| Abbreviation | Definition |
|---|---|
| ANWR | Alaskan National Wildlife Reserve |
| ANWR | Aransas National Wildlife Refuge |
| AO | Aesthetic Objective |
| AOEC | Association of Occupational and Environmental Clinics |
| AOEE | Assessment of Environmental Effects |
| AOP | Advanced Oxidation Processes |
| APA | Área de Proteço Ambiental (Environmental Protection Zone) |
| APAR | Affected Property Assessment Report |
| APCB | Air Pollution Control Board |
| APCB | Air Pollution Control Bureau |
| APCC | Air Pollution Control Commission |
| APCCU | Air Pollution and Climate Change Unit |
| APCD | Air Pollution Control Devices |
| APCD | Air Pollution Control District |
| APCD | Air Pollution Control Division |
| APCE | Air Pollution Control Equipment |
| APCEL | Asia Pacific Centre for Environmental Law |
| APCO | Air Pollution Control Officer |
| APCP | Air Pollution Control Program |
| APCU | Air Pollution Control Unit |