- Environmental Health 83
- Environmental Chemistry 58
- Ecotoxicology 54
- Waste Water Technology / Water Pollution Control / Water Management / Aquatic Pollution 54
- Atmospheric Protection/Air Quality Control/Air Pollution 53
- Environment, general 52
- Public Health 22
- Biostatistics 17
- Epidemiology 17
- Medicine/Public Health, general 17
- Vaccine 17
- Soil Science & Conservation 7
- Geochemistry 4
- Occupational Medicine/Industrial Medicine 4
- Terrestrial Pollution 4
- Biomedicine, general 3
- Pharmacology/Toxicology 3
- Pollution, general 3
- Health Promotion and Disease Prevention 2
- Animal Physiology 1