Human Health Impacts at Fort Belknap from Gold Mining

This page was written by Erin Klauk as part of the DLESE Community Services Project: Integrating Research in Education.

Assiniboine Mother and Child. Details

The human health effects due to cyanide leach gold mining are not well documented, and this is no exception in Montana. The State of Montana has done no formal studies to specifically study mine-related health effects. Pegasus, the last mining company at Zortman-Landusky, started to fund a health study with the $1.7 million supplemental money from the 1996 settlement, but because the company went bankrupt, the study never occurred (cyanide leach information).

Health problems from asthma and emphysema to thyroid problems and diabetes have been on the rise on the reservation in the past 25 years, especially among children. Other health impacts possibly due to the mining, such as lead poisoning and chemical burns from swimming in the water that flows out of the mining area, have also been reported (A Mountain of Unanswered Questions: Are Health Problems of Reservation Residents Related to the Mines? (more info) ).

Cyanide is known to be lethal to humans in very small quantities, with only a teaspoon of 2% cyanide solution causing death. Because of the number of cyanide spills and accidents, cyanide leach gold mining using large quantities of cyanide to remove gold from ore or crushed rock is creating more and more controversy. There is growing concern about both the environmental impacts and human health risks of using cyanide as a processing agent (More Cyanide Uncertianties: Lessons from the Baia Mare, Romania Spill-Water Quality and Politics).

In addition to physical human health effects, the Assiniboine and Gros Ventre Tribes of Fort Belknap have a strong cultural and spiritual connection with the Little Rockies. Spirit Mountain, which was a mountain peak of cultural significance to the Assiniboine and Gros Ventre people, was destroyed by the mine and replaced by a huge open pit (Case Studies - The Effects of Mining ( This site may be offline. ) ).

Agichide - Assiniboine Tribe. Details

To further investigate human health impacts from gold mining on the Fort Belknap Indian Reservation, follow the links below.

Resources on the Human Health Impacts on the Fort Belknap Indian Reservation

Resources containing information about the human health impacts on the Fort Belknap Indian Reservation:

  • A Mountain of Unanswered Questions: Are Health Problems of Reservation Residents Related to the Mines? . This article from Native News addresses the possibility of why health and environmental concerns on the Fort Belknap Indian Reservation may be related to water pollution from cyanide heap leach gold mining. (more info)
  • Current Issues in Wildlife Toxicology. This is a section from a short course about wildlife toxicology. This chapter briefly reviews several classes of toxic substances and discusses their significance in terms of risk to wildlife health. Types of toxins discussed are environmental endocrine disruptors, dioxin, phthalate esters and cyanide. (more info)
  • Cyanide Uncertainties: Observations on the Chemistry, Toxicity, and Analysis of Cyanide in Mining-Related Waters. This article discusses the use of cyanide compounds by mining industries. The article includes information about the chemistry and toxicity of cyanide, monitoring and analysis of cyanide at mine sites, and a case study about a cyanide spill in Kyrgyzstan. Examples of recent cyanide related mine accidents, and factors affecting cyanide toxicity to freshwater fish are also included in this article. (more info)
  • De-coding Cyanide: An Assessment of Gaps in Cyanide Regulation at Mines. This paper presents comments on environmental issues surrounding cyanide use in the metal mining industry, with emphasis on the various cyanide-leach processes used to extract gold and silver. Information is included about the chemical contents of impacted waters and soils, common cyanide cleanup techniques, long term impacts from cyanide, and the potential impacts to municipal waste and drinking water, and recommendations for the regulatory agencies and the mining industry. The author points out many shortcomings in both industrial practices as well as in analytical techniques and our understanding of the true effects of cyanide. (more info)
  • ToxFAQs for Cyanide . This fact sheet addresses common health questions about cyanide. Topics include a description of cyanide in its various forms, what happens to cyanide when it enters the environment, exposure routes, how cyanide affects health, and how to reduce your risk of exposure. (more info)
  • Toxicological Profile for Cyanide . This is a summary of the toxicological and health effects of cyanide. This site is authored by the Agency for Toxic Substances and Disease Registry and begins with a public health statement that summarizes in non-technical language, cyanide's relevant properties. Other topics include human health, chemical and physical information, production, import, use and disposal, potential for human exposure, analytical methods, and regulations and advisories. (more info)
  • Cyanide Hazards to Plants and Animals from Gold Mining and Related Water Issues. [Eisler and Weimeyer, 2004] This article from Reviews of Environmental Contamination and Toxicology discusses cyanide extraction of gold through milling of high-grade ores and heap leaching of low-grade ores. The article describes the procedure of extraction, as well as environmental problems that may occur from cyanide extraction. A variety of exclusion/cyanide reduction techniques are presented and discussed, and additional research is recommended. (citation and description)
  • Characterization and Availability of Cyanide in Solid Mine Tailings from Gold Extraction Plants.. [Zagury, Oudjehani and Deschenes, 2004] This article from Science of the Total Environment investigates the availability and fate of cyanide in gold mill solid tailings. To do this, tailings that were 6 to 9 years old and tailings that were 3 months old were sampled at various depths from two gold mining sites in Quebec, Canada. The study revealed a difference in physicochemical properties, cyanide concentration and speciation, viable bacterial populations and cyanide leaching behavior between aged and fresh solid mine tailings. (citation and description)

For ideas on how to use these webpages in a classroom, a Study Guide is provided.