Mercury United States

Major producers of mercury include the former Soviet Union, Spain, Yugoslavia, and Italy (USPHS 1994). In the United States, mercury consumption rose from 1305 metric tons in 1959 to 2359 tons in 1969 (Table 5.1). The major use of mercury has been as a cathode in the electrolytic... 

According to the U.S. Geological Survey (USGS), as of 2008, the world s primary mercury resources can be found in Ghina, Krygyzstan, Russia, Slovenia, Spain, and Ukraine. In the United States, mercury is found in states such as Alaska, Arkansas, Galifornia, Nevada, and Texas. 

Three forms of caustic soda are produced to meet customer needs purified diaphragm caustic (50% Rayon grade), 73% caustic, and anhydrous caustic. Regular 50% caustic from the diaphragm cell process is suitable for most appHcations and accounts for about 85% of the NaOH consumed in the United States. However, it caimot be used in operations such as the manufacture of rayon, the synthesis of alkyl aryl sulfonates, or the production of anhydrous caustic because of the presence of salt, sodium chlorate, and heavy metals. Membrane and mercury cell caustic, on the other hand, is of superior quaUty and... 

Mercury(II) fluoride has been used in the process for manufacture of fluoride glass (qv) for fiber optics (qv) appHcations (11) and in photochemical selective fluorination of organic substrates (12). It is available from Advance Research Chemicals, Aldrich Chemicals, Johnson/Matthey, Aesar, Cerac, Strem, and PCR in the United States. The 1993 annual consumption was less than 50 kg the price was 800—1000/kg. 

Chlor—alkah production is the largest iadustrial source of mercury release ia the United States (see Alkali and chlorine products). For the 1991 reporting year, chlor—alkah faciUties accounted for almost 20% of the faciUties that reported releases of mercury to the U.S. Environmental Protection Agency (EPA) for inclusion onto the Toxics Release Inventory (TRI) (25). 

Regulations. In order to decrease the amount of anthropogenic release of mercury in the United States, the EPA has limited both use and disposal of mercury. In 1992, the EPA banned land disposal of high mercury content wastes generated from the electrolytic production of chlorine—caustic soda (14), accompanied by a one-year variance owing to a lack of available waste treatment faciUties in the United States. A thermal treatment process meeting EPA standards for these wastes was developed by 1993. The use of mercury and mercury compounds as biocides in agricultural products and paints has also been banned by the EPA. 

California and Minnesota have placed restrictions on the disposal of fluorescent light tubes, which contain from 40—50 mg of mercury per tube, depending on size. After batteries, fluorescent lamps are the second largest contributor of mercury in soHd waste streams in the United States (3,14). A California law classifies the disposal of 25 or more fluorescent lamp tubes as hazardous waste. In Minnesota, all waste lamps generated from commercial sources are considered hazardous waste. Private homes are, however, exempt from the law (14). Other states have proposed similar regulations. Several companies have developed technologies for recovering mercury from spent lamps (14). 

A goal of reducing total mercury releases in the United States by 33% between 1988 to 1992, and 50% by 1995 was set by the EPA. The 1992 goal was more than achieved United States reportable mercury releases were reduced by 39% by 1991 (26). In the United States, discards of mercury in municipal soHd waste streams were approximately 643 t in 1989 (3). As a result of increased restrictions on the use and disposal of mercury, by the year 2000 mercury in municipal soHd waste streams is expected to be about 160 t (3). 

Exposure. The exposure of humans and animals to mercury from the general environment occurs mainly by inhalation and ingestion of terrestrial and aquatic food chain items. Pish generally rank the highest (10—300 ng/g) in food chain concentrations of mercury. Swordfish and pike may frequently exceed 1 p.g/g (27). Most of the mercury in fish is methyl mercury [593-74-8]. Worldwide, the estimated average intake of total dietary mercury is 5—10 p-g/d in Europe, Russia, and Canada, 20 pg/d in the United States, and 40—80 pg/d in Japan (27). 

Mercury consumption in the United States is summarized through 1992 in Table 7. Overall worldwide consumption of mercury declined in the 1980s and early 1990s. A detailed discussion of the uses and appHcations of mercury is available (3). 

