1 Subjects: “...Visual Pollution Objects (VPOs)...”

2 Subjects: “...enterprise pollution emission...”

3 Subjects: “...air pollution...”

4 Subjects: “...pollution...”

5 Subjects: “...pollutant emissions...”

6 Subjects: “...air pollution...”

7 Subjects: “...air pollution...”

8 Subjects: “...air pollution...”

9 Subjects: “...pollution impact...”

10 Subjects: “...organic and biogenic pollution...”

11 Subjects: “...pollution emission intensity...”

12 Subjects: “...pollutants...”

13 Subjects: “...air pollution...”

14 Subjects: “...pollutant removal...”

15 Subjects: “...marine pollution...”

16 Subjects: “...emission of pollutants...”