Most of the waste generated in the U.S. is disposed of in landfills. A modern landfill begins as a hole dug in the ground; it is lined with compacted soil or a man-made liner. As time goes by, the hole is filled and as more waste is added, the landfill often becomes a hill. When it reaches the point where it can take no more waste, the landfill is closed. A properly closed landfill contains a “cap” that limits water and moisture from seeping into it.

Inside a landfill, waste breaks down and produces gas. The main components of landfill gas are methane and carbon dioxide. Small amounts of other chemicals, such as volatile organic compounds (VOCs) and sulfur-containing compounds, also may be present. Landfill gas can have a bad, rotting odor.

How can I be exposed to landfill gas?

Landfill gas can be a hazard for nearby residents if it enters their homes. The gas produced in the ground travels through the soil and is usually released to the air. Sometimes, it can enter buildings, even those not directly over buried waste. In rare cases, buildings can have levels high enough to cause a fire if a spark were present.

How can landfill gas affect my health?

Landfill gas has an unpleasant odor that can cause headaches or nausea. The odor, however, is more irritating than a hazard to health. Although some compounds that make up landfill gas could be hazardous if present in large amounts, they should not cause adverse health effects if present in very small amounts.

Methane is the main chemical in landfill gas and it is highly flammable. If a spark is present and enough methane is mixed into the air, a fire may occur. Breathing methane, however, is only hazardous if it is present at levels high enough to decrease the amount of oxygen in the air. The adverse health effects are due to a lack of oxygen, not by breathing the methane gas itself. In a building, methane would be a fire hazard at levels much lower than those that could cause breathing problems.

Why is methane a fire hazard?

Methane burns very easily and often is used as natural gas for cooking and heating. It is lighter than air and collects at the top of enclosed spaces. When it rises through the soil and enters buildings, it gets trapped in the lower parts of a building, such as the basement. As more methane enters the building, the level in the air increases. When the methane level reaches 5 percent of the air, it can cause a fire or an explosion if a spark or flame is present.

What can be done at a landfill to stop the gas?

As waste in a landfill continues to decay, it continues to produce gas. Most landfills collect the gas in some way to control its release to the environment. This collected gas can be used as a fuel, converted to electricity or burned at the landfill. Buildings that are affected by landfill gas can install ventilation systems to remove any gas that may enter.

What should I do if I suspect landfill gas is entering my home?

Landfill gas is a hazard if methane reaches levels high enough to cause a fire. If you suspect that landfill gas is in your home, ventilate your home and basement with fresh air to decrease the level of methane. Seal sump pump pits and cracks in the basement to reduce the amount of gas that can enter. If landfill gas continues to be a problem, special ventilation systems, like those used to collect radon gas, can be used to remove landfill gas from the building.

Where can I get more information about landfill gas and my health?

Illinois Department of Public Health
Division of Environmental Health
525 W. Jefferson St.
Springfield, IL 62761
TTY (hearing-impaired use only) 800-547-0466

Where can I get more information regarding landfills?

Illinois Environmental Protection Agency
Bureau of Land
1021 North Grand Ave. East
Springfield, IL 62702

This fact sheet was supported in part by funds from the Comprehensive Environmental Response, Compensation, and Liability Act Trust Fund through a cooperative agreement with the Agency for Toxic Substances and Disease Registry,U.S. Department of Health and Human Services.

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Environmental Health Home

Illinois Department of Public Health
535 West Jefferson Street
Springfield, Illinois 62761
Phone 217-782-4977
Fax 217-782-3987
TTY 800-547-0466
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