Causes of solid waste pollution are pollutants from households, industrial units, manufacturing units, commercial establishments, landfills, hospitals and medical clinics. The pollutants from these places may be in the form of non-biodegradable matter or non-compostable degradable matter.
Trash collected from households often takes the form of plastic bags and organic waste. Solid feces flowing out of homes and into sewers pollute underground water. Commercial establishments also pile up a lot of such waste matter. Industrial units involved in manufacturing produce toxic solid waste, such as slag, from the industrial process of obtaining metals from their ores.
Hospitals and clinics also produce waste in the form of disposable syringes, used test tubes, plastic bags used for collecting blood, cotton swabs and used bandages. Such solid waste needs careful handling and disposal. The soil becomes polluted with dangerous medical waste when such matter is disposed of directly into landfills.
Solid waste is usually dumped in landfills. Landfills are large pits in the ground that act as garbage disposal places. The biodegradable matter in landfills becomes a part of the soil gradually. The toxic non-biodegradable and non-compostable matter poses a health hazard as it does not decompose but mixes with the soil and the underground water.
Industrial incinerators are used to burn trash on a large scale. They cause pollution by emitting greenhouse gases while burning solid waste.