- Soil Science & Conservation 8
- Ecotoxicology 6
- Environmental Chemistry 6
- Environmental Health 6
- Pollution, general 6
- Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution 6
- Atmospheric Protection/Air Quality Control/Air Pollution 2
- Climate Change/Climate Change Impacts 2
- Environment, general 2
- Hydrogeology 2
- Water Quality/Water Pollution 2