Methylmercury

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Methylmercury
Methylmercury.png
Methylmercury-cation-3D-vdW.png
Identifiers
3D model (JSmol)
ChEBI
ChemSpider
ECHA InfoCard 100.223.040 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
  • Key: MJOUBOKSWBMNGQ-UHFFFAOYSA-N Yes check.svgY
  • C[Hg+]
Properties
CH3Hg
Molar mass 215.63 g/mol
Related compounds
Related compounds
 Ethylmercury
Dimethylmercury
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Structures of two main types of complexes formed by methylmercury. X = anion, L = neutral Lewis base. MethylmercuryPrototypes.svg
Structures of two main types of complexes formed by methylmercury. X = anion, L = neutral Lewis base.

Methylmercury (sometimes methyl mercury) is an organometallic cation with the formula [CH3Hg]+. It is the simplest organomercury compound. Methylmercury is extremely toxic, and its derivatives are the major source of organic mercury for humans. It is a bioaccumulative environmental toxicant with a 50-day half-life. [1] [ clarification needed ] Methylmercury (derived biologically from dimethylmercury) is the causative agent of the infamous Minamata disease.

Contents

Structure and chemistry

"Methylmercury" is a shorthand for the hypothetical "methylmercury cation", sometimes written methylmercury(1+) cation or methylmercury(II) cation. This functional group is composed of a methyl group bonded to an atom of mercury. Its chemical formula is CH3Hg+ (sometimes written as MeHg+). The Methylmercury compound has an overall charge of +1, with Hg in the +2 oxidation state. Methylmercury exists as a substituent in many complexes of the type [MeHgL]+ (L = Lewis base) and MeHgX (X = anion). [2]

As a positively charged ion, it readily combines with anions such as chloride (Cl−), hydroxide (OH−) and nitrate (NO−3). It has particular affinity for sulfur-containing anions, particularly thiols (RS−). Thiols are generated when the amino acid cysteine and the peptide glutathione form strong complexes with methylmercury: [3]

[MeHg]+ + RSH → MeHg−SR + H+

Sources

Environmental sources

Structure of the complex of methylmercury and cysteine. Color code: dark blue = Hg, yellow = S. MCYSHG10sm.svg
Structure of the complex of methylmercury and cysteine. Color code: dark blue = Hg, yellow = S.

Methylmercury is formed from inorganic mercury by the action of microbes that live in aquatic systems including lakes, rivers, wetlands, sediments, soils and the open ocean. [5] This methylmercury production has been primarily attributed to anaerobic bacteria in the sediment. [6] Capable bacteria that can methylate mercury are mostly the sulfate-reducing bacteria (SRB), [7] [8] iron-reducing bacteria (FeRB) [9] and methanogens. [10] [11] Significant concentrations of methylmercury in ocean water columns [12] are strongly associated with nutrients and organic matter remineralization, which indicate that remineralization may contribute to methylmercury production. [13] Direct measurements of methylmercury production using stable mercury isotopes have also been observed in marine waters, [14] [15] but the microbes involved are still unknown. Increased methylmercury concentrations in water and fish have been detected after flooding of soils associated with reservoir creation (e.g. for hydroelectric power generation) and in thermokarst wetlands that form after permafrost thaw. [14] [16] [17] The increased methylmercury concentration is due to its ability to bio-accumulate and biο-magnify in aquatic food webs. [18]

There are various sources of inorganic mercury that may indirectly contribute to the production of methylmercury from microbes in the environment. Natural sources of mercury released to the atmosphere include volcanoes, forest fires, volatilization from the ocean [19] and weathering of mercury-bearing rocks. [20] Anthropogenic sources of mercury include the burning of wastes containing inorganic mercury and from the burning of fossil fuels, particularly coal. Although inorganic mercury is only a trace constituent of such fuels, their large scale combustion in utility and commercial/industrial boilers in the United States alone results in release of some 80.2 tons (73 metric tons) of elemental mercury to the atmosphere each year, out of total anthropogenic mercury emissions in the United States of 158 tons (144 metric tons)/year. [21]

In the past, methylmercury was produced directly and indirectly as part of several industrial processes such as the manufacture of acetaldehyde. However, currently there are few direct anthropogenic sources of methylmercury pollution in the United States. [21]

Whole-lake ecosystem experiments at IISD-ELA in Ontario, Canada, showed that mercury falling directly on a lake had the fastest impacts on aquatic ecosystems as opposed to mercury falling on the surrounding land. [22] This inorganic mercury is converted to methylmercury by bacteria. Different stable isotopes of mercury were added to lakes, wetlands, and uplands, simulating rain, and then mercury concentrations in fish were analyzed to find their source. [23] The mercury applied to lakes was found in young-of-the-year yellow perch within two months, whereas the mercury applied to wetlands and uplands had a slower but longer influx. [22] [23]

Acute methylmercury poisoning can occur either directly from the release of methylmercury into the environment or indirectly from the release of inorganic mercury that is subsequently methylated in the environment. For example, methylmercury poisoning occurred at Grassy Narrows in Ontario, Canada (see Ontario Minamata disease), as a result of mercury released from the mercury-cell Chloralkali process, which uses liquid mercury as an electrode in a process that entails electrolytic decomposition of brine, followed by mercury methylation in the aquatic environment. An acute methylmercury poisoning tragedy occurred also in Minamata, Japan, following release of methylmercury into Minamata Bay and its tributaries (see Minamata disease). In the Ontario case, inorganic mercury discharged into the environment was methylated in the environment; whereas, in Minamata, Japan, there was direct industrial discharge of methylmercury.

