PITTSBURGH (KDKA) – Residents in McKees Rocks, Neville Island, and other neighborhoods around the city of Pittsburgh have been complaining about a strange smell in the air.

Allegheny County tells KDKA the source of the smell is coming from the Neville Chemical Company on Neville Island. When KDKA first called the plant, the guard at the front gate said they were working on it.

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A supervisor said he’d call back, but he never did.

In an update provided by the Allegheny County Health Department, they said the odor appeared to be a result of a weather inversion.

Throughout the morning, viewers emailed and called the KDKA newsroom to report this strange smell. Officials say 22 people called 911, mostly from McKees Rocks and the city.

One viewer said it smelled like burning rubber, and it was so strong it seeped into their home, giving them a headache.

“It was burning my eyes. It smelled like sulfur. I put on Facebook that I smelled the demon coming,” said Denise Mongelli of Mt. Washington.

Another said the smell caused them to close their windows and it made their eyes water.

As of Thursday, authorities tell KDKA that there is no indication of any type of explosive danger or breathing danger. It’s simply just an irritant.

One local expert does not like that.

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“As a toxicologist, I took some issue with that because irritants can be quite serious,” said Jim Fabisiak, an associate professor in the Department of Environmental and Occupational Health at the University of Pittsburgh.

The Pitt professor wants to know what chemical, what concentration, and would we have even known without the weather inversion?

“Is everything just the usual operation at that plant or have they begun something new? Was there an accidental release?” Fabisiak said.

In the morning, the Allegheny County Health Department released this statement:

“The Allegheny County Health Department is aware of a strong odor being reported by residents primarily in McKees Rocks and other nearby areas. The odor was first reported around 4:30 a.m. and was immediately investigated by the county Emergency Management Agency. The odor appears to be the result of a weather inversion. The Health Department continues to monitor air quality in the area and will provide updates when available.”

Later in the day, the Allegheny County Health Department released a follow-up statement.

“The ACHD’s Air Quality team continues work to determine the source of the reported odors from early this morning. At this point, the ACHD has no information to indicate the odor would affect any population, sensitive or otherwise. However, the Health Department will continue to investigate to determine whether any enforcement action is required.”