Some landfills contain household and industrial chemicals. The chemicals pollute the soil and contaminate ground water. As the amount of garbage increases the space for landfill decreases. Many communities refuse new landfills because of the contamination. Some parts of the USA allow garbage to be burned in large incinerators.
Air pollution is created by burning.
This leaves ash which must still be deposited into a landfill. Ash is considered a hazardous waste. These are used for industrial products such as fluorescent lights and electrical transformers. They are very poisonous. They are not easily biodegradable and can remain in our environment for hundreds of years.