Minerals, Metals & Chemicals

A below-grade work area has been flooded with water so acidic that metal fixtures in the room, including the handrail, have been dissolved. Contents of the "water" include beryllium at 1,100 ug/L, cadmium at 600 ug/L, chromium at 9,000 ug/L, lead at 300 ug/L, mercury at 9 ug/L, and elevated levels of aluminum, calcium, copper, iron, manganese, and zinc with respect to background levels. (Photo courtesy of McGinnis & Associates). (Click here to enlarge stairs)

This page contains a list of minerals, metals and chemicals that appear to be incidental to the operation of the Yerington Anaconda Mine Site, including a brief description of their properties and potential impacts to human health. Two excellent sources of information are the McKay School of Mines at the University of Nevada in Reno, and the website mindat.org. It should be noted that air sampling at the YAMSite is in its infancy stages and we are therefore unable to discuss air impacts to human health to any great extent. Impacts discussed on this page primarily refer to groundwater.

Minerals, Metals and Chemicals associated with the Yerington Anaconda Mine Site are listed below in alphabetical order. Please note: Each material listed below contains a description of what it is, how it is used in our world, to what extent its presence has been detected on the mine site or vicinity, and what the potential health risks are associated with its presence. As of January 2005, there is insufficient evidence to suggest that the presence of any of these materials or any combination of them, has caused or is causing damage to human health at the mine site or anywhere else in Yerington or the general Mason Valley. The EPA and the ATSDR will be measuring and researching these items to a much greater extent in CY2005 and they should be able to begin supplying the public with a more comprehensive analysis of the associated risks by the end of 2005. You may click on the name to be taken to its description, or you may scroll down through the list.

Aluminum has been found in site tailings, tailings ponds, and leachite salts. Highly concentrated in the pregnant solution at 25,000,000 ug/L, it has been discovered in extremely elevated concentrations in down-gradient groundwater and the groundwater seep. Aluminum compounds are toxic to most plants and somewhat toxic to mammals; aluminum accumulates in the human body.

Aluminum metal presents a fire hazard when powdered. Pure aluminum is a silvery-white metal with many desirable characteristics. It is light, nontoxic (as the metal), nonmagnetic and non-sparking. It is somewhat decorative and is easily formed, machined, and cast. Pure aluminum is soft and lacks strength, but alloys with small amounts of copper, magnesium, silicon, manganese, and other elements have very useful properties. Aluminum is an abundant element in the earth's crust, but it is not found free in nature.

The ancient Greeks and Romans used alum in medicine as an astringent, and in dyeing processes. Aluminum is one of the elements which has an alchemical symbol; alchemy is an ancient pursuit concerned with the transformation of other metals into gold). The most abundant metal on Earth, it is found in soil, water and air. Its chemical and physical properties make it ideal for a wide variety of uses. Aluminum and its compounds are often used in food as additives, in drugs (e.g., antacids), and in consumer products (e.g., cooking utensils and aluminum foil).

Because aluminum is so pervasive in the environment, to the point of being unavoidable, researchers have long been studying its effects on humans. This research has revealed a link between aluminum intake and neurological dementia in kidney dialysis patients (dialysis encephalopathy). In recent years, the public and the media have become concerned about other possible adverse effects of aluminum on human health, including its role in Alzheimer's disease, Parkinson's disease and amyotrophic lateral sclerosis (Lou Gehrig's disease). In addition, questions have been raised about the potential risks to infants who drink baby formula containing aluminum.

While it is true that most of our daily intake of aluminum comes from food, only a very small percentage is actually absorbed by the body. Absorption depends on a variety of factors, including the type of aluminum compound, the composition of the food eaten, and the age and the health of the person consuming the food. Aluminum in drinking water is better absorbed by the body than aluminum in food, even though it is responsible for only a small fraction of the total daily intake. This means that drinking water could be a more significant source of aluminum than food. The reason for the difference in the absorption rates is unknown; much more research needs to be done before definitive conclusions can be drawn.

Historically, aluminum has been considered relatively non-toxic; healthy individuals can tolerate oral doses as high as 7 grams per day without experiencing harmful effects. However, abundant evidence now shows that aluminum may adversely affect the nervous system in both humans and animals. Patients with kidney disease who undergo dialysis regularly and who consequently may be exposed to high levels of aluminum in dialysis fluids and medications can develop dialysis encephalopathy, a progressive form of dementia characterized by tremors, convulsions, psychosis and other changes in speech and behavior. Most experts agree that high levels of aluminum in dialysis fluids and medications are responsible for the dementia, and that controlling the levels of aluminum significantly reduces the incidence of this disease.

Alzheimer's disease is a leading cause of death. The first recognizable symptoms of Alzheimer's disease, which mark the start of progressive mental deterioration, include memory lapses, disorientation, confusion, and depression. Scientists are investigating possible theories to determine the causes of Alzheimer's disease. These theories take into account the roles of genetic factors, abnormal proteins, infectious agents, environmental agents including aluminum, other metals or solvents, and metabolic changes. Aluminum exposure was suggested as a possible cause of Alzheimer's disease because the brain cells of Alzheimer's patients can contain from 10 to 30 times the normal concentrations of aluminum. However, it is not clear whether the accumulation of aluminum is a cause or a result of the disease. Several studies on humans have shown a slightly increased risk of Alzheimer's disease or related dementia in communities where the drinking water contains high concentrations of aluminum.

On the other hand, a number of other studies have shown no relationship between aluminum in drinking water and the onset of dementia. In addition, scientists have been unable to induce Alzheimer's disease-type changes in the brains of laboratory animals exposed to aluminum, or to explain the absence of Alzheimer's disease-type changes in brains of patients suffering from dialysis encephalopathy. Some studies have also shown little or no accumulation of aluminum in the brain tissues of Alzheimer's patients.

After weighing all the evidence, experts have concluded that even though a true association between dementia (including Alzheimer's disease) and high concentrations of aluminum in drinking water has not yet been proven, the possibility cannot be ruled out, especially for the most elderly. Aluminum has also been associated with other severe diseases of the nervous system, such as Lou Gehrig's and Parkinson's diseases. As with Alzheimer's disease, the significance, if any, of the association is unknown. The intake of large amounts of aluminum can also cause anemia, osteomalacia (brittle or soft bones), glucose intolerance, and cardiac arrest in humans.

Aluminum occurs naturally in many foods, but usually only in low concentrations. The tea plant is an exception, as it accumulates large amounts of aluminum, which can then leach from the tea leaves into brewed tea. Aluminum can also leach into food from cookware, utensils and wrappings, but studies to date have shown that the amount of aluminum leached from these sources is generally negligible. Certain foods, such as dairy products, grains and grain products, desserts and beverages, may contain levels of aluminum that are higher than naturally-occurring background levels owing to the use of aluminum compounds (e.g., sodium aluminum phosphate) as food additives.

The daily intake of aluminum can be greatly increased for individuals consuming maximum recommended doses of aluminum-based over-the-counter drugs such as antacids and buffered acetylsalicylic acid (ASA).

Patients with kidney disease who undergo dialysis regularly and who consequently may be exposed to high levels of aluminum in dialysis fluids and medications can develop dialysis encephalopathy, a progressive form of dementia characterized by tremors, convulsions, psychosis and other changes in speech and behavior. Most experts agree that high levels of aluminum in dialysis fluids and medications are responsible for the dementia, and that controlling the levels of aluminum significantly reduces the incidence of this disease.

Aluminum has also been associated with other severe diseases of the nervous system, such as Lou Gehrig's and Parkinson's diseases. As with Alzheimer's disease, the significance, if any, of the association is unknown. The intake of large amounts of aluminum can also cause anemia, osteomalacia (brittle or soft bones), glucose intolerance, and cardiac arrest in humans.

Although a Health Canada survey of infant formulas found that aluminum levels in formula were higher than levels in human or cow's milk, consumption of aluminum at this level is not considered to pose a health risk in baby formulas

There is no easy or inexpensive way to remove aluminum from tap water in the home. Steam distillation and a process called reverse osmosis are effective, but both processes require the purchase of expensive equipment and frequent maintenance. Natural aluminum found in untreated water is generally thought to be in a form that is not easily taken up by the body, and it is therefore of little concern in terms of health effects. It is only during the alum treatment process that aluminum appears to be changed to a form that may be more readily absorbed. (Back to Table)

Not to be confused with alimony or acrimony, antimony was found in very elevated concentrations in the pregnant solutions and the groundwater seep, (200 ug/L). It is somewhat diluted in the valley groundwater, (average 20 ug/L). Still, it is about four times the recommended health standard of 5 ug/L.

