EAST PALESTINE — In the months following the 2023 East Palestine train derailment, several residents in East Palestine and surrounding communities claimed that independent medical testing indicated high levels of thiodiglycolic acid (TDGA) — or vinyl chloride metabolite — in their urine samples.

Any detection of .50 is considered a reporting level of TDGA and some residents produced results that registered numbers twice that much.

Despite the high number of the metabolite showing up in area epidemiology, the Environmental Protection Agency (EPA) maintained the testing was flawed and “no pathway to exposure” existed.

But that narrative was challenged when Erin Haynes from the University of Kentucky (UK) presented results last month at “East Palestine: State of the Science” — a series of research presentations and updates on the environmental and public health impacts of the derailment — last month.

TDGA is the body’s major breakdown product of vinyl chloride and a biomarker for exposure to the chemical. Testing for the metabolite was the only way to detect vinyl chloride exposure, as vinyl chloride breaks down in the body rapidly.

The EPA began to challenge the validity of the TDGA metabolite test as soon as residents started disclosing urinalysis results, asserting test results can be too easily influenced by other variables such as smoking, consuming alcohol or the introduction of B-12 supplements to the body. The agency also repeatedly reiterated its claim that data collected did not support any connection between the high levels of TDGA detected and the train derailment.

Haynes’ research team, which began tracking health impacts in April of 2023 of chemicals released during the rail disaster and is funded by one of National Institute of Health (NIH) grants awarded to universities by then-President Joe Biden in 2024, found a vinyl chloride metabolite to be almost exclusive to those living in East Palestine.

Researchers from the UK tested urine from 19 East Palestine non-smoking residents in July 2023 — five months after the derailment – for the metabolite HEA, which can come from exposure to vinyl chloride, ethylene oxide or acrylonitrile. HEA or 2-hydroxyethyl mercapturic acid, is a primary metabolite of vinyl chloride. Like TDGA, HEA also has a short biological half-life (1-2 days), meaning it normally disappears from the body quickly.

Haynes had previously explained that Dr. Judy Westrick, the Director of Lumigen Instrument Center at Wayne State, was in the process of developing a more reliable process of screening urine samples for vinyl chloride biomarkers in February of 2024.

Wayne State detected HEA in 74% of East Palestine participants. For comparison, in a CDC national sample of 1,000 it was only detected in 5% and in a Marietta, Ohio sample group community, it showed up in zero of the urine samples. The research indicated East Palestine’s HEA levels were dramatically higher than typical U.S. background levels.

And while, researchers emphasized that levels were low, the presence of the chemical five months later is scientifically important. Because HEA clears from the body quickly, its presence five months after the derailment is scientifically notable. It indicates one of two possibilities:

– Ongoing environmental exposure. Residents may still have been encountering vinyl chloride or related chemicals in air, soil, dust, or water long after the derailment and controlled burn.

– Delayed release from body fat. Some volatile organic compounds (VOCs), including vinyl chloride, can be stored in adipose (fat) tissue or released over time during normal metabolism or weight change though that “retention behavior” is not known to apply to vinyl chloride.

In addition to the resident samples, four UK staff members in the village collected their own urine samples when arriving in East Palestine and again two days later. On arrival, two of the four had detectable HEA. After two days in East Palestine, all four had detectable HEA, suggesting ongoing environmental exposure at the time of their visit.

The research indicates continued exposure or prolonged internal release — both of which Haynes said warrant further investigation – and supports community concerns that exposure did not end with the initial plume or burn.