Dietary sources

Because methylmercury is formed in aquatic systems, and because it is not readily eliminated from organisms, it is biomagnified in aquatic food chains from bacteria, to plankton, through macroinvertebrates, to herbivorous fish and to piscivorous (fish-eating) fish. [24] [25] At each step in the food chain, the concentration of methylmercury in the organism increases. The concentration of methylmercury in the top-level aquatic predators can reach a level a million times higher than the level in the water. [24] [25] This is because methylmercury has a half-life of about 72 days in aquatic organisms resulting in its bioaccumulation within these food chains. Organisms, including humans, [26] fish-eating birds, and fish-eating mammals such as otters and cetaceans (i.e. whales and dolphins) that consume fish from the top of the aquatic food chain receive the methylmercury that has accumulated through this process, plus the toxins in their habitat. [24] [25] Fish and other aquatic species are the main source of human methylmercury exposure. [24]

The concentration of mercury in any given fish depends on the species of fish, the age and size of the fish and the type of water body in which it is found. [24] In general, fish-eating fish such as shark, swordfish, marlin, larger species of tuna, walleye, largemouth bass, and northern pike, have higher levels of methylmercury than herbivorous fish or smaller fish such as tilapia and herring. [27] [28] Within a given species of fish, older and larger fish have higher levels of methylmercury than smaller fish. Fish that develop in water bodies that are more acidic also tend to have higher levels of methylmercury. [24]

Biological impact

Human health effects

Ingested methylmercury is readily and completely absorbed by the gastrointestinal tract. It is mostly found complexed with free cysteine and with proteins and peptides containing that amino acid. The methylmercuric-cysteinyl complex is recognized by amino acids transporting proteins in the body as methionine, another essential amino acid. [29] Because of this mimicry, it is transported freely throughout the body including across the blood–brain barrier and across the placenta, where it is absorbed by the developing fetus. Also for this reason as well as its strong binding to proteins, methylmercury is not readily eliminated. Methylmercury has a half-life in human blood of about 50 days. [30]

Several studies indicate that methylmercury is linked to subtle developmental deficits in children exposed in utero such as loss of IQ points, and decreased performance in tests of language skills, memory function and attention deficits. [31] Methylmercury exposure in adults has also been linked to increased risk of cardiovascular disease including heart attack. [32] [33] [34] Some evidence also suggests that methylmercury can cause autoimmune effects in sensitive individuals. [35] Despite some concerns about the relationship between methylmercury exposure and autism, there are few data that support such a link. [36] Although there is no doubt that methylmercury is toxic in several respects, including through exposure of the developing fetus, there is still some controversy as to the levels of methylmercury in the diet that can result in adverse effects. Recent evidence suggests that the developmental and cardiovascular toxicity of methylmercury may be mitigated by co-exposures to omega-3 fatty acids and perhaps selenium, both found in fish and elsewhere. [33] [37] [38] [39] [40]

There have been several episodes in which large numbers of people were severely poisoned by food contaminated with high levels of methylmercury, notably the dumping of industrial waste that resulted in the pollution and subsequent mass poisoning in Minamata and Niigata, Japan [41] and the situation in Iraq in the 1960s and 1970s in which wheat treated with methylmercury as a preservative and intended as seed grain was fed to animals and directly consumed by people (see Basra poison grain disaster). These episodes resulted in neurological symptoms including paresthesias, loss of physical coordination, difficulty in speech, narrowing of the visual field, hearing impairment, blindness, and death. Children who had been exposed in utero through their mothers' ingestion were also affected with a range of symptoms including motor difficulties, sensory problems and intellectual disability.

At present, exposures of this magnitude are rarely seen and are confined to isolated incidents. Accordingly, concern over methylmercury pollution is currently focused on more subtle effects that may be linked to levels of exposure presently seen in populations with high to moderate levels of dietary fish consumption. These effects are not necessarily identifiable on an individual level or may not be uniquely recognizable as due to methylmercury. However, such effects may be detected by comparing populations with different levels of exposure. There are isolated reports of various clinical health effects in individuals who consume large amounts of fish; [42] however, the specific health effects and exposure patterns have not been verified with larger, controlled studies.

Many governmental agencies, the most notable ones being the United States Environmental Protection Agency (EPA), the United States Food and Drug Administration (FDA), Health Canada, and the European Union Health and Consumer Protection Directorate-General, as well as the World Health Organization (WHO) and the United Nations Food and Agriculture Organization (FAO), have issued guidance for fish consumers that is designed to limit methylmercury exposure from fish consumption. At present, most of this guidance is based on protection of the developing fetus; future guidance, however, may also address cardiovascular risk. In general, fish consumption advice attempts to convey the message that fish is a good source of nutrition and has significant health benefits, but that consumers, in particular pregnant women, women of child-bearing age, nursing mothers, and young children, should avoid fish with high levels of methylmercury, limit their intake of fish with moderate levels of methylmercury, and consume fish with low levels of methylmercury no more than twice a week. [43] [44]

Effects on fish and wildlife

Four vials of larvae of Jordanella after one month in normal water for the first batch, and in water containing 0.6PPB and 1.26PPB and 2.5PPB (parts per billion) of methylmercury for the three bottles at right. NATIONAL WATER QUALITY LABORATORY, 30 DAY GROWTH OF JORDANELLA. THE BOTTLES, LEFT TO RIGHT, CONTAIN, 1-THE CONTROL... - NARA - 551591.tif
Four vials of larvae of Jordanella after one month in normal water for the first batch, and in water containing 0.6PPB and 1.26PPB and 2.5PPB (parts per billion) of methylmercury for the three bottles at right.

