The presence ofmercury infish is a health concern for people who eat them, especially for women who are or may become pregnant, nursing mothers, and young children. Fish andshellfish concentrate mercury in their bodies, often in the form ofmethylmercury, a highly toxicorganomercury compound. This element is known tobioaccumulate in humans, so bioaccumulation inseafood carries over into human populations, where it can result inmercury poisoning. Mercury is dangerous to both naturalecosystems and humans because it is ametal known to be highlytoxic, especially due to itsneurotoxic ability to damage thecentral nervous system.^[1][2]

In human-controlled ecosystems of fish, usually done for market production of wanted seafood species, mercury clearly rises through the food chain via fish consuming smallplankton, as well as through non-food sources such as underwater sediment.^[3]

Fish products have been shown to contain varying amounts ofheavy metals, particularly mercury and fat-soluble pollutants fromwater pollution. Species of fish that arelong-lived and high on thefood chain, such asmarlin,tuna,shark,swordfish,king mackerel andtilefish contain higher concentrations of mercury than others.^[4]Cetaceans (whales anddolphins) also bioaccumulate mercury and other pollutants, so populations that eatwhale meat, such asthe Japanese,Icelanders,Norwegians andthe Faroese, are also vulnerable to mercury ingestion.

The consumption of fish is by far the most significant source of ingestion-related mercury exposure in humans and animals.^[5]Mercury andmethyl mercury are present in only very small concentrations inseawater. However, they are absorbed, usually as methyl mercury, byalgae at the start of thefood chain. This algae is then eaten by fish and other organisms higher in the food chain. Fish efficiently absorb methyl mercury, but excrete it very slowly.^[6] Instead, it accumulates, primarily in theviscera, although also in the muscle tissue.^[7] This results in thebioaccumulation of mercury, in a buildup in theadipose tissue of successivetrophic levels:zooplankton, smallnekton, larger fish, and so on.^[8] The older that such fish become, the more mercury they may have absorbed. Anything that eats these fish within thefood chain also consumes the higher level of mercury that the fish have accumulated, including humans.^[8] This process explains why predatory fish such asswordfish andsharks or birds likeosprey andeagles have higher concentrations of mercury in their tissue than could be accounted for by direct exposure alone. Species on the food chain can amass body concentrations of mercury up to ten times higher than the species they consume. This process is called biomagnification. For example, herring contains mercury levels at about 0.1 parts per million, while shark contains mercury levels greater than 1 part per million.^{[5]: Vol. 4}

There are three types of mercury emission:anthropogenic, re-emission, and natural, includingvolcanoes andgeothermal vents. Anthropogenic sources are responsible for 30% of all emissions, while natural sources are responsible for 10%, and re-emission accounts for the other 60%. While re-emission accounts for the largest proportion of emissions, it is likely that the mercury emitted from these sources originally came from anthropogenic sources.^[9]

Anthropogenic sources include coal burning,cement production,oil refining,artisan and small-scale gold mining, wastes from consumer products,dental amalgam, thechlor-alkali industry, production ofvinyl chloride, and the mining,smelting, and production ofiron and other metals.^[9] The total amount of mercury released by mankind in 2010 was estimated to be 1,960 metric tons. The majority of this comes from coal burning and gold mining, accounting for 24% and 37% of total anthropogenic output, respectively.^[9]

Re-emission, the largest emitter, occurs in a variety of ways. It is possible for mercury that has been deposited in soil to be re-emitted into themercury cycle viafloods. A second example of re-emission is aforest fire; mercury that has been absorbed intoplant life is re-released into theatmosphere. While it is difficult to estimate the exact extent of mercury re-emission, it is an important field of study. Knowing how easily and how often previously emitted mercury can be released helps us learn how long it will take for a reduction in anthropogenic sources to be reflected in the environment. Mercury that has been released can find its way into theoceans. A 2008 model estimated the total amount of deposition into the oceans that year to be 3,700 metric tons. It is estimated thatrivers carry as much as 2,420 metric tons.^[9] Much of the mercury deposited in the oceans is re-emitted, however; as much as 300 metric tons is converted into methyl mercury. While only 13% of this finds its way into the food chain, that is still 40 metric tons a year.^[9]

