Skip to main content
. 2022 Jul 18;19(14):8732. doi: 10.3390/ijerph19148732

Figure 1.

Figure 1

Huai River Policy line and PM10 concentrations. Note: The red line is China’s Huai River/Qinling Mountain Range winter heating policy line. The polygons represent counties, the third level of the administrative hierarchy in China. The coloring of the polygons corresponds to average PM10 concentrations from 2014 to 2015.