In recent years, there has been increasing recognition that methylmercury affects fish and wildlife health, both in acutely polluted ecosystems and ecosystems with modest methylmercury levels. Two reviews [24] [45] document numerous studies of diminished reproductive success of fish, fish-eating birds, and mammals due to methylmercury contamination in aquatic ecosystems.

In public policy

Reported methylmercury levels in fish, along with fish consumption advisories, have the potential to disrupt people's eating habits, fishing traditions, and the livelihoods of the people involved in the capture, distribution, and preparation of fish as a foodstuff for humans. [46] Furthermore, proposed limits on mercury emissions have the potential to add costly pollution controls on coal-fired utility boilers. Nevertheless, substantial benefits can be achieved globally by introducing mercury emission reduction measures because they reduce human and wildlife exposure to methylmercury. [47]

About 30% of the distributed mercury depositional input is from current anthropogenic sources, and 70% is from natural sources. The natural sources category includes re-emission of mercury previously deposited from anthropogenic sources. [48] According to one study, based on modeled concentrations, pre-Anthropocene tissue-bound levels in freshwater fish may not have differed markedly from current levels. [49] However, based on a comprehensive set of global measurements, the ocean contains about 60,000 to 80,000 tons of mercury from pollution, and mercury levels in the upper ocean have tripled since the beginning of the industrial revolution. Higher mercury levels in shallower ocean waters could increase the amount of the toxicant accumulating in food fish, exposing people to a greater risk of mercury poisoning. [50]

See also

Related Research Articles

Bioaccumulation is the gradual accumulation of substances, such as pesticides or other chemicals, in an organism. Bioaccumulation occurs when an organism absorbs a substance faster than it can be lost or eliminated by catabolism and excretion. Thus, the longer the biological half-life of a toxic substance, the greater the risk of chronic poisoning, even if environmental levels of the toxin are not very high. Bioaccumulation, for example in fish, can be predicted by models. Hypothesis for molecular size cutoff criteria for use as bioaccumulation potential indicators are not supported by data. Biotransformation can strongly modify bioaccumulation of chemicals in an organism.

<span class="mw-page-title-main">Mercury poisoning</span> Poisoning caused by mercury chemicals

Mercury poisoning is a type of metal poisoning due to exposure to mercury. Symptoms depend upon the type, dose, method, and duration of exposure. They may include muscle weakness, poor coordination, numbness in the hands and feet, skin rashes, anxiety, memory problems, trouble speaking, trouble hearing, or trouble seeing. High-level exposure to methylmercury is known as Minamata disease. Methylmercury exposure in children may result in acrodynia in which the skin becomes pink and peels. Long-term complications may include kidney problems and decreased intelligence. The effects of long-term low-dose exposure to methylmercury are unclear.

<span class="mw-page-title-main">Dimethylmercury</span> Organomercury chemical compound

Dimethylmercury is an extremely toxic organomercury compound with the formula (CH3)2Hg. A volatile, flammable, dense and colorless liquid, dimethylmercury is one of the strongest known neurotoxins. Less than 0.1 mL is capable of inducing severe mercury poisoning resulting in death.

<span class="mw-page-title-main">Biomagnification</span> Process of progressive accumulation in food chain

Biomagnification, also known as bioamplification or biological magnification, is the increase in concentration of a substance, e.g a pesticide, in the tissues of organisms at successively higher levels in a food chain. This increase can occur as a result of:

Ethylmercury (sometimes ethyl mercury) is a cation composed of an organic CH3CH2— species (an ethyl group) bound to a mercury(II) centre, making it a type of organometallic cation, and giving it a chemical formula C2H5Hg+. The main source of ethylmercury is thimerosal.

Environmental toxicants and fetal development is the impact of different toxic substances from the environment on the development of the fetus. This article deals with potential adverse effects of environmental toxicants on the prenatal development of both the embryo or fetus, as well as pregnancy complications. The human embryo or fetus is relatively susceptible to impact from adverse conditions within the mother's environment. Substandard fetal conditions often cause various degrees of developmental delays, both physical and mental, for the growing baby. Although some variables do occur as a result of genetic conditions pertaining to the father, a great many are directly brought about from environmental toxins that the mother is exposed to.

<span class="mw-page-title-main">Triclocarban</span> Antimicrobial agent

Triclocarban is an antibacterial chemical once common in, but now phased out of, personal care products like soaps and lotions. It was originally developed for the medical field. Although the mode of action is unknown, TCC can be effective in fighting infections by targeting the growth of bacteria such as Staphylococcus aureus. Additional research seeks to understand its potential for causing antibacterial resistance and its effects on organismal and environmental health.

