People notice the smell of dog poop, especially if they take a walk and find someone else's dog's poop on their shoes, but who considers what the smell means? Then take super-dog cities like Seattle and Portland where we outnumber the national average of one dog for every three people and, well, we're lucky to have air blowing in off rivers and oceans--I think.
The scientists intend to study the microbe populations in more cities. Imagine a bacterial atlas of the United States, adjusted seasonally, to help you decide where to take your next vacation and what areas to avoid in your search for clean air.
I see this bacteria count as one more justification for wacking non-scoopers upside the head with my plastic bag of poop. Instead, at those rare times when I see someone not picking up, I cheerfully offer them a bag because I carry extras.
*R. M. Bowers, A. P. Sullivan, E. K. Costello, J. L. Collett, R. Knight, N. Fierer. Sources of bacteria in outdoor air across cities in the midwestern United States. Applied and Environmental Microbiology, 2011; DOI: 10.1128/AEM.05498-11