Antimony is a silvery white metal of medium hardness that breaks easily. Small amounts of antimony are found in the earth's crust. Antimony ores are mined and then either changed into antimony metal or combined with oxygen to form antimony oxide. It is to harden lead alloy's and in solder, bearings, lead batteries, mascara, infrared detectors, plastics and chemicals. Most antimony oxide produced is added to textiles and plastics to prevent their catching on fire.

Most antimony will end up in the soil or sediment, where it attaches strongly to particles that contain iron, manganese, or aluminum. You may be exposed to antimony by breathing air, drinking water, and eating foods that contain it. You also may be exposed by skin contact with soil, water, and other substances that contain antimony. Much of the antimony found in sediment, soil, and rock is so strongly attached to dust and dirt or buried in minerals that it cannot easily affect your health. Some antimony in the environment is less tightly attached to particles and may be taken up by plants and animals.

Rats and guinea pigs that breathed very high levels of antimony for a short time died. Rats breathing high levels of antimony for several days had lung, heart, liver, and kidney damage. Breathing very low levels of antimony for a long time has resulted in eye irritation, hair loss, and lung damage in rats. Dogs and rats that breathed low levels of antimony for a long period had heart problems (changes in EKGs). Problems with fertility have been observed in rats that breathed very high levels of antimony for a couple of months. Lung cancer has been observed in some studies of rats breathing high concentrations of antimony. Antimony has not been classified for cancer effects by the Department of Health and Human Services (DHHS), the International Agency for Research on Cancer (IARC), or the Environmental Protection Agency (EPA).

Antimony can enter your body when you drink water or eat food, soil, or other substances that contain antimony. Antimony can also enter your body if you breathe air or dust containing antimony. It is not known if antimony can enter your body when it is placed on your skin. A small amount of the antimony you eat or drink enters the blood after a few hours. After you eat or drink very large doses of antimony, you may vomit. This will prevent most of the antimony from entering through the stomach and intestines into your blood. Antimony in your lungs will enter your blood after several days or weeks. The amount of antimony that will enter your blood from your lungs is not known. After antimony enters your blood, it goes to many parts of your body. Most of the antimony goes to the liver, lungs, intestines, and spleen. Antimony will leave your body in feces and urine over several weeks. It is associated with elevated levels of cholesterol and a decrease in blood sugar.

The concentration of antimony that is dissolved in rivers and lakes is very low, usually less than 5 parts of antimony in 1 billion parts of water (ppb). Antimony does not appear to accumulate in fish and other aquatic animals.

Soil usually contains very low concentrations of antimony, less than 1 part of antimony in a million parts of soil (ppm). However, concentrations close to 9 ppm have been found. The highest soil concentrations found at hazardous waste sites on the NPL and at antimony-processing sites range from 109 to 2,550 ppm. High concentrations of antimony may be found in soil because dust sent out during processing settles out from the air. Also, waste from antimony-processing and other antimony-using industries is usually dumped onto the soil.

Food usually contains small amounts of antimony. You eat and drink about 5 micrograms (5 millionths of a gram) of antimony every day. The average concentration of antimony in meats, vegetables, and seafood is 0.2–1.1 ppb. The antimony oxide that is added to many materials for fire protection is very tightly attached to these materials and does not expose people to antimony.

EPA has set a limit of 145 ppb (ug/L) in lakes and streams to protect human health from the harmful effects of antimony taken in through water and contaminated fish and shellfish. EPA has also set limits on the amount of antimony that industry can release. (Back to Table)

It is no secret that high levels of arsenic exist in the Mason Valley area. Under new federal guidelines effective in 2006, for example, the Yerington Paiute Tribe will have to install filtering systems to remove arsenic from its domestic water supply on the Campbell Ranch Reservation. The city of Fallon installed such a system in 2004. Locally, the highest levels of arsenic have been detected in various ponds at the site. One evaporation pond contained 42,000 ppb in 1978. The national drinking water standard effective 2006 will be 10 ppb, and down-gradient groundwater tested at 400 ppb in one well sampled by the USGS in 1978.

Exposure to higher than average levels of arsenic occurs mostly in the workplace, near hazardous waste sites, or in areas with high natural levels. At high levels, inorganic arsenic can cause death. Exposure to lower levels for a long time can cause a discoloration of the skin and the appearance of small corns or warts.

Arsenic can enter the water supply from natural deposits in the earth or from industrial and agricultural pollution. Arsenic is a natural element used for a variety of purposes within industry and agriculture. It is also a byproduct of copper smelting, mining, and coal burning. Industries in the United States release thousands of pounds of arsenic into the environment every year. Once released, arsenic remains in the environment for a long time.

It is widely believed that naturally occurring arsenic dissolves out of certain rock formations when ground water levels drop significantly. Surface arsenic-related pollutants enter the ground water system by gradually moving with the flow of ground water from rain, melting snow, and so on. The groundwater levels in Yerington area aquifers varies considerably during a typical year due to heavy summer drawdown for agricultural uses and significant recharges from winter mountain snowfalls.

Several studies have shown that inorganic arsenic can increase the risk of lung cancer, skin cancer, bladder cancer, liver cancer, kidney cancer, and prostate cancer. (Back to Table)

Barium was found at elevated levels in tailings ponds at the Yerington Anaconda Mine Site. Barium is a lustrous, machinable metal which exists in nature only in ores containing mixtures of elements. It is used in making a wide variety of electronic components, in metal alloys, bleaches, dyes, fireworks, ceramics and glass, as well as for medical test purposes. In particular, it is used in well drilling operations where it is directly released into the ground.

In water, the more toxic soluble barium salts are likely to be converted to insoluble salts which precipitate. Barium does not bind to most soils and may migrate to ground water. It has a low tendency to accumulate in aquatic life.

EPA has found barium to potentially cause gastrointestinal disturbances and muscular weakness when people are exposed to it at levels above the MCL for relatively short periods of time. Barium can also cause elevated blood pressure. EPA's standard drinking water level is 2 ppm; down-gradient groundwater has been measured at 20 ppm in some places.

Those barium compounds that dissolve well in water may cause harmful health effects in people. Ingesting high levels of barium compounds that dissolve well in water over the short term has resulted in

The effects in people of ingesting low levels of barium over the long term are not known. (Back to Table)

Pure beryllium and its metal alloys have applications in electrical components, tools, structural components for aircraft, missiles, and satellites, and other metal-fabricating uses. Beryllium is also used in consumer products, such as televisions, calculators, and personal computers. Beryllium compounds are commercially mined, and the beryllium is purified for use in nuclear weapons and reactors, aircraft and space vehicle structures, instruments, x-ray machines, and mirrors. Beryllium ores are used to make specialty ceramics for electrical and high-technology applications. Beryllium alloys are used in automobiles, computers, sports equipment (golf clubs and bicycle frames), and dental bridges. (Back to Table)

Boron was found in extremely high concentrations in the evaporation ponds. It was also discovered in significant amounts in the groundwater seep and tailings ponds, but has not been sampled in domestic wells. Boron is not found free in nature. It occurs usually as orthoboric acid in some volcanic spring waters and as borates in borax and colemanite. Ulexite is interesting as it is a natural fiber optic. Amorphous boron is used in pyrotechnic flares and rockets. Boric, or boracic, acid, is used as a mild antiseptic, a cleansing flux in welding and as a water softener in washing powders. Other uses include porcelain enamels, arthritis treatments, and a control (shield) for nuclear projects. Boric Acid is also used in North America for the control of cockroaches, silverfish, ants, fleas, and other insects. Boron compounds may be carcinogenic.

It occurs naturally in the environment due to the release into air, soil and water through weathering. It may also occur in groundwater in very small amounts. Humans add boron by manufacturing glass, combusting coal, melting copper, and through the addition of agricultural fertilizers. Plants absorb boron from the ground; through plant-consuming animals it can end up in food chains. Boron has been found in animal tissue, but it is not likely to accumulate.

