Concern is growing over the handling of toxic chemicals by U.S. authorities after a freight train derailed in the village of East Palestine, Ohio, earlier this month.

Multiple train cars can be seen on fire in images posted on social media from the village. Smoke can be seen rising from the blaze and filling the atmosphere.

About 50 Norfolk Southern freight train cars derailed on the night of February 3 in East Palestine, a town of 4,800 residents near the Ohio-Pennsylvania border, due to a mechanical problem on the axle of one of the train cars.

There were a total of 20 hazardous material cars on the train, 10 of which derailed, according to the National Transportation Safety Board (NTSB), a U.S. government agency responsible for civil transportation accident investigation.

The NTSB said five derailed hazmat cars were carrying vinyl chloride, a colorless gas that burns easily and is produced industrially for commercial use.

Evan Lambert, a reporter, was arrested for trespassing while covering a news conference where Governor Mike DeWine was giving an update about the accident.

"No journalist expects to be arrested when you're doing your job, and I think that's really important that that doesn't happen in our country," Lambert said after being held for about five hours before being released from jail.

'One of the deadliest environmental emergencies'

After hundreds of residents evacuated their homes, the emergency crew conducted a controlled release of the chemicals on February 6 to avert a possible explosion, but the operations were said to have discharged toxic and potentially deadly fumes into the air.

Vinyl chloride exposure is associated with an increased risk of a rare form of liver cancer, as well as primary liver cancer, brain and lung cancer, lymphoma and leukemia.

The controlled burn would also release phosgene and hydrogen chloride. Phosgene is a highly toxic gas that can cause vomiting and breathing trouble that was used as a weapon in World War I.

A group of state, federal, and local officials issued a statement on February 8, saying that "evacuated residents in and around East Palestine can now safely return home."

"Air quality samples in the area of the wreckage and in nearby residential neighborhoods have consistently showed readings at points below safety screening levels for contaminants of concern," they alleged.

"This is one of the deadliest environmental emergencies," U.S. Congressman Jamaal Bowman, a New York Democrat, tweeted on Monday. "And no one is talking about it."

East Palestine "is undergoing an ecological disaster" because authorities "blew up the train derailment cars carrying hazardous chemicals," U.S. Congresswoman Marjorie Taylor Greene, a Georgia Republican, said.

More dangerous chemicals found

The U.S. Environmental Protection Agency reportedly sent a letter to Norfolk Southern, stating that more dangerous chemicals were found on the derailed train.

Among the substances were ethylene glycol monobutyl ether, ethylhexyl acrylate and isobutylene. Sil Caggiano, a hazardous materials specialist, said ethylhexyl acrylate is especially concerning.

Contact with ethylhexyl acrylate, a carcinogen, can cause burning and irritation of the skin and eyes. Breathing it in can irritate the nose and throat and cause coughing and shortness of breath.

"I was surprised when they quickly told the people they can go back home but then said if they feel like they want their homes tested, they can have them tested. I would've far rather they did all the testing," Caggiano said.

Caggiano added it was likely that some of these chemicals could still be present in homes and on objects until they are cleaned thoroughly.

"There's a lot of what-ifs, and we're going to be looking at this thing five, 10, 15, 20 years down the line and wondering," he warned. "Cancer clusters could pop up, you know, well water could go bad."

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Residents file class action lawsuit

So far, no injuries have been reported from the derailment or the controlled release, but some people have complained about smelling chlorine and smoke in the air and having headaches. The fire from the controlled release of the chemicals is no longer burning. 

People have reported dead fish and frogs in local streams, and photos of dead chickens, dogs and foxes have also been shared on social media.

Marina Davis, a resident of East Palestine, told CGTN that local people have "so much anxiety" about the current situation and are not sure what is the right way to clean stuff. 

"Do we need to get rid of everything and just buy new?" she asked.

Four class action negligence lawsuits have been filed by residents and business owners who say they were impacted by the chemical train derailment in East Palestine.

All four complainants asked judges to declare the lawsuits class actions, which would allow other people impacted by the derailment to become plaintiffs. The suits estimated that there could be anywhere from 1,000 to nearly 2,000 people possibly included in the class action.

The lawsuits also want the courts to order Norfolk Southern to pay damages, including any current or future medical costs for exposure to toxins.

The U.S. Environmental Protection Agency said on Sunday that it continues to conduct air monitoring throughout the East Palestine community.

"Air monitoring since the fire went out has not detected any levels of concern in the community that can be attributed to the incident at this time," the agency wrote in an update while acknowledging that "residents may still smell odors from the site."

U.S. train derailment reveals grave system flaws

The recent derailment and explosion of a train in Ohio in the United States revealed grave flaws in the country's rail system, British newspaper The Guardian has reported.

The Ohio catastrophe is a "wake-up call" to the dangers of more deadly train derailments, said the report published Saturday.

Ron Kaminkow, an Amtrak locomotive engineer and former Norfolk Southern freight engineer, blamed "ineffective oversight and a largely self-monitoring industry that has cut the nation's rail workforce to the bone in recent years as it puts record profits over safety."

The Pittsburgh region alone has seen eight train derailments over the last five years, according to the public health advocacy group Rail Pollution Protection Pittsburgh, and about 1,700 annually occur nationally.

U.S. rail companies laid off more than 20,000 rail workers between 2018 and 2019, representing the biggest layoffs in rail since the Great Recession. The nation's rail force has since dipped below 200,000, the lowest level ever, and down from 1 million at its peak, said the report.

(With input from agencies)