GEOFF BENNETT: In Eastern Ohio, residents have been on edge for more than a week following an explosive train derailment and a toxic chemical leak.

Evacuation orders have been lifted, and the all-clear has been given, but, in East Palestine, a small community of about 5,000 people on the Pennsylvania border, that has done little to calm anxieties.

It was like something out of a disaster movie.

A massive train derailment led to an explosion, causing ominous plumes of smoke to billow over the quiet village of East Palestine.

But it is what is in that smoke that has residents still concerned about returning home.

The train, operated by Norfolk Southern, was carrying several toxic chemicals, including the used in plastic and paint manufacturing, including carcinogenic vinyl chloride.

Residents within a one-mile radius of the derailment were ordered to evacuate immediately.

Resident Melissa Henry recalled the moment she knew she had to leave with her son.

MELISSA HENRY, East Palestine, Ohio, Resident: It smelled like really, really strong paint thinner.

And then his eyes turned like bloodshot, and he started coughing.

And I was like, yes, we are leaving.

GEOFF BENNETT: After a controlled release of the toxic chemical from five of the derailed train cars, local officials consulted the Environmental Protection Agency and lifted the evacuation order on Wednesday.

TRENT CONAWAY, Mayor of East Palestine, Ohio: We know everybody's frustrated, everybody wants to be in their homes.

We did the best we can.

The number one goal is public safety.

GEOFF BENNETT: Now residents are reluctantly returning with deep anxiety about the lasting impact of the chemical leak on their health.

Linda Murphy lives roughly three miles from the site of the train derailment.

She is worried about what she is seeing in waterways near her home.

LINDA MURPHY, East Palestine, Ohio, Resident: There were several dead fish floating at multiple locations.

That is what we bathe in.

That's what we drink.

That's what we cook with.

And they could not reassure me that the water was safe to drink.

GEOFF BENNETT: Officials say the derailment was likely caused by a mechanical issue with a rail car axle.

Even though there have been no deaths reported, there is deep concern about the long-term effects.

And we are joined now by Ohio Governor Mike DeWine.

Governor DeWine, welcome to the "NewsHour."

GOV.

MIKE DEWINE (R-OH): Thank you.

Good to be with you.

GEOFF BENNETT: Your office deemed it safe for residents to return to East Palestine of -- Wednesday of last week.

Days later, we learned that the EPA informed the railroad have several other chemicals that were not publicly discussed.

How can you assure people that the area is safe when we're still learning more about the severity of this disaster?

GOV.

MIKE DEWINE: You know, where you rely on the experts, what they tell us?

We continue to monitor the air.

We continue to monitor the water.

They continue to tell us, the EPA continues to tell us that it is in fact safe.

Where we have seen some traces is in the water, which has gone into the into the Ohio River.

Again, the experts tell us that it is such a small, small quantity that there's - - we really should not worry about it.

But we're continue to monitor it.

In addition to that, we have gone around to the different, not only the public water sources and tested all of them, and we will continue to test them, but we have gone around to people in that area who have private wells and offer to test that -- those private wells as well.

GEOFF BENNETT: A question about that, because neither the railroad nor the Ohio EPA is sure how much of these chemicals spilled into the soil and into the water.

And, as you mentioned, there are a number of people who rely on private wells for their drinking water, as is the case in many rural areas across this country.

How can you assure people that their drinking water is safe, not just today, but moving forward?

GOV.

MIKE DEWINE: We're going to continue to test it.

We have an obligation to the people to continue to test.

And that's what -- that's what we have done.

The soil itself is in the process of being removed.

The only way you can really clean it up -- it was obviously a big, massive big spill.

The only way you really can clean it up and to be sure it's gone is to go down and dig it out and remove it.

And that's what's happening.

GEOFF BENNETT: Who is shouldering the cost of that remediation right now?

GOV.

MIKE DEWINE: It's the railroad.

Look, the railroad caused this problem.

And they're the ones who are shouldering the burden of cleaning it up.

GEOFF BENNETT: Are you confident that Norfolk Southern can be trusted to handle this work and cover the costs moving forward?

GOV.

MIKE DEWINE: Look, we're not taking anyone's word for anything.

We're monitoring what they're doing every single day.

We have people on the ground.

We're following what they're doing.

And we're going to hold them accountable.

That's our job.

GEOFF BENNETT: What's your message to folks in East Palestine, in the affected areas, who really aren't sure what to believe, and don't trust the railroad, they don't trust that the help -- they don't trust the help that's coming from the railroad, and they don't really trust the word of elected officials?

GOV.

MIKE DEWINE: Well, we're not asking them to trust the railroad.

We're not asking them to trust really elected officials.

What we're asking them to do is to follow the science.

And the experts, that best experts that we can find are monitoring this.

They're going to continue to monitor it.

They're going to continue to test the water and monitor the air.

And that will -- that will continue.

So it is -- we're asking them to, I guess, accept what the experts are saying, the best people that we can find about what is safe.

I understand people's concern.

If I lived there, I would have concerns as well.

But, again, we have been very transparent.

I have been over there several times myself.

We have held a number of press conferences.

We're going to continue to publish what the test is finding, what the test results are.

And I think by being transparent, by being as open as we can, that's how you engender trust from the public.

But we don't take anything for granted.

We're going to hold the railroad accountable.

GEOFF BENNETT: Do you have any sort of larger concerns about rail safety, given Norfolk Southern's track record?

GOV.

MIKE DEWINE: Well, sure.

I mean, we want to see what the results when the federal government finishes their investigation.

They're the ones who come in and do the analysis of why this occurred.

And so, again, yes, you certainly do.

You can't go through a situation like we just went through and are dealing with right now and not be concerned, when we're -- railroads are carrying very toxic material.

And they have a catastrophic wreck such as this, yes, sure, it's very concerning.

GEOFF BENNETT: Ohio Governor Mike DeWine, thanks for your time.

We appreciate it.

GOV.

MIKE DEWINE: Thank you.