Simple and sensitive method for the determination of methylmercury in hair using thin-layer chromatography with thermal decomposition gold amalgamation atomic absorption spectrophotometry.

An improved method is described for the determination of methylmercury (MeHg) in human hair that is based on thin-layer chromatography and thermal decomposition gold amalgamation atomic absorption spectrophotometry. The dithizone extraction and application procedure of this technique were optimized, thus improving its sensitivity and robustness and enabling the use of less toxic solvents than other approaches. The limit of detection was 0.

Trends in mercury concentrations and methylation in Minamata Bay, Japan, between 2014 and 2018.

Methylmercury concentrations in Minamata Bay are high, but the cause is unclear. We conducted a basic study on the behavior of methylmercury in Minamata Bay seawater; the findings suggest that mercury methylation may occur throughout the year in Minamata Bay. Seawater temperature, salinity, and concentrations of dissolved organic carbon were the environmental factors that affected methylation, and the degree of methylation was closely related to bacterial community structure.

Development of Human Hair Reference Material Supporting the Biomonitoring of Methylmercury.

A certified reference material, NIMD-01, was developed for the analysis of mercury speciation in human hair. We collected the hair of Vietnamese males from a barbershop in Hanoi in 2016 and prepared 1200 bottles containing 3 g of sieved and blended hair powder. The certified value was given on a dry-mass basis, with the moisture content obtained by drying at 85°C for 4 h.

Food sources are more important than biomagnification on mercury bioaccumulation in marine fishes.

Marine animals often accumulate various harmful substances through the foods they ingest. The bioaccumulation levels of these harmful substances are affected by the degrees of pollution in the food and of biomagnification; however, which of these sources is more important is not well-investigated for mercury (Hg) bioaccumulation. Here we addressed this issue in fishes that inhabit the waters around Minamata Bay, located off the west coast of Kyushu Island in Kumamoto Prefecture, Japan.

Mercury speciation in preserved historical sludge: Potential risk from sludge contained within reclaimed land of Minamata Bay, Japan.

In the latter half of the 1950s, a large amount of methylmercury (MeHg) was discharged directly into Minamata Bay, Japan by a chemical factory, resulting in the contamination of the fish and shellfish. Ultimately, an outbreak of MeHg intoxication, called Minamata disease, occurred. From 1977 to 1988, the Kumamoto Prefectural Government dredged and transferred sediments exceeding 25 μg/g of total mercury (THg, dry basis) into a strictly segregated area of the bay near the wastewater outlet, then this area was landfilled.

The spatial distribution of total mercury in sediments in the Yatsushiro Sea, Japan.

The Yatsushiro Sea in Japan is contaminated with mercury in wastewater discharge from the Chisso Company, which produced acetaldehyde from 1932 onwards. In this study, we investigated the current spatial distribution of total mercury (T-Hg) in sediments, both at the surface and at different depths, using 43 sediment cores and 22 surface sediment samples collected from the Yatsushiro Sea in August 2017. Altogether, 821 surface and core samples were analyzed for their T-Hg concentrations.

Vertical Distribution of Total Mercury and Mercury Methylation in a Landfill Site in Japan.

Mercury is a neurotoxin, with certain organic forms of the element being particularly harmful to humans. The Minamata Convention was adopted to reduce the intentional use and emission of mercury. Because mercury is an element, it cannot be decomposed.

Chemical characteristics of dissolved mercury in the pore water of Minamata Bay sediments.

Methylmercury concentrations in fish from the historically polluted Minamata Bay remain higher than in fish from other coastal seas around Japan. To obtain a better understanding of this phenomenon, the chemical characteristics of pore water from Minamata Bay sediments were investigated. Samples were taken from two stations over a 1-year period.

The dynamics of mercury near Idrija mercury mine, Slovenia: Horizontal and vertical distributions of total, methyl, and ethyl mercury concentrations in soils.

The distributions of the total mercury (T-Hg), methylmercury (MeHg), and ethylmercury (EtHg) concentrations in soil and their relationship to chemical composition of the soil and total organic carbon content (TOC, %) were investigated. Core samples were collected from hill slope on the right and left riverbanks of the Idrija River. Former smelting plant is located on the right bank.

An inter-laboratory comparison of different analytical methods for the determination of monomethylmercury in various soil and sediment samples: A platform for method improvement.