Much (an estimated 40%) of the mercury that eventually finds its way into fish originates withcoal-burning power plants andchlorine production plants.^[10] The largest source of mercury contamination in the United States is coal-fueled power plant emissions.^[11] Chlorine chemical plants use mercury to extract chlorine from salt, which in many parts of the world is discharged as mercury compounds in waste water, though this process has been largely replaced by the more economically viable membrane cell process, which does not use mercury. Coal contains mercury as a natural contaminant. When it is fired for electricity generation, the mercury is released as smoke into the atmosphere. Most of this mercury pollution can be eliminated if pollution-control devices are installed.^[10]

Mercury in theUnited States frequently comes frompower plants, which release about 50% of the nation's mercuryemissions.^[12] In other countries, such asGhana,gold mining often uses mercurycompounds, leading to workers receiving significant quantities of mercury while performing their jobs. Such mercury from gold mines is specifically known to contribute tobiomagnification in aquaticfood chains.^[13]

Elemental mercury often comes fromcoal power plants, andoxidized mercury often comes fromincinerators. Oil-fired power plants also contribute mercury to the environment.^[1] Theenergy industry therefore is a key player in the introduction of mercury into theenvironment. When addressing the issue of reducing seafood mercury bioaccumulation on a global scale, it is important to pinpoint major energy producers and consumers whose exchange of energy may be the root of the problem.^{[citation needed]}

The farming ofaquatic organisms, known asaquaculture, often involvesfish feed that contains mercury. A study by Jardine has found no reliable connection between mercury in fish food affecting aquaculture organisms or aquatic organisms in the wild.^[14] Even so, mercury from other sources may affect organisms grown through aquaculture. InChina, farmed fish species, such asbighead carp,mud carp, andSiniperca chuatsi, carried 90% of total mercury content in all of the measured fish in a study by Cheng. This study also concluded that mercury bioaccumulates through food chains even in controlled aquaculture environments. Both total mercury and methyl mercury absorption was found to be derived from sediments containing mercury, not mainly from fish feed.^[3]

TheHawaii Institute of Marine Biology has noted that fish feed used in aquaculture often containsheavy metals such as mercury,lead, andarsenic, and has dispatched these concerns to organizations such as theFood and Agriculture Organization of theUnited Nations.^{[citation needed]}

Mercury can get intofreshwater systems bypoint sources and extended flooding.^[8] InCanada, mercury poisoning inGrassy Narrows was likely caused by a spill at apaper mill, which is a point source. Non-point sources include floods that create hospitable habitats forbacteria that can convert mercury tomethylmercury, which is the toxic form that bioaccumulates through aquaticfood webs. The effects of these different sources of mercury have been studied at theExperimental Lakes Area inOntario, Canada, using research procedures including whole-lake ecosystem experiments and non-lethal fish musclebiopsies.^[8]

TheU.S. Geological Survey (USGS) projects that in the next several decades there will be a 50 percent increase in mercury levels.^{[citation needed]} The study also shows that the increases are connected through industrial emissions and are not natural as previously thought.^{[citation needed]} However, by decreasing emissions from industrial plants, the possibility of decreasing the high level of mercury remains plausible.^[15] Several nations are currently implementing systems that will detect and therefore later be able to control the output of mercury into the atmosphere. Air pollution control devices (APCDs) have been implemented inSouth Korea as thegovernment is starting to take inventory of mercury sources. Mercury pollution can also be removed byelectrostatic precipitators (ESPs). Bag-based filters are also used infactories that may contribute mercury to the environment.Flue-gas desulfurization, normally used to eliminatesulfur dioxide, can also be used in conjunction with APCDs to remove additional mercury beforeexhausts are released into the environment.^[1] Even so, countries such as South Korea have only begun to use inventories of mercury sources, calling into question how fast anti-mercury measures will be put into factories.

