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Occurrence

Mercury is an extremely rare element in the Earth's crust, having an average crustal abundance by mass of only 0.08 parts per million (ppm).[19] However, because it does not blend geochemically with those elements that constitute the majority of the crustal mass, mercury ores can be extraordinarily concentrated considering the element's abundance in ordinary rock. Sony VAIO VGN-SR390NAB Battery

The richest mercury ores contain up to 2.5% mercury by mass, and even the leanest concentrated deposits are at least 0.1% mercury (12,000 times average crustal abundance). It is found either as a native metal (rare) or incinnabar, corderoite, livingstonite and other minerals, with cinnabar (HgS) being the most common ore.[20] Sony VAIO VGN-SR390NAH Battery

Mercury ores usually occur in very young orogenic belts where rock of high density are forced to the crust of the Earth, often in hot springs or other volcanic regions.[21]

Beginning in 1558, with the invention of the patio process to extract silver from ore using mercury, mercury became an essential resource in the economy of Spain and its American colonies. Sony VAIO VGN-SR41M/P Battery

Mercury was used to extract silver from the lucrative mines in New Spain and Peru. Initially, the Spanish Crown's mines in Almaden in Southern Spain supplied all the mercury for the colonies.[22]Mercury deposits were discovered in the New World, and more than 100,000 tons of mercury were mined from the region of Huancavelica, Peru, over the course of three centuries following the discovery of deposits there in 1563. Sony VAIO VGN-SR41M/S Battery

The patio process and later pan amalgamation process continued to create great demand for mercury to treat silver ores until the late 19th century.[23]

Former mines in Italy, the United States and Mexico which once produced a large proportion of the world supply have now been completely mined out or, in the case of Slovenia (Idrija) and Spain (Almadén), shut down due to the fall of the price of mercury. Sony VAIO VGN-SR49VN/H Battery

Nevada's McDermitt Mine, the last mercury mine in the United States, closed in 1992. The price of mercury has been highly volatile over the years and in 2006 was $650 per 76-pound (34.46 kg) flask.[24]

Mercury is extracted by heating cinnabar in a current of air and condensing the vapor. The equation for this extraction isSony VAIO VGN-SR51B/P Battery

HgS + O2 ? Hg + SO2

In 2005, China was the top producer of mercury with almost two-thirds global share followed by Kyrgyzstan.[25] Several other countries are believed to have unrecorded production of mercury from copper electrowinning processes and by recovery from effluents. Sony VAIO VGN-SR51B/S Battery

Because of the high toxicity of mercury, both the mining of cinnabar and refining for mercury are hazardous and historic causes of mercury poisoning.[26] In China, prison labor was used by a private mining company as recently as the 1950s to create new cinnabar mercury mines. Sony VAIO VGN-SR51MF Battery

Thousands of prisoners were used by the Luo Xi mining company to establish new tunnels.[27] In addition, worker health in functioning mines is at high risk.

The European Union directive calling for compact fluorescent bulbs to be made mandatory by 2012 has encouraged China to re-open deadly cinnabar mines to obtain the mercury required for CFL bulb manufacture. Sony VAIO VGN-SR51MF/P Battery

As a result, environmental dangers have been a concern, particularly in the southern cities of Foshan and Guangzhou, and in the Guizhou province in the south west.[27]

Abandoned mercury mine processing sites often contain very hazardous waste piles of roasted cinnabar calcines. Sony VAIO VGN-SR51MF/S Battery

Water run-off from such sites is a recognized source of ecological damage. Former mercury mines may be suited for constructive re-use. For example, in 1976 Santa Clara County, California purchased the historic Almaden Quicksilver Mine and created a county park on the site, after conducting extensive safety and environmental analysis of the property.[28] Sony VAIO VGN-SR51MF/W Battery

Chemistry

Mercury exists in two main oxidation states, I and II. Higher oxidation states are unimportant, but have been detected, e.g., mercury(IV) fluoride (HgF4) but only under extraordinary conditions.[29] Sony VAIO VGN-SR51MR Battery

Compounds of mercury(I)

Different from its lighter neighbors, cadmium and zinc, mercury forms simple stable compounds with metal-metal bonds. The mercury(I) compounds are diamagnetic and feature the dimeric cation, Hg2+
2. Stable derivatives include the chloride and nitrate. Sony VAIO VGN-SR59VG Battery

Treatment of Hg(I) compounds complexation with strong ligands such as sulfide, cyanide, etc. induces disproportionation to Hg2+and elemental mercury.[30] Mercury(I) chloride, a colorless solid also known as calomel, is really the compound with the formula Hg2Cl2, with the connectivity Cl-Hg-Hg-Cl. Sony VAIO VGN-SR59VG/H Battery

It is a standard in electrochemistry. It reacts with chlorine to give mercuric chloride, which resists further oxidation.

