Editing Soil test (section)

==Soil contaminants==
Common mineral [[soil contaminant]]s include [[arsenic]], [[barium]], [[cadmium]], [[copper]], [[Mercury (element)|mercury]], [[lead]], and [[zinc]].

Lead is a particularly dangerous soil component. The following table from the [[University of Minnesota]] categorizes typical soil concentration levels and their associated health risks.<ref>{{cite web |author=Carl J. Rosen |title=Lead in the Home Garden and Urban Soil Environment |url=https://conservancy.umn.edu/server/api/core/bitstreams/d04616ad-7af4-49f7-81a1-a8da9a0d2697/content |access-date=2012-11-08 |publisher=Extension.umn.edu}}</ref>

{| class="wikitable"
|+ Children and pregnant women should avoid contact with soil estimated total lead levels above 300 [[Parts per million|ppm]]
! Lead Level !! Extracted lead (ppm) !! Estimated total lead (ppm)
|-
| Low || <43 || <500
|-
| Medium || 43-126 || 500-1000
|-
| High || 126-480 || 1000-3000
|-
| Very high || >480 || >3000
|}
The following is a non-exhaustive list of recommendations to limit exposure to lead in garden soils:
# Locate gardens away from old painted structures and heavily traveled roads
# Give planting preferences to fruiting crops (tomatoes, squash, peas, sunflowers, corn, etc.)
# Incorporate organic materials such as finished [[compost]], humus, and peat moss
# Lime soil as recommended by soil test (a pH of 6.5 minimizes lead availability)
# Discard old and outer leaves before eating leafy vegetables; peel root crops; wash all produce
# Keep dust to a minimum by maintaining a mulched and/or moist soil surface