This visualization displays a treemap of particulate matter contributions by source type across three global regions. Each region is rendered as a separate SVG group positioned absolutely, with colored rectangles representing emission sources. The code uses D3.js v5's `d3.hierarchy` and `d3.treemap` to compute tile layouts, while `d3.select` and `d3.append` handle DOM creation. Colors are mapped to source categories via a predefined `typeColors` object, and the data comes from a static JSON file containing regional emission breakdowns.