When animals absorb large amounts of boron over a relatively long period of time through food or drinking water, the male reproductive organs will be affected. When animals are exposed to boron during pregnancy their offspring may suffer from birth defects or delayed development. Furthermore, animals are likely to suffer from nose irritation when they breathe in boron. (Back to Table)

Cadmium was measured at 600 ug/L in the groundwater seep and evaporation ponds at the Yerington Anaconda Mine Site. Down-gradient water measured 170. The EPA drinking water standard is 5 ug/L. Cadmium is a naturally occurring metallic element, one of the components in the earth’s crust, and present everywhere in our environment. Natural sources include underlying bedrock or transported parent material such as glacial till and alluvium. Anthropogenic input of cadmium to soils occurs by aerial deposition and sewage sludge, manure and phosphate fertilizer application. Cadmium is much less mobile in soils than in air and water.

Cadmium is a natural, usually minor constituent of surface and groundwater. It may exist in water as the hydrated ion, as inorganic complexes such as carbonates, hydroxides, chlorides or sulfates, or as organic complexes with humic acids. Cadmium may enter aquatic systems through weathering and erosion of soils and bedrock, atmospheric deposition direct discharge from industrial operations, leakage from landfalls and contaminated sites, and the dispersive use of sludge and fertilizers in agriculture. Much of the cadmium entering fresh waters from industrial sources may be rapidly adsorbed by particulate matter, and thus sediment may be a significant sink for cadmium emitted to the aquatic environment.

Rivers containing excess cadmium can contaminate surrounding land, either through irrigation for agricultural purposes, dumping of dredged sediments or flooding. It has also been demonstrated that rivers can transport cadmium for considerable distances.

The major route for cadmium intake is ingestion (for non smokers). This is largely due to the presence of trace levels of cadmium in foodstuffs of natural origin or of the use of phosphate fertilizers and sludge on agricultural soils. There are generally little or no differences noted in cadmium levels between indoor and outdoor air in non-smoking environments. Smoking, however, may substantially affect indoor ambient air cadmium concentrations.

Cadmium is recognized to produce toxic effects on humans. Long-term occupational exposure can cause adverse health effects on the lungs and kidneys. Under normal conditions, adverse human health effects have not been encountered from general population exposure to cadmium. Cadmium mainly accumulates in one specific organ, the kidneys. At high levels it can reach a critical threshold and can lead to serious kidney failure. However, most recent studies have shown that these effects are reversible, at least at low exposures, once exposure to cadmium is reduced.

When people are exposed to it at levels above the MCL for relatively short periods of time, the EPA has found cadmium to potentially cause nausea, vomiting, diarrhea, muscle cramps, salivation, sensory disturbances, liver injury, convulsions, shock and renal failure. It also has the potential to cause the following effects from a lifetime exposure at levels above the MCL: kidney, liver, bone and blood damage. (Back to Table)

The highest levels of calcium have been observed in the groundwater sweep at 640,000 ug/L, in the pregnant solution at 420,000 and in down-gradient groundwater at 310,000. It is regularly use in processing of various ores. In the processing of sulfide ores at the mine site, calcium oxide, (lime), was added to solutions to maintain an alkaline Ph. These solutions were later discarded in evaporation ponds and tailings dumps.

The ATSDR has not established a "safe" level for calcium oxide. Symptoms of over-exposure include:

Calcium in various forms has been approved for use by the EPA in pesticides. Calcium is also an essential building block for bone and plant structure although, at the levels above, even moderate ingestion should turn anyone to stone. (Back to Table)

Chloride has been observed at the mine site at 1,000 mg/L in evaporation ponds. Chloride is found in combination with many elements, including copper and sulfur which were both present in great abundance at the Yerington site. Chloride is often associated with cadmium and cyanide. A slight smell of chlorine can be detected when present in water; indeed, chlorides in water usually dissipate into the air in fairly short period of time. Webster's defines "chloride" as a "compound in which chlorine is combined with any of certain other elements or with a radical."

Chlorides may be organic or inorganic. Organic chlorides contain the element carbon; inorganic chlorides may contain a metallic or a nonmetallic element. Most metals combine with chlorine by losing an electron to form chlorides known as salts. Chloride salts have high melting and boiling points and conduct electricity well when dissolved in water or melted. Chloride salts include sodium chloride, or common table salt, and silver chloride, which is used in photography. Nonmetallic elements and some metals form chlorides by sharing a pair of electrons with chlorine atoms. These chlorides have low melting and boiling points and react with water to form hydrochloric acid.

The health effects of chloride depend largely upon what they become associated with and should be studied with that thought in mind. Cadmium chloride, for instance, is definitely carcinogenic. Vinyl chloride, used in the manufacture of plastics, is very toxic. Copper chloride is the form of copper that is best suited for conducting electricity. (Back to Table)

Chromium was found at extremely high levels, (7,000 to 9,000 ug/L), in the evaporation ponds, groundwater seep, and pregnant solution. In down-gradient water in 1978, it was discovered at 400 ug/L. Chromium is a naturally occurring element found in rocks, animals, plants, soil, and in volcanic dust and gases. It is present in the environment in several different forms, the most common of which are chromium(0), chromium(III), and chromium(VI). No taste or odor is associated with chromium compounds. Chromium enters the air, water, and soil mostly in the chromium(III) and chromium(VI) forms.

Chromium is used to harden steel, manufacture stainless steel, and form many useful alloys. It is used in plating to produce a hard, beautiful surface and to prevent corrosion. Chromium gives glass an emerald green color and is widely used as a catalyst. In air, chromium compounds are present mostly as fine dust particles that eventually settle over land and water. Chromium can strongly attach to soil and only a small amount can dissolve in water and move deeper in the soil to underground water.

The metal chromium, which is the chromium(0) form, is used for making steel. Chromium(VI) and chromium(III) are used for chrome plating, dyes and pigments, leather tanning, and wood preserving. Chromium is an essential body nutrient, but elevated levels are dangerous to human health. It can enter the body by:

Breathing high levels of chromium(VI) can cause irritation to the nose, such as runny nose, nosebleeds, and ulcers and holes in the nasal septum. Ingesting large amounts of chromium(VI) can cause stomach upsets and ulcers, convulsions, kidney and liver damage, and even death. Skin contact with certain chromium(VI) compounds can cause skin ulcers. Some people are extremely sensitive to chromium(VI) or chromium(III). Allergic reactions consisting of severe redness and swelling of the skin have been noted. Several studies have shown that chromium(VI) compounds can increase the risk of lung cancer.

EPA has set a limit of 100 µg/L chromium(III) and chromium(VI) per liter of drinking water (100 µg/L). The Occupational Safety and Health Administration (OSHA) has set limits of 500 µg/L water soluble chromium(III) compounds per cubic meter of workplace air (500 µg/m³), 1,000 µg/m³ for metallic chromium(0) and insoluble chromium compounds, and 52 µg/m³ for chromium(VI) compounds for 8-hour work shifts and 40-hour work weeks. (Back to Table)

Cobalt was found at 7,400 ug/L in down-gradient groundwater, 47,000 ug/L in the groundwater seep, and 54,000 ug/L in the pregnant solutions. It was also detected at 28,000 ug/L in the evaporation ponds. Background measured in at 5 ug/L. Cobalt is a metal that may be stable (non-radioactive, as found in nature), or unstable (radioactive, man-made). The most common radioactive isotope of cobalt is cobalt-60, which is used in many medical and industrial applications. Cobalt is generally considered to be one of the more dangerous substances with respect to human health.

Small amounts of cobalt are naturally found in small amounts in most rocks, soil, water, plants, and animals. However, cobalt is usually found in the environment combined with other elements such as oxygen, sulfur, and arsenic. Cobalt is even found in water in dissolved or ionic form, typically in small amounts. A biochemically important cobalt compound is vitamin B₁₂ or cyanocobalamin. Vitamin B₁₂ is essential for good health in animals and humans.

Cobalt metal is usually mixed with other metals to form alloys, which are harder or more resistant to wear and corrosion. These alloys are used in a number of military and industrial applications such as aircraft engines, magnets, and grinding and cutting tools. They are also used in artificial hip and knee joints. Cobalt compounds are used as colorants in glass, ceramics, and paints, as catalysts, and as paint driers. Cobalt colorants have a characteristic blue color; however, not all cobalt compounds are blue.

