Three weeks after the toxic train derailment in Ohio, an independent analysis of Environmental Protection Agency data has found nine air pollutants at levels that, if they persist, could raise long-term health concerns in and around East Palestine.

The analysis by Texas A&M University researchers stands in contrast to statements by state and federal regulators that air near the crash site is completely safe, despite residents complaining about rashes, breathing problems and other health effects.

In response on Friday, EPA officials said that air quality levels of 79 chemicals they are monitoring remain below levels of concern for short-term exposure, and that current concentrations are likely to dissipate.

But the data only adds to questions and concerns that have weighed on residents for weeks, as they wonder how contaminated their community has become.

In its examination of EPA data, the Texas A&M researchers found elevated levels of chemicals known to trigger eye and lung irritation, headaches and other symptoms, as well as some that are known or suspected to cause cancer.

It would take months, if not years, of exposure to the pollutants for serious health effects, said Weihsueh Chiu, one of the researchers.

EPA officials emphasized this point Friday. They stressed that the safety threshold the researchers used to analyze the data assumes constant exposure over a lifetime, and said they don't expect the pollution to remain at high concentrations "anywhere near that long."

The Texas researchers said it was "good news" that levels of benzene and related chemicals were not elevated in the air sampling. But they said EPA measured acrolein, a hazardous substance found in smoke, at concentrations that could have long-term health effects, along with other chemicals at lower levels that in combination could also raise health concerns if they remained at these levels for months or years.

Of the cars that derailed from the Norfolk Southern train on Feb. 3, 11 of them were carrying chemicals used to make plastic. As temperatures inside one rail car rose to levels that authorities feared would cause a massive explosion, they carried out a "controlled release" of the chemicals on Feb. 6.

EPA collected the data between Feb. 4 and Feb. 21, and posted the data publicly but without context that shows "potential concern about long-term health effects," said Chiu, a professor of veterinary physiology and pharmacology at Texas A&M. While some of the highest air pollution readings EPA reported were collected in the days after the controlled chemical release, some more recent samples still remain elevated, Chiu said.