Indicative of its tendency to bond to itself, mercury forms mercury polycations, which consist of linear chains of mercury centers, capped with a positive charge. One example is Hg32+(AsF6–)2.[31] Sony VAIO VGN-SR70B/S Battery

Compounds of mercury(II)

Mercury(II) is the most common oxidation state and is the main one in nature as well. All four mercuric halides are known. The form tetrahedral complexes with other ligands but the halides adopt linear coordination geometry, somewhat like Ag+ does. Sony VAIO VGN-SR72B/P Battery

Best known is mercury(II) chloride, an easily sublimating white solid. HgCl2forms coordination complexes that are typically tetrahedral, e.g. HgCl42–.

Mercury(II) oxide, the main oxide of mercury, arises when the metal is exposed to air for long periods at elevated temperatures.Sony VAIO VGN-SR72B/S Battery

It reverts to the elements upon heating near 400 °C, as was demonstrated by Priestly in an early synthesis of pure oxygen.[7]Hydroxides of mercury are poorly characterized, as they are for its neighbors gold and silver.

Being a soft metal, mercury forms very stable derivatives with the heavier chalcogens. Sony VAIO VGN-SR73JB/S Battery

Preeminent is mercury(II) sulfide, HgS, which occurs in nature as the ore cinnabar and is the brilliant pigment vermillion. Like ZnS, HgS crystallizes in two forms, the reddish cubic form and the black zinc blende form.[4] Mercury(II) selenide (HgSe) and mercury(II) telluride (HgTe) are also known, Sony VAIO VGN-SR74FB/S Battery

these as well as various derivatives, e.g. mercury cadmium telluride and mercury zinc telluridebeing semiconductors useful as infrared detectormaterials.[32]

Mercury(II) salts form a variety of complex derivatives with ammonia. These include Millon's base (Hg2N+), the one-dimensional polymer (salts of HgNH2+)n), and "fusible white precipitate" or [Hg(NH3)2]Cl2. Sony VAIO VGN-SR90FS Battery

Known as Nessler's reagent, potassium tetraiodomercurate(II) (HgI42–) is still occasionally used to test for ammonia owing to its tendency to form the deeply colored iodide salt of Millon's base.

Mercury fulminate, (a detonator widely used in explosives);[4] Sony VAIO VGN-SR90NS Battery

Compounds of mercury(IV)

Mercury(IV) is the rarest oxidation state of mercury which is known to exist. The only known mercury(IV) compound is mercury(IV) fluoride.

Organomercury compounds

Organic mercury compounds are historically important but are of little industrial value in the western world. Sony VAIO VGN-SR90S Battery

Mercury(II) salts are a rare examples of simple metal complexes that react directly with aromatic rings. Organomercury compounds are always divalent and usually two-coordinate and linear geometry. Unlike organocadmium and organozinc compounds, organomercury compounds do not react with water. Sony VAIO VGN-SR90US Battery

They usually have the formula HgR2, which are often volatile, or HgRX, which are often solids, where R is aryl or alkyl and X is usually halide or acetate. Methylmercury, a generic term for compounds with the formula CH3HgX is a dangerous family of compounds that is found in some a polluted water.[33] They arise by a process known as biomethylation. Sony VAIO VGN-SR91NS Battery

Applications

Mercury is used primarily for the manufacture of industrial chemicals or for electrical and electronic applications. It is used in some thermometers, especially ones which are used to measure high temperatures. Sony VAIO VGN-SR91PS Battery