The Environmental Protection Agency (EPA) identifies the most serious hazardous waste sites in the nation. These sites make up the National Priorities List (NPL) and are the sites targeted for long-term federal cleanup activities. Stable cobalt has been found in at least 426 of the 1,636 current or former NPL sites. If you are exposed to cobalt, many factors determine whether you'll be harmed. These factors include the dose (how much), the duration (how long), and how you come in contact with it.

Cobalt cannot be destroyed in the environment. You may be exposed to small amounts of cobalt by breathing air, drinking water, and eating food containing it. Children may also be exposed to cobalt by eating dirt. You may also be exposed by skin contact with soil, water, cobalt alloys, or other substances that contain cobalt. Soils near cobalt-containing mineral deposits, mining and smelting facilities, or industries manufacturing or using cobalt alloys or chemicals may contain much higher levels of cobalt. The concentration of cobalt in surface and groundwater in the United States is generally low-between 1 and 10 parts of cobalt in 1 billion parts of water (ppb) in populated areas; concentration may be hundreds or thousands times higher in areas that are rich in cobalt-containing minerals or in areas near mining or smelting operations. In most drinking water, cobalt levels are less than 1-2 ppb.

Cobalt can enter your body when you breathe in air containing cobalt dust, when you drink water that contains cobalt, when you eat food that contains cobalt, or when your skin touches materials that contain cobalt. If you breathe in air that contains cobalt dust, the amount of inhaled cobalt that stays in your lungs depends on the size of the dust particles. The amount that is then absorbed into your blood depends on how well the particles dissolve. If the particles dissolve easily, then it is easier for the cobalt to pass into your blood from the particles in your lungs. If the particles dissolve slowly, then they will remain in your lungs longer. Some of the particles will leave your lungs as they normally clean themselves out. Some of the particles will be swallowed into your stomach. The most likely way you will be exposed to excess cobalt is by eating contaminated food or drinking contaminated water.

Studies in animals suggest that exposure to high amounts of non-radioactive cobalt during pregnancy might affect the health of the developing fetus. Birth defects, however, have not been found in children born to mothers who were treated with cobalt for anemia during pregnancy. The doses of cobalt used in the animal studies were much higher than the amounts of cobalt to which humans would normally be exposed.

Non-radioactive cobalt has not been found to cause cancer in humans or in animals following exposure in the food or water. Cancer has been shown, however, in animals who breathed cobalt or when cobalt was placed directly into the muscle or under the skin. Based on the animal data, the International Agency for Research on Cancer (IARC) has determined that cobalt is possibly carcinogenic to humans. (Back to Table)

The YAMSite was at one time ranked as one of the major worldwide producers of copper. Although it is now virtually mined out, the methods used to mine and extract copper from the ore would naturally dictate that large quantities of it would be found in various areas at the site. Indeed, while normal background groundwater for copper is about 20 ug/L around the site, copper has been identified at:

Location	Measurement ug/L
Evap Pond	330,000
Down-gradient groundwater	150,000
Groundwater seep	25,000
Pregnant solution	3,000,000
Tailings	5,600
Tailings ponds	570
Leachite salts	71,000
Off-site leachite salts	83

The actual chemicals used in the electrowinning solution consist of kerosene, sulfuric acid and, often, cyanide. A process is usually used to recycle the solution to keep the cost of extraction down, but there comes a point where the solution must be discarded. It can be collected and transported off-site for a final extraction of copper and separation of the sulfuric acid from the kerosene, but it was not unusual for the mining operation to place the solution into an on-site pond that may, or may have not, been lined. In any event, it would not be unusual for the soil to be contaminated from the solution.

Metal finishing solutions are subjected to a variety of forces that cause them to become unusable. The key contributing factors are: (1) depletion of bath chemicals; (2) chemical break-down of process chemicals or chemical side reactions; (3) contamination from impurities in make-up water, chemicals or anodes; (4) anodic/cathodic etching of parts and inert electrodes; (5) corrosion of parts, racks, bussing, tanks, heating coils, etc.; (6) drag-in of non-compatible chemicals; (7) buildup of by-products (e.g., carbonates); (8) breakdown of maskant, fume suppressant and wetting agents; (9) errors in bath additions; and (10) airborne particles entering the tank.

Drinking or breathing fuel oils may cause nausea or nervous system effects. However, exposure under normal use conditions is not likely to be harmful. Little information is available about the health effects that may be caused by fuel oils. People who use kerosene stoves for cooking do not seem to have any health problems related to their exposure.

The International Agency for Research on Cancer (IARC) has determined that some fuel oils (heavy) may possibly cause cancer in humans, but for other fuel oils (light), there is not enough information to make a determination. IARC has also determined that occupational exposures to fuel oils during petroleum refining are probably carcinogenic in humans. Some studies with mice have suggested that repeated contact with fuel oils may cause liver or skin cancer. However, other mouse studies have found this not to be the case. No studies are available in other animals or in people on the carcinogenic effects of fuel oils.

Touching sulfuric acid will burn your skin, and breathing sulfuric acid can result in tooth erosion and respiratory tract irritation. Drinking sulfuric acid can burn your mouth, throat, and stomach; it can result in death. If you get sulfuric acid in your eyes, it will cause your eyes to water and will burn. People who have breathed large quantities of sulfuric acid at work have shown an increase in cancers of the larynx. However, most of the people were also smokers who were exposed to other chemicals and acids as well. The ability of sulfuric acid to cause cancer in laboratory animals has not been studied. The International Agency for Research on Cancer (IARC) has determined that occupational exposure to strong inorganic acid mists containing sulfuric acid is carcinogenic to humans. IARC has not classified pure sulfuric acid for its carcinogenic effects. (Back to Table)

Fluoride was found at 470 mg/L in the Evaporation Ponds, but at only 2.5 mg/L or less in other areas. The EPA requires treatment to reduce fluoride in water below 4.0. It has been widely hailed as a cavity preventative in human teeth; in the 1950's, there was a widespread dental practice have having significant amounts of it coated onto teeth by dentists.

Now, if course, we ask, "What about swallowing a little bit each day for the rest of your life? What about drinking it in your water? Is it safe?" Independent research studies have shown that fluoride has been directly linked to: kidney and bladder disorders; bone malformation; arthritis; skin disease; calcified deposits in the aorta; interference with thyroid function, causing hypothyroidism; and weakening of the immune system; damage to connective-tissue collagen, to ligaments, tendons, bones, arteries and DNA. However, there have been no studies as of January 2005 to determine the amounts of fluoride in off-site domestic water wells and it should also be note that there is active and naturally occurring geothermal activity in northern Mason Valley; such activity is known to add fluoride to ground water. (Back to Table)

Click here and you will be referred to the appropriate place on the webpage "Radioactivity"

Measurements taken in the fall of 2005 indicate that high levels of Gamma exist on the mine site in the Process Area, the old Truck Wash, and along tailings just north of the administrative building and on the same side of the road leading from Highway 95A to Weed Heights. Gammas are rays, not particles. From a human health standpoint, they are much more dangerous than alpha or beta particles.

Gamma rays can easily pass completely through the body or be absorbed by tissue, and they are therefore a radiation hazard for the entire body. Several feet of concrete and several inches of lead shielding may be required to contain more energetic gamma rays. Small amounts of gamma rays bombard our bodies constantly, primarily from naturally occurring radioactive materials in rocks and soil. Some gamma rays enter our bodies in the air we breathe, the food we eat, and the water we drink. Gamma rays passing through the body produce ionization in tissue. This process can harm the body's cells. Gamma rays can also be of benefit. They are helpful in destroying some types of cancers and tumors. They are also used to inspect metal for flaws and to preserve foods. (Back to Table)

Iron is one of those elements found virtually everywhere and is an essential ingredient to life. The lowest levels found on the site were 50 ug/L in the tailings. Measurements went as high as 30,000,000 in 1978 in the evaporation ponds. Although ATSDR has no toxilogical facts regarding iron, it could be presumed that any significant intake of iron at 30,000,000 ug/L would at least give a humanoid a very magnetic personality.

