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Siegel, S. Fetal exposure presents the greatest risk because mercury particularly targets developing nerve cells. The mercury released by burning coal is converted into a far more toxic form when it enters the food chain.
Mercury is released into the air from a coal-fired power plant, and falls to the ground with snow and rain. From there, it drains into watersheds, rivers, and lakes and settles into sediment. At this point it is brought into contact with bacteria who can convert elemental mercury into the more toxic methylmercury.
This process can also take place directly in the oceans, where large amounts of methylmercury are produced. Small organisms in these water bodies take up the mercury when they consume the bacteria, or feed on the bottom where mercury-laden sediments accumulate. Fish and larger creatures take up even more mercury when they eat the smaller organisms, and with every step of the food chain, the toxic effects are compounded.
Plants will also readily take up methylmercury through their roots, which can then be consumed by herbivores. An older animal will accumulate more mercury over its lifetime than a younger animal — this is called bioaccumulation.
Also, animals that eat higher on the food chain accumulate more mercury. Because marine food chains are long, marine mammals, predatory fish, and scavengers acquire more mercury than terrestrial herbivores like caribou and moose. Fish are considered the primary source of human exposure to mercury. Alaska issued a state fish consumption advisory based on mercury contamination for the first time in In July , regulators in Alaska finally added pike from the Kuskokwim and lower Yukon rivers to the list of restricted species in the state with more freshwater restrictions expected to follow.
The study found that fish consumption was not the source of the mercury. Local citizens have organized Community Advocates for Safe Emissions to push for tougher controls on mercury pollution from the Lafarge cement plant, which uses coal fly ash from power plants and fires its kilns with coal.
The plant is New York state's second-largest emitter of mercury. In the radio ads, Rev. Tracey Bianchi, an evangelical pastor and mother from suburban Chicago, argues mercury poisoning is a pro-life issue because it can cause permanent brain damage and developmental disabilities in the unborn.
The campaign also includes billboards in Arizona, Pennsylvania and Ohio and emails to nearly 10 million evangelicals and Catholics. Mitch Hescox, EEN president. In October , EPA announced it will set standards to require oil- and coal-fired power plants to reduce air pollution. The move settles a lawsuit filed by environmental groups to push EPA to issue limits on mercury emission. Now the EPA has agreed to set pollution standards by March on mercury and other harmful emissions from power plants.
Many power plants will be required to install expensive scrubber equipment to capture heavy metals and particulates. Currently only about a third of power plants use scrubbers. Environmentalists estimate that the new rules could save 35, lives per year by Jim Pew, an attorney at Earthjustice, hailed the agreement as "the Holy Grail of pollution control. In a motion filed on December 7, , the EPA asked for an extension in the current court-ordered schedule for issuing rules that would reduce harmful air emissions from large and small boilers and solid waste incinerators, which would cut emissions of pollutants, including mercury and soot.
EPA is under a current court order to issue final rules on January 16, and is seeking in its motion to the court to extend the schedule to finalize the rules by April The agency said the additional time is needed "to re-propose the rules based on a full assessment of information received since the rules were proposed.
On August 18, , the Public Employees for Environmental Responsibility PEER filed regulatory comments with the EPA , saying that in allowing virtually unlimited reuse of coal ash and other highly toxic combustion wastes, the EPA is allowing the most potent pollutants to reach the environment in the manufacture, use, and disposal of second generation coal ash products.
Coal combustion produces the nation's second biggest waste stream, second only to coal mining, and under EPA sponsorship, 60 million tons nearly half the total of coal ash and other coal waste are used in mine fill, cement, wallboard, snow and ice control, agriculture and even cosmetics.
In summer , the EPA put forward a proposal that would, at most, classify coal ash as hazardous only when it is in sludge or "wet storage. In comments filed with the EPA regulatory docket, PEER points out that due to stronger air pollution controls on emissions of mercury and other toxics, the mercury levels in coal ash and other wastes has been rising and will likely nearly double between and PEER said the data EPA used to make its May regulatory determination that coal ash is not hazardous is no longer representative of today's waste stream, and that EPA is ignoring its own scientific findings about mercury and other toxics reaching the environment from cross-media transfers e.
