- Atmospheric Protection/Air Quality Control/Air Pollution 5
- Environment, general 5
- Ecotoxicology 4
- Environmental Chemistry 4
- Environmental Health 4
- Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution 4
- Climate Change/Climate Change Impacts 1
- Hydrogeology 1
- Soil Science & Conservation 1
- Water Quality/Water Pollution 1