“We were pushing railroads to take more precautions to deal with braking and to deal with a whole range of things that were not dealt with. Norfolk Southern failed its responsibility,” Biden added.

The chemical spill took place on February 3 last year, when a 2.7 kilometre-long train came off the tracks near in East Palestine, a small regional town of about 4700 people near the Ohio-Pennsylvania border.

Eleven of the derailed carriages were filled with dangerous chemicals such as butyl acrylate, ethylene glycol, and vinyl chloride – a colourless gas that is used to make plastic and is linked to higher rates of cancer.

In a bid to stop an anticipated explosion, authorities conducted a controlled burn to release toxic vinyl chloride into the air, but not long after, residents started experiencing symptoms such as headaches, nose bleeds, skin rashes, and respiratory problems.

When this masthead visited East Palestine last week after the first anniversary of the derailment, many locals believed the area was still contaminated, pointing to chemical sheen in creeks and inadequate testing by the Environmental Protective Authority, which had failed to pick up some of the toxins in the aftermath of the crash.

Loading

Some residents, such as 34-year-old mother Ashley McCollum, had spent months living in a hotel with her family because she was too scared to return to her house near the train tracks.

“Every time I went back I’d have some kind of reaction,” she said, sitting in the small room she shared with her boyfriend, son, and two dogs. “I would have rashing, I would have excessive bowel movements, stomach cramping, eyes burning, a chemical taste in my mouth, lips tingling, ear pain.”

After Biden’s visit, Tom Devine from the Government Accountability Project, a whistleblower group that has been investigating the ongoing health and safety concerns of residents, said the president needed to hold the Environmental Protection Agency accountable, not just the rail company.

He said Biden should also order “credible and independent sampling” and “retract the government’s reassurances that the town is safe” given “residents’ grotesque medical nightmares belie that claim”.

“The jury is out whether he is serious, or the trip was for show,” Devine said.

Environmental Protection Agency administrator Michael Regan acknowledged that the past year had been filled with “fear, uncertainty and disarray”.

But he added that the authority had removed more than 176,000 tonnes of contaminated soil from the community for safe disposal.

It had also shipped more than 43 million gallons of wastewater off-site, he said, and had collected more than 45,000 samples in and around the community.

“I’m certain you all are well on your way to bounce him back to be stronger than ever before,” he told residents.

Get a note directly from our foreign correspondents on what’s making headlines around the world. Sign up for the weekly What in the World newsletter here.