Total Mercury Concentration of Wild Caught Fish Purchased from Grocery Stores: A Potential Public Health Concern

Methylmercury is a highly toxic organic compound that bioaccumulates and biomagnifies in the human body when absorbed by the gastrointestinal tract after ingestion.1 Thus, monitoring methylmercury levels in fish is crucial for protecting public health and preventing dramatic scenarios such as the Minamata disease crisis in Japan. In this study, three different species of wild caught fish – Sockeye Salmon (Oncorhynchus nerka) from Alaska, USA; tuna imported from Vietnam; and swordfish (Xiphias gladius) imported from Indonesia – were collected from a Harris Teeter grocery store in Washington D.C. Total mercury concentration was measured by ICP-MS and the analyzed samples’ concentrations were 19.8 ± 2.9 ppb, 2.67 ± 0.01 ppm, and 380 ± 9 ppb for Sockeye Salmon, swordfish, and tuna, respectively.

Total Mercury Concentration of Wild Caught Fish Purchased from Grocery Stores: A Potential Public Health Concern

Methylmercury is a highly toxic organic compound that bioaccumulates and biomagnifies in the human body when absorbed by the gastrointestinal tract after ingestion.1 Thus, monitoring methylmercury levels in fish is crucial for protecting public health and preventing dramatic scenarios such as the Minamata disease crisis in Japan. In this study, three different species of wild caught fish – Sockeye Salmon (Oncorhynchus nerka) from Alaska, USA; tuna imported from Vietnam; and swordfish (Xiphias gladius) imported from Indonesia – were collected from a Harris Teeter grocery store in Washington D.C. Total mercury concentration was measured by ICP-MS and the analyzed samples’ concentrations were 19.8 ± 2.9 ppb, 2.67 ± 0.01 ppm, and 380 ± 9 ppb for Sockeye Salmon, swordfish, and tuna, respectively.

Total mercury pathways from artisanal and small-scale gold mining in Sukabumi using system dynamics model

Artisanal and small-scale gold mining (ASGM) has been operated in Sukabumi District, West Java, Indonesia, for more than two decades. ASGM uses mercury in a ball mill gold ore processing, and the waste is released into the environment during and after this process. Previous studies have found that mercury-contaminated water, air, sediments, soil, and aquatic biota. This study aimed to predict and analyze total mercury pathways from ASGM in the air, water, sediment, fish, and humans using a system dynamics model. The results showed that the total mercury concentration in water was low and still meets the standard, while the total mercury concentration in sediment had already exceeded the standard. Biomagnification occurred to plankton feeder fish and top predator fish, but still below the level of tolerance mercury. Mercury levels in top predator fish and humans take a long time to exceed the standard (77 and 67 months after entering the body, respectively). The percentage error of 17.67% compared to the experimental data showed that the prediction of the developed system dynamics model is acceptable. Therefore, the model can be used to predict the total mercury pathways in the environment, especially in the ASGM area.

Polar microbes and their implications in the aquatic mercury cycle

<p>The methylmercury has the feature, in addition to its high toxicity for living organisms, to be easily incorporated, bioaccumulated and biomagnified through the food web in aquatic systems. Recently, the microorganisms implicated in the transformation of mercury to methylmercury have been found much more diverse than previously thought. Among them, 9 methanogenic Archaea strains are able to methylate the mercury in pure culture. However, few proofs exist <em>in situ</em> in polar aquatic systems. Antarctic polar regions receive atmospheric mercury through long-range transport of foreign emissions. In a context of increasing releases of heavy metals in aquatic environments and atmosphere, it is a crucial objective to elucidate the fate of mercury in Antarctic polar aquatic ecosystems and the role Archaea could play in mercury transformations. Hence, microbial diversity was investigated in pristine Antarctic lakes (South Shetland Islands, Antarctic, Chile) and continental sub-Antarctic beaver ponds (Tierra del Fuego, Chile) where benthic total mercury concentration was 14 ±6.5 and 89 ±13 ppm, respectively. Until 6.3% of the active community could be constituted by putative methylators and a positive significant correlation was found between total mercury concentration and putative methylator relative abundance (linear model, p-value=0.001). Putative methylator Archaea <em>Methanoregula</em> and <em>Methanosphaerula</em> have been detected but did not seem active in the studied ecosystems (RNA metabarcoding VS DNA metabarcoding).</p><p>Combined with these molecular data, mercury methylation and methylmercury demethylation activities were performed by addition of enriched stables isotopes of inorganic mercury and methylmercury, respectively and we expect to find highest methylation rates in the rich-organic matter ecosystems such as sub-Antarctic beaver ponds.</p>

Selenium and mercury in the hair of raccoons (Procyon lotor) and European wildcats (Felis s. silvestris) from Germany and Luxembourg

This study examined the concentration of total mercury (THg) and selenium (Se), as well as the molar ratio of Se:THg in hair samples of terrestrial animals. THg and Se concentrations were measured from the hair of raccoons (Procyon lotor) and European wildcats (Felis s. silvestris) from Germany and Luxembourg. Median THg concentrations in hair from raccoons and wildcats were 0.369 and 0.273 mg kg−1 dry weight (dw), respectively. Se concentrations were higher in the hair of raccoons than of wildcats (0.851 and 0.641 mg kg−1 dw, respectively). Total mercury concentration in hair of raccoons from Luxembourg was almost 5× higher that found in hair of raccoons from Germany; however, Se concentration was similar. Thus, molar ratio of Se:THg was ~4× higher in the hair of raccoons from Germany than those from Luxembourg. Significant negative correlation was found between THg concentration and Se:THg molar ratio in both wildcats and raccoons.

Mercury content in the wool of domestic animals in Cherepovets

Mercury (Hg) and its compounds are considered as one of the ten major dangerous groups of chemicals. The content of mercury in the coat was 136 cats and 113 dogs in the territory of the Vologda Region in Cherepovets. The total mercury concentration in the wool samples was measured on a mercury analyzer RA-915 +. The values of the mercury index in cats range from less than 0,001 mg / kg to 13,00 mg / kg, in dogs from less than 0,001 mg / kg to 1,858 mg / kg. Statistical difference in the content of mercury in wool between cats and dogs was revealed. The Hg content in cats is 3,5 times higher than the dogs have. Comparison analysis showed the concentration of mercury in the wool of cats and dogs have no statistically significant differences. The authors noted that cats had 4 times more mercury who ate fish. The average content of Hg in the wool of dogs is slightly different for those who ate fish.