Contamination

Lead and other metals are chemical elements that occur naturally in soils. Human activities have moved materials around so that some areas have higher levels of these chemicals, and other contaminants can be present too. Soils are more likely to be contaminated if they are near certain sources, such as:

• Urban areas with lots of human activity
• Older painted structures
• Busy roadways
• Old orchard lands
• Factories, manufacturing facilities, or industry
• Treated lumber
• Places with evidence of past burning or chemical spills (stains, odors, etc.).

If contamination is a concern, these 10 Healthy Gardening Practices are steps you can take to improve the soil, protect the health of people and plants, and keep gardening!

1. Use clean soil and compost. If you are concerned about contamination in your garden soil, consider having it tested by a New York State-certified laboratory.
2. Use raised beds. Build beds deep enough for the roots of your crops, and maintain them by adding compost often.
3. Avoid treated wood. Railroad ties, telephone poles, pressure-treated wood and some painted wood contain chemicals that can get into soil.
4. Maintain soil nutrients and pH. Healthy garden soils have a good nutrient balance and a pH near neutral (6.5 – 7).
5. Cover (or mulch) soil. Use compost, straw or bark mulch in garden beds, and stones or wood chips in paths and non-growing areas. This helps reduce soil splash, dust and tracking of soil home.
6. Keep an eye on children. Make sure children do not eat soil or put dirty toys or other objects in their mouths. Young children can be more sensitive to certain chemicals in soil, such as lead.
7. Leave the soil in the garden. Avoid bringing garden soil into your home. Remove soil from garden tools and  harvested vegetables while at the garden, and change your shoes before going indoors.
8. Wash your hands. Wash up after gardening, and have children who play or work in the garden do the same. Consider wearing gloves, and remember to remove them when leaving the garden.
9. Wash and/or peel produce. Wash vegetables thoroughly – especially leafy and root crops, which are more likely to  have soil on them. Consider peeling if appropriate.
10. Put a barrier under play areas. Separate children’s play areas from underlying soil with landscape fabric or other durable material. Put clean play materials such as sand or wood chips on top. Check the barrier over time to be sure underlying soil isn’t mixing with play materials.

Credit: Healthy Soils, Healthy Communities Project

“Metals in Urban Garden Soils“. Healthy Soils, Healthy Communities fact sheet with information about metals commonly found in urban garden soils, including sources, behavior in garden soil, concerns about human and plant health, what gardeners can do, and related topics. 9pg (PDF).

“What Gardeners Can Do: 10 Best Practices for Healthy Gardening” Short overview of steps you can take to avoid contact with contaminants and improve your soil. English and Spanish versions, 1-2pg (PDF).

“Sources and Impacts of Contaminants in Soils”. Cornell Waste Management Institute fact sheet. 6pg (PDF).

“Understanding Your Test Results: Lead in Chicken Run Soils and Chicken Eggs.” Recommendations for gardeners, 6pg (PDF).

“What Gardeners Can Do: Tips for Urban Chicken Keepers” Short overview of key strategies to help keep lead and other contaminants out of your backyard chicken eggs. English and Spanish versions, 2pg, (PDF).