In addition to gases, our lower atmosphere contains a large variety of bacteria. These bacteria get blown into the air from a number of sources, such as soil, dust, leaves and debris. What you probably don’t want to know is that a surprisingly large amount of aerosol bacteria come from dog feces.
Noah Feirer at the University of Boulder and his colleagues analyzed the bacterial content in 96 near-surface atmospheric samples from four Midwestern cities. They compared the DNA content in those samples to the DNA in databases of bacterial communities found in leaf litter and other potential sources, including human, cow and dog feces. They found a strong match to the dog poop bacteria, particularly in atmospheric samples taken during winter.
Other than taking greater care to quickly pick up after our pets, I’m not sure what can be done about this. Unfortunately, this is probably not the worst thing we’re going to find in our air.