Lead & Arsenic soil

A soil analysis is recommended if land is suspected to contain elevated amounts of lead and arsenic. Suspected areas are gardens:

within 20’ of buildings once painted with lead-based paints
within 100’ of high traffic roadways and parking lots
within 1 mile of existing or former smelters, fossil fuel-fired power plants or cement manufacturing facilities
located on a pre-1947 orchard site
located on or near tailings from current or former metal ore mines

Lead & Arsenic in Plant Parts

Seeds and fruits have lower concentrations then do leaves, stems, or roots.
Roots and tubers have highest concentrations, with the skin having higher concentrations than does the inner flesh
Tree fruits contain very low Pb and As concentrations

Wash garden crops with water before bringing inside and again inside with soap and water
Pare root and tuber crops (such as potatoes, carrots and radishes) and discard parings.
Do not compost unused plant parts, peelings and parings for later use in the garden
Select plants less sensitive to elevated lead and arsenic levels

Land use

Grow only ornamental plants in gardens with high levels of lead and arsenic
Build containers or raised beds with “clean” soil with a barrier between the uncontaminated soil and underlying contaminated soil.
Replace contaminated soil (may require disposal as a “dangerous waste”

Personal hygiene

Soil amendments

Plant lead concentrations decrease with increasing soil pH
Amend soils to as near neutral as possible
Increase soil organic matter
Use of phosphate-containing soil amendments sometimes can reduce plant uptake of soil lead (except if soils are also high in arsenic).

Updated July 15, 2004