Two years after the derailment, researchers are stepping in to track how low-level, long-term environmental exposures are affecting the health of East Palestine residents.

On Feb. 3, 2023, a Norfolk Southern freight train carrying hazardous materials derailed after a railcar's wheel bearing overheated, causing a fire. Three days later, officials conducted a "controlled release" of several tank cars that were filled with vinyl chloride, a toxic and flammable gas that can cause certain cancers, to prevent an explosion.