An inter-laboratory study was conducted to compare results from different analytical methods for monomethylmercury (MeHg) concentrations in 17 soil and sediment samples. The samples were collected from mercury-contaminated areas, including Minamata Bay and Kagoshima Bay in Japan, the Idrija mercury mine in Slovenia, and an artisanal small-scale gold mining area in Indonesia. The Hg in these samples comes from several different sources: industrial waste from an acetaldehyde production facility, volcanic activity, Hg mining activity, and artisanal and small-scale gold mining activity (ASGM).

Distribution of total mercury and methylmercury around the small-scale gold mining area along the Cikaniki River, Bogor, Indonesia.

This study investigates the distribution of total mercury (T-Hg) and methylmercury (MeHg) in the soil and water around the artisanal and small-scale gold mining (ASGM) area along the Cikaniki River, West Java, Indonesia. The concentration of T-Hg and MeHg in the forest soil ranged from 0.07 to 16.

Distribution and characteristics of methylmercury in surface sediment in Minamata Bay.

This study was carried out to evaluate the present-day chemical properties of methylmercury in surface sediment in Minamata Bay where a dredging project was completed 28years ago. Present-day sediment from Minamata Bay consists of sandy silt, and the average loss-on-ignition in surface sediment was 7.0±2.

Tracking the fate of mercury in the fish and bottom sediments of Minamata Bay, Japan, using stable mercury isotopes.

Between 1932 and 1968, industrial wastewater containing methylmercury (MeHg) and other mercury (Hg) compounds was discharged directly into Minamata Bay, Japan, seriously contaminating the fishery. Thousands of people who consumed tainted fish and shellfish developed a neurological disorder now known as Minamata disease. Concentrations of total mercury (THg) in recent fish and sediment samples from Minamata Bay remain higher than those in other Japanese coastal waters, and elevated concentrations of THg in sediments in the greater Yatsushiro Sea suggest that Hg has moved beyond the bay.

Reevaluation of Minamata Bay, 25 years after the dredging of mercury-polluted sediments.

A detailed investigation of mercury concentrations in the bottom sediments of Minamata Bay was performed in May, 2012. A total of 691 sediment samples were obtained from 107 sampling points in the bay. The weighted average total mercury concentration and the total mass of mercury in the bottom sediments of Minamata Bay were estimated to be 2.

Effect of seasonal variation in seawater dissolved mercury concentrations on mercury accumulation in the muscle of red sea bream (Pagrus major) held in Minamata Bay, Japan.

Japanese stingfish (Sebastiscus marmoratus) and Bambooleaf wrasse (Pseudolabrus japonicas) are monitored annually for mercury pollution in Minamata Bay, Japan. The average total mercury concentration in the muscle of these two species in Minamata Bay was 0.36 mg kg(-1) wet weight and 0.

Sensitive determination method for mercury ion, methyl-, ethyl-, and phenyl-mercury in water and biological samples using high-performance liquid chromatography with chemiluminescence detection.

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-CS(2)), and then injected onto a HPLC instrument coupled with a tris(2,2'-bipyridine)ruthenium(III) chemiluminescence detection system. The emetine-CS(2) complexing agent was effectively used to measure the concentration in addition to serving as a separation and detection reagent.

Mercury contamination in humans in Upper Maroni, French Guiana between 2004 and 2009.

We measured hair mercury concentration in Amerindians between 2004 and 2009 in Upper Maroni, French Guiana. Hair samples were collected from 387 residents (males: 153, females: 234). Average hair mercury concentration was high (males: 9.

Head hair total mercury and methylmercury levels in some Ghanaian individuals for the estimation of their exposure to mercury: preliminary studies.

The extent of human exposure to mercury in some individuals in Ghana was evaluated by analysing samples of human head hair for total mercury and methylmercury. The average level of total mercury was 0.843 microg g(-1) (in range of 0.

Environmental and human exposure assessment monitoring of communities near an abandoned mercury mine in the Philippines: a toxic legacy.

Abandoned mines are an important global concern and continue to pose real or potential threats to human safety and health including environmental damage/s. Very few countries had government mine regulation and reclamation policies until the latter part of the century where legal, financial and technical procedures were required for existing mining operations. Major reasons for mine closure may be mainly due to poor economies of the commodity making mining unprofitable, technical difficulties and national security.

Spatial variations of mercury in sediment of Minamata Bay, Japan.

Mercury-contaminated effluent was discharged into Minamata Bay from a chemical plant over a period of approximately 40 years until 1968. In October 1977, the Minamata Bay Pollution Prevention Project was initiated to dispose of sedimentary sludge containing mercury concentrations higher than 25 mg kg(-1). In March 1990, the project was completed.