Treatment of mercury vapor toxicity by combining deferasirox and deferiprone in rats

Neurological risks arising from the bioaccumulation of heavy metal contaminants: A focus on mercury

This study investigated the concentrations of heavy metals in the water sources of the upstream region of the Huangpu River, the Yangtze River Estuary, and various areas in Shanghai, as well as the heavy metal concentrations in the blood of Shanghai residents. It aimed to analyze the heavy metal elements absorbed by the human body and the resulting pathological effects. The results revealed that surface water primarily contains five heavy metals: copper (Cu), lead (Pb), zinc (Zn), arsenic (As), and mercury (Hg), while water sediments primarily contain seven heavy metals: Cu, cadmium (Cd), Pb, chromium (Cr), Zn, As, and Hg. The main heavy metals present in the human body are Pb, Hg, As, and Cd. By reviewing previous articles, it was found that heavy metal concentrations in human blood are higher than those in surface water, suggesting uncertainties in the heavy metal content of surface water and its tendency to settle at the bottom. Furthermore, a comparison of heavy metal content in sediments revealed that Hg is the most readily absorbed heavy metal by the human body and is also a toxic environmental pollutant. Within the cell, Hg is highly toxic to mitochondria and may cause oxidative stress and neurodegenerative disease. This study concludes that water sediments serve as the major source of pollution in the human body and pose significant health risks, thereby necessitating the implementation of effective preventive measures.

Mutagenic, Carcinogenic, and Teratogenic Effect of Heavy Metals

Heavy metal (HM)-induced toxicity and its associated complications have become a major issue in the medical world. HMs are not biodegradable, enter into the food chain, and gets accumulated in the living systems. Increased concentrations and accumulation of HMs can cause severely damaging effects and severe complications in living organisms and can even lead to the death of the organism. In Ayurvedic medicine, ingredients of natural origin, including whole plants or certain portions of the plant, animal sources, and minerals, are used for therapeutic purposes as medicine, both alone and in combination. HM such as cadmium, copper, zinc, lead, chromium, nickel, and arsenic cause hazardous effects on animals, human health, and the environment. This review focuses on mutagenic, carcinogenic, and teratogenic effects of HM , mechanism, organ toxicity, available remedies in the market, and their side effects. Also, emphasis is given to alternative systems of medicine to treat HM toxicity.

Mercury pollution in Peru: geographic distribution, health hazards, and sustainable removal technologies

Peru is one of the great gold producers worldwide. However, a significant portion of the gold produced in Peru derives from artisanal small-scale gold mining (ASGM) in the Andes and Amazon. In ASGM, gold amalgamation with mercury (Hg) is a critical procedure to refine gold through the formation of Au-Hg alloys. Due to the rudimentary and improvised techniques conducted by small-scale and informal miners, Hg contamination has become of great concern and is strictly associated with ASGM. Multiple studies have evidenced notably high concentrations of Hg in consumable fish species, rivers, sediments, and air in locations where ASGM is one of the main sources of income to local communities and is carried out aggressively. In the present review, we have conducted a systematic search for national and international literature reporting the concentration and distribution of Hg pollution across environmental compartments, biota, and human samples in Peru. The results and data retrieved from the articles were quantitatively and qualitatively analyzed, and the distribution of Hg across environmental compartments was visualized through a geographic information system. Additionally, we reviewed the use of adsorption techniques as alternatives to treat Hg⁰ vapor from the gold shop and smelter flues, one of the main sources of hazardous levels of Hg exposure.

