I just got off the subway and the entire station was filled with an noxious odor such that people were gagging as they exited.
When I got to the street, I saw a cooking oil recovery truck parked right next to the fresh air intake for the subway station pumping oil from a restaurant.
Since the truck is filled with mixed fats, oils & grease, (commonly known as FOG waste) which are in various states of decomposition and decay, is there a possibility that Hydrogen Sulfide is being formed?