Inorganic mercury (Hg2+) accumulation in autotrophic and mixotrophic planktonic protists: Implications for Hg trophodynamics in ultraoligotrophic Andean Patagonian lakes

AbstractThe Greenland Ice Sheet is currently not accounted for in Arctic mercury budgets, despite large and increasing annual runoff to the ocean and the socio-economic concerns of high mercury levels in Arctic organisms. Here we present concentrations of mercury in meltwaters from three glacial catchments on the southwestern margin of the Greenland Ice Sheet and evaluate the export of mercury to downstream fjords based on samples collected during summer ablation seasons. We show that concentrations of dissolved mercury are among the highest recorded in natural waters and mercury yields from these glacial catchments (521–3,300 mmol km−2 year−1) are two orders of magnitude higher than from Arctic rivers (4–20 mmol km−2 year−1). Fluxes of dissolved mercury from the southwestern region of Greenland are estimated to be globally significant (15.4–212 kmol year−1), accounting for about 10% of the estimated global riverine flux, and include export of bioaccumulating methylmercury (0.31–1.97 kmol year−1). High dissolved mercury concentrations (~20 pM inorganic mercury and ~2 pM methylmercury) were found to persist across salinity gradients of fjords. Mean particulate mercury concentrations were among the highest recorded in the literature (~51,000 pM), and dissolved mercury concentrations in runoff exceed reported surface snow and ice values. These results suggest a geological source of mercury at the ice sheet bed. The high concentrations of mercury and its large export to the downstream fjords have important implications for Arctic ecosystems, highlighting an urgent need to better understand mercury dynamics in ice sheet runoff under global warming.

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The Prevalence of Inorganic Mercury in Human Kidneys Suggests a Role for Toxic Metals in Essential Hypertension

Toxics ◽

10.3390/toxics9030067 ◽

2021 ◽

Vol 9 (3) ◽

pp. 67

Author(s):

Roger Pamphlett ◽

Philip A. Doble ◽

David P. Bishop

Keyword(s):

Essential Hypertension ◽

Toxic Metals ◽

Inductively Coupled Plasma ◽

Dominant Role ◽

Inorganic Mercury ◽

Experimental Studies ◽

Human Kidney ◽

Proximal Tubules ◽

Age Related ◽

Icp Ms

The kidney plays a dominant role in the pathogenesis of essential hypertension, but the initial pathogenic events in the kidney leading to hypertension are not known. Exposure to mercury has been linked to many diseases including hypertension in epidemiological and experimental studies, so we studied the distribution and prevalence of mercury in the human kidney. Paraffin sections of kidneys were available from 129 people ranging in age from 1 to 104 years who had forensic/coronial autopsies. One individual had injected himself with metallic mercury, the other 128 were from varied clinicopathological backgrounds without known exposure to mercury. Sections were stained for inorganic mercury using autometallography. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) was used on six samples to confirm the presence of autometallography-detected mercury and to look for other toxic metals. In the 128 people without known mercury exposure, mercury was found in: (1) proximal tubules of the cortex and Henle thin loops of the medulla, in 25% of kidneys (and also in the man who injected himself with mercury), (2) proximal tubules only in 16% of kidneys, and (3) Henle thin loops only in 23% of kidneys. The age-related proportion of people who had any mercury in their kidney was 0% at 1–20 years, 66% at 21–40 years, 77% at 41–60 years, 84% at 61–80 years, and 64% at 81–104 years. LA-ICP-MS confirmed the presence of mercury in samples staining with autometallography and showed cadmium, lead, iron, nickel, and silver in some kidneys. In conclusion, mercury is found commonly in the adult human kidney, where it appears to accumulate in proximal tubules and Henle thin loops until an advanced age. Dysfunctions of both these cortical and medullary regions have been implicated in the pathogenesis of essential hypertension, so these findings suggest that further studies of the effects of mercury on blood pressure are warranted.

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In Situ Voltammetric Sensor of Potentially Bioavailable Inorganic Mercury in Marine Aquatic Systems Based on Gel-Integrated Nanostructured Gold-Based Microelectrode Arrays

ACS Sensors ◽

10.1021/acssensors.0c02111 ◽

2021 ◽

Author(s):

Mary-Lou Tercier-Waeber ◽

Melina Abdou ◽

Marianna Fighera ◽

Justyna Kowal ◽

Eric Bakker ◽

...

Keyword(s):

Inorganic Mercury ◽

Microelectrode Arrays ◽

Aquatic Systems ◽

Voltammetric Sensor ◽

Nanostructured Gold

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Occurrence of Volcanogenic Inorganic Mercury in Wild Mice Spinal Cord: Potential Health Implications

Biological Trace Element Research ◽

10.1007/s12011-021-02890-0 ◽

2021 ◽

Author(s):

A. Navarro-Sempere ◽

M. García ◽

A. S. Rodrigues ◽

P. V. Garcia ◽

R. Camarinho ◽

...

Keyword(s):

Spinal Cord ◽

Inorganic Mercury ◽

Elemental Mercury ◽

Potential Health ◽

Wild Mice ◽

Gaseous Elemental Mercury ◽

Lumbar Level ◽

Quantification Analysis ◽

Spinal Cord Potential ◽

Cord Potential

AbstractMercury accumulation has been proposed as a toxic factor that causes neurodegenerative diseases. However, the hazardous health effects of gaseous elemental mercury exposure on the spinal cord in volcanic areas have not been reported previously in the literature. To evaluate the presence of volcanogenic inorganic mercury in the spinal cord, a study was carried out in São Miguel island (Azores, Portugal) by comparing the spinal cord of mice exposed chronically to an active volcanic environment (Furnas village) with individuals not exposed (Rabo de Peixe village), through the autometallographic silver enhancement histochemical method. Moreover, a morphometric and quantification analysis of the axons was carried out. Results exhibited mercury deposits at the lumbar level of the spinal cord in the specimens captured at the site with volcanic activity (Furnas village). A decrease in axon calibre and axonal atrophy was also observed in these specimens. Given that these are relevant hallmarks in the neurodegenerative pathologies, our results highlight the importance of the surveillance of the health of populations chronically exposed to active volcanic environments.

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