Mercury content in fish does not affect all populations equally. Certain ethnic groups, as well as young children, are more likely to suffer the effects of methyl mercury poisoning. In the United States, Wallace gathered data that indicated 16.9% of women who self-identify asNative American,Asian,Pacific Islander, or multiracial exceed the recommendedreference dose of mercury.^[16] A study done on children of theFaroe Islands in the North Atlantic showed neurological problems stemming from mothers consumingpilot whale meat during pregnancy^[17] (seeWhaling in the Faroe Islands). A 2020 NBER paper found that in coastal Colombia, those born during periods when fish catches have high mercury content have worse educational and labor market outcomes than those born during periods of low mercury content in fish.^[18]

While various studies have shown high concentrations of mercury accumulated in fish, medical cases often go unreported and pose a difficulty in correlating mercury in fish with human poisoning. Environmental issues cover a broad range of areas, but medical cases that are associated with pollutants released into the environment by factories or construction areas causepublic health issues that affect not only the environment but also human well-being. Substances poisonous to thehuman body in a particular amount or dose may not cause any symptoms over time. While there are limits to how much of anything the body can have, mercury is a particular poison that produces immediate physical symptoms when the body has been accumulating it over a period of time.^{[clarification needed]}

In the United States, theEnvironmental Protection Agency (EPA) estimates the amount of mercury in human blood that is not likely to posefatal health outcomes. The agency is in charge of enforcing regulations and policies that cover a range of environmental topics.^[19] Analysis of blood mercury concentrations in childbearing women has documented that exposure to methyl mercury (MeHg) occurs primarily through the consumption of fish.^[20] TheU.S. Food and Drug Administration (FDA) highly recommends against pregnant women and young children consuming raw fish. Pregnant women and young children often lack strong immune systems and are more at risk for foodborne illnesses.^[21]

In the United States, EPA provides advice about the levels of mercury that are non-fatal in humans. Symptoms of exposure to high levels of methyl mercury include disturbedvision,hearing, and speech, lack of coordination, andmuscle weakness. Medical studies have examined the correlation of fish consumption and health issues. American studies have presented evidence of fish consumption and its effects onchild development.Longitudinal studies agree that human activities release mercury that accumulates inmarine life.^{[22][failed verification]} Addressing the issues of fish consumption forces health officials to recognize the sources of mercury in the human body. SpecificNative American tribes are vulnerable to a high exposure of mercury. Studies have determined that thesenative peoples in the U.S. suffer more from mercurypoisoning and illness than any othercohort group in the country. This is due to the fact that fish is a main source of protein. Exposure risk was assessed through a medical study, thus raisingjudicial issues of whether thepublic health of these groups is a priority in the United States.^[23]

Even in countries, such asSweden, that have phased out mercury in thedental industry and manufacturing, lingering quantities of mercury still exist inlakes and coastal areas. Moreover, global contributions of mercury to the environment also affect that country. A study in Sweden selected 127 women who had a high level of fish consumption. Around 20% of the women selected, after hair and blood samples, were found to have exceeded the EPA-recommendedreference dose of 0.1 micrograms of methyl mercury per kilogram of body weight. Additionally, the study concluded that there was "no margin of safety for neuraldevelopmental effects in fetus[es]"^[24] without removing the offending species of fish from the diets of the women. This indicates that families intending to raise children should be especially careful about exposing their unborn babies to mercury via fish.

