Here in the United States, the Environmental Protection Agency has launched a formal safety review of various chemicals, including vinyl chloride, one of the substances released into the air in eastern Ohio after a Norfolk Southern train derailed and triggered a massive fire earlier this year. Vinyl chloride has been linked to heightened cancer risk. It can be found in commonly used plastic products and in polyvinyl chloride plastic, or PVC. Following the February crash in East Palestine, Ohio, residents reported respiratory and other health problems. The incident brought scrutiny to so-called bomb trains that transport crude oil and other dangerous chemicals through communities across the U.S. The EPA review will take at least three years.