Iron can be found in abundance near geothermal activity. It is credited with staining sinks and commodes in an ugly "brown-rust" color. (Back to Table)

Kerosene is a petroleum product that was used extensively in lamps until the discovery and spread of electricity. It is currently used in jet aircraft engines and as a solvent. See Electrowinning Processing and Solutions

Lead has generally been detected in relatively low amounts in various areas of the YAM Site. However, it was detected in 1978 at 3,000 ug/L in evaporation ponds and at 44,000 mg/kg in leachite salts. A heavy, bluish-gray element in its natural form, lead is one of the world's oldest known metals. People have used lead for thousands of years as a building material and to make pottery and other objects. Today, lead is important to many industries, especially to those that produce chemicals, nuclear energy, and petroleum. Unfortunately, it was not really understood until the latter part of the 20th Century that lead is also toxic to humans, which is why lead is no longer added to gasoline in the United States.

The largest single use of lead is in the manufacture of lead-acid storage batteries. These batteries contain pure lead and lead compounds, and certain parts of them are made of a lead-antimony alloy. Storage batteries provide power for the electrical systems of airplanes, automobiles, and many other vehicles. Batteries must be properly destroyed to prevent environmental pollution; usually, old batteries are stripped of their lead, which is recycled.

Pure lead is soft and has little strength. Lead producers often alloy (mix) it with small amounts of other metals to form lead alloys. The added metals, such as antimony and tin, increase the strength of lead and give it other properties. Lead also combines chemically with chlorine, oxygen, and other elements to form various compounds.

Exposure to lead can happen from breathing, eating contaminated foods or drinking contaminated water. Children can be exposed from eating lead-based paint chips or playing in contaminated soil. Lead can damage the nervous system, kidneys, and reproductive system. Lead has been found in at least 1,026 of 1,467 National Priorities List sites identified by the Environmental Protection Agency (EPA). At high levels, lead may decrease reaction time, cause weakness in fingers, wrists, or ankles, and possibly affect the memory. Lead may cause anemia, a disorder of the blood. It can also damage the male reproductive system.

The CDC recommends that children ages 1 and 2 be screened for lead poisoning. Children who are 3 to 6 years old should be tested for lead if they have never been tested for lead before and if they receive services from public assistance programs; if they live in or regularly visit a building built before 1950; if they live in or visit a home built before 1978 that is being remodeled; or if they have a brother, sister, or playmate who has had lead poisoning. CDC considers children to have an elevated level of lead if the amount in the blood is 10 µg/L. Contrary to popular myth, "lead" pencils do not contain lead, but do contain graphite.

The EPA requires lead in air not to exceed 1.5 micrograms per cubic meter (1.5 µg/m³) averaged over 3 months. EPA limits lead in drinking water to 15 µg per liter. Although lead has recently been detected in off-site groundwater, comprehensive studies of groundwater to the north of the Yerington Anaconda Mine with respect to potential contaminants will probably not get under way until after additional off-site monitoring wells are installed, sometime in late 2005. (Back to Table)

Not to be confused with Manganese, magnesium was found at 800 ug/L in tailings ponds and 22,000,000 ug/L in the pregnant solutions. Magnesium plays a vital role in the life processes of plants and animals. Chlorophyll, which green plants use in photosynthesis, contains magnesium. Plants produce carbohydrates, a class of foods essential to living things, by means of photosynthesis. Magnesium also takes part in the duplication of substances called DNA and RNA, which have a key part in determining the heredity of all organisms.

Magnesium plays a vital role in the life processes of plants and animals. Chlorophyll, which green plants use in photosynthesis, contains magnesium. Plants produce carbohydrates, a class of foods essential to living things, by means of photosynthesis. Magnesium also takes part in the duplication of substances called DNA and RNA, which have a key part in determining the heredity of all organisms. Together, boron, calcium, magnesium, and vitamin D help to prevent osteoporosis. Magnesium is used for a variety of nonstructural purposes because it is extremely active chemically. For example, pieces of magnesium are placed next to buried steel pipelines and water tanks. If magnesium were not present, oxygen and other chemicals in the earth would corrode the steel.

Although burning magnesium and the use of magnesium in powder form have their dangers, there is no evidence to show that the magnesium found at the Yerington mine poses any danger to public health in its present form. (Back to Table)

From a high of 620,000 ug/L in the Groundwater Seep to 420,000 in the evaporation ponds, we have some undefined concerns with manganese. The background level appears to be approximately 10 to 20 ug/L. Manganese, pronounced MANG guh neez, is a brittle, silver-gray metallic element. All plants and animals require small amounts of it. Manganese is also an important substance in steel and has many other industrial uses. Manganese is plentiful in the earth's crust. In human beings and other animals, a lack of manganese disrupts growth and results in disorders of the bones and central nervous system. A diet that includes beans, nuts, green leafy vegetables, or whole grain and cereals provides adequate amounts of manganese.

Impotence and loss of libido have been noted in male workers afflicted with manganism. Impaired brain function may be related to high levels of manganese. There is no research available with which to quantify risks associated with cancer or other serious health problems as of December 2003.

EPA has established a Reference Dose for manganese of 0.14 milligrams per kilogram body weight per day (mg/kg/d) based on CNS effects in humans. This is estimated to be an intake for the general population that is not associated with adverse health effects; and this is not meant to imply that higher are necessarily associated with toxicity. Some individuals may, in fact, consume a diet that contributes more than 10 mg/day without any cause for concern. (Back to Table)

In years gone by, mercury was used in thermometers. It was also readily available for scientific experiments in elementary and secondary schools, and it was not uncommon to see a youngster possessing a vial of mercury from which shinny coatings of coins could be made. The Yerington site showed levels at 5.2 ug/l in tailing seepings in 1978. What does this mean?

Artificially high levels of mercury in the bloodstream of unborn babies and young children may harm the developing nervous system. Whether an exposure to mercury will harm a person's health depends on a number of factors. Almost all people have at least trace amounts of mercury in their tissues, reflecting mercury’s widespread presence in the environment. Mercury has been associated with neurological problems in humans and may be a carcinogen.

Anyone who has concerns about mercury exposure should consult a doctor. Doctors may be able to identify exposure and health risks by measuring the amounts of mercury in blood, urine, breast milk, finger and toenails, and hair. Over time, the body can rid itself of some mercury. Methylmercury is removed from the body naturally, but it may take months to a year for the levels to drop significantly.

The MCLG for mercury has been set at 2 parts per billion (ppb) because EPA believes this level of protection would not cause any significant health problems. This level has been established by EPA because EPA believes, given present technology and resources, this is the lowest level to which water systems can reasonably be required to remove this contaminant should it occur in drinking water. These standards are called National Primary Drinking Water Regulations. All public water supplies must abide by these regulations.

Due to elevated levels of mercury, people are advised to refrain from consuming fish from the Carson River. In 2004, relatively small containers of mercury caused panic and school closures in Douglas County. Nevertheless, as of February 2005, there is no scientific evidence to suggest that the levels of mercury present at the Yerington Anaconda Mine Site are dangerous to human health. (Back to Table)

Molybdenum is a refractory metallic element used principally as an alloying agent in steel, cast iron, and super alloys to enhance hardness, strength, toughness, and wear and corrosion resistance. Its high melting point, which is 2617 °C, makes it one of the strongest and most commonly used heat-resistant metals. To achieve desired metallurgical properties, molybdenum, primarily in the form of molybdic oxide or ferromolybdenum, is frequently used in combination with or added to chromium, columbium (niobium), manganese, nickel, tungsten, or other alloy metals. Molybdenum finds significant usage as a refractory metal in numerous chemical applications, including catalysts, lubricants, and pigments. It was ascertained at 500 ug/L in the site evaporation ponds in a study released in 1978.

Although no MCL has been established for molybdenum, elevated levels have been associated with high levels of uric acid in the bloodstream. High levels of uric acid, left untreated, causes gout, which is an extremely painful affliction of the joints, (usually a big toe). (Back to Table)

The presence of nickel has been ascertained at 2 ug/L in tailings ponds and 30,000 ug/L in the groundwater seep. The down gradient groundwater measured 5,400 ug/L in 1978. Nickel is common in the environment and can be hammered into thin sheets or drawn into wires. One pound (0.4 kilogram) of pure nickel could be drawn into a wire 80 miles (130 kilometers) long. The Chinese used an alloy of nickel more than 2,000 years ago. Nickel is used in structural work and in electroplating chiefly because it resists corrosion. It is also commonly used in nickel cadmium batteries as well as a multitude of other applications.