A still increasing amount is used as gaseous mercury in fluorescent lamps, while most of the other applications are slowly phased out due to health and safety regulations and is in some applications replaced with less toxic but considerably more expensive Galinstan alloy. Sony VAIO VGN-SR91S Battery

Medicine

Mercury and its compounds have been used in medicine, although they are much less common today than they once were, now that the toxic effects of mercury and its compounds are more widely understood. The element mercury is an ingredient in dental amalgams. Sony VAIO VGN-SR91US Battery

Thiomersal (called Thimerosal in the United States) is an organic compound used as a preservative in vaccines, though this use is in decline.[34] Another mercury compound Merbromin (Mercurochrome) is a topical antiseptic used for minor cuts and scrapes is still in use in some countries. Sony VAIO VGN-SR92NS Battery

Since the 1930s some vaccines have contained the preservative thiomersal, which is metabolized or degraded to ethyl mercury. Although it was widely speculated that this mercury-based preservative can cause or trigger autism in children, scientific studies showed no evidence supporting any such link.[35] Sony VAIO VGN-SR92PS Battery

Nevertheless thiomersal has been removed from or reduced to trace amounts in all U.S. vaccines recommended for children 6 years of age and under, with the exception of inactivated influenza vaccine.[36]

Mercury in the form of one of its common ores, cinnabar, is used in various traditional medicines, especially in traditional Chinese medicine. Sony VAIO VGN-SR92S Battery

Review of its safety has found cinnabar can lead to significant mercury intoxication when heated, consumed in overdoseor taken long term, and can have adverse effects at therapeutic doses, though this is typically reversible at therapeutic doses. Although this form of mercury appears less toxic than others, its use in traditional Chinese medicine has not yet been justified as the therapeutic basis for the use of cinnabar is not clear.[37] Sony VAIO VGN-SR92US Battery

Today, the use of mercury in medicine has greatly declined in all respects, especially in developed countries. Thermometersandsphygmomanometers containing mercury were invented in the early 18th and late 19th centuries, respectively. In the early 21st century, their use is declining and has been banned in some countries, states and medical institutions.Sony VAIO VGN-SR93DS Battery

In 2002, the U.S. Senatepassed legislation to phase out the sale of non-prescription mercury thermometers. In 2003, Washington and Maine became the first states to ban mercury blood pressure devices.[38] Mercury compounds are found in some over-the-counter drugs, including topicalantiseptics, stimulant laxatives, diaper-rash ointment, eye drops, and nasal sprays.Sony VAIO VGN-SR93JS Batery

The FDA has "inadequate data to establish general recognition of the safety and effectiveness", of the mercury ingredients in these products.[39] Mercury is still used in some diuretics, although substitutes now exist for most therapeutic uses. Sony VAIO VGN-SR93PS Batttery

Production of chlorine and caustic soda

Chlorine is produced from sodium chloride (common salt, NaCl) using electrolysis to separate the metallic sodium from the chlorine gas. Usually the salt is dissolved in water to produce a brine. Sony VAIO VGN-SR93YS Battery

By-products of any such chloralkali process are hydrogen (H2) andsodium hydroxide (NaOH), which is commonly called caustic soda or lye. By far the largest use of mercury[40][41] in the late 20th century was in the mercury cell process (also called the Castner-Kellner process) where metallic sodium is formed as an amalgam at acathode made from mercury; Sony VAIO VGN-SR94FS Battery

this sodium is then reacted with water to produce sodium hydroxide.[42] Many of the industrial mercury releases of the 20th century came from this process, although modern plants claimed to be safe in this regard.[41] After about 1985, all new chloralkali production facilities that were built in the United States used either membrane cell or diaphragm cell technologies to produce chlorine. Sony VAIO VGN-SR94GS Battery

Laboratory uses

Some medical thermometers, especially those for high temperatures, are filled with mercury; however, they are gradually disappearing. In the United States, non-prescription sale of mercury fever thermometers has been banned since 2003.[43] Sony VAIO VGN-SR94HS Battery

Mercury is also found in liquid mirror telescopes. The mirror is formed by rotating liquid mercury on a disk, the parabolic form of the liquid thus formed reflecting and focusing incident light. Such telescopes are cheaper than conventional large mirror telescopes by up to a factor of 100, but the mirror cannot be tilted and always points straight up. Sony VAIO VGN-SR94VS Battery

