Lead Safety for the Home Gardener
April 8, 2016 - Author: Terry McLean
- Lead occurs naturally in soil, but at high levels it can potentially be harmful to your health
- Previous land use can be a contributing factor to soil lead levels – common sources of elevated lead levels in urban soils are from the past use of leaded gasoline and lead-based paint in homes
- Before growing a vegetable garden, get your soil tested if you are unsure of your soil lead levels
- Locate vegetable gardens as far as possible from roads, driveways, and old painted structures
- If soil lead levels exceed 300 ppm, prevent children from accessing that soil (young children are at risk for eating soil - direct ingestion) by covering it with mulch; planting ground covers or turf; or installing stones/pavement
- If gardening in low lead soils (100 - 400 ppm is the US Environmental Protection Agency’s low lead range), improve soil health by adding organic matter like compost, and maintaining soil pH between 6.5 and 7.5
- Vegetables do not readily uptake lead from the soil or water
- Do not plant a vegetable garden if soil lead levels exceed 400 ppm; generally, it is considered safe to use garden produce grown in soils with total lead levels less than 300 ppm
- If elevated soil lead >300ppm is a concern, use raised beds or containers, fill with fresh, non-contaminated soil; select low risk crops
- If elevated soil lead is a concern, another option is to use raised beds or containers for your vegetable garden, and fill with fresh, non-contaminated soil
Irrigation with lead contaminated water does not significantly increase soil lead levels. If you are concerned about watering with lead contaminated water, you can:
- Purchase a lead filer that attaches to your garden hose
- Purchase a rain barrel or make a rain water catchment system that is best for your garden
- Work with Flint's OASIS TEAM to get water bumped from the Flint River delivered to your garden
Crops by Risk
Depending on the soil lead levels you can plant different crops to manage potential risks
Low Risk Crops
Fruiting Crops -- can be safely planted in soils with lead levels of 400 ppm or lower. Examples include:
Do not plant if your soil test results lead levels are 300 ppm or higher. If you have low soil lead levels these are safe crops. Examples include:
- Soil dust or particles on the surface of fruits and vegetables is the primary concern with produce grown in lead contaminated soil
- Thoroughly wash your hands, and wash produce in filtered water prior to consuming; peel root crops and discard the outer and older leaves of leafy vegetables; do not compost the peelings or leaves
- Wear gloves while gardening, and avoid tracking soil into your home
Can I Still Garden?
In general, vegetables and fruits grown in urban soils are considered insignificant sources of lead in diets. With proper urban soil management practices, the benefits associated with urban agriculture through improved nutrtiion and food security far outweigh the potential risks posed by elevated soil lead.
- Check with your local Extension office for updates and soil testing services at http://msue.anr.msu.edu/. or call 1-888-678-3464.
- Edible Flint's services are available to area gardeners, including soil testing, garden kits and training. Visit http://www.edibleflint.org/; 810-244-8530
- The Neighborhood Engagement Hub's resources include a community tool-shed, a mobile toolkit, and a place to hold meetings. Call 810-620-0078 or 810-620-1299.
- Lead in Residential Soils: Sources, Testing, and Reducing Exposure, Penn State University Extension, 2016 Penn State College of Agricultural Sciences http://agsci.psu.edu
- Lead in Urban Soils: A Real or Perceived Concern for Urban Agriculture?, Brown, Chaney, Hettiarachchi; Journal of Environmental Quality; 45:26-36; January 2016, http://www.ncbi.nlm.nih.gov/pubmed/26828157
- Lead in the Home Garden and Urban Soil Environment, 2016 University of Minnesota Extension, Rosen, FO-02543, http://www.extension.umn.edu/garden/yard-garden/soils/lead-in-home-garden/