On March 16, , the U. Environmental Protection Agency EPA announced its proposed emissions standards to limit mercury, acid gases and other toxic pollution from power plants, to prevent an estimated 91 percent of the mercury in coal from being released to the air.
The EPA estimates that there are approximately 1, units affected by the action, including 1, existing coal-fired units. There are currently no existing national limits on the amount of mercury and other toxic air pollution released from power plant smokestacks. Bush was vacated by a court. The proposed toxics rule would reduce emissions of heavy metals , including mercury Hg , arsenic , chromium , and nickel , and acid gases, including hydrogen chloride HCl and hydrogen fluoride HF.
The proposed standards should reduce mercury emissions from power plants burning coal and oil by 91 percent, acid gas pollution by 91 percent, direct particulate matter emissions by 30 percent, and sulfur dioxide SO2 emissions by 53 percent, down to 2. The EPA's proposed standards are projected to save as many as 17, lives every year by ; prevent up to , cases of childhood asthma symptoms and 11, fewer cases of acute bronchitis among children every year; avoid more than 12, emergency room and hospital visits annually; and prevent , lost work days every year.
The EPA also projects that the proposed standards will create up to 31, short-term construction jobs and 9, long-term utility jobs.
Requirements of the new standards include: [13]. Environmentalists were immediately critical, " Sierra Club and others were reportedly preparing for a legal challenge to the EPA's stay. In June , it was reported that proposed clean air rules released by the EPA to cut mercury emissions from coal plants would exempt lignite coal-fired plants. The EPA in setting mercury standards is putting lignite coal - found mostly in Texas - in a different category than other coal.
Some speculated the exemption was to win over swing states that use lignite before the presidential election. The EPA is now recommending court-ordered standards to comply with the Clean Air Act that call for a 91 percent reduction for mercury and acid gasses, and 55 percent for sulfur dioxide.
State attorneys general could return to court if they feel final recommendations - when they become law in November - do not comply with the Clean Air Act. The EPA proposal gives other coal-fired power plants up to four years to meet the new standards. In December , the Obama administration announced the new rule - the Mercury and Air Toxics Standards - to limit emissions of mercury, arsenic, and other toxic substances from sources such as power plants.
Under the new rule, power plants can emit 1. When dropped, elemental mercury breaks into smaller droplets which can go through small cracks or become strongly attached to certain materials. At room temperature, exposed elemental mercury can evaporate to become an invisible, odorless toxic vapor. If heated, it is a colorless, odorless gas.
Learn about how people are most often exposed to elemental mercury and about the adverse health effects that exposures to elemental mercury can produce. Elemental mercury is an element that has not reacted with another substance. When mercury reacts with another substance, it forms a compound, such as inorganic mercury salts or methylmercury.
In its inorganic form, mercury occurs abundantly in the environment, primarily as the minerals cinnabar and metacinnabar, and as impurities in other minerals. Mercury can readily combine with chlorine, sulfur, and other elements, and subsequently weather to form inorganic salts.
Inorganic mercury salts can be transported in water and occur in soil. Dust containing these salts can enter the air from mining deposits of ores that contain mercury. Emissions of both elemental or inorganic mercury can occur from coal-fired power plants, burning of municipal and medical waste, and from factories that use mercury.
Inorganic mercury can also enter water or soil from the weathering of rocks that contain inorganic mercury salts, and from factories or water treatment facilities that release water contaminated with mercury.
Although the use of mercury salts in consumer products, such as medicinal products, have been discontinued, inorganic mercury compounds are still being widely used in skin lightening soaps and creams. Mercuric chloride is used in photography and as a topical antiseptic and disinfectant, wood preservative, and fungicide. In the past, mercurous chloride was widely used in medicinal products, including laxatives, worming medications, and teething powders.
It has since been replaced by safer and more effective agents.
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