Contaminants in Soil
Soil is considered “contaminated” when an element or chemical is present at levels which could pose a health risk. Contamination can occur through industrial releases, homeowner maintenance activities, or naturally due to local geology. This fact sheet answers questions about the public health risks of contaminated soil and how you can reduce your exposure.
What Contaminants Could be in My Soil?
The type of contaminants in your soil is dependent on nearby land usage. Soils near industrial areas can be contaminated with metals, such as arsenic, cadmium, lead, and manganese; and organic chemicals, such as those found in oil, gas, and cleaning solvents. In urban areas, petroleum-based chemicals are found in soils near fuel stations, roadways, and parking lots, especially those that are treated with asphalt or coal tar sealants. Painting or staining exterior wood surfaces can contaminate underlying soil with organic chemicals, and existing patio decks, playground equipment, and other features may contaminate soil with metals. Outdoor burning and pesticide application can also contaminate soils.
What Contaminants Could be Naturally Elevated in my Soil?
Lead and arsenic, which are non-essential elements for human life, can be naturally present in soil at harmful levels. Though found at low levels in Illinois soils, there is no known “safe” level of lead exposure to the human body. Children exposed to lead may experience reduced IQ and attention span, hyperactivity, impaired growth, and learning disabilities. Arsenic, a human carcinogen, is found statewide in Illinois soils at levels exceeding cancer guidelines. In some regions, arsenic levels may also exceed health guidelines for non-cancer effects, such as skin abnormalities and numbness in the hands and feet.
How Could I Be Exposed to Contaminants in Soil?
The primary way people are exposed to contaminants in soil is through ingestion. After working or playing in soil, some of the soil on your hands may be accidently ingested if you don’t wash them before eating, drinking, or smoking. Exposure can also occur when you eat homegrown fruits and vegetables.
Other routes of exposure to soil contaminants include inhalation of dust from disturbed, dry soil and skin contact when gardening, working, or playing in soil without gloves.
How Can I Reduce Exposure to Contaminants in Soil?
You can reduce your exposure to soil contaminants by taking the following precautions:
- Wear gloves when working with soil and wash hands before eating or drinking.
- Discourage children from eating soil. Do not let children play in soil you know or suspect to be contaminated.
- Wash all produce grown in your garden using running water. Discard the outer leaves of greens before washing. Peel all root vegetables that were in direct contact with soil.
- Limit outdoor activities and keep windows closed on windy days. Fences, bushes, and grass help reduce dispersion of contaminated soil.
- Vacuum carpeting, rugs, and upholstery often. Regular vacuuming will keep dust from accumulating. Wet mop and wet wipe surfaces in the home where children may play.
- Take off your shoes when you go inside and leave outdoor shoes in the garage or the entryway. Heavily soiled clothes should be washed separately.
How Can I Plant a Safer Garden if I’m Concerned about Contaminants?
You can plant a safer garden by taking the following precautions:
- Locate your garden away from old painted buildings. Buildings built before 1978 are potential sources of lead.
- Locate your garden away from roadways where heavy metals and petroleum-based chemicals may contaminate nearby soils.
- Locate your garden away from seal-coated driveways or sidewalks that may contaminate nearby soils with petroleum byproducts and other organic chemicals.
- Build raised beds. Use untreated wood for your frame, apply fabric sheeting at the bottom of the raised bed, and fill with clean soil. The National Gardening Association provides instructions on proper raised bed construction and upkeep.
How Do I Find Out if My Soil is Contaminated?
Conducting a soil test can tell you what contaminants are in your soil. The University of Illinois Extension provides resources regarding soil quality and testing. Contact an educator to discuss your soil concerns and testing options.