Children exposed to mercury are particularly susceptible topoisoning since the ratio of food, water, and air intake versus individual body weight is much higher than that ofadults.^[25] Additionally, children undergo fast growth that causes them to be more susceptible to damaging exposure to methylmercury, as well as the long term consequences of such exposure duringchildhood development.^[25] Young age plays an important role in terms of damage caused by mercury, and much literature on mercury focuses onpregnant women and specific precautions designed to prevent youth mercury exposure. Prenatal methylmercury exposure does causebehavioral problems in infants and worsenedcognitive test performance. Additionally, Hughner estimates that 250,000 women may be exposing their unborn babies to levels of methyl mercury above recommended federal levels.^[26]

Economically, there does not seem to be a difference in mercury exposure based onsocioeconomic bracket and the ability to buyfish from the market. One study shows "no significant differences in mercury levels intuna,bluefish, andflounder as a function of type of store or economic neighborhood".^[27]

Certaincountries havecultural differences that lead to morefish consumption and therefore more possible exposure toseafood methylmercury. InGhana, the local population traditionally consumes large quantities of fish, leading to potentially dangerous amounts of mercury in thebloodstream.^[13]

In the Lower Amazon, mercury contamination in fish is driven by anthropogenic activities such as gold mining and deforestation, which release mercury into aquatic ecosystems.^[28][29] Studies report mercury concentrations in fish muscle tissue ranging from 0.01 to 0.67 μg/g, with carnivorous species likePlagioscion squamosissimus showing higher levels due to biomagnification, sometimes exceeding the World Health Organization's safety threshold of 0.5 μg/g.^[28] Local communities relying on fish as a dietary staple face potential health risks from mercury exposure. Mercury levels in aquatic species, including fish and shrimp (Macrobrachium amazonicum), indicate broader environmental contamination, particularly near mining areas.^[30] In theAmazonian Basin, during therainy season,herbivorous fish dominate the diet of 72.2% of the women selected from a particular Amazonianvillage. Analysis also shows increase of mercury content in the hair of humans who eat fish on a daily basis in the Amazon.^[31]

The most serious case of mercury poisoning in recent history was in the Japanese city ofMinamata, in the 1950s.Minamata poisoning demonstrated that significantprenatal andpostnatal exposure to high levels of methylmercury caused serious neurological problems. Minamata victims also showed higher than normal signs ofpsychiatric diseases, along with thosediseases being caused by underlying neurological issues.^[32]

A 2014 USGS survey of mercury levels in the United States water system found that methylmercury concentrations in fish were typically highest in wetland areas including the coastal plain streams in the Southeast. Fish methylmercury levels were also high in the Western US, but only in streams that had been mined for mercury or gold.^{[33][full citation needed]}

In the 1950s, inhabitants of the seaside town ofMinamata, onKyushu island in Japan, noticed strange behavior in animals. Cats would exhibit nervous tremors, dance, and scream. Within a few years, this was observed in other animals; birds would drop out of the sky. Symptoms were also observed in fish, an important component of the diet, especially for the poor. When human symptoms started to be noticed around 1956 an investigation began.Fishing was officially banned in 1957. It was found that theChisso Corporation, apetrochemical company and maker ofplastics such asvinyl chloride, had been discharging heavy metal waste into the sea for decades. They used mercury compounds as catalysts in their syntheses. It is believed that about 5,000 people were killed and perhaps 50,000 were to some extent poisoned by mercury.Mercury poisoning in Minamata, Japan, is now known asMinamata disease.

TheAmerican College of Obstetricians and Gynecologists noted that, considering all the dangers and benefits, the overall result of eating fish in the United States is likely to improve personal health rather than damage it.^[17] The College argues that theomega-3 polyunsaturated fatty acids found in fish have a health benefit that outweighs the harm from mercury orpolychlorinated biphenyls. Even so, the College suggested limiting fish consumption for pregnant women. A risk-benefit study weighing the risks of mercury consumption against the benefits derived from fish in Alaska showed that the benefits outweigh the risks when consuming salmon for both cardiovascular health and infant neurological development, and that methyl mercury data for non-oily fish need to be of high quality before relative risk can be reliably identified.^[34] TheSeychelles Child Development Study traced more than seven hundred mother-child pairs for nine years and found no neurological problems in the children resulting from both prenatal and postnatal methylmercury exposure. A study done with marketed fish inOman concluded that, except in a few rare cases, the fish available for consumption had lower levels of mercury than limits defined by various health organizations.^[35] Some, citing these studies, have suggested the creation of place-based consumption advisories.^[36] However place-based approaches do not take into account cases of severe mercury poisoning, such as that found inMinamata disease.

