Wednesday, July 17, 2013

Risks of Mining Rare Earths

Open pit rare earth mining poses several risks to the environment and human health. Rare earth ores are normally extracted using strip mining which consists of vegetation clearing, soil removal, drilling and often blasting followed by stripping and removal of the ore of interest. Any open pit mining operation allows harmful substances to enter the air, soil and water. Rare earth mining poses additional risks due to the presence of radioactive substances as well as the chemicals used during processing. The toxicity of the rare earth elements themselves are still not understood.

Nearly all open pit mining operations have the potential to release aluminum, arsenic, cadmium, cobalt, copper, gold, iron, lead, manganese, silver, zinc, barium, beryllium, sulfide minerals, fluorine and asbestos. The risks to the environment and human health of many of these substances is listed in the table below.

Effects on the environment and human health

Rare Earth Elements
Toxicity and effects on the environment and human health still not understood

Sulfide Minerals
Creates sulfuric acid – acid mine drainage, decreasing the pH of water, which acids in the further release of sulfide minerals further decreasing the pH (positive feedback loop) decreased pH allows more metals and acid to be released into the environment

Can enter air, soil, water. Aquatic organisms are more sensitive to aluminum. Toxic to fish. In humans elevated levels cause developmental problems in children and pulmonary issues.

Can enter air, soil, water. Very mobile – travels long distances in the air before settling. Toxic to humans, human carcinogen. Increases risk of skin cancer. Low levels cause nausea, change in heart rhythms, low white blood cell count. Chronic exposure causes gastrointestinal issues, fatigue, blood disorders, and neuropathy. At high levels will cause death. All mammals experience same effects as humans. In aquatic organisms causes genetic mutations and cancer. In plants causes wilting, dehydration and death.

Once released will accumulate in soils. In plants decreases photosynthesis rates and water absorption. Major health concern for humans, especially children under 7 years of age. Causes negative effects on the cardiovascular, endocrine, muscular, nervous, reproductive and respiratory system, may cause death. Likely a carcinogen. Same effects are seen in mammals, birds and fish.

Can impair gastrointestinal, muscular and neurobehavioral function.

Toxic in large amounts. In aquatic plants and animals causes decreased growth and reproduction and increased mortality. In mammals (including humans) impairs the nervous and cardiovascular systems. At elevated levels will cause liver and kidney issues.

Can enter groundwater. Harmful effects on the muscular system, disruption of heart rhythms and paralysis. Ingestion results in gastrointestinal irritation and kidney damage. Toxicity of barium to aquatic and terrestrial organisms is unknown.
Very mobile, can travel in the air and able to enter soil and water. Inhalation causes acute beryllium disease (reddening and swelling of the lungs). Human carcinogen (lung cancer).

Toxic to plants and animals at high levels. Aquatic organisms are extremely sensitive to copper exposure – causes death in aquatic organisms. Slowed growth and development in terrestrial organisms. Irritant to nose and throat when inhaled. Causes nausea, vomiting, diarrhea when ingested. Can lead to kidney and liver damage or death at high levels.

Thorium-232 and Uranium-238 are radioactive substances that persist in the environment for thousands of years. They produce over 30 other radioactive substances as they undergo decay. Ability to alter biologic molecules and cause mutations and cancer.

Almost all wastes and by-products generated during rare earth mining and processing are radioactive, containing uranium or thorium. Uranium-238 and Thorium-232 are the most common isotopes found associated with rare earth elements. Uranium-238 is water soluble and is a common contaminate of groundwater. Thorium-232 is able to travel long distances, it is very mobile and can contaminate air, soil and water. Radioactive substances are often taken up by plants and from there they are able to bioaccumulate.  Uranium-238 and Thorium-232 and their decay products remain in the environment for thousands of years and pose serious risks. Radioactive decay releases energetic particles, these particles can dislodge electrons found in biologic molecules such as in water, protein and DNA. The ionizing radiation from radioactive decay is a known human carcinogen. The Uranium-238 decay chain includes Radium 226 which produces radon-222 (gas) and bismuth-214 both of which are dangerous radioactive substances.Radon-222 is inhaled and once in the lungs there is a great risk of developing cancer. Radon-222 is carcinogenic to all organisms.

 Methods for proper handling and disposal of uranium and thorium have not yet been developed and this is one of the greatest challenges faced by the rare earth industry. Several projects have been shut down or delayed due to issues with thorium handling and disposal. Among them are the Lynas Corp. Plant in Malaysia and a Mistsubishi rare earth plan in Malaysia. Environmental and human health concerns over thorium are also the main reasons that the Chinese have slowed their production of rare earths. While Canada does have strict environmental laws in comparison to many other nations, Canada's environmental laws were not written with rare earth mining in mind. Canada's Metal Mining Effluent Regulations (MMER) were not designed to manage or regulate all of the hazardous substances released during rare earth mining and ore processing. The MMER does not consider thorium and uranium harmful substances and does not impose controls upon their release into the environment. Since their release during mining activities is not associated with the nuclear fuel cycle they are not regulated by the Canadian Nuclear Safety Commission (CNSC).  The MMER imposes maximum daily discharge limits on arsenic, copper, cyanide, lead, nickel, zinc, total suspended solids and radium-226. The other harmful substances that could be released are not regulated.

Harsh chemicals are also used during the processing of rare earth ores. Strong acids and bases and other toxic chemicals that further ad to the risks associated with extracting rare earth ores. These chemicals must be transported to the mine site putting other areas at risk should spillage occur during transport. Spills or accidents may occur on site with the handling of these chemicals. Wastes produced also need to be properly managed to prevent their entrance into the surrounding environment.

Rare earth mining also releases many air pollutants including: nitrogen dioxide, sulphur dioxide, carbon monoxide, particulate matter and dustfall. Greenhouse gases, carbon dioxide, methane and nitrous oxide, are also released. Many companies market their rare earth operations as 'green' operations with a respect for the environment as a few uses of rare earth elements are in products designed to conserve energy or lower carbon emissions (greenhouse gases). However the procedures used to obtain these metals are quite damaging to the environment and they themselves release greenhouse gases. In addition the vast majority of rare earth metals are not for 'green' technologies. Rare earths are found in batteries, magnets, motors, LCD screens, catalytic converters, glass polishing compounds, they are used in oil refining and have been declared vital to the U.S. National Defense as they are used in missile guidance systems and  in laser based targeting equipment.

Canadian environmental laws are insufficient to protect the environment and humans from the risks associated with rare earth mining. In addition, very little is known about the risks associated with the rare earth elements themselves. Therefore, further study and reevaluation of environmental laws should be carried out before any rare earth mine projects are considered.

Unfortunately, many companies such as Matamec are currently 'fast tracking' their projects to meet market demand rather than allowing for further study and a reevaluation of environmental laws to ensure the safety of surrounding environments. Matamec recently entered into a memorandum of understanding with Toyota Tsusho Corp. to fast track the development of the Kipawa Rare Earths project.

Please help us convince the government of Quebec and Canada that further study is needed before this project can proceed to fully evaluate the risks this project would impose on the pristine Kipawa Lake watershed and the health risks to nearby communities.

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1 comment:

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