Ebook Pediatric environmental health (4/E): Part 2
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Ebook Pediatric environmental health (4/E): Part 2
Chapter 33Mercury >■KEY POINTSSigns and symptoms of mercury toxicity depend on the form of mercury. Elemental mercury exposure occurs by inhaling the Ebook Pediatric environmental health (4/E): Part 2 colorless, odorless vapor. Organic (melhylmercury) exposure occurs ữom consuming certain ocean sh or sh taken from contaminated fresh water lakes or streams.Elemental or inorganic mercury exposure typically is diagnosed by increased urine mercury levels.Organic (mcthylmcrcury) exposure typically is Ebook Pediatric environmental health (4/E): Part 2 diagnosed by increased blood total mercury levels.Autism is not caused by vaccines.imerosal, containing ethylmercury, has been removed from childhoodEbook Pediatric environmental health (4/E): Part 2
vaccines and now is only used as a preservative in multi-dose vaccines (eg, in uenza, meningococcal B).e only proven e eclive treatment for mercury eChapter 33Mercury >■KEY POINTSSigns and symptoms of mercury toxicity depend on the form of mercury. Elemental mercury exposure occurs by inhaling the Ebook Pediatric environmental health (4/E): Part 2ee forms: the metallic element (IIg°, quicksilver or elemental mercury), inorganic salts (Hg ’, or mercurous salts, and Hg* ,or mercuric salts), and organic compounds (methylmercury, ethylmercury, and phenyhnercury) (Table 33-1). Solubility, reactivity, biological effects, and toxicity vary among th Ebook Pediatric environmental health (4/E): Part 2ese forms.©Pediatric Enúonmenlal fetal th 4ttEditionTable 33-1. Sourcesand Routes of Exposure for Different Forms of MercuryMERCURY FORMSOURCE sROUTEEbook Pediatric environmental health (4/E): Part 2
OF EXPOSUREElemental or inorganicThermometers, sphygmomanometers. CFL or uorescent light bulbs; dental amalgams; mercury used in religious or ritual pChapter 33Mercury >■KEY POINTSSigns and symptoms of mercury toxicity depend on the form of mercury. Elemental mercury exposure occurs by inhaling the Ebook Pediatric environmental health (4/E): Part 2Ingestion or dermal absorptionMethyl mercury (organic)Shark, tuna, tile sh. sword sh; sh taken from mercury-contaminated lakes, rivers, or streamsIngestionEthylmercury (thimerosal)Multi-dose vaccines (meningococcal B and in uenza)InjectionAbbreviations: CFL. compact uorescant lightNaturally occurrin Ebook Pediatric environmental health (4/E): Part 2g mercury sources include cinnabar (orc) and fossil fuels, such as coal and petroleum. Environmental contamination has resulted from mining, smelting,Ebook Pediatric environmental health (4/E): Part 2
and industrial discharges (principally by burning fossil fuels). Atmospheric mercury contributes to local and global contamination. Mercury in lakes Chapter 33Mercury >■KEY POINTSSigns and symptoms of mercury toxicity depend on the form of mercury. Elemental mercury exposure occurs by inhaling the Ebook Pediatric environmental health (4/E): Part 2ressively bioaccumulate. The result is that certain predator fish from oceans or freshwater may contain higher levels of mercury. Very high exposures to methylmercury in fish in the 1950s following industrial release of mercury into Minamata Bay. Japan, caused serious disturbances in fetal brain dev Ebook Pediatric environmental health (4/E): Part 2elopment among exposed pregnant women and thousands of cases of acuteadult methylmercury toxicity, and an estimated 2()().()()() individuals had neuroEbook Pediatric environmental health (4/E): Part 2
logic manifestations of chronic methyl mercury exposure.1 To reduce consumption of the most highly contaminated fish species, states have issued advisChapter 33Mercury >■KEY POINTSSigns and symptoms of mercury toxicity depend on the form of mercury. Elemental mercury exposure occurs by inhaling the Ebook Pediatric environmental health (4/E): Part 2 limiting intake of large ocean fish, such as tuna, swordfish, king mackerel, tilefish, and shark, have been issued by the US federal government.1 Edible seaweed and fish oil supplements have not been found to contain mercury, but there is no ongoing program for sampling these marine-derived foods a Ebook Pediatric environmental health (4/E): Part 2nd supplements? ' Methylmercury use as a fungicide on seed grains has been banned in theUnited States since the early 1970s. Consumption of mercury-trEbook Pediatric environmental health (4/E): Part 2
