1. Air pollution: refers to the phenomenon that some substances enter the atmosphere due to human activities or natural processes and show sufficient concentration in a sufficient time, thus endangering human comfort, health and welfare or the environment.
2. Water pollution: refers to the phenomenon that the chemical, physical, biological or radioactive characteristics of a water body are changed due to the intervention of a substance, thus affecting the effective utilization of water, endangering human health or destroying the ecological environment, resulting in the deterioration of water quality.
3. Noise pollution: refers to the phenomenon that the generated environmental noise exceeds the national environmental noise emission standard and interferes with the normal life, work and study of others.