1 Subjects: “...radioactive pollution...”

2 Subjects: “...pollution indices...”

3 Subjects: “...environmental pollution...”

4 Subjects: “...pollutant emissions...”

5 Subjects: “...air pollution...”

6 Subjects: “...pollution...”

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

8 Subjects: “...pollutant removal...”

9 Subjects: “...air pollution...”

10 Subjects: “...persistent organic pollutants...”

11 Subjects: “...persistent organic pollutants...”

12 Subjects: “...marine pollution...”

13 Subjects: “...historically polluted area...”