{"version":"1.0","type":"rich","title":"PM2.5 in US","description":"A choropleth map of the United States displays county-level PM2.5 concentration for each year from 2000 to 2018, using a yellow-to-blue color scale to indicate air pollution levels. An interactive vertical slider and a play button animate through the years. Built with React and D3, it uses `d3.geoPath` for the map, `d3.interpolateRdYlBu` for the color gradient, and TopoJSON for state and county boundaries. Data comes from county PM2.5 measurements, with missing areas in grey.","provider_name":"VizHub AI Studio","provider_url":"https://vizhub.com","html":"<iframe src=\"https://vizhub.com/viz/aca84947f6894e58a7964a8760a40d3d?mode=embed\" width=\"960\" height=\"500\" scrolling=\"no\" frameborder=\"0\"></iframe>","width":960,"height":500,"cache_age":3600}