This interactive map, which was created by Tom Marthaler and Ted Timmons, shows the biggest sources of pollution in the Los Angeles region. A cluster of oil fields (they are several), refineries, airports and treatment plants are among the biggest contributors to that pollution. However, it's what these places are plotted againsthospitalsparks and schoolsthat's shows the real problem. For example, the blue crosses on the map represent hospitals and the blue homes represent schools. As for those black marks, they're oil wells that have been buried or capped. 

Marthaler and Timmons want to go the extra mile and make the map even more thorough to show how pollutions travels through wind patterns. That's a sight (and a truth) that some people might not be ready for.

[via The Atlantic Cities]