Selenium is an element that is known to counteract some of the dangers of ingesting mercury.^[26] Multiple studies have been done, such as those inNew Jersey andSweden, that take into account selenium as well as mercury levels. Fish often do contain selenium in conjunction with bioaccumulated mercury, which may offset some of the dangers associated with the mercury ingested.

The danger level fromconsuming fish depends on species and size. Size is the best predictor of increased levels of accumulated mercury.Sharks, such as themako shark, have very high levels of mercury. A study onNew Jerseycoastal fish indicated that one third of the sampled fish had levels of mercury above 0.5parts per million, a level that could pose a human health concern forconsumers who regularly eat this fish.^[26] Another study of marketplace fish caught in waters surroundingSouthern Italy showed that, undoubtedly, greater fish weight leads to additional mercury found in fish body tissues. Moreover, the concentration, measured inmilligrams of mercury perkilogram of fish, steadily increases with the size of the fish.Anglerfish off the coast of Italy were found with concentrations as high as 2.2 milligrams of mercury per kilogram, higher than the recommended limit of 1 milligram of mercury per kilogram. Annually,Italy catches approximately a third of its fish from theAdriatic Sea, where these anglerfish were found.^[37]

Fish that consume theirprey in a certain manner may contain much higher concentrations of mercury than other species.Grass carp off the coast of China hold far less internal mercury than dobighead carp. The reason for this is that bighead carp arefilter feeders, while grass carp are not. Thus, bighead carp gather more mercury by eating large amounts of small plankton, as well as sucking up sediments that collect a sizable amount of methyl mercury.^[3]

US government scientists tested fish in 291 streams around the country for mercury contamination. They found mercury in every fish tested, according to the study by theU.S. Department of the Interior. They found mercury even in fish of isolated rural waterways. Twenty-five percent of the fish tested had mercury levels above the safety levels determined by EPA for people who eat the fish regularly.^[11]

Since theMinamata disaster,Japan has improved on itsmercury regulation. During the 1970s Japan made strides to reduce mercury demand and production. Chief among these efforts was the reduction of inorganic mercury produced bymines. It was halted by 1974, and demand fell from 2,500 tons per year in 1964, its peak, to 10 tons per year in recent years.^[42] Since these initial strides, Japan has introduced a list of regulations governing the mercury content of a variety of materials.

Regulation of these potential sources of pollution reduces the amount of mercury that ends up infish and, throughbiomagnification, inhumans. In addition to enactinglegislation controlling the mercury levels in potential pollutants, Japan has directly influenced theenvironment by issuing regulations setting acceptable levels of environmental mercurypollution.

It is Japan's goal to promote international mercury legislation in hopes of preventing any country from experiencing what it did.^[42] Despite Japan's extensive regulation and experience with mercury-based disasters, there is still little information provided to the public. The Japanese Federal Fish Advisory's recommendations are less strict than those inAmerica.^[43]

The United States has regulated mercury emissions under the authority of theClean Air Act.

EPA first attempted to regulate power plant mercury emissions with theClean Air Mercury Rule in 2005.^[44] TheGeorge W. Bush administration intended for the regulation to use acap-and-trade system to control emissions across multiple industries. The rule was challenged in litigation, and in 2008 theU.S. Court of Appeals for the District of Columbia Circuit vacated the rule, stating that EPA had improperly excluded power plants from designation as emittinghazardous air pollutants.^[45]

EPA subsequently classified mercury emissions from power plants as hazardous under section 112 of the Clean Air Act. The 2012Mercury and Air Toxics Standards (MATS) regulation, issued by theBarack Obama administration, targets airborne mercury emissions from power plants and other stationary sources.^[46][47] Airborne mercury is dissolved in the oceans, wheremicroorganisms convert waterborne mercury intomethyl mercury, which enters thefood chain and is stored in fish tissue.

