A new peer-reviewed pilot study has found that some residents of East Palestine, Ohio, are showing long-term changes to their immune systems months after the toxic train derailment that engulfed the town in chemical fumes.
Blood samples taken six months after the disaster indicate that the bodies of those living closest to the site are still “responding to toxic chemical exposures”, according to the research led by the University of Kentucky. The findings point to signs of chronic inflammation, altered cell counts and a pattern of immune activity that resembles the body’s response to an infection—but researchers believe it is likely a reaction to the chemicals themselves.
Compared with a control group from a similar community that did not experience the derailment, East Palestine residents showed higher numbers of red blood cells, elevated haemoglobin levels and increased inflammation. They also had more of the specialised cells that the body dispatches to engulf and “eat” chemical toxins in order to remove them, alongside higher levels of proteins that work to repair damaged tissue. At the same time, the study found lower numbers of cells that fight infection—a combination the authors say is “suggestive” of a sustained response to a toxicant.
“This pilot shows evidence that the bodies of those who lived in close proximity to the site were still fighting and repairing from a toxic exposure,” said Erin Haynes, a study co-author at the University of Kentucky.
Haynes explained that volatile organic compounds (VOCs) and other toxicants can attack every organ in the human body, but there is a scarcity of research into how the immune system fights and repairs itself after chemical exposures. “We really wanted to look at the body’s ability to fight a toxicant or foreign substance,” she said. “It looks like their bodies were fighting an infection, but it was probably the exposure.”
The research is the first long-term health study conducted since the derailment in February 2023, when 38 cars of a Norfolk Southern freight train came off the rails near the town of 4,700 people on the edge of the Appalachian hills. Eleven of the cars carried hazardous materials, including vinyl chloride, a chemical used to make PVC plastic. Two days after the crash, fearing a “major explosion”, officials carried out a controlled burn of vinyl chloride, releasing hydrogen chloride and phosgene—a highly toxic gas that can cause vomiting and breathing trouble—into the air. In total, approximately 1.1 million pounds of vinyl chloride were burned.
In the immediate aftermath, a potent chemical odour hung in the air for weeks. Testing later showed levels of dioxin—a byproduct of burning vinyl chloride—were as much as 14 times higher than what the US Environmental Protection Agency (EPA) had determined to be safe. The EPA required Norfolk Southern to test directly for dioxins after community concerns; subsequent soil analysis found concentrations roughly ten times higher than background soil samples surrounding East Palestine. VOCs and other toxic substances, including butyl acrylate, ethylhexyl acrylate, ethylene glycol monobutyl ether, isobutylene and benzene residue, were also emitted.
Long-term exposure to VOCs such as vinyl chloride has been linked to increased inflammation and immune changes, and the study notes that prolonged air exposure triggers the production of proteins that repair damaged tissue—exactly the pattern seen in residents’ blood. VOCs are known to irritate the eyes, nose and throat, cause headaches, nausea and dizziness, and can damage the central nervous system, liver and kidneys; some are linked to cancer.
When regulators lifted the evacuation order in February 2023, they said air monitoring showed no risks from VOCs, but public health advocates warned that the monitors may not have been able to detect all hazardous chemicals and byproducts. The National Transportation Safety Board later said the derailment was “100% preventable”, citing a defective, overheating wheel bearing as the likely cause.
Individual experiences and the complexity of exposure
Jessica Boersma, a city council member and chiropractor who lives less than a quarter of a mile from the derailment site, spent significant time coordinating with first responders and was seriously exposed. Her blood tests from the pilot study showed elevated levels of the proteins that repair tissue. She reported experiencing gall bladder pain, irregular menstrual cycles, elevated cortisol levels, and an itchy throat and nose that felt like an allergic reaction in the six months after the wreck. “I feel pretty normal now, but I’m interested in getting involved because I want proof – clinical, and black-and-white data – that show health markers that I could follow,” Boersma said. “We have a starting point with this.”
However, not everyone who took part in the study showed immune changes. Ron and Peggy Caratelli live about eight-tenths of a mile from the site. They evacuated as soon as orders were issued and stayed away for about a month. Their blood samples had no markers of immune system impacts. “There was an overwhelming smell and we could taste it, it made our eyes burn, and we could feel it in our lungs,” Peggy told researchers. Ron has suffered from chronic obstructive pulmonary disease, but Peggy said it is unclear whether it stems from the wreck or 35 years of smoking. She added that he had not eaten particularly well. “I don’t want to blame our problems on the wreck,” she said, but she hopes the studies can shed light on effects on the broader community.
The researchers caution that the pilot study did not look for specific diseases and that the findings do not prove the derailment caused the observed changes or that any individual has an illness or will develop future health problems. They also note that stress is strongly linked to immune dysregulation, and residents reported severe anxiety in the wake of the disaster. The study’s authors stressed: “The findings do not prove that the train derailment caused the observed changes or that any individual has an illness or will develop future health problems.”
The University of Kentucky team now plans to examine a larger group of residents and first responders for the same immune markers, as part of a broader effort to track long-term health problems in East Palestine. A comparison community, Cambridge, Ohio, is being used for control because its residents are similar to those in East Palestine but did not experience the derailment. Meanwhile, Norfolk Southern has carried out extensive cleanup, removing millions of gallons of liquid waste and tons of contaminated soil, with physical restoration completed and ongoing water monitoring. Concerns remain among residents about long-term health effects, including cancer, tumours and tremors, even after remediation.
Legal efforts have also unfolded. Multiple class action lawsuits were filed against Norfolk Southern, and a $600 million class settlement was reached. Some residents sought to overturn personal injury releases signed as part of that settlement, claiming they were pressured and that long-term health risks were downplayed. A federal judge rejected those attempts in May 2026, ruling residents had the option to waive future claims and provided insufficient evidence of fraud. Appeals have been resolved, and direct payment claim awards are expected to be mailed in June 2026. Separately, a whistleblower group has alleged that soil samples were manipulated by the EPA and Norfolk Southern, and that testing intentionally avoided areas with potential dioxin contamination. The derailment has also spurred renewed efforts in Congress to pass rail safety reforms.