It is present in the environment in many forms. Much of the lead that we come in contact with is in the soil. It gathers near lead-painted buildings that have been weathered, or have been scraped, sanded or sandblasted.
Lead is present in all soils at a normal level.
At normal levels, it doesn t cause health problems. Soils with lead level of 300 to 500 ppm are considered moderately contaminated, but o.k. for gardens. Soils with levels above 500 ppm should not be used for gardening at all. The soil should be removed or isolated with a permanent grass cover or mulch. Airborne lead from industrial emissions and auto exhaust also adds lead to the soil.