Spatial variations of mercury in sediment of Minamata Bay, Japan

Tomiyasu, Takashi; Matsuyama, Akito; Eguchi, Tomomi; Fuchigami, Yoko; Oki, K.; Horvat, Milena; Rajar, Rudi; Akagi, Hirokatsu

doi:10.1016/j.scitotenv.2005.09.090

Cited by 67 publications

(34 citation statements)

References 17 publications

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“…Nevertheless, the burial of Hg released from chloralkali plant in the other impacted reservoirs having low sedimentation rates might be a longer process than here and does not necessarily eliminate the risk of food chain contamination by Hg. For example, in the infamous Minamata Bay (Japan), in which no river flows in, the highest THg concentrations in sediments as well as highest Hg methylation concentration were reported at 10-and 35-cm depth, although Hg discharges have been discontinued for over 30 years (Tomiyasu et al 2006(Tomiyasu et al , 2014. Moreover, Hg concentrations in mussels were also reported to be higher than background concentration, which demonstrate that sediments remain a source of MeHg for several decades (Tomiyasu et al 2006).…”

Section: Environmental Implications Of Phasing Out Hg Technology In Cmentioning

confidence: 99%

“…For example, in the infamous Minamata Bay (Japan), in which no river flows in, the highest THg concentrations in sediments as well as highest Hg methylation concentration were reported at 10-and 35-cm depth, although Hg discharges have been discontinued for over 30 years (Tomiyasu et al 2006(Tomiyasu et al , 2014. Moreover, Hg concentrations in mussels were also reported to be higher than background concentration, which demonstrate that sediments remain a source of MeHg for several decades (Tomiyasu et al 2006). However, in such a context of the Olt River, it is of the utmost importance to avoid dredging in the future and prevent the possible releases of Hg from the sediments.…”

Section: Environmental Implications Of Phasing Out Hg Technology In Cmentioning

confidence: 99%

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Persistent Hg contamination and occurrence of Hg-methylating transcript (hgcA) downstream of a chlor-alkali plant in the Olt River (Romania)

Bravo

Loizeau

Dranguet

et al. 2015

Environ Sci Pollut Res

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Chlor-alkali plants using mercury (Hg) cell technology are acute point sources of Hg pollution in the aquatic environment. While there have been recent efforts to reduce the use of Hg cells, some of the emitted Hg can be transformed to neurotoxic methylmercury (MeHg). Here, we aimed (i) to study the dispersion of Hg in four reservoirs located downstream of a chlor-alkali plant along the Olt River (Romania) and (ii) to track the activity of bacterial functional genes involved in Hg methylation. Total Hg (THg) concentrations in water and sediments decreased successively from the initial reservoir to downstream reservoirs. Suspended fine size particles and seston appeared to be responsible for the transport of THg into downstream reservoirs, while macrophytes reflected the local bioavailability of Hg. The concentration and proportion of MeHg were correlated with THg, but were not correlated with bacterial activity in sediments, while the abundance of hgcA transcript correlated with organic matter and Cl− concentration, indicating the importance of Hg bioavailability in sediments for Hg methylation. Our data clearly highlights the importance of considering Hg contamination as a legacy pollutant since there is a high risk of continued Hg accumulation in food webs long after Hg-cell phase out

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Section: Environmental Implications Of Phasing Out Hg Technology In Cmentioning

confidence: 99%

Section: Environmental Implications Of Phasing Out Hg Technology In Cmentioning

confidence: 99%

Persistent Hg contamination and occurrence of Hg-methylating transcript (hgcA) downstream of a chlor-alkali plant in the Olt River (Romania)

Bravo

Loizeau

Dranguet

et al. 2015

Environ Sci Pollut Res

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“…However, severe mercury contamination of natural environments can often be attributed to inappropriate human activities. Examples include the Minamata Bay in Japan, where the local fish-consuming villagers were exposed and poisoned by high levels of methylmercury in their seafood due to contamination by a nearby acetaldehyde production facility (Eto, 2000;Tomiyasu et al, 2006). The Y12 nuclear weapons plant facility at Oak Ridge (TN, USA) used mercury for lithium isotope separation during the 1950s and 1960s, and this resulted in an estimated 75-150 tonnes of mercury inadvertently being released to the local environment, including the East Fork Poplar Creek (Han et al, 2006).…”

Section: Introductionmentioning

confidence: 99%

High diversity of bacterial mercuric reductase genes from surface and sub-surface floodplain soil (Oak Ridge, USA)

