GEOFF BENNETT: Now to the continuing concerns over a major chemical spill in Eastern Ohio caused by a train derailment.

Another train derailed outside Detroit today.

Early reports found that one of the cars that went off the tracks did have hazardous materials, but chemicals did not leak out.

But, in Ohio, anger and anxiety are running high nearly two weeks after the incident there.

Frustration, fear and unanswered questions Wednesday night in East Palestine, Ohio.

LISA SIMMONS, Resident of East Palestine, Ohio: I think most of the residents here are concerned that they're going to sweep this under the rug.

We have got dead fish in the streams.

There's a lot of reports of pets and animals dying.

And we just want to make sure that we're taking care of here.

GEOFF BENNETT: Residents worried about the danger of returning to their homes, given the potential long-term effects of toxic chemicals in the air, soil and water following that fiery train derailment.

That's with evacuation orders lifted last week.

No one was injured in the derailment, but, as the cleanup continues, there are more questions about the chemicals released into the environment, including vinyl chloride, linked to cancer and known to cause dizziness, headaches and other short-term symptoms that residents have complained about.

Many now worried about the effect on the community's children.

BARB KUGLER, Resident of East Palestine, Ohio: My grandkids are only 6 months and 2 years old.

So I was very concerned with them growing up in this town what they will have to endure.

GEOFF BENNETT: State officials insist that tests done by the EPA and others show the air is safe to breathe and the water is safe to drink.

But some residents say they aren't convinced.

KATHY DYKE, Resident of Negley, Ohio: I honestly feel that the police department the fire department, all the first responders, they don't have the answers to give us because I don't think they know.

GOV.

MIKE DEWINE (R-OH): Good afternoon, everybody.

GEOFF BENNETT: Earlier this week, Ohio Governor Mike DeWine was asked if he would feel comfortable returning to his home if he lived near the site of the derailment.

GOV.

MIKE DEWINE: I think that I would be drinking the bottled water.

I would be alert and concerned.

But I think I would probably be back in my house.

GEOFF BENNETT: Notably missing from last night's community meeting, the company that owns the trains that derailed, Norfolk Southern, the company telling "PBS NewsHour" in a statement: "Unfortunately, after consulting with community leaders, we have become increasingly concerned about the growing physical threat to our employees."

The company says it's creating a $1 million charitable fund for the community and has paid more than $1 million in relief so far.

Today, EPA Administrator Michael Regan visited the community.

MICHAEL REGAN, Environmental Protection Agency Administrator: We are absolutely going to hold Norfolk Southern accountable.

And I can promise you that.

GEOFF BENNETT: At least five lawsuits have been filed against Norfolk Southern, including a class action suit by some East Palestine residents.

To help us understand more about the potential risks residents of East Palestine could face, I'm joined by Peter DeCarlo, associate professor of environmental health and engineering at Johns Hopkins University.

Thank you for being with us.

And, Peter DeCarlo, if you lived in East Palestine, what would you need to hear, what would you need to see from officials in order to feel safe living there?

PETER DECARLO, Johns Hopkins University: So, I think, ultimately, given the public information available, I wouldn't feel comfortable moving back quite yet.

And what I'd need to see is evidence that the -- there are no more emissions coming from the accident site and that the inside of my home was safe to be in.

And so I haven't seen data that suggests that either of those things are true yet.

And, for me, with two small children, I would certainly not want to move back at this point.

GEOFF BENNETT: The EPA is not providing that data, or the data that you're seeing does not suggest that it's safe?

PETER DECARLO: So, the EPA is providing monitoring and stationary sampling data.

The monitoring data is from these handheld monitors that are really not designed to measure outside air quality.

I believe these are also the instruments they're using to screen people's homes and let people know that it's safe to move back.

As an atmospheric measurement person, I would not feel comfortable with that level of screening.

I would want more information.

I'd want to know what chemicals were present.

And so that, by the EPA's definition, would require air sampling, which means you take air into a stainless steel container, you take that back to a lab, and you do much more detailed measurements and characterization of what chemicals are present and at what concentrations.

And that's the type of information that's needed to know that the air is safe.

There's also surfaces in the home where some of the plume from the large fire that we all saw could have deposited.

And so we don't know what chemicals are made exactly when you burn something like vinyl chloride.

We know that it's no longer vinyl chloride.

It's going to be a mixture of a whole host of different potentially toxic chemicals.

And so if those accumulate on surfaces in your home, that becomes another thing to worry about.

We spend most of our lives indoors, and most of it in our homes.

And so making sure that that's a safe environment to go back to, especially if there are vulnerable populations involved -- that's young children, elderly, people with preexisting health conditions - - making sure that that home environment is safe and then really confirming that it's safe is key, if I were to move back.

GEOFF BENNETT: A question about that, because we heard from a grandmother in our report.

Her grandkids are 6 months old and 2 years old.

What are some of the special safety considerations for children?

PETER DECARLO: I mean, I have two young boys, 8 and 6.

And when they were that age, if it was on the floor, if it was a toy, it was in their mouth.

I'd be really concerned about indoor surfaces and potential exposures that could happen in that case.

And so, especially with young children who are touching everything, we know that kids are more vulnerable to chemical exposures, so, extra careful, especially when young children are involved, because they -- there are just so many more ways that these types of chemicals can get into their bodies.

GEOFF BENNETT: The release of these chemicals in East Palestine caused the deaths of 3,500 fish.

Some residents have reported headaches and rashes in the days since the derailment.

The EPA is telling people that it's safe to return to their homes.

But there are people in East Palestine who wonder how both things can be true, how, on the one hand, they're being told it's safe and yet, on the other hand people are experiencing physical symptoms.

PETER DECARLO: Yes, I mean, I think our noses are not detailed chemical information instruments to measure air quality, but they are detectors for measuring something's not right.

And so, when people are reporting smells, you know that there are still chemicals that are present in that environment that were not there before.

And so it's important to really characterize what chemicals are present.

Certainly, early on in the accident, and during the burn of the train car contents, you probably have the worst potential for exposure.

But that doesn't mean there aren't residual exposures to some of these chemicals that are continuing to happen.

So, again, it's really important to characterize in a very detailed and systematic way what's in the air and what's potentially, especially in the indoor environment, on surfaces.

GEOFF BENNETT: What about the-long term impact?

How long might it take to fully understand the full picture of consequences here?

PETER DECARLO: I mean, I think that's a -- that's a really difficult question to answer, because the data that's publicly available at this point really doesn't tell me, as a measurement scientist, what's still going on.

I really need to understand, are there continuing emissions?

And without the data to tell us what's there and what continues to be emitted, if things continue to be emitted, we don't really know.

We can't put a timeline on any of this.

And so, fundamentally, we need the measurement data to understand exposure and to understand how long potentially this could last.

GEOFF BENNETT: Peter DeCarlo with Johns Hopkins University, thanks for your time and for your insights.

PETER DECARLO: Thank you.