Toxicity of Organomercury Compounds

Organic Pollutants An Ecotoxicological Perspective, Second Edition 

and 23.7 ppm, respectively. Thus, symptoms of neurotoxicity were observed in individuals containing brain concentrations of Hg substantially lower than those associated with lethal toxicity. Interestingly, the proportion of the total mercury accounted for as organomercury declined with time, indicating that demethylation slowly occurred in the brain. 

The acute toxicity of different types of organomercury compounds to mammals, 

there is not a great deal of difference between the three classes in acute toxicity all are highly toxic. However, methyl mercury is more persistent than the other two types, and so has the greater potential to cause chronic toxicity. The latter point is important when considering the possibility of sublethal effects. 

Another major incident concerning methyl mercury was the severe pollution of Minamata bay in Japan (see Box 8.1). Here fish, fish-eating and scavenging birds, and humans feeding upon fish all died from organomercury poisoning. There may have been localized declines of marine species in this area due to methyl mercury, but there is no clear evidence of this. 

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Their extreme toxicity necessitates stringent precautions during their preparation and handling. The toxicity of organomercury compounds is often greater than that of the mercury in them the volatile alkylmercury class is particularly dangerous. 

A number of organomercury compounds are known. These compounds and their toxicities are discussed further in Chapter 12. 

The lethal dose of organomercury compounds is in the range 10- 60 mg/kg body weight although acute toxicity is much less common than chronic damage due to long-term contamination by relatively small amounts of these materials. Organic mercury compounds... 

Since the 1950s, diuretic therapy has changed dramatically. Earlier, the major diuretics were acidforming salts, xanthines, organomercurial compounds, and carbonic anhydrase inhibitors. Either because of toxicity or lack of efficacy, these agents are rarely if ever used. 

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