 The train fire in the United States has created a serious threat to the environment. After freight train burning in an Ohio village near the Pennsylvania state line, following a derailment that prompted an evacuation order and a declaration of a state of emergency. The train was carrying products from Madison, Illinois to Conway, Pennsylvania. Rail operator Norfolk Southern said, air quality was being monitored throughout a one-mile zone that was evacuated and there had been no dangerous readings to report, he said. The rail operator said the train had more than 100 cars, 20 of which were classified as carrying hazardous materials, defined as cargo that could pose any kind of danger, including flammables, combustibles or environmental risks. Fire Chief Keith Drabick said, officials were most concerned about a shipment of the chemical vinyl chloride, but safety features of the rail car carrying that were still functioning. The rail car that was carrying that is doing its job, he said. Vinyl chloride used to make the polyvinyl chloride hard plastic resin used in a variety of plastic products is associated with increased risk of liver cancer and other cancers according to the US Federal Government's National Cancer Institute. Emergency crews would keep their distance until rail officials told them it was safe to approach, Drabick said. When they say it's time to go in and put the fire out, my guys will go in and put the fire out. Officials said 68 agencies from three states and a number of counties responded to the derailment, which happened about 50 miles northwest of Pittsburgh. The US National Transportation Safety Board said on that it was launching a go team to investigate the derailment. Mayor Trent Conaway of the village of East Palestine said surveillance from the air showed an entanglement of cars with fires still burning and heavy smoke continuing to billow from the scene as officials tried to determine what was in each car from the labels outside. The evacuation order and shelter in place warnings would remain in effect until further notice. Officials said.