Why are we doing this, and why is Gardenroots important?
At the first Iron King Mine Humboldt Smelter Superfund Site (IKMHSSS) Community meeting in August 2008, members of the Dewey-Humboldt, Arizona community expressed tremendous concern questioning whether it is it safe to grow, and consume vegetables from their garden, and looked to The University of Arizona (UA) for assistance. The numbers of inquiries has provided substantial evidence that this community is concerned with their water, food and soil quality, and deserves answers. The IKMHSSS is immediately adjacent to the town of Dewey-Humboldt, Arizona, and was added to the US EPA National Priority List in March 2008. Due to past mining and smelting operations, arsenic, lead and other metals have contaminated soil, sediments, surface water and groundwater on-site at levels above background. The Iron King tailings have highly elevated levels of arsenic (average arsenic level is 4,430 mg/kg) and lead and wind and water erosion of these tailings has led to elevated residential soil levels. In a community presentation given by the US EPA in April 2010, arsenic and lead ambient air concentrations significantly exceeded the EPA’s Residential Regional Screening Levels and 68 residential and public areas exceeded arsenic and lead soil background levels. There is a complete dearth of information concerning the uptake of these toxicants into vegetables grown by the community in these soils. All soils contain natural levels of arsenic and lead, but unfortunately soils have become the largest sink for anthropogenic arsenic release to the environment. Particularly, Arizona has over 350,000 acres of mine tailing waste, and offsite releases of arsenic and/or lead-laden dust from mine tailings piles are of particular concern for neighboring communities. At the national and state regulatory level, insufficient attention is being given to the measured or expected elevated surface soil arsenic levels at residential or public spaces, and no “unsafe” arsenic or lead soil standards are available, or have been formulated for Arizona soils.
For more information about the Iron King Mine and Humboldt Smelter Superfund Site, please visit:
U.S. Environmental Protection Agency
Arizona Department of Environmental Quality