Cancer may spread to the head and neck from other parts of the body and cause oral pain. With some cancers, pain may be felt in parts of the body not near the cancer. This is called referred pain.
Soil erosion. If you define land pollution as irreversible damage to the land, you have to include soil erosion as a type of pollution too. Many people think soil is soil, always there, never changing, ever ready to grow whatever crops we choose to bury in it.
Water pollution. Water pollution is the contamination of water bodies (e.g. lakes, rivers, oceans, aquifers and groundwater). This form of environmental degradation occurs when pollutants are directly or indirectly discharged into water bodies without adequate treatment to remove harmful compounds.