Liquid mercury is a part of popular secondary reference electrode (called the calomel electrode) in electrochemistry as an alternative to the standard hydrogen electrode. The calomel electrode is used to work out the electrode potential of half cells.[47]Last, but not least, the triple point of mercury, ?38.8344 °C, is a fixed point used as a temperature standard for the International Temperature Scale (ITS-90).[4] Sony VAIO VGN-SZ35B/B Battery

Niche uses

Gaseous mercury is used in mercury-vapor lamps and some "neon sign" type advertising signs and fluorescent lamps. Those low-pressure lamps emit very spectrally narrow lines, which are traditionally used in optical spectroscopy for calibration of spectral position. Sony VAIO VGN-SZ54B/B Battery

Commercial calibration lamps are sold for this purpose; however simply reflecting some of the fluorescent-lamp ceiling light into a spectrometer is a common calibration practice.[48] Gaseous mercury is also found in some electron tubes, including ignitrons, thyratrons, and mercury arc rectifiers.[49] Sony VAIO VGN-SZ55B/B Battery

It is also used in specialist medical care lamps for skin tanning and disinfection (see pictures).[50] Gaseous mercury is added to cold cathode argon-filled lamps to increase the ionization andelectrical conductivity. An argon filled lamp without mercury will have dull spots and will fail to light correctly. Sony VAIO VGN-SZ55GN/B Battery

Lighting containing mercury can be bombarded/oven pumped only once. When added to neon filled tubes the light produced will be inconsistent red/blue spots until the initial burning-in process is completed; eventually it will light a consistent dull off-blue color.[51] Sony VAIO VGN-SZ56 Battery

Cosmetics

Mercury, as thiomersal, is widely used in the manufacture of mascara. In 2008, Minnesota became the first state in the US to ban intentionally added mercury in cosmetics, giving it a tougher standard than the federal government.[52] Sony VAIO VGN-SZ561N Battery

A study in geometric mean urine mercury concentration identified a previously unrecognized source of exposure (skin care products) to inorganic mercury among New York City residents. Population-based biomonitoring also showed that mercury concentration levels are higher in consumers of seafood and fish meals.[53] Sony VAIO VGN-SZ562N Battery

Historic uses

Many historic applications made use of the peculiar physical properties of mercury, especially as a dense liquid and a liquid metal:

In Islamic Spain, it was used for filling decorative pools. Later, the American artist Alexander Calder built a mercury fountainfor the Spanish Pavilion at the 1937 World Exhibition in Paris. Sony VAIO VGN-SZ57N Battery

  • The fountain is now on display at the Fundació Joan Miróin Barcelona.[54]

Mercury was used inside wobbler lures. Its heavy, liquid form made it useful since the lures made an attractive irregular movement when the mercury moved inside the plug. Sony VAIO VGN-SZ58GN Battery

  • Such use was stopped due to environmental concerns, but illegal preparation of modern fishing plugs has occurred.
  • The Fresnel lenses of old lighthouses used to float and rotate in a bath of mercury which acted like a bearing.[55]

Mercury sphygmomanometers (blood pressure meter), barometers, diffusion pumps, coulometers, and many other laboratory instruments. Sony VAIO VGN-SZ58GN/C Battery

  • As an opaque liquid with a high density and a nearly linear thermal expansion, it is ideal for this role.[56]

As an electrically conductive liquid, it was used in mercury switches (including home mercury light switches installed prior to 1970), tilt switches used in old fire detectors, and tilt switches in many modern home thermostats,[57] Sony VAIO VGN-SZ58N Battery

  • Owing to its acoustic properties, mercury was used as the propagation medium in delay line memory devices used in early digital computers of the mid-20th century.

