Fig. 1: Average Exposure Concentration Distribution of Particulate Matter and Its Components from 2010 to 2015.
From: Sustainable development reduces particulate matter emissions and mitigates aging’s cognitive impact

Color scales represent the average concentrations of particulate matter and its components (μg/m³), with red indicating higher concentrations and blue indicating lower concentrations. The maps, arranged from top to bottom and left to right, show the spatial distributions of PM₁, PM₂.₅, PM₁₀, BC (black carbon), OM (organic matter), NH₄⁺ (ammonium), SO₄²⁻ (sulfate), and NO₃⁻ (nitrate).