Lead in Surface Soil, Pure Earth Soil Sampling Results, August 2014. This map, produced by the nongovernmental organization Pure Earth, shows the results of soil sampling taken at 339 locations around the former Kabwe mine in 2014. The U.S. EPA considers lead a hazard in children’s play areas at or above 400 mg/kg. Source: in Bose-O’Reilly et al., “Lead intoxicated children in Kabwe, Zambia,” p. 420. Township names were added by Human Rights Watch.