Experimental mercury vapor turbines were installed to increase the efficiency of fossil-fuel electrical power plants.[58] Sony VAIO VGN-SZ61MN/B Battery

The South Meadow power plant in Hartford, CT employed mercury as its working fluid, in a binary configuration with a secondary water circuit, or a number of years starting in the late 1920s in a drive to improve plant efficiency. Several other plants were built, including the Schiller Station in Portsmouth, NH, which went online in 1950. Sony VAIO VGN-SZ61VN/X Battery

  • The idea did not catch on industry-wide due to the weight and toxicity of mercury, as well as the advent of supercritical steam plants in later years.[59][60]

Similarly, liquid mercury was used as a coolant for some nuclear reactors; however, sodium is proposed for reactors cooled with liquid metal, because the high density of mercury requires much more energy to circulate as coolant.[61] Sony VAIO VGN-SZ61WN/C Battery

Mercury was a propellant for early ion engines in electric space propulsion systems. Advantages were mercury's high molecular weight, low ionization energy, low dual-ionization energy, high liquid density and liquid storability at room temperature. Sony VAIO VGN-SZ640N/B Battery

Disadvantages were concerns regarding environmental impact associated with ground testing and concerns about eventual cooling and condensation of some of the propellant on the spacecraft in long-duration operations. The first spaceflight to use electric propulsion was a mercury-fueled ion thruster developed by NASA Lewis and flown on the Space Electric Rocket Test "SERT-1" spacecraft launched by NASA at its Wallops Flight Facility in 1964. Sony VAIO VGN-SZ645P3 Battery

The SERT-1 flight was followed up by the SERT-2 flight in 1970. Mercury and caesium were preferred propellants for ion engines until Hughes Research Laboratory performed studies finding xenon gas to be a suitable replacement. Xenon is now the preferred propellant for ion engines as it has a high molecular weightSony VAIO VGN-SZ650N/C Battery

  • , little or no reactivity due to its noble gas nature, and has a high liquid density under mild cryogenic storage.[62][63]
  • Mercury has been used to produce liquid mirror telescopes.[64]

Others applications made use of the chemical properties of mercury: Sony VAIO VGN-SZ660N/C Battery

Mercury was used for preserving wood, developing daguerreotypes, silvering mirrors, anti-fouling paints (discontinued in 1990), herbicides (discontinued in 1995), handheld maze games, cleaning, and road leveling devices in cars. Mercury compounds have been used in antiseptics, laxatives, antidepressants, and in antisyphilitics. Sony VAIO VGN-SZ670N/C Battery

  • It was allegedly used by allied spies to sabotage Luftwaffe planes: a mercury paste was applied to bare aluminium, causing the metal to rapidly corrode; this would cause structural failures.[65]

Chloralkali process: The largest industrial use of mercury during the 20th century was in electrolysis for separating chlorine and sodium from brine; Sony VAIO VGN-SZ680ND Battery

mercury being the anode of the Castner-Kellner process. The chlorine was used for bleaching paper (hence the location of many of these plants near paper mills) while the sodium was used to make sodium hydroxide for soaps and other cleaning products. This usage has largely been discontinued, replaced with other technologies that utilize membrane cells.[66] Sony VAIO VGN-SZ691N/X Battery

  • As electrodes in some types of electrolysis, batteries (mercury cells), sodium hydroxide and chlorine production, handheld games, catalysts, insecticides.
  • Mercury was once used as a gun barrel bore cleaner.[67][68]

From the mid-18th to the mid-19th centuries, a process called "carroting" was used in the making of felt hats. Sony VAIO VGN-SZ71E/B Battery

Animal skins were rinsed in an orange solution (the term "carroting" arose from this color) of the mercury compound mercuric nitrate, Hg(NO3)2·2H2O.[69] This process separated the fur from the pelt and matted it together. This solution and the vapors it produced were highly toxic. Sony VAIO VGN-SZ71VN/X Battery

The United States Public Health Service banned the use of mercury in the felt industry in December 1941. The psychological symptoms associated with mercury poisoning are said by some to have inspired the phrase "mad as a hatter". Sony VAIO VGN-SZ71WN/C Battery

  • Lewis Carroll's "Mad Hatter" in his book Alice's Adventures in Wonderland was a play on words based on the older phrase, but the character himself does not exhibit symptoms of mercury poisoning.[70]

Gold and silver mining. Historically, mercury was used extensively in hydraulic gold mining in order to help the gold to sink through the flowing water-gravel mixture. Sony VAIO VGN-SZ74B/B Battery

