When the Environmental Protection Agency ordered dioxin tests last week after the recent train derailment and fire in East Palestine, Ohio, it acknowledged that residents may be facing a familiar and infamous enemy from the past.

Dioxin contamination, toxic chemicals known to cause cancer, disrupt the immune system and cause reproductive harm, have been at the center of notorious environmental cleanups from Times Beach, Missouri to Love Canal, New York to «Mount Dioxin» in Pensacola, Florida.

Dioxins do not break down easily. Once in the food chain, the compounds tend to accumulate in people and animals. Key, the smoke-belching fire in eastern Palestine offered the right recipe for creating these compounds, experts say.

“I saw that cloud over eastern Palestine and I was immediately concerned about dioxins,” said Dr. Ted Schettler, a retired physician who is the scientific director of the Science and Environmental Health Network, a nonprofit group. «This is exactly the circumstance in which dioxins are expected to form.»

It is not yet clear if dioxins were created in the derailment or what level of contamination existed in eastern Palestine before the disaster. Sampling and testing is expensive and can take a long time, experts said. It may take weeks or months before the risk is clear.

During testimony before Congress Thursday, Debra Shore, the EPA’s regional administrator for Midwestern states, including Ohio, said tests of materials shipped to a contaminated waste facility in Indiana showed «very low levels» of dioxins.

EPA saying that would require Norfolk Southern to «perform direct testing» for dioxins and perform cleanup anywhere levels are found that are unacceptable for human health. The EPA has said it believes the risk of dioxin being produced during the fire is low. Norfolk Southern will also complete a background study to assess the level of dioxins already in the environment prior to the derailment.

In a statement to NBC News on Tuesday, EPA deputy press secretary Khanya Brann said the agency would review all aspects of a sampling plan to ensure it was as «protective as possible» and would modify it if it doesn’t meet compliance. agency standards.

In a news release Wednesday, the EPA announced that it had approved a Norfolk Southern plan for soil sampling. The plan requires contractors to inspect at least 277 sites within 2 miles of the derailment for visible ash. Samples will be taken from sites with visible ash; Samples will also be taken from at least 20% of the ashless sites. The tests will take at least a week to return results.

In an emailed statement, Norfolk Southern said it had submitted several plans to the EPA for approval to address dioxin testing.

“We have committed to pay for cleanup activities to date and will continue to do so, as we safely and thoroughly clean the site, and are reimbursing residents for the disruption this has caused to their lives,” the statement said. Norfolk Southern. . “We are listening to the concerns of the community as the restoration work progresses.”

Over the past few decades, environmental health regulations have dramatically reduced the risk of dioxins for most of the US and helped remove dioxins from the public eye. Now, the threat in eastern Palestine highlights the toxic history of the compounds, the risk they could pose to residents of eastern Palestine, and why outside experts have pleaded with the EPA to closely monitor complicated sampling processes and proof.

Dioxins, even in small amounts, could reshape food webs, affect people’s long-term health, and alter the long-term prospects of East Palestine.

«It doesn’t take much compared to other toxic chemicals,» said Dr. Arnold Schecter, who has wrote a textbook on dioxins and their health effects.

Dioxins are a byproduct of industrial processes and have historically been associated with paper mills, the vinyl industry, and medical waste incinerators.

But they can be created any time there is a poorly controlled fire involving chlorine, which is why the derailment and smoke cloud in eastern Palestine is so worrisome.

Five of the railcars derailed in eastern Palestine contained vinyl chloride.

“When you burn vinyl chloride, you can create quite a lot of dioxins,” said Linda Birnbaum, a toxicologist and former director of the National Institute of Environmental Health Sciences.

She said residents in and around East Palestine may have inhaled dioxins in the cloud of smoke created by the incident.

Any dioxin produced could settle in the soil and water where the smoke was traveling. There, they could begin to affect animals, contaminate locally produced food, and pose a risk to anyone who works or plays with the land.

Image: Olivia Holley, 22, and Taylor Gulish, 22, collect water samples from Leslie Run Creek on February 25, 2023 in East Palestine, Ohio.  Holley and Gulish are testing the water for pH and total dissolved solids (TDS).
Olivia Holley, 22, and Taylor Gulish, 22, collect water samples from Leslie Run Creek in East Palestine, Ohio, on February 25, testing the water for pH and total dissolved solids.File by Michael Swensen/Getty Images

“If you eat it, it goes down into your body and basically goes to your liver and is distributed throughout your body,” Birnbaum said.

Dioxins are stored in fat tissue and can remain inside the body for years, he said.

Health conditions can manifest decades after exposure. In 1976 in Seveso, Italy, a chemical plant exploded, leaking dioxins to nearby towns. About 200 people developed cases of chloracne, a skin condition that resembles acne and forms only in the most severe exposures.

Resident studies decades later reported increases in cancer risks, deaths from diabetes, and effects on fertility.

After dioxin was sprayed throughout the town of Times Beach, the federal government bought the whole city in 1983 and relocated its residents. After more than a decade of cleanup, the the emptied city became a state park.

In 1996, the EPA began the process to relocate residents in a Pensacola neighborhood away from «Mount Dioxin,» a mound of contaminated soil left behind by an abandoned wood treatment plant. He the cleanup has taken almost three decades.

The EPA published its first health assessment of dioxins in 1985, which identified the compounds as possible carcinogens. The agency regulates its levels in drinking water and soil; the Food and Drug Administration monitors dioxins in the food supply.

“Because of the regulations that have come into effect, the levels have dropped dramatically,” Birnbaum said, estimating that the average person’s body contains about a tenth as much dioxin as it did 30 or 40 years ago. «There is an international consensus that dioxins are bad chemicals and we don’t want to have them.»

Experts said that a sampling program for eastern Palestine would require careful design and highly sensitive testing because even small amounts of dioxins can be dangerous.

Birnbaum said dioxins in soil need to be tested down to parts per trillion levels, meaning they could detect one dioxin in the midst of a trillion other particles. Drinking water samples require even more perceptive testing.

“Dioxin concentrations that can cause adverse effects in people are extremely low. You are trying to measure things at very low levels. Sensitive methodologies are needed,” Birnbaum said.

The experts said a transparent sampling plan should be made publicly available.

“Are you going to take samples of the air, the soil, the sediment, the water? What are you going to sample and in how many places will you sample? said Stephen Lester, a toxicologist and scientific director of the Center for Health, Environment and Justice. «Sampling results are only as good as sampling procedures.»

Schettler questioned whether Norfolk Southern should oversee the sampling efforts, given the legal and financial implications if dioxins are discovered and the scientific precision necessary for public confidence.

“Norfolk should pay for the analysis; the public should not pay for it. But Norfolk Southern shouldn’t be doing the testing,” Schettler said. “It really has to be done by the agency or a disinterested third party.”