This image emphasizes the spatial distribution of toxics moreso than the contents of air pollution itself. The mapping asks us to question borders, and to question both the notion of absolute control over toxic spread and the notion that toxic spread can be intentionally manipulated.
I like the graphic on the left side that says "Pollution Has No Borders." I'm not sure if your caption explains where exactly this part of the image comes from, but I think elaborating on that would make the image ethnographically stronger.
Your caption mentions that decongestion solutions have moved polluting enterpises away from the center and into the peripheries of the city--what exactly are these industries that cause air pollution? And who is most vulnerable in these peripheral locations near the political borders of the city--is this a residential area?
This is a strong visualization that helps further your argument that air pollution is not simply "naturally" dispersed "universally" but in fact spatially differentiated. The constructed nature of this image also reinforces another idea I think you want us to pause on, which is that air pollution is hard to see, even for the people the most concerned about alleviating unjust exposure.
I very much enjoyed the “collage” quality of this image, the product of purposeful juxtapositions that draw out a critical understanding of the idea of containment and toxicity.