Mercury poisoning: Difference between revisions

Mercury in its various forms is particularly harmful to [[fetus]]es as an [[environmental toxin in pregnancy]], as well as to [[infant]]s. Women who have been exposed to mercury in substantial excess of dietary selenium intakes during pregnancy are at risk of giving birth to children with serious [[birth defects]]. Mercury exposures in excess of dietary selenium intakes in young children can have severe neurological consequences, preventing nerve sheaths from forming properly. Mercury inhibits the formation of [[myelin]].{{fact|date=June 2015}}

==Sources of mercury poisoning==

Compounds of mercury tend to be much more toxic than either the elemental or the salts. These compounds have been implicated in causing [[brain damage|brain]] and [[hepatitis|liver damage]]. The most dangerous mercury compound, [[dimethylmercury]], is so toxic that even a few [[microliter]]s spilled on the skin, or even on a latex glove, can cause death, as in the case of [[Karen Wetterhahn]].<ref name=bris/><ref name=osha/>

{{Main|Mercury in fish}}

[[Methylmercury]] is the major source of organic mercury for all individuals.<ref name=Clifton>{{cite journal |journal= Pediatr Clin North Am |year=2007 |volume=54 |issue=2 |pages=237–69, viii |title= Mercury exposure and public health |author= Clifton JC 2nd |doi=10.1016/j.pcl.2007.02.005 |pmid=17448359}}</ref> Due to [[bioaccumulation]] it works its way up through the [[food web]] and thus biomagnifies, resulting in high concentrations among populations of some species. Top predatory fish, such as [[tuna]] or [[swordfish]], are usually of greater concern than smaller species. The US [[Food and Drug Administration|FDA]] and the [[United States Environmental Protection Agency|EPA]] advise women of child-bearing age, nursing mothers, and young children to completely avoid [[swordfish]], [[shark]], [[king mackerel]] and [[tilefish]] from the Gulf of Mexico, and to limit consumption of [[albacore|albacore ("white") tuna]] to no more than {{convert|6|oz|g|lk=on|abbr=on}} per week, and of all other fish and shellfish to no more than {{convert|12|oz|g|abbr=on}} per week.<ref name="fda2004">[http://nepis.epa.gov/Exe/ZyNET.exe/300065VC.TXT?ZyActionD=ZyDocument&Client=EPA&Index=2000+Thru+2005&Docs=&Query=&Time=&EndTime=&SearchMethod=1&TocRestrict=n&Toc=&TocEntry=&QField=&QFieldYear=&QFieldMonth=&QFieldDay=&IntQFieldOp=0&ExtQFieldOp=0&XmlQuery=&File=D%3A\zyfiles\Index%20Data\00thru05\Txt\00000008\300065VC.txt&User=ANONYMOUS&Password=anonymous&SortMethod=h|-&MaximumDocuments=1&FuzzyDegree=0&ImageQuality=r75g8/r75g8/x150y150g16/i425&Display=p|f&DefSeekPage=x&SearchBack=ZyActionL&Back=ZyActionS&BackDesc=Results%20page&MaximumPages=1&ZyEntry=1&SeekPage=x&ZyPURL What you need to know about mercury in fish and shellfish - Advice for women who might become pregnant women who are pregnant nursing mothers young children.] U.S. [[Food and Drug Administration|FDA]] and U.S. [[United States Environmental Protection Agency|EPA]] Advisory EPA-823-F-04-009, March 2004.</ref> A 2006 review<!--, conducted by Dr. Dariush Mozaffarian and Dr. Eric B. Rimm,--> of the risks and benefits of fish consumption found, for adults, the benefits of one to two servings of fish per week outweigh the risks, even (except for a few fish species) for women of childbearing age, and that avoidance of fish consumption could result in significant excess [[coronary heart disease]] deaths and suboptimal [[neural development]] in children.<ref name="Mozaffarian D, Rimm EB 2006 1885–99">{{cite journal |journal=JAMA |year=2006 |volume=296 |issue=15 |pages=1885–99 |title= Fish intake, contaminants, and human health: evaluating the risks and the benefits |author= Mozaffarian D, Rimm EB |url=http://jama.ama-assn.org/cgi/content/full/296/15/1885 |pmid=17047219 |doi=10.1001/jama.296.15.1885}}</ref><!-- (Dr. Rimm has reported in the past that he has received payment or honoraria for presentations about food and diets from both the Culinary Institute of America and the International Chefs Association, among others.)-->

Methylmercury exposure during rodent gestation, a developmental period that approximately models human neural development during the first two trimesters of gestation,<ref>{{cite journal |last=Bayer |first=SA |author2=Altman, J |author3=Russo, RJ |author4= Xhang, X |title=Timetables of neurogenesis in the human brain based on experimentally determined patterns in the rat |journal= Neurotoxicology |year=1993 |volume=14 |issue=1 |pages=83–144 |url=http://www.ncbi.nlm.nih.gov/pubmed/8361683 |PMID=8361683}}</ref> <ref>{{cite journal |last=Rice |first=DC |author2=Barone, S |title=Critical periods of vulnerability for the developing nervous system: evidence from human and animal models |journal= Environmental Health Perspectives |year=2000 |volume=108 |issue=3 |pages=511-533 |url=http://www.jstor.org/discover/10.2307/3454543?uid=3739448&uid=2&uid=3737720&uid=4&sid=21106484789763 |PMID=10852851}}</ref> has long-lasting behavioral consequences that appear in adulthood and, in some cases, may not appear until aging. Prefrontal cortex or dopamine neurotransmission could be especially sensitive to even subtle gestational methylmercury exposure<ref>{{cite journal |last=Newland |first=MC |author2=Reed, MN |author3=Rasmussen, E |title=A hypothesis about how early developmental methylmercury exposure disrupts behavior in adulthood |journal= Behavioural Processes |year=2015 |volume=114 |pages=41-51 |url=http://dx.doi.org/10.1016/j.beproc.2015.03.007 |doi=10.1016/j.beproc.2015.03.007}}</ref> and suggests that public health assessments of methylmercury based on intellectual performance may underestimate the impact of methylmercury in public health.

 

 

===Inorganic mercury compounds===

| author =Langford NJ, Ferner RE

| title =Toxicity of mercury