- Environment, general 269
- Atmospheric Protection/Air Quality Control/Air Pollution 130
- Ecotoxicology 128
- Environmental Chemistry 121
- Environmental Health 121
- Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution 121
- Earth Sciences, general 63
- Ecology 56
- Geography, general 42
- Soil Science & Conservation 31
- Hydrogeology 20
- Civil Engineering 15
- Engineering, general 14
- Chemistry/Food Science, general 13
- Environmental Physics 13
- Climate Change/Climate Change Impacts 12
- Physics, general 12
- Water Quality/Water Pollution 12
- Atmospheric Sciences 10
- Environmental Management 10