EPA stated that the MATS regulation would prevent about 90% of power plant mercury.^[47] The agency estimated the total expected health benefits are estimated at $37 billion–$90 billion by 2016.^{[citation needed]} EPA estimated the economic cost at $9.6 billion annually.^{[citation needed]}.

In 2020 theTrump administration weakened the MATS rule by disavowing EPA's previous calculations and justifications, thereby making the rule subject to legal challenges.^[48]

EPA published wastewater regulations (effluent guidelines) for mercury in industrial categories where mercury is used in the manufacturing process, includingbattery manufacturing;^[49]inorganic chemicals manufacturing;^[50] oil and gas extraction (drilling fluids andcuttings);^[51] and nonferrous metals manufacturing (smelting).^[52]

In EU, the regulation (EU) 2017/852^[53] covers the full life cycle of mercury. This legislation prohibits the manufacture, export and import of a large range of mercury-added products; puts an end to all uses of mercury catalysts and large electrodes in industrial processes and reduces the use of and pollution from dental amalgam. Recently, the EU estimated the Mercury content in the topsoils based on a large Land Cover Survey named LUCAS.^[54] The mercury content in EU topsoils has a median of 38 μg per Kg with a total content of around 45,000 tons^[55] in the 0–20 cm of EU.

Some believe that legislation on a global scale is needed for this issue because mercury pollution is estimated to be so far-reaching. Pollution from one country does not stay localized to that country. Despite this,international regulation has been slow to take off. The first forms of international legislation appeared in the 1970s, beginning as agreements about shared bodies of water.^[56] The next step was theStockholm Declaration, which urged countries to avoid polluting the oceans by dumping.^[57] The 1972Oslo Convention and the 1974Paris Convention were adopted by parts ofEurope. Both lessened polluting the ocean with mercury, the former by banning the dumping ofships andaircraft into the ocean and the latter by obligating participants to reduce land-based pollution on coastlines.^[58][59] The first real global legislation regarding mercury pollution was theBasel Convention of 1989. This convention attempts to reduce the movement of mercury across borders and primarily regulates theimport andexport oftoxic chemicals, including mercury.^[56] In 1998 the Convention on Long-Range Transboundary Air Pollution was adopted by most of theEuropean Union, the United States, andCanada. Its primary objective is to cut emissions ofheavy metals. The convention is the largest international agreement on mercury established to date.^[56] In the early 21st century, the focus of mercury regulation has been on voluntary programs.^[56] The next phase in legislation is a global effort, and this appears to be what the Minamata Convention hopes to accomplish. TheMinamata Convention, named after the Japanese city that suffered horribly from mercury pollution, has taken four years of negotiation but was finally adopted by delegates from over 140 countries. The convention was ratified after 50 countries signed it. The Minamata Convention requires all participants to eliminate, where possible, the release of mercury from small-scalegold mining. It also requires a sharp reduction in emission fromcoal burning.^[60]

The complexities associated with mercury transport and environmental fate are described by EPA in its 1997Mercury Study Report to Congress.^[5] Because methyl mercury and high levels of elemental mercury can be particularly toxic to a fetus or young children, government agencies, including the EPA and FDA, recommend that women who are pregnant or plan to become pregnant within the next one or two years, as well as young children, avoid eating more than 6 ounces (170g, one average meal) offish per week.^[21]

In the United States, the FDA established an action level for methylmercury in commercial marine and freshwater fish that is 1.0 parts per million (ppm). In Canada, the limit for the total of mercury content is 0.5 ppm. The "Got Mercury?" website (sponsored byTurtle Island Restoration Network, a non-profit organization) includes a calculator for determining mercury levels in fish.^[61]

Species with characteristically low levels of mercury includeshrimp,tilapia,salmon,pollock, andcatfish (FDA March 2004). The FDA characterizes shrimp, catfish, pollock, salmon,sardines, and canned light tuna as low-mercury seafood, although recent tests have indicated that up to 6 percent of canned light tuna may contain high levels.^[62] A study published in 2008 found that mercury distribution in tuna meat is inversely related to the lipid content, suggesting that the lipid concentration within edible tuna tissues has a diluting effect on mercury content.^[63] These findings suggest that choosing to consume a type of tuna that has a higher natural fat content may help reduce the amount of mercury intake, compared to consuming tuna with a low fat content. Also, many of the fish chosen forsushi contain high levels of mercury.^[64]