Electrolytic Preparation of Chlorine and Caustic Soda. The preparation of chlorine [7782-50-5] and caustic soda [1310-73-2] is an important use for mercury metal. Since 1989, chlor—alkali production has been responsible for the largest use for mercury in the United States. In this process, mercury is used as a flowing cathode in an electrolytic cell into which a sodium chloride [7647-14-5] solution (brine) is introduced. This brine is then subjected to an electric current, and the aqueous solution of sodium chloride flows between the anode and the mercury, releasing chlorine gas at the anode. The sodium ions form an amalgam with the mercury cathode. Water is added to the amalgam to remove the sodium [7440-23-5] forming hydrogen [1333-74-0] and sodium hydroxide and relatively pure mercury metal, which is recycled into the cell (see Alkali and chlorine products). 

Explosives. Mercury, in the form of organic complexes, eg, mercury fulminate [628-86-4] has had long usage in explosives (see Explosives and propellants). In the United States all mercury for use in explosives is diverted to military uses. An explosive based on mercuric 5-nitrotetra2ole [60345-95-1] has been developed, but its use is on a small scale and in research and development only (3). 

Alkyl mercury compounds were used widely in the United States as seed disinfectants until prohibited in 1970. Subsequentiy, in 1972, the EPA prohibited the use of ah mercury compounds in agriculture (15). 

The control of mercury in the effluent derived from the manufacturing processes used in the preparation of inorganic and organic mercurials is mandated bylaw in the United States. The concentrations and the total amounts vary with the industry and the location, but generally it is requited that the... 

Manufacture and Processing. Until World War II, phthaUc acid and, later, phthaUc anhydride, were manufactured primarily by Hquid-phase oxidation of suitable feedstocks. The favored method was BASF s oxidation of naphthalene [91-20-3] by sulfuric acid ia the presence of mercury salts to form the anhydride. This process was patented ia 1896. During World War I, a process to make phthaUc anhydride by the oxidation of naphthalene ia the vapor phase over a vanadium and molybdenum oxide catalyst was developed ia the United States (5). Essentially the same process was developed iadependendy ia Germany, with U.S. patents being granted ia 1930 and 1934 (6,7). 

Caustic soda concentrations of 50% are produced directly from equation 11. This advantage is offset by higher operating cell voltages and some mercury contamination of the environment. This latter problem has been diminished or solved to an acceptable extent (31) however, it continues to influence the choice of cells for new plants. No new mercury cells have been installed in the United States since 1970 (32). 

Mercury in fish has been found in waters in the United States and Canada. Mercury in the waters is converted into methyl mercury by aquatic vegetation. Small fish consume such vegetation and in turn are eaten by larger fish and eventually by humans food with more than 0.5 ppm of mercury (0.5 mg/kg) cannot be sold in the United States for human consumption. 

In many ways, both Canada and the United States continue to be involved in a unique experiment of co-operative management of serious environmental issues which plague a shared international resource. Despite the institutional complexity and the history of abuse that man s activities have wrought on the Great Lakes, the experiment to restore and protect them has had several successes typhoid and cholera were eradicated eutrophication problems are now largely under control and where adequate control programs for toxic chemicals have been implemented and enforced (e.g., mercury, DDT, PCBs), there have been associated declines in concentrations in the lakes. These successes have been due in no small way to the spirit of co-operation that has continued to exist between Canada and the United States and the unique institutional arrangements entered into by the two countries. 

Alpers CN, Hunerlach MP, May JT, Hothem RL (2005) Mercury contamination from historical gold mining in California. United States Geological Survey Fact Sheet 2005-3014, Sacramento, California. 

How will mercury concentrations in air, land, water, and biota respond to changes in mercmy emissions This book proposes a framework for a carefully designed national-scale monitoring program, necessary but currently not in place in the United States, to help answer this question. 

While methylmercury occurs naturally in tlie environment, it is reasonable to expect that methylmercury levels have increased in modem times as a result of increased inorganic mercury concentrations. Whether methylmercmy concentrations have increased to a similar extent as inoiganic mercuiy is not known. It is clear, however, that elevated fish mercuiy concentrations can currently be found in remote lakes, rivers, reservoirs, estuaries, and marine conditions, typically in predators such as sportfish at the top of food webs. As of 2003, 45 states had fish consumption advisories related to mercuiy, and 76% of all fish consumption advisories in the United States were at least partly related to mercury (USEPA 2004a). The number of advisories is increasing with time, although this is due at least partly to more sites being sampled (Wiener et al. 2003). 

FIGURE 1.5 Anthropogenic mercury emissions in the United States, 1990-1999. Short tons per year. Emissions shown for gold mines in 1990 and 1996 are assumed to be equal to emissions for those mines in 1999. Source From USEPA 2004c.)... 

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