Earlier this week, we shared with you a map detailing the city's several hundred toxic sites, which are just everywhere. But toxicity isn't just for ground-dwelling solid waste and pools of chemical runoff. It's in the air, too! Mostly hovering above the Upper West Side, it turns out.

NYC Clean Heat makes environmental degradation into a fun game with its Spot the Soot! page, which offers site visitors a cheery, colorful Google Map sprinkled with colored dots depicting the sorts of filth being pumped into the air at a given location. Those red and orange dots congregated on the UWS like a clump of Gummy Bears? They represent locations where heavy heating oils—No. 6 and No. 4— burn brightly into the night, spewing matter like sulfur and nickel and other impurities that are difficult to burn cleanly. This, in turn, releases a high amount of particulate matter, which can embed in people's lungs and aggravate existing respiratory diseases like asthma, as well as cause heart attacks or other "cardiovascular episodes."

Why is the Upper West Side such a hotbed of pollution? Its high density of large buildings, Kenneth Camilleri, an operations manager for NYC Clean Heat, told DNAinfo. The Upper East Side and Midtown aren't far behind.

The good news is that as of last year, No. 6 oil is no longer allowed by the city, and none of the three-year permits granted to burn it will be renewed in 2015. At least we'll always have our Superfund sites.