1. Decrease in anthropogenic lead, cadmium and zinc in Greenland snows since the late 1960s
2. and , “Lead Poisoning and Lead Adsorption,” Longmans, Green & Co. London (1912).
3. Agency for Toxic Substances and Disease Registry, Public Health Service, “The Nature and Extent of Lead Poisoning in the U.S.”, A Report to Congress, July 1988.
4. U.S. Environmental Protection Agency, “Quality Criteria for Lead”, EPA-600/8-83/028, 1986.