Øregaard

Sørensen

2007

The ISME Journal

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DNA was extracted from different depth soils (0-5, 45-55 and 90-100 cm below surface) sampled at Lower East Fork Poplar Creek floodplain (LEFPCF), Oak Ridge (TN, USA). The presence of merA genes, encoding the mercuric reductase, the key enzyme in detoxification of mercury in bacteria, was examined by PCR targeting Actinobacteria, Firmicutes or b/c-Proteobacteria. b/c-Proteobacteria merA genes were successfully amplified from all soils, whereas Actinobacteria were amplified only from surface soil. merA clone libraries were constructed and sequenced. b/c-Proteobacteria sequences revealed high diversity in all soils, but limited vertical similarity. Less than 20% of the operational taxonomic units (OTU) (DNA sequences X95% identical) were shared between the different soils. Only one of the 62 OTU was X95% identical to a GenBank sequence, highlighting that cultivated bacteria are not representative of what is found in nature. Fewer merA sequences were obtained from the Actinobacteria, but these were also diverse, and all were different from GenBank sequences. A single clone was most closely related to merA of a-Proteobacteria. An alignment of putative merA genes of genome sequenced mainly marine a-Proteobacteria was used for design of merA primers. PCR amplification of soil a-Proteobacteria isolates and sequencing revealed that they were very different from the genome-sequenced bacteria (only 62%-66% identical at the amino-acid level), although internally similar. In light of the high functional diversity of mercury resistance genes and the limited vertical distribution of shared OTU, we discuss the role of horizontal gene transfer as a mechanism of bacterial adaptation to mercury.

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“…Mercury species in the other samples were not detected, because the concentration of T-Hg in water samples obtained from non-contaminated sites was at a sub-ng L -1 level, 10 and T-Hg concentrations in Idrija River water have been reported to be at a ng L -1 level. 26 The complex formation of dithiocarbamate ligands with various transition metal ions, such as Ni 2+ , Cu 2+ , Pd 2+ , Pb 2+ , and Zn…”

Section: Determination Of Sub-μg L -1 Level Contaminated Water Samplesmentioning

confidence: 99%

“…Mercury is released through volcanic, 1,2 mining, 3 and industrial activities, [4][5][6][7] and then spreads through the environment in various chemical forms. The level of mercury contamination and the chemical form vary greatly depending on the surrounding environment.…”

Section: Introductionmentioning

confidence: 99%

Sensitive Determination Method for Mercury Ion, Methyl-, Ethyl-, and Phenyl-mercury in Water and Biological Samples Using High-Performance Liquid Chromatography with Chemiluminescence Detection

et al. 2012

Self Cite

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A sensitive determination method for mercury speciation analysis was developed. Four mercury species, mercury ion, methylmercury, ethylmercury, and phenylmercury, were complexed with emetine-dithiocarbamate (emetine-CS2), and then injected onto a HPLC instrument coupled with a tris(2,2′-bipyridine)ruthenium(III) chemiluminescence detection system. The emetine-CS2 complexing agent was effectively used to measure the concentration in addition to serving as a separation and detection reagent. The calibration curves for these mercury complexes were linear in the range of 0.050 -10 μg L -1 (as Hg). The limit of detection for (emetine-CS2)2Hg, emetine-CS2-methylmercury, emetine-CS2-ethylmercury, and emetine-CS2-phenylmercury were 30, 17, 21, and 22 ng L -1 , respectively. The sensitivity of this method enables the determination of mercury species in water samples at sub-ppb levels. Furthermore, the method was applied to biological samples in combination with acid leaching and liquid-liquid extraction using emetine-CS2 as an extraction reagent. The determination results were in good agreement with the values of the certified reference materials.

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Spatial variations of mercury in sediment of Minamata Bay, Japan

Cited by 67 publications

References 17 publications

Persistent Hg contamination and occurrence of Hg-methylating transcript (hgcA) downstream of a chlor-alkali plant in the Olt River (Romania)

Persistent Hg contamination and occurrence of Hg-methylating transcript (hgcA) downstream of a chlor-alkali plant in the Olt River (Romania)

High diversity of bacterial mercuric reductase genes from surface and sub-surface floodplain soil (Oak Ridge, USA)

Sensitive Determination Method for Mercury Ion, Methyl-, Ethyl-, and Phenyl-mercury in Water and Biological Samples Using High-Performance Liquid Chromatography with Chemiluminescence Detection

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