This scatter plot displays the relationship between PM2.5 air quality levels and the number of health complaints across eight dates in March 2023. Each point’s shape and color encode a severity level: circles represent level 1 (green), triangles level 2 (orange), and squares level 3 (red). The visualization uses D3 v6 with an SVG renderer, employing `d3.scaleLinear` for both axes, `d3.axisBottom` and `d3.axisLeft` for tick marks, and `d3.symbol` with a `shapeMap` to generate distinct point glyphs. The data is hardcoded in the script as a constant array.