Skin effects, (rashes), are the most common effects in people who are sensitive to nickel. Workers who breathe very large amounts of nickel compounds develop chronic bronchitis and lung and nasal sinus cancers. Ingesting large amounts of nickel affects the reproduction and development in rats and mice. People working in nickel refineries or nickel-processing plants have experienced chronic bronchitis and reduced lung function, (These persons breathed amounts of nickel much higher than levels found in the environment). Workers who drank water containing high amounts of nickel had stomach aches and suffered adverse effects to their blood and kidneys. Nickel has been found in at least 862 of the 1,636 National Priority List sites identified by the Environmental Protection Agency (EPA).

Nickel is a known carcinogen. It is not known whether children differ from adults in susceptibility to nickel. Although human studies that examined whether nickel can harm the fetus are inconclusive, animal studies have found increases in newborn deaths and decreased newborn weight after ingesting very high amounts of nickel. Nickel can be transferred from the mother to an infant in breast milk and can cross the placenta.

The EPA recommends that drinking water should contain no more than 0.7 milligrams of nickel per liter of water (0.7 mg/L). To protect workers, the Occupational Safety and Health Administration (OSHA) has set a limit of 1 mg of nickel per cubic meter of air (1 mg/m³) for metallic nickel and nickel compounds in workplace air during an 8-hour workday, 40-hour workweek (Back to Table)

Nitrate is any kind of compound that contains the inorganic nitrate ion. Nitric acid is a nitrate. Most metals form nitrate salts when combined with nitric acid. In nature, there are relatively few nitrate minerals. Two important nitrates, potassium nitrate and ammonium nitrate, are used as fertilizers to replenish nitrogen in the soil. Such materials were removed from the Yerington site for farming use in the Mason Valley; it is not known whether or not those materials also contained elevated uranium, (tenorm), or other contaminants.

Bacteria in the soil form nitrates from organic compounds containing nitrogen. A major source of nitrates is septic tanks and septic drainage fields. When measured levels in domestic wells exceed standards, it is usually necessary to install water processing and purification plants to supply water. Plants use nitrates to make proteins. Nitrates can also form in the atmosphere. There, nitrogen oxide may combine with water to produce nitric acid, a part of the pollutant acid rain. Nitrates are also used in explosives, fireworks, heart medicine, and photographic films. People take in nitrates daily, primarily from vegetables. Consuming large amounts of nitrates can help produce toxic substances in the body. The "Blue Baby Syndrome" can be produced in infants under six months.

There is no extensive analysis of nitrates associated with mining operations as of December 2003. Nitrate was measured at 17 in Domestic Well 1, (DW-1), in a 1983 study by Applied Hydrology. DW-1 is located west of 21 Luzier Street in Yerington. Other wells tested in 1983 and later in 1999 show moderate to low levels of nitrates. Due to the extensive farming in the areas north of the mine and due to the presence of numerous septic tanks and fields, no association can be made between mining operations and nitrates in domestic wells at this time. Residents are advised to have their domestic wells tested for bacteria and nitrates at least once a year. (Back to Table)

Potassium was found in the pregnant solutions at 140,000 ug/L, the groundwater seep at 50,000 and down gradient groundwater at 26,000. It was also found in off-site leachite salts at 5,000 mg/kg. Potassium is a relatively abundant element and makes up nearly 2-1/2 percent of the earth's crust. Large deposits of its principal compounds, including potassium chloride and potassium sulfate, occur in parts of Canada and Germany. The Dead Sea is another major source of potassium compounds.

Plants require potassium for growth. Soil must contain potassium compounds to produce crops of high quality and yield. Potassium chloride is widely used in commercial fertilizers for most crops. But potassium sulfate is a better fertilizer for tobacco and crops that would be harmed by chloride. Such material was removed from the Yerington Anaconda Mine for use by local farmers, and it is not known if that material contained other contaminants found at the site, such as uranium.

Potassium also is essential for human beings and other animals; it plays a part in metabolism, the process by which organisms change food into energy and new tissue. Potassium balances the acid/alkaline system, transmits electrical signals between nerves and cells, aids in the regulation of the body's water balance and is essential for efficient muscle contraction. A deficiency may cause severe dehydration. Potassium functions to maintain the normal acid-base (pH) balance in the blood and tissues. A deficiency has been linked to rheumatoid arthritis.

Potassium forms an alloy with sodium that is used as a heat transfer medium in some types of nuclear reactors. Potassium chloride is the most common potassium compound. It is used in fertilizers, as a salt substitute and to produce other chemicals. Potassium hydroxide is used to make soaps, detergents and drain cleaners. Potassium carbonate is used to make some types of glass and soaps and is obtained commercially as a byproduct of the production of ammonia. Potassium super oxide can create oxygen from water vapor and carbon dioxide. It is used in respiratory equipment and is produced by burning potassium metal in dry air. Potassium nitrate also known as saltpeter or nitre, is used in fertilizers, match heads and pyrotechnics.

Potassium cyanide is an extremely poisonous white compound used in the extraction of gold and silver from ores, in electroplating, and in photography, and as a fumigant and insecticide. Potassium chloride has been associated with acute poisoning in humans. However, there is insufficient data available upon which to establish upper "safe" levels of potassium. While potassium itself does not appear to be carcinogenic, some compounds are. (Back to Table)

Seriously elevated levels of radiation were discovered in an on-site evaporation pond in 2004. High levels of radiation were also discovered in the soils in areas that were used for processing the ores and cleaning mining trucks and equipment, as well as the vat-leach areas. In January of 2005, radiation warning signs were installed on the perimeter fences and in February, some locations near the process work areas were roped off. Workers evaluating the site are wearing protective clothing and being monitored for radiation exposure.

Although there is a radioactive danger associated with many areas of the site, no health assessment or study has been undertaken to evaluate possible adverse effects on former employees of the operating companies. Access to the site was extremely curtailed in late 2004 and is now limited to those who are adequately protected and have legitimate reason to be there.

Former employees who suspect that they may have suffered adverse health affects should contact their physicians. At some point in the future, this website may be expanded to serve as a registry for people who suspect that their health has been impacted by activities at the Yerington Anaconda Mine. (Back to Table)

Those individuals interested in a further, in-depth study of radionuclides are referred to www.nuclides.net

The isotopes of radioactive elements are called radionuclides or radioisotopes. While there are hundreds of radionuclides, many of them are rarely encountered. People are much more likely to encounter a few that are used routinely for medical, military, or commercial purposes. The list below includes twelve radionuclides. They are the ones most commonly used and most commonly found in Superfund Sites:

(Italicized radionuclides have been discovered at or associated with the Yerington mine site) (Back to Table)

Refer to Radium 226, above. Under normal conditions, there is almost no danger of absorbing hazardous amounts of radium because it occurs in such tiny quantities in the environment.

Radium originates from the radioactive decay of uranium and thorium. Radium-226 is found in the uranium-238 decay series, and radium-228 and -224 are found in the thorium-232 decay series. Radium-228 is principally a beta emitter and has a half-life of 5.76 years.

Long-term exposure to radium increases the risk of developing several diseases. Inhaled or ingested radium increases the risk of developing such diseases as lymphoma, bone cancer, and diseases that affect the formation of blood, such as leukemia and aplastic anemia. These effects usually take years to develop. External exposure to radium's gamma radiation increases the risk of cancer to varying degrees in all tissues and organs. (Back to Table)

Radon is a radioactive chemical element that occurs naturally as a gas that is produced by the radioactive decay (breakdown) of radium. Radon gas is colorless and odorless. Radon gas may become a health hazard in certain buildings. The main sources of radon in buildings are the soil and rocks beneath basements. Tailings from the Yerington Mine were used throughout the area as fill material for building lots, parking lots, and roadways. Many houses on the Yerington Paiute Reservation have tested at high levels of radon. For information on how to test for radon, contact the Yerington Paiute Tribal Environmental Offices at (775) 463-7866.