<span class="mw-page-title-main">Metal toxicity</span> Harmful effects of certain metals

Metal toxicity or metal poisoning is the toxic effect of certain metals in certain forms and doses on life. Some metals are toxic when they form poisonous soluble compounds. Certain metals have no biological role, i.e. are not essential minerals, or are toxic when in a certain form. In the case of lead, any measurable amount may have negative health effects. There is a popular misconception that only heavy metals can be toxic, but lighter metals such as beryllium and lithium can be toxic too. Not all heavy metals are particularly toxic, and some are essential, such as iron. The definition may also include trace elements when abnormally high doses may be toxic. An option for treatment of metal poisoning may be chelation therapy, a technique involving the administration of chelation agents to remove metals from the body.

<span class="mw-page-title-main">Environmental toxicology</span> Multidisciplinary field of science

Environmental toxicology is a multidisciplinary field of science concerned with the study of the harmful effects of various chemical, biological and physical agents on living organisms. Ecotoxicology is a subdiscipline of environmental toxicology concerned with studying the harmful effects of toxicants at the population and ecosystem levels.

<span class="mw-page-title-main">Mercury (element)</span> Chemical element with atomic number 80 (Hg)

Mercury is a chemical element; it has symbol Hg and atomic number 80. It is also known as quicksilver and was formerly named hydrargyrum from the Greek words hydor'water' and argyros'silver', from which its chemical symbol is derived. A heavy, silvery d-block element, mercury is the only metallic element that is known to be liquid at standard temperature and pressure; the only other element that is liquid under these conditions is the halogen bromine, though metals such as caesium, gallium, and rubidium melt just above room temperature.

<span class="mw-page-title-main">Mercury in fish</span>

The presence of mercury in fish is a health concern for people who eat them, especially for women who are or may become pregnant, nursing mothers, and young children. Fish and shellfish concentrate mercury in their bodies, often in the form of methylmercury, a highly toxic organomercury compound. This element is known to bioaccumulate in humans, so bioaccumulation in seafood carries over into human populations, where it can result in mercury poisoning. Mercury is dangerous to both natural ecosystems and humans because it is a metal known to be highly toxic, especially due to its neurotoxic ability to damage the central nervous system.

<span class="mw-page-title-main">Mercury cycle</span> Biogeochemical cycle

The mercury cycle is a biogeochemical cycle influenced by natural and anthropogenic processes that transform mercury through multiple chemical forms and environments.

<span class="mw-page-title-main">Mercury regulation in the United States</span>

Mercury regulation in the United States limit the maximum concentrations of mercury (Hg) that is permitted in air, water, soil, food and drugs. The regulations are promulgated by agencies such as the Environmental Protection Agency (EPA) and Food and Drug Administration (FDA), as well as a variety of state and local authorities. EPA published the Mercury and Air Toxics Standards (MATS) regulation in 2012; the first federal standards requiring power plants to limit emissions of mercury and other toxic gases.

Persistent, bioaccumulative and toxic substances (PBTs) are a class of compounds that have high resistance to degradation from abiotic and biotic factors, high mobility in the environment and high toxicity. Because of these factors PBTs have been observed to have a high order of bioaccumulation and biomagnification, very long retention times in various media, and widespread distribution across the globe. Most PBTs in the environment are either created through industry or are unintentional byproducts.

<span class="mw-page-title-main">Aquatic-terrestrial subsidies</span>

Energy, nutrients, and contaminants derived from aquatic ecosystems and transferred to terrestrial ecosystems are termed aquatic-terrestrial subsidies or, more simply, aquatic subsidies. Common examples of aquatic subsidies include organisms that move across habitat boundaries and deposit their nutrients as they decompose in terrestrial habitats or are consumed by terrestrial predators, such as spiders, lizards, birds, and bats. Aquatic insects that develop within streams and lakes before emerging as winged adults and moving to terrestrial habitats contribute to aquatic subsidies. Fish removed from aquatic ecosystems by terrestrial predators are another important example. Conversely, the flow of energy and nutrients from terrestrial ecosystems to aquatic ecosystems are considered terrestrial subsidies; both aquatic subsidies and terrestrial subsidies are types of cross-boundary subsidies. Energy and nutrients are derived from outside the ecosystem where they are ultimately consumed.

<span class="mw-page-title-main">Marine mercury pollution</span> Mercury contamination in sea and sediments

Mercury is a heavy metal that cycles through the atmosphere, water, and soil in various forms to different parts of the world. Due to this natural mercury cycle, irrespective of which part of the world releases mercury it could affect an entirely different part of the world making mercury pollution a global concern. Mercury pollution is now identified as a global problem and awareness has been raised on an international action plan to minimize anthropogenic mercury emissions and clean up mercury pollution. The 2002 Global Mercury Assessment concluded that "International actions to address the global mercury problem should not be delayed". Among many environments that are under the impact of mercury pollution, the ocean is one which cannot be neglected as it has the ability to act as a "storage closet" for mercury. According to a recent model study the total anthropogenic mercury released into the ocean is estimated to be around 80,000 to 45,000 metric tons and two-thirds of this amount is estimated to be found in waters shallower than 1000m level where much consumable fish live. Mercury can bioaccumulate in marine food chains in the form of highly toxic methylmercury which can cause health risks to human seafood consumers. According to statistics, about 66% of global fish consumption comes from the ocean. Therefore, it is important to monitor and regulate oceanic mercury levels to prevent more and more mercury from reaching the human population through seafood consumption.

