In the Mexico City park, I noticed that they had two types of trash cans. In the US we'd have recyclable and non-recyclable, but here they have organic and non-organic. That seems to make pretty good sense because it allows them to separate the stuff that will rot and stink from the stuff that won't rot and stink. I'm not sure exactly how they handle it differently.
One thing we've noticed in a lot of the smaller towns is a really bad odor. I'm not sure if it is from the trash or something else, but this is the cool time of the year. I imagine some of the places would be much worse during the summer.