Mercury cycling in the water column and upper sediments of a contaminated area, the Largo do Laranjo, Aveiro (Portugal), was evaluated after determination of reactive and non-reactive mercury concentrations in the water column and pore waters of sediments, collected in several places of this bay. In the water column, reactive mercury concentrations varied between 10 and 37 pmol dm(-3), the high...

A detailed understanding of the formation of the potent neurotoxic methylmercury is needed to explain the large observed variability in methylmercury levels in aquatic systems. While it is known that organic matter interacts strongly with mercury, the role of organic matter composition in the formation of methylmercury in aquatic systems remains poorly understood. Here we show that phytoplankto...

Cetaceans present a high capacity to accumulate trace elements and have been considered a good bioindicator of contamination. The study assesses the concentration of selenium (Se) and mercury (Hg), as organic mercury (HgOrg) in the liver and kidney of a dolphin incidentally caught in fishing nets along two Brazilian areas (southeast and south). No significant differences were observed in the co...

Fast and reliable analytical methods for mercury speciation would aid in understanding mercury offgas chemistry. Presently, the U.S. Environmental Protection Agency (EPA) regulates only total mercury; however, many studies indicate that mercury toxicity is highly dependent on the mercury speciation. For example, amalgams and mercury sulfides have relatively low toxicities, while organomercury a...

Mercury at low concentrations represents a major hazard to microorganisms. Inorganic mercury has been reported to produce harmful effects at 5 microg/l in a culture medium. Organomercury compounds can exert the same effect at concentrations 10 times lower than this. The organic forms of mercury are generally more toxic to aquatic organisms and birds than the inorganic forms. Aquatic plants are ...

Poisoning with organic mercury is uncommon (Cumings, 1959) and there have been few detailed pathological studies (Hunter and Russell, 1954; Brown, 1954). With the increasing use of insecticides and fungicides containing organic mercury more cases may be encountered. There has also been described from Japan another type of organic mercurial poisoning (Kurland, Faro, and Siedler, 1960); the occur...

Reported here is, for the first time, an important study of solvent effect on structural diversity in inorganic-organic mercury(II) complexes. As a result, the first supramolecular isomer in mercury(II) complexes is obtained. Importantly, a previously unobserved in situ generation of both inorganic (Cl(-)) and organic ([CH(3)-L1-CH(3)](2+)) ions was also observed.

In this procedure a single-beam spectrophotometer is used without background correction. By the method of Magos [Analyst (London) 96, 847 (1971)] mercury in undigested urine is complexed to L-cysteine in acid solution. At high pH and in the presence of stannous ions, mercury ions are reduced to elemental mercury. The mercury vapor is partitioned above the reagent solution in a specially designe...

BACKGROUND Organic mercury (Hg) is a global pollutant of concern and selenium is believed to afford protection against mercury risk though few approaches exist to rapidly assess both chemicals in biological samples. Here, micro-scale and rapid methods to detect organic mercury (< 1.5 ml total sample volume, < 1.5 hour) and total selenium (Se; < 3.0 ml total volume, < 3 hour) from a range of bio...

Organic mercury (Hg) species exert their toxicity primarily in the central nervous system. The food relevant Hg species methylmercury (MeHg) has been frequently studied regarding its neurotoxic effects in vitro and in vivo. Neurotoxicity of thiomersal, which is used as a preservative in medical preparations, is to date less characterised. Due to dealkylation of organic Hg or oxidation of elemen...