Mercury contamination in California waterways poses a threat to both the environment and human health. This naturally occurring heavy metal may be released into the environment from natural geological sources, but most commonly occurs from anthropogenic mining operations. This metal poses a threat not only for its effects on organisms, but also for difficulty of removal from waterways and the trouble in efficiently detecting it. The roots of mercury poisoning in waterways began with the historic mining of gold within California's streambed and hillsides; since the California Gold Rush, mercury has been used for gold extraction for its ability as a catalyze with the precious metal. due to the process of extraction and washing, mercury used would either be burned away as a hazardous vapor, or washed away into waterflows, resulting in widespread contamination of river and lake sediments. mercury continues to be released today through anthropogenic sources, though state and federal agencies work to manage and ban these practices and to mitigate its effect on the environmental and on people. Many water bodies in the state of California bear fish consumption advisories due to mercury content.

Mercury methylation is the process of forming methylmercury (MeHg). The methylation of mercury can occur abiotically or biotically. Biotically, the primary methylators of mercury are sulfate-reducing and iron-reducing bacteria. Three mechanisms have been proposed for the biotic methylation of mercury by sulfate-reducing bacteria. Mercury methylation can be problematic as methylmercury is toxic and can be bio-magnified through the food web.

Mercury is a poisonous element found in various forms in Canada. It can be emitted in the atmosphere naturally and anthropogenically, the main cause of mercury emission in the environment. Mercury pollution has become a sensitive issue in Canada for the past few decades and many steps have been taken for prevention at local, national, and international levels. It has been found to have various negative health and environmental effects. Methylmercury is the most toxic form of mercury which is easily accessible as well as digestible by living organisms and it is this form of mercury causing serious harm to human and wildlife health.

<span class="mw-page-title-main">Mercury contamination in Grassy Narrows</span> Environmental & health disaster 1962 - 1970

Mercury contamination in Grassy Narrows was an uncontrolled discharge of between 9,000 kilograms (20,000 lb) and 11,000 kilograms (24,000 lb) of mercury from the Dryden Mill's chloralkali plant in Dryden into the headwaters of the Wabigoon River in the Kenora District of Northwestern Ontario from 1962 until 1970. It was described as "one of the worst cases of environmental poisoning in Canadian history." The contamination poisoned many people in the Grassy Narrows First Nation and Whitedog First Nation communities.

