This chart displays daily PM2.5 emissions from multiple monitoring stations in the Metropolitan City of Cagliari, using a logarithmic y-scale to accommodate wide value ranges. A dashed threshold line marks the WHO guideline of 25 μg/m³, with tooltips showing each station’s value and its percentage above or below this limit. The visualization relies on React components and D3 v7, employing `d3.scaleLog`, `d3.line`, and `d3.Delaunay` for Voronoi-based hover detection. Hovering over any point highlights the corresponding station’s full time series in color.