According to the FDA, the risk from mercury by eating fish and shellfish is not a health concern for most people.^[21] However, certain seafood might contain levels of mercury that may cause harm to an unborn baby (and especially its brain development and nervous system). In a young child, high levels of mercury can interfere with the development of the nervous system. The FDA provides three recommendations for young children, pregnant women, and women of child-bearing age:

1. Do not eatshark,swordfish,king mackerel, ortilefish (Gulf of Mexico) because they might contain high levels of mercury.
2. Eat up to 12 ounces (2 average meals of 170 g each) a week of a variety of fish andshellfish that are lower in mercury. Five of the most commonly eaten fish and shellfish that are low in mercury are:shrimp,canned light tuna,salmon,pollock, andcatfish. Another commonly eaten fish,albacore or ("white") tuna depending on its origin might have more mercury than canned light tuna. So, when choosing your two meals of fish and shellfish, it is recommended that you should not eat more than up to 6 ounces (one average meal) of albacore tuna per week.
3. Check local advisories about the safety of fish caught by family and friends in your local lakes, rivers, and coastal areas. If no advice is available, eat up to 6 ounces (one average meal of 170 g) per week of fish you catch from local waters, but consume no other fish during that week.

Research suggests that selenium content in fish is protective against the toxic effects of methylmercury content.^[65] Fish with higher ratios of selenium to methylmercury (Se:Hg) are better to eat since the selenium binds to the methylmercury allowing it to pass through the body un-absorbed.

In 2012 theEuropean Food Safety Authority (EFSA) reported on chemical contaminants they found in the food of over 20 European countries. They established that fish meat and fish products were primarily responsible for methylmercury in the diet of all age classes. Particularly implicated were swordfish, tuna, cod, pike, whiting and hake. The EFSA recommend a tolerable weekly intake for methylmercury of 1.3 μg/kg body weight.^[66]

• Diagnosis Mercury: Money, Politics and Poison
• Mercury pollution in the ocean
• Mercury in tuna
• Safe Harbor Certified Seafood
• Whale meat

• Kidd K and Batchelar K (2011)"Mercury" In: Wood CM, Farrell AP and Brauner CJ,Fish Physiology: Homeostasis and Toxicology of Non-Essential Metals, pp. 238–297. Academic Press.ISBN 9780123786340.
• Lubick, N. (2009). "Ocean mercury on the increase".Nature.doi:10.1038/news.2009.218.
• Rasmussen, RS; Nettleton, J; Morrissey, MT (2005)."A Review of Mercury in Seafood: special focus on tuna"(PDF).Journal of Aquatic Food Product Technology.14 (4):71–100.doi:10.1300/J030v14n04_06.S2CID 94568585. Archived fromthe original(PDF) on 2016-04-15. Retrieved2012-01-09.

• Health policy for pregnant women The NRDC created the chart below as a guideline to how much tuna can be eaten by children, pregnant women or women wanting to conceive, based on their weight.
• Recommendations for Fish Consumption in Alaska Bulletin No. 6 June 15, 2001 Mercury and National Fish Advisories Statement from Alaska Division of Public Health
• Methylmercury in Sport Fish: Information for Fish Consumers
• FDA Tests Show Mercury in White Tuna 3 Times Higher than Can Light, Says Mercury Policy Project
• Federal Study Shows Mercury In Fish Widespread, Inescapable
• Mercury Awareness Program Highlighted on Pacifica Radio | Turtle Island Restoration Network A Mercury Calculator from Got Mercury?
• Fish, Mercury & Nutrition: The Net Effects Documentary produced byPrairie Public Television

• Environmental impact of fishing
• Mercury (element)

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