References

  1. ↑ Halliday, Tim; Davey, Basiro (2007). Water and health in an overcrowded world. Oxford: Oxford University Press. pp. 79, 80, 95. ISBN   9780199237302.
  2. ↑ Canty, Allan J.; Chaichit, Narongsak; Gatehouse, Bryan M.; George, Edwin E.; Hayhurst, Glen (1981). "Coordination chemistry of methylmercury(II). Synthesis, hydrogen-1 NMR, and crystallographic studies of cationic complexes of Me Hg(II) with ambidentate and polydentate ligands containing pyridyl and N-substituted imidazolyl donors and involving unusual coordination geometries". Inorganic Chemistry . 20 (8): 2414–2422. doi:10.1021/ic50222a011.
  3. ↑ Nolan, Elizabeth M.; Lippard, Stephen J. (2008). "Tools and Tactics for the Optical Detection of Mercuric Ion". Chemical Reviews. 108 (9): 3443–3480. doi:10.1021/cr068000q. PMID   18652512.
  4. ↑ Taylor, Nicholas J.; Wong, Yau S.; Chieh, Peter C.; Carty, Arthur J. (1975). "Syntheses, X-ray crystal structure, and vibrational spectra of L-cysteinato(methyl)mercury(II) monohydrate". Journal of the Chemical Society, Dalton Transactions (5): 438. doi:10.1039/DT9750000438.
  5. ↑ Ullrich, Susanne; Tanton, Trevor; Abdrashitova, Svetlana (2001). "Mercury in the Aquatic Environment: A Review of Factors Affecting Methylation". Critical Reviews in Environmental Science and Technology. 31 (3): 241–293. Bibcode:2001CREST..31..241U. doi:10.1080/20016491089226. S2CID   96462553.
  6. ↑ Compeau, G.C.; Bartha, R. (1985-08-01). "Sulfate-Reducing Bacteria: Principal Methylators of Mercury in Anoxic Estuarine Sediment". Applied and Environmental Microbiology. 50 (2): 498–502. Bibcode:1985ApEnM..50..498C. doi:10.1128/AEM.50.2.498-502.1985. ISSN   0099-2240. PMC   238649 . PMID   16346866.
  7. ↑ Compeau, G. C.; Bartha, R. (August 1985). "Sulfate-Reducing Bacteria: Principal Methylators of Mercury in Anoxic Estuarine Sediment". Applied and Environmental Microbiology. 50 (2): 498–502. Bibcode:1985ApEnM..50..498C. doi:10.1128/aem.50.2.498-502.1985. ISSN   0099-2240. PMC   238649 . PMID   16346866.
  8. ↑ Gilmour, Cynthia C.; Henry, Elizabeth A.; Mitchell, Ralph (November 1992). "Sulfate stimulation of mercury methylation in freshwater sediments". Environmental Science & Technology. 26 (11): 2281–2287. Bibcode:1992EnST...26.2281G. doi:10.1021/es00035a029. ISSN   0013-936X.
  9. ↑ Wang, Yuwei; Roth, Spencer; Schaefer, Jeffra K; Reinfelder, John R; Yee, Nathan (2020-12-22). "Production of methylmercury by methanogens in mercury contaminated estuarine sediments". FEMS Microbiology Letters. 367 (23). doi:10.1093/femsle/fnaa196. ISSN   1574-6968. PMID   33242089.
  10. ↑ Wang, Yuwei; Roth, Spencer; Schaefer, Jeffra K; Reinfelder, John R; Yee, Nathan (2020-12-22). "Production of methylmercury by methanogens in mercury contaminated estuarine sediments". FEMS Microbiology Letters. 367 (23). doi:10.1093/femsle/fnaa196. ISSN   1574-6968. PMID   33242089.
  11. ↑ Hamelin, Stéphanie; Amyot, Marc; Barkay, Tamar; Wang, Yanping; Planas, Dolors (2011-09-15). "Methanogens: Principal Methylators of Mercury in Lake Periphyton". Environmental Science & Technology. 45 (18): 7693–7700. Bibcode:2011EnST...45.7693H. doi:10.1021/es2010072. ISSN   0013-936X. PMID   21875053.
  12. ↑ Mason, R.P.; Fitzgerald, W.F. (1990-10-04). "Alkylmercury species in the equatorial Pacific". Nature. 347 (6292): 457–459. Bibcode:1990Natur.347..457M. doi:10.1038/347457a0. S2CID   4272755.
  13. ↑ Sunderland, Elsie M.; Krabbenhoft, David P.; Moreau, John W.; Strode, Sarah A.; Landing, William M. (2009-06-01). "Mercury sources, distribution, and bioavailability in the North Pacific Ocean: Insights from data and models". Global Biogeochemical Cycles. 23 (2): GB2010. Bibcode:2009GBioC..23.2010S. CiteSeerX   10.1.1.144.2350 . doi:10.1029/2008GB003425. ISSN   1944-9224. S2CID   17376038.
  14. 1 2 Schartup, Amina T.; Balcom, Prentiss H.; Soerensen, Anne L.; Gosnell, Kathleen J.; Calder, Ryan S.D.; Mason, Robert P.; Sunderland, Elsie M. (2015-09-22). "Freshwater discharges drive high levels of methylmercury in Arctic marine biota". Proceedings of the National Academy of Sciences. 112 (38): 11789–11794. Bibcode:2015PNAS..11211789S. doi: 10.1073/pnas.1505541112 . ISSN   0027-8424. PMC   4586882 . PMID   26351688.
  15. ↑ Lehnherr, Igor; St.Louis, Vincent L.; Hintelmann, Holger; Kirk, Jane L. (2011). "Methylation of inorganic mercury in polar marine waters". Nature Geoscience. 4 (5): 298–302. Bibcode:2011NatGe...4..298L. doi:10.1038/ngeo1134.
  16. ↑ St.Louis, Vincent L.; Rudd, John W.M.; Kelly, Carol A.; Bodaly, R.A. (Drew); Paterson, Michael J.; Beaty, Kenneth G.; Hesslein, Raymond H.; Heyes, Andrew; Majewski, Andrew R. (2004-03-01). "The Rise and Fall of Mercury Methylation in an Experimental Reservoir". Environmental Science & Technology. 38 (5): 1348–1358. doi:10.1021/es034424f. ISSN   0013-936X. PMID   15046335.