eated seedChapter 33: Mercurygrains caused widespread mercury poisoning among people in Iraq and China and has been responsible for neurologic disordeChapter 33Mercury >■KEY POINTSSigns and symptoms of mercury toxicity depend on the form of mercury. Elemental mercury exposure occurs by inhaling the Ebook Pediatric environmental health (4/E): Part 2n these emissions since 2011 (https:// www.epa .gov.'1 ma t s).Elemental mercury has been used in sphygmomanometers, thermometers, and thermostat switches. Dental amalgams contain 40% to 50% mercury as well as silver and other metals. Fluorescent light bulbs, including tubes and compact bulbs, and d Ebook Pediatric environmental health (4/E): Part 2isc (button) batteries also contain mercury. Indiscriminate disposal of these items is a source of environmental mercury contamination when they are bEbook Pediatric environmental health (4/E): Part 2
uried in landfills or burned in waste incinerators rather than recycled. Skin lightening creams and soaps can contain toxicamounts of inorganic mercurChapter 33Mercury >■KEY POINTSSigns and symptoms of mercury toxicity depend on the form of mercury. Elemental mercury exposure occurs by inhaling the Ebook Pediatric environmental health (4/E): Part 2 to vaporize and remove the mercury. Elemental or inorganic mercury is used in some folk remedies and rituals, including Sanleria (a Cuban-based religion). Voodoo (a Haitian-based set of rituals). Espirilismo (a Puerto Rican based spiritual belief system), and Indian Ayurvedic medicine.' 4ROUTES OF Ebook Pediatric environmental health (4/E): Part 2EXPOSUREElemental Mercury and Inorganic MercuryElemental mercury is a Equid at room temperature and readily volatilizes to a colorless and odorless vaEbook Pediatric environmental health (4/E): Part 2
por. When inhaled, elemental mercury vapor easily passes through pulmonary alveolar membranes and enters the blood, where it distributes primarily intChapter 33Mercury >■KEY POINTSSigns and symptoms of mercury toxicity depend on the form of mercury. Elemental mercury exposure occurs by inhaling the Ebook Pediatric environmental health (4/E): Part 2nic mercury (Hg: *), which hinders its elimination. Approximately 80% of inhaled mercury is absorbed in the body. In contrast, less than 0.1% of elemental mercury is absorbed from the gastrointestinal tract after ingestion, and only minimal absorption occurs with dermal exposure.Inorganic Mercury Sa Ebook Pediatric environmental health (4/E): Part 2ltsInorganic mercury salts arc poorly absorbed after ingestion, although mercuric salts lend to be extremely caustic and cause stomach bleeding when iEbook Pediatric environmental health (4/E): Part 2
ngested. Mercurous salts may be less caustic to the intestinal tract but can result in nephrotoxicity after ingestion or skin application.Organic MercChapter 33Mercury >■KEY POINTSSigns and symptoms of mercury toxicity depend on the form of mercury. Elemental mercury exposure occurs by inhaling the Ebook Pediatric environmental health (4/E): Part 2on.® Pediatric Enkonmenlal fcfelth4tl£ditioncontributing to concern about consumption of methylmercury-contaminated fish.1 Methylmercury passes through the placenta, is concentrated in the fetus, and is transferred into human milk. Phenylmercury is well absorbed after ingestion and dermal contact. I Ebook Pediatric environmental health (4/E): Part 2n contrast to other organic mercury compounds, the carbon-mercury chemical bond of phenylmercury is relatively unstable, resulting in the release of eEbook Pediatric environmental health (4/E): Part 2
lemental mercury that can be inhaled and absorbed across pulmonary membranes.Chapter 33Mercury >■KEY POINTSSigns and symptoms of mercury toxicity depend on the form of mercury. Elemental mercury exposure occurs by inhaling the Chapter 33Mercury >■KEY POINTSSigns and symptoms of mercury toxicity depend on the form of mercury. Elemental mercury exposure occurs by inhaling theGọi ngay
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