Thin mercury particles may form mercury-gold amalgam and therefore increase the gold recovery rates.[4] Large-scale use of mercury stopped in the 1960s. However, mercury is still used in small scale, often clandestine, gold prospecting. It is estimated that 45,000 metric tons of mercury used in California forplacer mininghave not been recovered.[71] Mercury was also used in silver mining.[72] Sony VAIO VGN-SZ750N/C Battery

Historic medicinal uses

Mercury(I) chloride (also known as calomel or mercurous chloride) has been used in traditional medicine as a diuretic, topical disinfectant, and laxative.Mercury(II) chloride (also known as mercuric chloride or corrosive sublimate) Sony VAIO VGN-SZ75B/B Battery

was once used to treat syphilis (along with other mercury compounds), although it is so toxic that sometimes the symptoms of its toxicity were confused with those of the syphilis it was believed to treat.[73] It is also used as a disinfectant. Blue mass, a pill or syrup in which mercury is the main ingredient, Sony VAIO VGN-SZ76 Battery

was prescribed throughout the 19th century for numerous conditions including constipation, depression, child-bearing and toothaches.[74] In the early 20th century, mercury was administered to children yearly as a laxative and dewormer, and it was used in teething powders for infants. Sony VAIO VGN-SZ770N/C Battery

The mercury-containing organohalide merbromin (sometimes sold as Mercurochrome) is still widely used but has been banned in some countries such as the U.S.[75]

Toxicity and safety

Mercury and most of its compounds are extremely toxic and must be handled with care; Sony VAIO VGN-SZ77N Battery

in cases of spills involving mercury (such as from certainthermometers or fluorescent light bulbs), specific cleaning procedures are used to avoid exposure and contain the spill.[76] Protocols call for physically merging smaller droplets on hard surfaces, combining them into a single larger pool for easier removal with an eyedropper, or for gently pushing the spill into a disposable container. Sony VAIO VGN-SZ780 Battery

Vacuum cleaners and brooms cause greater dispersal of the mercury and should not be used. Afterwards, fine sulfur, zinc, or some other powder that readily forms an amalgam (alloy) with mercury at ordinary temperatures is sprinkled over the area before itself being collected and properly disposed of. Sony VAIO VGN-SZ78N Battery

Cleaning porous surfaces and clothing is not effective at removing all traces of mercury and it is therefore advised to discard these kinds of items should they be exposed to a mercury spill.

Mercury can be inhaled and absorbed through the skin and mucous membranes, so containers of mercury are securely sealed to avoid spills and evaporation. Sony VAIO VGN-SZ791N/X Battery

Heating of mercury, or of compounds of mercury that may decompose when heated, is always carried out with adequate ventilation in order to avoid exposure to mercury vapor. The most toxic forms of mercury are its organic compounds, such as dimethylmercury and methylmercury. Sony VAIO VGN-SZ84NS Battery

However, inorganic compounds, such as cinnabar are also highly toxic by ingestion or inhalation.[77] Mercury can cause both chronic and acute poisoning.

Releases in the environment

Preindustrial deposition rates of mercury from the atmosphere may be about 4 ng /(1 L of ice deposit). Sony VAIO VGN-SZ84PS Battery

Although that can be considered a natural level of exposure, regional or global sources have significant effects. Volcanic eruptions can increase the atmospheric source by 4–6 times.[78]

Natural sources, such as volcanoes, are responsible for approximately half of atmospheric mercury emissions. Sony VAIO VGN-SZ84S Battery

The human-generated half can be divided into the following estimated percentages:[79][80][81]

65% from stationary combustion, of which coal-fired power plants are the largest aggregate source (40% of U.S. mercury emissions in 1999). This includes power plants fueled with gas where the mercury has not been removed. Sony VAIO VGN-SZ84US Battery

  • Emissions from coal combustion are between one and two orders of magnitude higher than emissions from oil combustion, depending on the country.[79]

11% from gold production. The three largest point sources for mercury emissions in the U.S. are the three largest gold mines. Sony VAIO VGN-SZ85NS Battery

  • Hydrogeochemical release of mercury from gold-mine tailings has been accounted as a significant source of atmospheric mercury in eastern Canada.[82]
  • 6.8% from non-ferrous metal production, typically smelters.

