- Environment, general 3
- Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution 3
- Communications Engineering, Networks 2
- Earth Sciences, general 2
- Ecology 2
- Geography, general 2
- Signal, Image and Speech Processing 2
- Water Industry/Water Technologies 2
- Atmospheric Protection/Air Quality Control/Air Pollution 1
- Ecotoxicology 1
- Environmental Chemistry 1
- Environmental Health 1