  17. ↑ Tarbier, Brittany; Hugelius, Gustaf; Kristina Sannel, Anna Britta; Baptista-Salazar, Carluvy; Jonsson, Sofi (2021-04-26). "Permafrost Thaw Increases Methylmercury Formation in Subarctic Fennoscandia". Environmental Science & Technology. 55 (10): 6710–6717. Bibcode:2021EnST...55.6710T. doi: 10.1021/acs.est.0c04108 . ISSN   0013-936X. PMC   8277125 . PMID   33902281.
  18. ↑ Chen, Xiaojia; Balasubramanian, Rajasekhar; Zhu, Qiongyu; Behera, Sailesh N.; Bo, Dandan; Huang, Xian; Xie, Haiyun; Cheng, Jinping (2016-04-01). "Characteristics of atmospheric particulate mercury in size-fractionated particles during haze days in Shanghai". Atmospheric Environment. 131: 400–408. Bibcode:2016AtmEn.131..400C. doi:10.1016/j.atmosenv.2016.02.019. ISSN   1352-2310.
  19. ↑ "Mercury in the Environment". U.S. Geological Survey. Archived from the original on 2015-07-18. Retrieved 2013-09-20.
  20. ↑ Tewalt, S. J.; Bragg, L. J.; Finkelman, R. B., 2005, Mercury in U.S. coal -- Abundance, distribution, and modes of occurrence, U.S. Geological Survey Fact Sheet 095-01. Access-date=January 12, 2006.
  21. 1 2 U. S. Environmental Protection Agency, 1997, "Mercury study report to congress, Volume II: An inventory of anthropogenic mercury emissions in the United States" Archived 2008-09-11 at the Wayback Machine , table ES-3, sum of Utility boilers and Commercial/industrial boilers. Report: EPA-452/R-97-004.
  22. 1 2 "Mercury: What it does to humans and what humans need to do about it". IISD Experimental Lakes Area. 2017-09-23. Retrieved 2020-07-03.
  23. 1 2 Grieb, Thomas M.; Fisher, Nicholas S.; Karimi, Roxanne; Levin, Leonard (2019-10-03). "An assessment of temporal trends in mercury concentrations in fish". Ecotoxicology. 29 (10): 1739–1749. doi:10.1007/s10646-019-02112-3. ISSN   1573-3017. PMID   31583510. S2CID   203654223.
  24. 1 2 3 4 5 6 7 reviewed in Wiener, J.G., Krabbenhoft, D.P., Heinz, G.H., and Scheuhammer, A.M., 2003, "Ecotoxicology of mercury", Chapter 16 in Hoffman, D.J., B.A. Rattner, G.A. Burton, Jr., and J. Cairns, Jr., eds., Handbook of Ecotoxicology, 2nd edition.: Boca Raton, FL: CRC Press, p. 409–463.
  25. 1 2 3 Lavoie, Raphael A.; Jardine, Timothy D.; Chumchal, Matthew M.; Kidd, Karen A.; Campbell, Linda M. (2013-11-13). "Biomagnification of Mercury in Aquatic Food Webs: A Worldwide Meta-Analysis". Environmental Science & Technology. 47 (23): 13385–13394. Bibcode:2013EnST...4713385L. doi:10.1021/es403103t. ISSN   0013-936X. PMID   24151937.
  26. ↑ Burros, Marian (2008-01-23). "High Mercury Levels Are Found in Tuna Sushi". The New York Times.
  27. ↑ Mercury Levels in Commercial Fish and Shellfish Archived 2006-01-10 at the Wayback Machine Accessed March 25, 2009.
  28. ↑ What You Need to Know about Mercury in Fish and Shellfish Accessed March 25, 2009.
  29. ↑ Kerper, L.; Ballatori, N.; Clarkson, T.W. (May 1992). "Methylmercury transport across the blood–brain barrier by an amino acid carrier". American Journal of Physiology. 262 (5 Pt 2): R761–765. doi:10.1152/ajpregu.1992.262.5.R761. PMID   1590471.
  30. ↑ Carrier, G; Bouchard, M; Brunet, RC; Caza, M (2001). "A Toxicokinetic Model for Predicting the Tissue Distribution and Elimination of Organic and Inorganic Mercury Following Exposure to Methyl Mercury in Animals and Humans. II. Application and Validation of the Model in Humans". Toxicology and Applied Pharmacology . 171 (1): 50–60. Bibcode:2001ToxAP.171...50C. doi:10.1006/taap.2000.9113. PMID   11181111.
  31. ↑ Rice, DC; Schoeny, R; Mahaffey, K (2003). "Methods and rationale for derivation of a reference dose for methylmercury by the U.S. EPA". Risk Analysis. 23 (1): 107–115. Bibcode:2003RiskA..23..107R. doi:10.1111/1539-6924.00294. PMID   12635727. S2CID   6735371.
  32. ↑ Salonen, J. T.; Seppänen, K.; Nyyssönen, K.; Korpela, H.; Kauhanen, J.; Kantola, M.; Tuomilehto, J.; Esterbauer, H.; Tatzber, F.; Salonen, R. (1995). "Intake of Mercury from Fish, Lipid Peroxidation, and the Risk of Myocardial Infarction and Coronary, Cardiovascular, and Any Death in Eastern Finnish Men". Circulation. 91 (3): 645–655. doi:10.1161/01.CIR.91.3.645. PMID   7828289.
  33. 1 2 Guallar, E; Sanz-Gallardo, MI; Van't Veer, P; Bode, P; Aro, A; Gómez-Aracena, J; Kark, JD; Riemersma, RA; Martín-Moreno, JM; Kok, FJ; Heavy Metals Myocardial Infarction Study Group (2002). "Mercury, fish oils, and the risk of myocardial infarction". The New England Journal of Medicine. 347 (22): 1747–1754. doi: 10.1056/NEJMoa020157 . PMID   12456850. S2CID   23031417.
  34. ↑ Choi, A.L., Weihe, P., Budtz-Jørgensen, E., Jørgensen, P.J., Salonen, J.T., Tuomainen, T.-P., Murata, K., Nielsen, H.P., Petersen, M.S., Askham, J., and Grandjean, P., 2009, Methylmercury Exposure and Adverse Cardiovascular Effects in Faroese Whaling Men: Environmental Health Perspectives, v. 117, no. 3, p. 367–372.