Minor sources of radon include water that comes from wells and building materials such as granite and gypsum that come from the ground. Some areas have a high concentration in the ground. The gas seeps from soil and rocks into water and air. Radon may enter a basement through cracks or other openings. If the building is in a high-radon area, the gas may build up inside to an unhealthy level.

Radon atoms decay by giving off a form of radiation called an alpha particle. Samples of domestic wells taken late in 2004 in areas north of the YAMsite indicate increasing levels of alpha, beta and gamma readings. For this reason, there is some concern that radon gas may be in the groundwater. Up until March of 2005, there have been no tests for the presence of radon in the domestic wells.

Alpha particles released by radon and its daughters in the body disrupt the normal genetic or chemical processes of living cells, causing cells to grow abnormally or to die. Over time, such cell damage may lead to cancer. During the 1960's and 1970's, studies of uranium miners who breathed large amounts of radon in the air of mines, showed unusually high rates of lung cancer. Smokers who are exposed to high radon levels are also at increased risk. The United States Environmental Protection Agency (EPA) estimates that radon may cause as many as 10 percent of cancer deaths in the country. (Back to Table)

Selenium most often occurs in nature combined with such metals as copper, lead, and silver. Human beings and other animals require tiny amounts of selenium in their diet to help the body convert fats and protein into energy. Foods that supply selenium include meat and fish.

Very high level exposures of selenium have resulted in dizziness, fatigue, irritation, collection of fluid in the lungs, and severe bronchitis. The exact levels at which these effects occur are not known. Upon contact with skin, selenium compounds have caused rashes, swelling, and pain. It is known that selenium compounds can be harmful at daily dietary levels 5–10 times higher than the daily requirement. Accidentally swallowing a large amount of selenium could be life-threatening without immediate medical treatment. When too much selenium is eaten over long periods of time, brittle hair and deformed nails can result. People could also lose feeling and control in the arms and legs. Very high amounts of selenium caused reproductive effects in rats and monkeys, but it is not known if reproductive effects would occur in humans exposed to similar levels. Exposure to high levels has caused malformations in birds but, as of this writing, it has not been shown to cause birth defects in humans or in other mammals.

According to the ATSDR, the Department of Health and Human Services has determined that selenium sulfide is reasonably anticipated to be a carcinogen. This compound has produced liver tumors in rats and mice and lung tumors in mice fed daily at very high levels. Selenium sulfide is very different from the selenium compounds found in foods and in the environment. Selenium sulfide has not caused cancer in animals when it is placed on the skin, and the use of anti-dandruff shampoos containing selenium sulfide is considered safe. It should be noted that both sulfur and selenium are present at the site in large quantities.

The EPA maximum contaminant level (MCL) for selenium in drinking water is 50 parts of selenium per billion parts of water (50 ppb). Selenium has been detected at 100 ug/L in down gradient groundwater, 1,000 in the groundwater seep, and at significantly high risk levels, (unquantified), in the pit lake water. (Back to Table)

Sodium is the 6th most common chemical element in the earth's crust. Sodium never occurs pure--that is, as a separate element--in nature, but combines with many other elements and forms compounds. A very familiar sodium compound is sodium chloride, (common table salt.)

Humans require a certain level of sodium to maintain a normal flow of water between the body fluids and the cells. Sodium also plays a part in tissue formation and muscle contraction. Many studies show that foods in a balanced diet contain enough sodium for the body's normal needs, without the addition of table salt. In fact, it is commonly accepted that too much sodium in a person's diet can lead to high blood pressure.

The concentration of salts, including sodium, increases in water and other fluids during the evaporation process. Since evaporation was one method of getting rid of many fluids used at the mine site, it is not unnatural that elevated levels of sodium would be present in certain mine site areas. In the evaporation ponds, it was measured at 2,100 mg/L. Groundwater background was determined to be 90,000 ug/L, but it was discovered at 290,000 ug/L in down gradient groundwater, 1,800,000 ug/L in the groundwater seep, and 2,100,000 ug/L in the pregnant solutions. For information on sodium sulfates, see the next topic. (Back to Table)

When a base completely neutralizes an acid, it results in what is defined as a normal salt. Sodium sulfate, also called Glauber's salt, is a normal salt. Anhydrous sodium sulfate is found in nature as the mineral thenardite. It is obtained (with other chemicals) by evaporation of natural brines. The principal use of sodium sulfate is in processing wood pulp for making kraft paper. It is also used in glass manufacture, textile dyeing, and synthetic detergents. Sodium Sulfates are non-carcinogenic. Sulfates of various types were found on the mine site, principally in evaporation ponds where they could be expected as a neutral result of the evaporation process. (Back to Table)

At the Leviathin Mine south of Gardnerville and north of Holbrook Junction in Nevada, sulfur was mined and shipped to the Yerington Mine Site for conversion into sulfuric acid for use in the extraction of copper from ore. Sulfur is used in a wide variety of products and industrial processes. Plants and animals need small amounts of sulfur to live.

Sulfuric acid is the world's most important commercial chemical. Manufacturers use sulfuric acid to make such products as dyes, paints, paper, textiles, and a number of industrial chemicals. The compound is also used in the production of metals and in petroleum refining.
Sulfuric acid is a clear, colorless, oily liquid that is very corrosive. It is used in the manufacture of fertilizers, explosives, other acids, and glue, as well as in lead-acid batteries, (used in most vehicles).

Touching sulfuric acid will burn the skin; breathing sulfuric acid can result in tooth erosion and respiratory tract irritation. Drinking sulfuric acid can burn your mouth, throat, and stomach and can result in death. People who have breathed large quantities of sulfuric acid at work have shown an increase in cancers of the larynx but, most of the people were also smokers.

The many chemicals and electrowinning solutions used at the Yerington mine were left as they were when Arimetco abandoned the site. They remained in ponds, pipelines and vats, and were not removed until the Spring of 2003. Sulfuric acid, per se, no longer exists at the site, but acid levels are elevated in associated groundwater. (Back to Table)

According to the EPA, "The MCLG for thallium has been set at 0.5 parts per billion (ppb) because EPA believes this level of protection would not cause any of the potential health problems...." Based on this MCLG, "EPA has set an enforceable standard called a Maximum Contaminant Level (MCL). MCLs are set as close to the MCLGs as possible, considering the ability of public water systems to detect and remove contaminants using suitable treatment technologies. The MCL has been set at 2 ppb because EPA believes, given present technology and resources, this is the lowest level to which water systems can reasonably be required to remove this contaminant should it occur in drinking water." Thallium was detected at the site at 5 ppb as background in the groundwater, but at 20 in down gradient groundwater, and at 200 in the groundwater seep and pregnant solutions. It is at about 100 ppb in tailings and ponds.

Thallium is quite toxic to human beings. Its toxic effects are cumulative--that is, they build up over an extended period of time. Too much exposure to thallium may cause nerve damage, emotional change, cramps and convulsions, and eventually coma and death due to respiratory paralysis. In the long term, exposure to thallium causes changes in blood chemistry; damage to liver, kidney, intestinal and testicular tissues; and hair loss.

Thallium and its compounds have various uses, limited due to the chemical's highly toxic nature. A radioactive isotope of the element, Tl-201, is useful for diagnosing certain types of heart disease. The compound thallium sulfate is widely used in ant and rat poisons. (Back to Table)

Thorium is a radioactive substance that occurs naturally in the environment. It has been shown to cause an increase in cancers of the lung, pancreas, and blood in workers exposed to high levels of it in the air. Uranium and thorium have both been found at the mine site and in groundwater in very elevated levels that continue to be evaluated as of April 2005. Radon is also present in elevated amounts in buildings and homes built on foundations where mine tailings were used as fill material.

The uranium series begins with uranium 238, the heaviest isotope of uranium, which has 92 protons and 146 neutrons. In the decay process and after losing an alpha particle, the nucleus has 90 protons and 144 neutrons. It is no longer uranium but a radioactive isotope of thorium. The thorium, in turn, breaks down in several steps to radium 226. The radium 226 decays into radon, a naturally occurring radioactive gas. Radon may become a health hazard if it accumulates in certain buildings, especially poorly ventilated ones. The series continues until the isotope becomes a stable form of lead.

