keeps her awake at night. Her mother anticipates that Yaneli will need at least two more surgeries to address the injuries. Nevertheless, she recently attended prom at Driscoll Children’s Hospital in Corpus Christi, where her cancer was treated. Now 16 years old, Yaneli spent a good part of the night dancing.

“It’s, like, a little bit of a relief,” Yaneli’s mother, Karla Ortiz, said when she heard the news about the proposed EPA rules. “It’s less risky for everyone else as well, so hopefully they won’t have to go through what we went through or other families went through.”