6.4% from cement production. Sony VAIO VGN-SZ85S Battery

  • 3.0% from waste disposal, including municipal and hazardous waste, crematoria, and sewage sludge incineration. This is a significant underestimate due to limited information, and is likely to be off by a factor of two to five.

3.0% from caustic soda production. Sony VAIO VGN-SZ85US Battery

  • 1.4% from pig iron and steel production.
  • 1.1% from mercury production, mainly for batteries.
  • 2.0% from other sources.

The above percentages are estimates of the global human-caused mercury emissions in 2000, excluding biomass burning, an important source in some regions.[79] Sony VAIO VGN-SZ94NS Battery

Current atmospheric mercury contamination in outdoor urban air is (0.01–0.02 µg/m3) indoor concentrations are significantly elevated over outdoor concentrations, in the range 0.0065–0.523 µg/m3 (average 0.069 µg/m3).[83]

Mercury also enters into the environment through the improper disposal (e.g., land filling, incineration) of certain products. Sony VAIO VGN-SZ94PS Battery

Products containing mercury include: auto parts, batteries, fluorescent bulbs, medical products, thermometers, and thermostats.[84] Due to health concerns (see below), toxics use reduction efforts are cutting back or eliminating mercury in such products. For example, most thermometers now use pigmented alcohol instead of mercury, and galinstan alloy thermometers are also an option. Sony VAIO VGN-SZ94S Battery

Mercury thermometers are still occasionally used in the medical field because they are more accurate than alcohol thermometers, though both are commonly being replaced by electronic thermometers and less commonly by galinstan thermometers. Mercury thermometers are still widely used for certain scientific applications because of their greater accuracy and working range. Sony VAIO VGN-SZ94US Battery

The United States Clean Air Act, passed in 1990, put mercury on a list of toxic pollutants that need to be controlled to the greatest possible extent. Thus, industries that release high concentrations of mercury into the environment agreed to install maximum achievable control technologies (MACT). Sony VAIO VGN-SZ95NS Battery

In March 2005 EPA rule[85] added power plants to the list of sources that should be controlled and a national cap and trade rule was issued. States were given until November 2006 to impose stricter controls, and several States are doing so. The rule was being subjected to legal challenges from several States in 2005 and decision was made in 2008. Sony VAIO VGN-SZ95S Battery

The Clean Air Mercury Rule was struck down by a Federal Appeals Court on February 8, 2008. The rule was deemed not sufficient to protect the health of persons living near coal-fired power plants. The court opinion cited the negative impact on human health from coal-fired power plants' mercury emissions documented in the EPA Study Report to Congress of 1998.[86] Sony VAIO VGN-SZ95US Battery

Historically, one of the largest releases was from the Colex plant, a lithium-isotope separation plant at Oak Ridge. The plant operated in the 1950s and 1960s. Records are incomplete and unclear, but government commissions have estimated that some two million pounds of mercury are unaccounted for.[87] Sony VAIO VGN-TZ121 Battery

A serious industrial disasters was the dumping of mercury compounds into Minamata Bay, Japan. It is estimated that over 3,000 people suffered various deformities, severe mercury poisoning symptoms or death from what became known as Minamata disease.[88] Sony VAIO VGN-TZ13 Battery

Occupational exposure

Due to the health effects of mercury exposure, industrial and commercial uses are regulated in many countries. The World Health Organization, OSHA, and NIOSH all treat mercury as an occupational hazard, and have established specific occupational exposure limits. Sony VAIO VGN-TZ130N/B Battery

Environmental releases and disposal of mercury are regulated in the U.S. primarily by the United States Environmental Protection Agency.

Case control studies have shown effects such as tremors, impaired cognitive skills, and sleep disturbance in workers with chronic exposure to mercury vapor even at low concentrations in the range 0.7–42 ?g/m3.[89][90Sony VAIO VGN-TZ131 Battery

] A study has shown that acute exposure (4 – 8 hours) to calculated elemental mercury levels of 1.1 to 44 mg/m3resulted in chest pain, dyspnea, cough, hemoptysis, impairment of pulmonary function, and evidence of interstitial pneumonitis.[91] Acute exposure to mercury vapor has been shown to result in profound central nervous system effects, including psychotic reactions characterized by delirium, hallucinations, and suicidal tendency. Sony VAIO VGN-TZ132/N Battery