Thorium has been shown to cause an increase in cancers of the lung, pancreas, and blood in workers exposed to high levels of it in the air. People who had large amounts of thorium injected into their blood for special x-ray tests had more than the usual number of liver tumors, cancers of the blood, such as leukemia, and tumors of the bone, kidney, spleen, and pancreas. Thorium is used to make ceramics, gas lantern mantles, and metals used in the aerospace industry and in nuclear reactions. Thorium can also be used as a fuel for generating nuclear energy. (Back to Table)

Tungsten has been found in high amounts in the Fallon, Nevada area during an investigation into the causes of a "leukemia cluster" among children residing in, or formerly residing in, that area. It was dismissed as being causal after the investigation results were posted in late 2003 but, further analysis results released in early 2005 have placed tungsten firmly back on the suspect list. During that investigative process, three other locales including Yerington, Pahrump and Lovelock in Nevada were also sampled, and a comparison was also made to Sierra Vista in Arizona. The conclusion was that tungsten is not elevated in sufficient amounts in the Yerington area to be of any concern. Studies of the Yerington Anaconda Mine site available as of April 2005 do not list tungsten as an item that has been researched.

However, it was also noted that tungsten does exist in elevated amounts in the East Walker River that runs through the Mason Valley and that Yerington participants were excreting tungsten in the urine in amounts second only to Fallon in the survey. All three Nevada cities used in the study ranked above the 95th percentile in tungsten in urine in the U.S. www.cdc.gov/nceh/clusters/Fallon/tungsten_report.pdf

Tungsten is a naturally occurring element that, in most environments, is a solid. In nature, it occurs in rocks and soil as minerals, but never as the pure metal. As an element, tungsten can be neither created nor destroyed chemically, although tungsten can change forms in the environment. Tungsten has many uses. It has the highest melting point of all metals, and remains strong at very high temperatures. For these reasons, it is used in equipment that must withstand high temperatures. Tungsten is added to steel to make steel harder, stronger, and more elastic. Tungsten steel tools last longer than ordinary steel tools. Tungsten and carbon form tungsten carbide, an extremely hard substance used in the tips of high-speed cutting tools, and in mining and petroleum drills.

It should be noted that there are high levels of other elements at the mine site and in the Mason Valley and studies to evaluate how tungsten might react with those elements in the environment and in human tissues have not yet been undertaken. It should also be noted that, since tungsten is naturally occurring in so many places and ores, that it would not be out of the ordinary to discover elevated levels of tungsten in various process areas of the mine site. (April 2005) (Back to Table)

There are volumes and volumes of information available on uranium at the CDC, ATSDR, and USEPA websites. What appears here is a condensation.

Uranium is not a stranger to copper mining operations. Although there were verbal denials that uranium existed at the Yerington site, documented evidence was discovered in mine archives at the University of Wyoming in Laramie in the summer of 2003. That evidence reflected that, not only was uranium at the Yerington mine, but it was also available in sufficient amounts that Anaconda ran tests in 1976 to determine if it would be economically feasible to extract uranium as part of the mining process. In fact, yellowcake was produced at least once at the mine site and it is appears that the material was dumped in evaporation ponds on the northwest portion of the site. Anaconda, probably due to a declining market for uranium at the time, elected not to produce uranium as part of its operations.

A 1978 USGS study, release several years later, showed that uranium was present in the evaporation ponds and that various heavy metals had made their way into the groundwater below the site. The list of metals in the evaporation ponds was completely identical to the list found in the groundwater, except that uranium was not listed in the groundwater. Hydrologists and environmental personnel have, however, indicated to this website that it would be highly unlikely for uranium to be left behind in the migration from the evaporation ponds to the groundwater.

That, and subsequent studies, confirmed that a groundwater plume is traveling to the north of the mine site. Groundwater is known to travel in a general northerly direction from the site to the northern part of the Mason Valley, where it veers east. Elevated levels of uranium were detected in domestic wells north of the mine site in 2004.

A chunk of uranium the size of a softball can release more energy than a trainload of coal that weighs 3 million times as much. Uranium also produces the tremendous explosions in nuclear weapons. It was discovered in rich amounts in Arizona and New Mexico on the Navajo Reservation in the 1940's and countless Navajos who worked the mines in the '40's and '50's died later of lung cancer.

All isotopes of uranium are radioactive. The three natural uranium isotopes found in the environment, U-234, U-235, and U-238, undergo radioactive decay by emission of an alpha particle accompanied by weak gamma radiation. The dominant isotope, U-238, forms a long series of decay products that includes the key radionuclides radium-226, and radon-222. The decay process continues until a stable, non-radioactive decay product is formed. The release of radiation during the decay process raises many health concerns.

Because uranium has been discovered in elevated amounts in the area north of the mine site, affected residents are being provided with free bottled water by ARCo. All persons who live north or northeast of the mine site, as far as the Churchill Power Station, are urged by the webmaster to have their wells tested for uranium content, (contact USEPA for details). Domestic wells on the Yerington Paiute Reservation north of Campbell Lane have tested well above MCL's for uranium content. As of this date, no domestic wells north of the reservation have been tested, so it is not known how far the contamination may have spread. (April 2005) (Back to Table)

Vanadium is generally found in extremely small amounts in nature; trace amounts of vanadium also have been found in meteorites. But, at the Yerington Anaconda Mine site, vanadium was discovered in the groundwater seep at 120,000 ug/L, in down gradient groundwater at 14,000 ug/L, and in the pregnant solutions at 61,000 ug/L.

Vanadium is used chiefly by steel manufacturers, who produce it in the form of an iron alloy called ferrovanadium. Vanadium strengthens steel by improving both its hardness at high temperatures and its ability to withstand shock. It also makes steel resistant to corrosion. Manufacturers use this strong, rust-resistant alloy steel in producing axles, gears, and springs for airplanes, automobiles, and locomotives. High-speed cutting tools also are made of alloy steel containing vanadium. Vanadium resists attack by many chemicals, but it allows neutrons to penetrate readily. These properties make the metal suitable for use in nuclear reactors.

Exposure to high levels of vanadium can cause harmful human health effects. Breathing high levels of vanadium affects the lungs, throat, and eyes. Workers who breathed it sometimes have lung irritation, coughing, wheezing, chest pain, runny nose, and a sore throat. These effects stop soon after quitting breathing of contaminated air. No other significant health effects of vanadium have been found in people. Animals that have ingested very large doses have died. Lower, but still high levels of vanadium in the water of pregnant animals resulted in minor birth defects. Some animals that breathed or ingested vanadium over a long term had minor kidney and liver changes.

The National Institute for Occupational Safety and Health (NIOSH) recommends that 35 mg/m³ of vanadium is considered to be immediately dangerous to life and health. There is no evidence as of April 2005 that vanadium is carcinogenic. (Back to Table)

Exposure to large amounts of zinc can be harmful. It can cause stomach cramps, anemia, and changes in cholesterol levels. Zinc has been found in at least 953 of the 1,636 National Priority List sites identified by the Environmental Protection Agency (EPA). At the Yerington site, zinc has been measured at 56,000 ug/L in evaporation ponds, 14,000 in down-gradient groundwater, 61,000 in the pregnant solutions, and 120,000 in the groundwater seep. There is, as of April 2005, no MCL standard listed for drinking water by EPA.

Zinc is never found in a pure state in nature. It is one of the most common elements in the earth's crust and is found in air, soil, and water, and is present in all foods. Zinc has many commercial uses as coatings to prevent rust, in dry cell batteries, and as a mixer with other metals to make alloys like brass, and bronze. A zinc and copper alloy is used to make pennies in the United States. In Germany, a zinc is used to wash dishes.

There has been no determination as to whether or not excess zinc causes cancer. Harmful effects generally begin at levels 10-15 times higher than the amount needed for good health. In addition to the above, it can cause anemia and decrease the levels of good cholesterol. It is not known if high levels of zinc affect reproduction in humans, but rats fed large amounts of zinc became infertile. Inhaling large amounts of zinc (as dusts or fumes) can cause a specific short-term disease called metal fume fever. Putting low levels of certain zinc compounds on the skin of rabbits, guinea pigs, and mice caused skin irritation. Skin irritation will probably occur in people. (Back to Table)