(NewsNation) — A laboratory on wheels is driving around East Palestine, Ohio, testing for chemicals in the air as many residents continue to experience symptoms from the toxic train derailment last month.

The Environmental Protection Agency’s Trace Atmospheric Gas Analyzer, or TAGA bus, is able to test for chemical compounds instantly. The EPA is calling the mobile lab the agency’s most complex piece of equipment for chemical testing in East Palestine.

“The chemicals we’re looking for are the ones that were on the train itself. So, we’re looking at vinyl chloride, we’re also looking at acrylates,” said Dave Mickunas, the EPA chemist in charge of the bus.

The TAGA bus is not testing for dioxins, which impacted residents have raised concerns about. According to Mickunas, those cannot be detected in the air.

Mickunas told NewsNation he has 100% confidence in the results the TAGA bus provides, but many East Palestine residents no longer believe what government agencies are reporting.

The EPA has reiterated to the East Palestine community that the air, drinking water and soil are safe several times since the Feb. 3 train derailment.

“People wouldn’t continue to have symptoms if it was all totally OK,” said Scott Snyder, who lives within one mile of the crash site with his wife Wendy Snyder.

Wendy and Scott are part of a larger group filing a class action lawsuit against Norfolk Southern

Wendy is still experiencing symptoms one month after the derailment, describing them as, “constant headaches, waking up feeling like you’re hungover. Very fatigued, the sore throats. …”

Last week, Wendy’s eyeballs were too swollen for her optometrist to conduct a routine eye exam. Scott told NewsNation he wasn’t able to get his blood tested for vinyl chloride, one of the chemicals the train was carrying, because the labs near him are not equipped to test for it yet.

“When we’re both at work, we feel better. we don’t have (symptoms). When we come home, it just comes right back,” said Scott.

Apart from health, the Snyders are grieving what they believe could be the loss of their longtime home and its value, saying friends and family don’t come to visit anymore.

“Honestly, we used to live in blissful ignorance, and you’d hear the trains go through. And you knew there was stuff on there, potentially, that could be bad, but you never knew it could be something like this. And now that the genie’s out of that bottle, you don’t get to put it back. And anxiety comes. You hear those trains and you wonder, can this happen again?” said Scott.

Locals told NewsNation they are gearing up for Thursday’s Senate hearing about heath and the environment in light of the derailment, where representatives from Norfolk Southern will be speaking. Some East Palestine residents have also asked to testify.