On certain days, residents in some Pittsburgh neighborhoods and outlying municipalities can often smell a rotten-egg odor, but they might not have known where it was coming from or how prevalent it was.

The Allegheny County Health Department announced Tuesday it will now offer publicly trackable information about how much hydrogen sulfide, the rotten-egg gas, is in the county’s air.

The gas, H2S, is colorless and often emits a rotten egg-like smell and is a common byproduct of industrial processes like those used in oil and natural gas refineries, kraft paper production, coke ovens and tanneries, as well as from sewage treatments and landfills, according to the health department.

According to the EPA, lower, longer-term exposure to hydrogen sulfide can cause eye irritation, headache, and fatigue.

Allegheny County Executive Rich Fitzgerald said hydrogen sulfide does not pose the same health concerns as other emissions, and noted that the county’s overall air quality has vastly improved over the past decade, but he said hydrogen sulfide tracking is still necessary.

“(Hydrogen Sulfide) is still a nuisance to our residents in higher concentrations and needs to be addressed,” said Fitzgerald. “The new H2S dashboard will add another layer of regulatory focus for this particular type of emission.”

The new dashboard displays up-to-date information from the county’s two hydrogen sulfide monitors located in North Braddock and Liberty. The Allegheny County H2S Dashboard is available on the county’s website.

Pennsylvania has hydrogen sulfide regulations, but the federal EPA does not have air quality standards for the gas. The Allegheny County Health Department abides by state regulations through laws incorporated in 1971, according to a release.

The county said that hydrogen sulfide emissions are released at non-specific points during an industrial process and cannot be easily traced, but added that it has issued violations for H2S and will continue to do so.

For the past several years, Pittsburgh-area residents have been tracking the smell associated with hydrogen sulfide through private apps, such as Smell Pittsburgh. The smells tend to proliferate during the weather phenomenon known as an inversion. This dashboard adds another data point for tracking the smelly gas.

“The smell associated with H2S has long been a concern for Allegheny County residents,” said Acting Health Director Patrick Dowd. “Hourly H2S readings have been available on the department’s website for years, but creating this dashboard allows for the data to be understood in a much more straightforward and discernable way.”

The Pittsburgh region is also receiving other new investments in air quality monitoring, according to U.S. Rep Summer Lee, D-Swissvale.

Lee said in a press release that Southwestern Pennsylvania has already been awarded nearly $2 million to monitor levels of harmful air pollution, and the EPA is issuing an additional $236 million nationwide from the Inflation Reduction Act for grants for “monitoring near industrial facilities, multipollutant monitoring, and air quality sensors in disadvantaged communities.”

Additional details about the Pittsburgh region’s new air quality investments will be detailed on Thursday.

Copyright ©2025— Trib Total Media, LLC (TribLIVE.com)