- Ecology 9
- Environment, general 8
- Ecotoxicology 7
- Microbiology 7
- Science, Humanities and Social Sciences, multidisciplinary 7
- Science, multidisciplinary 7
- Atmospheric Protection/Air Quality Control/Air Pollution 6
- Environmental Chemistry 5
- Environmental Health 5
- Plant Sciences 5
- Soil Science & Conservation 5
- Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution 5
- Agriculture 4
- Microbial Ecology 4
- Applied Microbiology 2
- Environmental Management 2
- Geoecology/Natural Processes 2
- Life Sciences, general 2
- Nature Conservation 2
- Plant Physiology 2