  35. ↑ Hultman, P; Hansson-Georgiadis, H (1999). "Methyl mercury–induced autoimmunity in mice". Toxicology and Applied Pharmacology. 154 (3): 203–211. Bibcode:1999ToxAP.154..203H. doi:10.1006/taap.1998.8576. PMID   9931279.
  36. ↑ https://www.cdc.gov/vaccines/pubs/pinkbook/downloads/appendices/B/excipient-table-2.pdf [ bare URL PDF ]
  37. ↑ Choi, AL; Cordier, S; Weihe, P; Grandjean, P (2008). "Negative confounding in the evaluation of toxicity: The case of methylmercury in fish and seafood". Critical Reviews in Toxicology. 38 (10): 877–893. doi:10.1080/10408440802273164. PMC   2597522 . PMID   19012089. Review. Erratum in: "Erratum". Critical Reviews in Toxicology. 39: 95. 2009. doi:10.1080/10408440802661707. S2CID   218989377.
  38. ↑ Strain, JJ; Davidson, PW; Bonham, MP; Duffy, EM; Stokes-Riner, A; Thurston, SW; Wallace, JM; Robson, PJ; Shamlaye, CF; Georger, LA; Sloane-Reeves, J; Cernichiari, E; Canfield, RL; Cox, C; Huang, LS; Janciuras, J; Myers, GJ; Clarkson, TW (2008). "Associations of maternal long-chain polyunsaturated fatty acids, methyl mercury, and infant development in the Seychelles Child Development Nutrition Study". Neurotoxicology. 29 (5): 776–82. Bibcode:2008NeuTx..29..776S. doi:10.1016/j.neuro.2008.06.002. PMC   2574624 . PMID   18590765.
  39. ↑ Khan, MA; Wang, F (2009). "Mercury-selenium compounds and their toxicological significance: Toward a molecular understanding of the mercury-selenium antagonism". Environmental Toxicology and Chemistry. 28 (8): 1567–77. doi:10.1897/08-375.1. PMID   19374471. S2CID   207267481. Review.
  40. ↑ Heath, JC; Banna, KM; Reed, MN; Pesek, EF; Cole, N; Li, J; Newland, MC (2010). "Dietary selenium protects against selected signs of aging and methylmercury exposure". Neurotoxicology. 31 (2): 169–79. Bibcode:2010NeuTx..31..169H. doi:10.1016/j.neuro.2010.01.003. PMC   2853007 . PMID   20079371.
  41. ↑ Myers, G.J.; Davidson, P.W.; Weiss, B. (2004). "Methyl mercury exposure and poisoning at Niigata, Japan" (PDF). SMDJ Seychelles Medical and Dental Journal. 7 (Special Issue): 132–133. Archived from the original (PDF) on May 5, 2006. Retrieved January 12, 2006.
  42. ↑ For example: Hightower, JM; Moore, D (2003). "Mercury levels in high-end consumers of fish". Environmental Health Perspectives. 111 (4): 604–8. doi:10.1289/ehp.5837. PMC   1241452 . PMID   12676623.
  43. ↑ Information on characteristic levels of methylmercury by species can be found at "FDA - Mercury Levels in Commercial Fish and Shellfish". Archived from the original on 2006-01-10. Retrieved 2006-01-03.
  44. ↑ A wallet-card guide for consumers can be found at http://www.nrdc.org/health/effects/mercury/protect.asp
  45. ↑ Scheuhammer, Anton M.; Meyer, Michael W.; Sandheinrich, Mark B.; Murray, Michael W. (2007). "Effects of Environmental Methylmercury on the Health of Wild Birds, Mammals, and Fish". Ambio: A Journal of the Human Environment. 36 (1): 12–19. doi:10.1579/0044-7447(2007)36[12:EOEMOT]2.0.CO;2. ISSN   0044-7447. PMID   17408187. S2CID   13126984.
  46. ↑ Wheatley, B; Wheatley, M (2000). "Methylmercury and the health of indigenous peoples: a risk management challenge for physical and social sciences and for public health policy". The Science of the Total Environment. 259 (1–3): 23–29. Bibcode:2000ScTEn.259...23W. doi:10.1016/S0048-9697(00)00546-5. PMID   11032132.
  47. ↑ Jozef M. Pacyna, Kyrre Sundseth, Elisabeth G. Pacyna, Wojciech Jozewicz, John Munthe, Mohammed Belhaj & Stefan Aström (2010), "An Assessment of Costs and Benefits Associated with Mercury Emission Reductions from Major Anthropogenic Sources", Journal of the Air & Waste Management Association, 60:3, 302–315, DOI: 10.3155/1047-3289.60.3.302
  48. ↑ Pirrone, N.; Cinnirella, S.; Feng, X.; Finkelman, R.B.; Friedli, H.R.; Leaner, J.; Mason, R.; Mukherjee, A.B.; Stracher, G.B.; Streets, D.G.; Telmer, K. (2010). "Global Mercury Emissions to the Atmosphere from Anthropogenic and Natural Sources". Atmospheric Chemistry and Physics. 10 (13): 5951–5964. Bibcode:2010ACP....10.5951P. doi: 10.5194/acp-10-5951-2010 .
  49. ↑ Hope, Bruce K.; Louch, Jeff (2013). "Pre-Anthropocene Mercury Residues in North American Freshwater Fish". Integrated Environmental Assessment and Management. 10 (2): 299–308. doi:10.1002/ieam.1500. PMID   24458807. S2CID   205932358.
  50. ↑ Carl H. Lamborg, Chad R. Hammerschmidt, Katlin L. Bowman, Gretchen J. Swarr, Kathleen M. Munson, Daniel C. Ohnemus, Phoebe J. Lam, Lars-Eric Heimbürger, Micha J. A. Rijkenberg & Mak A. Saito (2014) A global ocean inventory of anthropogenic mercury based on water column measurements, Nature, 512, 65–68, doi:10.1038/nature13563
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