Mercury blood

Schober SE, Sinks TH, Jones RL, Bolger, PM, McDowell M, Osterloh J, Garrett ES, Canady RA, Dillon CF, Sun Y, Joseph CB, Mahaffey KR. 2003. Blood mercury levels in US children and women of childbearing age, 1999-2000. J Am Med Assoc 289 1667-1674. 

A knowledge of physiology and pharmacokinetics is needed (Fanis et al. 1993 Monteiro and Furness 2001). Levels of mercuiy normally vary among internal tissues, and the time to equilibrate within each tissue varies. For example, blood mercury levels normally reflect veiy recent exposure, while brain and liver levels reflect longer-term exposure. Tissue-specific mechanisms of detoxification and seqnestration, among other processes, must be understood to define the bioactive moiety in observed tissue bmdens before a clear expression of toxicity can be derived (Woodetal. 1997). 

Meyer MW, Evers DC, Daulton T, Braselton WE. 1995. Common loons (Gavia immer) nesting on low pH lakes in northern Wisconsin have elevated blood mercury content. Water Air Soil Pollut 80 871-880. 

Human intake of total mercury from the diet normally ranges between 7 and 16 pg daily (Schumacher et al. 1994 Richardson et al. 1995). Fish consumption accounts for much of this exposure in the form of methylmercury 27% of the intake, and 40% of the absorbed dose. Intake of inorganic mercury arises primarily from foods other than fish, and is estimated at 1.8 pg daily with 0.18 pg absorbed daily (Richardson etal. 1995). In certain areas of India, blood mercury concentrations of people who ate fish were three to four times higher than non-fish eaters (Srinivasen and Mahajan 1989). In some countries, mercury in dental amalgams accounts for 2.8 pg daily, equivalent to as much as 36% of the total mercury intake and 42% of the absorbed dose (USPHS... 

Richardson etal. 1995). Some Canadian aboriginal peoples had grossly elevated blood mercury concentrations of >100 to 660 pg Hg/L, although there was no definitive diagnosis of methylmercury poisoning (Wheatley and Paradis 1995). 

Monkeys, Macaca fascicularis adults age 7-10 years Monkeys, Macaca fascicularis female adults Monkeys, Macaca spp. Exposed in utero maternal doses of 0, 50, 70, or 90 pg methylmercury/ kg BW daily resulted in blood mercury levels in treated infants of 1.0-2.5 mg/L offspring were conditioned and tested for ability to respond to a lit button for an apple juice reward and other tasks Daily dose of methylmercury chloride in apple juice for 150 days equivalent to daily doses of 0.0, 0.4, 4.0, or 50.0 pg methylmercury/kg BW Various... 

Mercury content, in pg/L, of 100 in urine and 280 in blood Mercury content, in pg/L, of 250 in urine and 500 in blood Increased tremors Increased prevalence of abnormal psychomotor scores Disturbances in tests on verbal intelligence and memory Short-term memory loss Increased tremor frequency and reaction time... 

The New Hampshire Department of Health and Human Services is determining blood mercury concentrations and related freshwater fish consumption, studying speciated arsenic in urine, and analyzing phthalates in urine and PBDEs in serum and breast milk (APHL 2004, 2006). In 2004, New Hampshire received about 300,000 to support its biomonitoring program (APHL 2004). 

Mercury Blood mercury Use of epidemiology studies to develop biomarker-response relationship in humans Appendix B... 

Mercury Blood mercury Biomarker to toxic effect in humans, although this relationship is for cord blood biomarker to external dose in humans Biomarker results can be used directly for estimation of human risk exposure apportionment and intervention possible... 

T. M. Bellanger, E. M. Caesar, L. Trachtman, Blood mercury levels and fish consumption in Louisiana, J. Louisiana State Med. Soc. (Official Organ of the Louisiana State Medical Society), 152 (2000), 64-73. 

Nova Scotia, Dr. Stephen Beauchamp studies toxic chemicals, such as mercury. Loons in Nova Scotia s Kejimkujik National Park are among the living creatures that he studies. Kejimkujik loons have higher blood mercury levels (5 pg Hg/1 g blood) than any other North American loons (2 pg Hg/1 g blood). Mercury is also found in high levels in the fish the loons eat. Mercury causes behavioural problems in the loons. As well, it may affect the loons reproductive success and immune function. 

Example Mercury is a known contaminant of seafood, and regulatory bodies such as the US Food and Drug Administration (FDA) recommend consumption of certain fish on the basis of their ppm levels of methylmercury substances, with a set action level for mercury in seafood of 1 ppm. The US EPA has also set an official reference dose (RfD) for mercury at 0.1 p,gkg per day in humans (corresponding to a blood mercury level of 5.8 p.g 1 or 5.8ppb), which is defined as the amount of mercury an individual (including sensitive subpopulations) can be exposed to on a daily basis over their lifetime without appreciable risk of effects. 

A 5-year-old Chinese boy developed motor and vocal tics. His parents had given him a Chinese herbal spray to treat mouth ulcers. The spray contained mercury 878 ppm. Mercury poisoning was confirmed by the blood mercury concentration (183 nmol/1, normal value for adults under 50 nmol/1). 

Because methyl mercury freely distributes throughout the body, monitoring of mercury in the blood is usually carried out to identify exposure to methyl mercury. The concentration of total mercury in blood among people who are not occupationally exposed is influenced by their consumption of fish. Heavy consumers of lake fish have higher blood mercury levels than those who eat fish only rarely. People who never eat fish have blood levels of around 2 pg Hg/L, while the mercury concentrations of those who eat fish three... 

During long-term constant exposure (several months) to methyl mercury in food, there is a linear relationship between daily intake of methyl mercury and the concentration of mercury in blood. The mercury concentration in blood (pg/L) corresponds to the daily intake of methyl mercury (pg/ day) multiplied by 0.5-1. When exposure is continuous, the blood mercury concentration is proportional to the concentration in the brain, the critical organ for methyl mercury toxicity. Because of mercury s short half-life in the blood (2-4 days), evaluation of blood mercury is of limited clinical value if a substantial amount of time has passed since time of exposure [43]. 

Chelating agents for mercury, such as cysteine and penicillamine, have been used as intervention measures to reduce the concentration of inorganic mercury. However, chelation therapy has yielded variable success in cases of alkyl mercury poisoning. Studies of MMM suggest that chelators may reduce brain and blood mercury levels if started within a few days after exposure. Surgical gallbladder drains and oral administration of a nonabsorbable thiol resin have been applied in order to interrupt biliary excretion and reabsorption of mercury by the intestine. 

In contrast with the long-term (perhaps permanent) effects noted in the previous study, Yang et al. (1994) reported that recovery from chronic elemental mercury intoxication may be complete when patients are removed early from the exposure environment. A 29-year-old worker in a Taiwanese lampsocketmanufacturing facility, with an initial urinary mercury concentration of 610 g/L (in a 24-hour sample) and a blood mercury concentration of 237 g/L (reference range, <10 g/L), exhibited a variety of symptoms, including blurred vision, dysarthria, prominent gingivitis, tremors (usually postural and... 

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