Use of mercury isotopes to quantify sources of human inorganic mercury exposure and metabolic processes in the human body

The pathways of human mercury (Hg) exposure are complex and accurate understanding of relative contributions from different pathways are crucial for risk assessment and risk control. In this study, we determined total Hg concentration and Hg isotopic composition of human urine, dietary components, and inhaled air in the Wanshan Hg mining area (MA), Guiyang urban area (UA), and Changshun background area (BA) to understand Hg exposure sources and metabolic processes in human body. At the three studied sites, total gaseous mercury (TGM) showed negative δ²⁰²Hg (-3.11‰ to + 1.12‰) and near-zero Δ¹⁹⁹Hg (-0.16‰ to + 0.13‰), which were isotopically distinguishable from Hg isotope values of urine (δ²⁰²Hg: -4.02‰ to - 0.84‰; Δ¹⁹⁹Hg: -0.14‰ to 0.64‰). We observed an offset of -1.01‰ to -1.6‰ in δ²⁰²Hg between TGM and urine samples, and an offset of -1.01‰ to 0.80‰ in δ²⁰²Hg between rice and urine samples, suggesting that lighter isotopes are more easily accumulated in the kidneys and excreted by urine. We proposed that the high positive Δ¹⁹⁹Hg in urine samples of UA was derived from fish consumption. The results of a binary mixing model based on Δ¹⁹⁹Hg were compared with those from a classic dietary model. The results from the MIF binary model showed that fish consumption accounted for 22% of urine Hg in the families at UA, whereas fish consumption contributed limited Hg to MA and BA. This study highlighted that Hg isotopes can be a useful tracer in understanding the sources and fates of Hg in human bodies.

A review of pitfalls and progress in chelation treatment of metal poisonings

Most acute and chronic human metal poisonings are due to oral or inhalation exposure. Almost 80% of published animal experiments on chelation in metal poisoning used single or repeated intraperitoneal, intramuscular or intravenous administration of metal and chelator, impeding extrapolation to clinical settings. Intramuscular administration of dimercaptopropanol (BAL) has until now been used in acute arsenic, lead, and mercury poisonings, but repeated BAL administration increased the brain uptake of As, Pb and Hg in experimental animals. Also, diethyl dithiocarbamate (DDC) has been used as antidote in acute experimental animal parenteral Cd poisoning, and both DDC and tetraethylthiuram disulfide (TTD, disulfiram, Antabuse) have been used in nickel allergic patients. However, even one dose of DDC given immediately after oral Cd or Ni increased their brain uptake considerably. The calcium salt of ethylenediamminetetraacetic acid (CaEDTA) but not dimercaptosuccinic acid (DMSA) increased the brain uptake of Pb. In oral Cd or Hg poisoning, early oral administration of DMSA or dimercaptopropane sulfonate (DMPS) increased survival and reduced intestinal metal uptake. Oral administration of Prussian Blue or resins with fixed chelating groups that are not absorbed offer chelation approaches for decorporation after oral exposure to various metals. Diethylenetriaminepentaacetic acid (DTPA) nebulizers for pulmonary chelation after inhalation exposure need further development. Also, combined chelation with more than one compound may offer extensive advances. Solid knowledge on the chemistry of metal chelates together with relevant animal experiments should guide development of chelation procedures to alleviate and not aggravate the clinical status of poisoned patients.

Effect of mercury vapor inhalation on rat ovary: Stereology and histopathology

AIM

Mercury, an environmental contaminant, is a risk factor for health in whole living organisms. In this study, we investigated whether mercury vapor (HgO) inhalation has an effect on rat ovary.

METHODS

Twelve Wistar albino rats were divided equally into experimental (Hg) and control groups (n = 6). Animals in the Hg group were exposed to HgO for 45 days at a dose 1 mg/m(3)/day, after which, histological and stereological assessment were carried out.

RESULTS

Ovaries exposed to HgO had histo-morphometric alterations. HgO inhalation resulted in reduction of the total number of primordial, primary and Graaf follicles. Also, mean volume of ovary, medulla and cortex, corpus luteum (c. luteum) and Graaf follicles was decreased in the Hg group. Moreover, there was a significant increase in total volume of the atretic follicles. On light microscopy, thickening of tunica albuginea, increase of fibrils within the connective tissue, congestion of the capillaries and venous vessels, thinned walls and fibrin deposition in some large blood vessels, and edema were seen. Also, irregular follicle and oocyte borders, and hydropic degeneration in follicular granulosa cells were detected.

CONCLUSION

Structural alterations could be attributed to the toxic influence of HgO on rat ovary. The use of Hg should therefore be more controlled to minimize its toxic effect.