The most common sources of smelly and health-affecting industrial pollution, particularly sulfur dioxide and nitrogen dioxide, are included. However, Hydrogen S

The most common sources of smelly and health-affecting industrial pollution, particularly sulfur dioxide and nitrogen dioxide, are included. However, Hydrogen Sulfide is not, and it is a common one found specifically in both petroleum engineering. He mentioned that the smell was similar to the petroleum cracking plants in the north Salt Lake valley, so I'm assuming that is it. Regardless, AQI measurements are relatively aggregate, and if the pollution is produced very locally, it might be off the charts in that location, but diffuse down to a moderate measurement on a broader scale.