Occupational exposure has resulted in broad-ranging functional disturbance, including erethism, irritability, excitability, excessive shyness, and insomnia. With continuing exposure, a fine tremor develops and may escalate to violent muscular spasms. Tremor initially involves the hands and later spreads to the eyelids, lips, and tongue. Sony VAIO VGN-TZ132N Battery

Long-term, low-level exposure has been associated with more subtle symptoms of erethism, including fatigue, irritability, loss of memory, vivid dreams and depression.[92][93]

Treatment

Research on the treatment of mercury poisoning is limited. Currently available drugs for acute mercurial poisoning include chelators N-acetyl-D, L-penicillamine(NAP), Sony VAIO VGN-TZ150N/B Battery

British Anti-Lewisite (BAL), 2,3-dimercapto-1-propanesulfonic acid (DMPS), and dimercaptosuccinic acid (DMSA). In one small study including 11 construction workers exposed to elemental mercury, patients were treated with DMSA and NAP.[94] Chelation therapy with both drugs resulted in the mobilization of a small fraction of the total estimated body mercury. Sony VAIO VGN-TZ150N/N Battery

DMSA was able to increase the excretion of mercury to a greater extent than NAP.[95]

Fish

Fish and shellfish have a natural tendency to concentrate mercury in their bodies, often in the form of methylmercury, a highly toxic organic compound of mercury. Species of fish that are high on the food chain, such as shark, swordfish, king mackerel, albacore tuna, and tilefish contain higher concentrations of mercury than others. Sony VAIO VGN-TZ160CB Battery

As mercury and methylmercury are fat soluble, they primarily accumulate in the viscera, although they are also found throughout the muscle tissue.[96] When this fish is consumed by a predator, the mercury level is accumulated. Since fish are less efficient at depurating than accumulating methylmercury, fish-tissue concentrations increase over time. Sony VAIO VGN-TZ160N/B Battery

Thus species that are high on the food chain amass body burdens of mercury that can be ten times higher than the species they consume. This process is called biomagnification. Mercury poisoning happened this way in Minamata, Japan, now called Minamata disease.

Regulations

In the United States, the Environmental Protection Agency is charged with regulating and managing mercury contamination. Sony VAIO VGN-TZ16GN/B Battery

Several laws give the EPA this authority, including the Clean Air Act, the Clean Water Act, the Resource Conservation and Recovery Act, and the Safe Drinking Water Act. Additionally, the Mercury-Containing and Rechargeable Battery Management Act, passed in 1996, phases out the use of mercury in batteries, and provides for the efficient and cost-effective disposal of many types of used batteries.[97] Sony VAIO VGN-TZ16N Battery

North America contributed approximately 11% of the total global anthropogenic mercury emissions in 1995.[98]

In the European Union, the directive on the Restriction of the Use of Certain Hazardous Substances in Electrical and Electronic Equipment (see RoHS) bans mercury from certain electrical and electronic products, Sony VAIO VGN-TZ16N/B Battery

and limits the amount of mercury in other products to less than 1000 ppm.[99] There are restrictions for mercury concentration in packaging (the limit is 100 ppm for sum of mercury, lead, hexavalent chromium and cadmium) and batteries (the limit is 5 ppm).[100] In July 2007, the European Union also banned mercury in non-electrical measuring devices, such as thermometers and barometers. Sony VAIO VGN-TZ17/N Battery

The ban applies to new devices only, and contains exemptions for the health care sector and a two-year grace period for manufacturers of barometers. [101]

Norway enacted a total ban on the use of mercury in the manufacturing and import/export of mercury products, effective January 1, 2008.[102] Sony VAIO VGN-TZ170N/B Battery

In 2002, several lakes in Norway were found to have a poor state of mercury pollution, with an excess of 1 mg/g of mercury in their sediment. Sony VAIO VGN-TZ170N/N Battery,Sony VAIO VGN-TZ17GN/B Battery,Sony VAIO VGN-TZ17N Battery,Sony VAIO VGN-TZ18/N Battery,Sony VAIO VGN-TZ180N/RC Battery,Sony VAIO VGN-TZ185N/WC Battery

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