CNN — US Sen. Sherrod Brown echoed officials’ beliefs Sunday that the water and air are safe in East Palestine, Ohio, after a train carrying hazardous materials derailed there earlier this month, but he acknowledged that residents are “right to be skeptical.”

“We think the water’s safe,” the senator, a Democrat, told CNN’s “State of the Union,” days after he visited the community, citing comments made by the administrators of the state and federal Environmental Protection Agencies. “But when you return to your home, you should be tested again for your water and your soil and your air, not to mention those that have their own wells.”

The senator’s comments come 16 days after the Norfolk Southern train derailed in the small community of less than 5,000 people, where residents have described rashes, sore throats and nausea after returning home following controlled detonations of some of the tanks that were carrying toxic chemicals, including vinyl chloride, which has the potential to kill at high levels and increase cancer risk.

An evacuation order was lifted five days after the derailment, when officials deemed the air and water safe. But many residents remain unconvinced, complaining about the lingering smell of chemicals, headaches and pain.

Anger and frustration continued to boil over this week, as residents demanded answers of officials and Norfolk Southern. Hundreds of residents attended a town hall, expressing concern about air and water safety and their mounting distrust of civil leaders.

“Why are people getting sick if there’s nothing in the air or in the water,” one resident yelled during the town hall.

Officials have sought to reassure residents, acknowledging that while some waterways were contaminated, killing thousands of fish downstream, they believe those contaminants to be contained. No vinyl chloride has been detected in any down-gradient waterways near the train derailment, Tiffani Kavalec, the Ohio Environmental Protection Agency’s division chief of surface water, told CNN earlier this week.

And state officials have repeatedly determined water from the municipal system – which is pulled from five deep wells covered by solid steel casing – is safe to drink, though the state EPA has encouraged those who use private wells to get that water tested, since they may be closer to the surface.

The CEO of Norfolk Southern – which pulled out of the town hall this week, citing safety concerns – met with residents and local leaders Saturday, promising in an open letter that “we are here and will stay here for as long as it takes to ensure your safety and to help East Palestine recover and thrive.”

After visiting the community Thursday, Brown pledged to hold the rail company accountable for the impacts on the community, saying in a news conference he would “make sure Norfolk Southern does what it says it’s going to do, what it’s promised.”

Brown reiterated that Sunday. The company has promised to provide a $1,000 payment to residents within the zip code, but the senator said it would need to go far beyond that and live up to its commitment to “making everybody whole.”

“Whatever (residents) need, everything that’s happened here – all the cleanup, all the drilling, all the testing, all the hotel stays, all of that is on Norfolk Southern. They caused it, there’s no question they caused it,” Brown said, adding the total cost could amount to either tens or hundreds of millions of dollars.

The company has also started a $1 million fund “as a down payment on our commitment to help rebuild,” Alan Shaw, Norfolk Southern’s CEO, said in his open letter Saturday. It has also “implemented a comprehensive testing program to ensure the safety of East Palestine’s water, air, and soil.”

In addition to local and state officials, federal medical experts have also been deployed.

Ohio Gov. Mike DeWine Thursday asked the US Centers for Diseases Control and Prevention and the US Department of Health to send teams. In response, the Biden administration said it deployed experts to help assess what dangers remain, and the CDC similarly confirmed Friday it would send a team to assess public health needs.

As for the derailment itself, the National Transportation Safety Board continues to work “vigorously” to determine its cause. Investigators are reviewing multiple videos of the train prior to its derailment, including one that shows “what appears to be a wheel bearing in the final stage of overheat failure moments before the derailment,” the agency has said.

CNN’s Christina Maxouris, Artemis Moshtaghian, Aya Elamroussi and Samantha Beech contributed to this report.