Did dioxins spread after the Ohio train derailment?

U.S. Senators Sherrod Brown and J.D. Vance sent a letter to the directors of the Ohio Environmental Protection Agency last week asking why it was not testing for dioxins, a harmful suite of chemicals the senators claimed got into the air in East Palestine when officials burned off the vinyl chloride in the rail tank cars. Scientists say burning vinyl chloride can indeed generate highly toxic dioxins, some of the most dangerous human-made compounds. Some say it is important to test for the compounds now, before they have a chance to bioaccumulate, or build up, in the plants and animals that people eat.