MERCURY is a metal found in elemental, organic, and inorganic forms in the nature. This substance is present in the composition of earth crust, soil, air, and even in some tissues of plants and sea animals. Each year nearly 3400 tons of MERCURY compounds are released in the environment, which 95% settle in the soil, 3% in the oceans, and 2% in the atmosphere. Different industrial products like medicines, health products (soaps, creams, skin lightening creams), medical instruments (thermometer, sphygmomanometer), some substances in dentistry (amalgam), mirrors, and even some of toys contein MERCURY. All of these compounds may enter into the human body via skin, gastrointestinal and respiratory tracts and cause serious harms. They may cause different signs of TOXICITY, local and general signs and symptoms, and in some cases even they may end up to death. When MERCURY TOXICITY is suspected, in addition to primary evaluations, some special laboratory tests may be of a great help.In order to provide a treatment, the basic steps for all toxicities must be performed to prevent further serious damages,and of course the care giver has to pay attention to specific and non specific features of this TOXICITY.

Background and aims: Methyl MERCURY is a well- known environmental pollutant and toxicant to the nervous tissue, particularly during development of prodecure of brain. Low concentration of methyl MERCURY chloride (MMC) can be transferred to the fetus through the placenta and to newborn offspring through dam. This study aimed at investigating the TOXICITY significant difference effect of methyl MERCURY chlyoride on nearborn rat.Methods: In this experimental study 21 adult female Wistar rats were devided in 3 groups, 2 experimental and 1 control group, the experimental groups were inoculated with MMC 0.5 and 4.5 mg/kg on the 15th, 16th and 17th gestation days. On day 25 after birth, 6 newborn rats from each experimental group were anesthetized. Blood samples were collected, alanine amino transferase (ALT), gamma glutamyle transferase (GGT), aspartate amino transferase (AST), alkaline phosphatase (ALP), tri iodo thyronine (T3), thyroxine (T4) and growth hormone (GH) were determined according to routine laboratory methods and the amount of MERCURY accumulation in some tissues were measured using atomic absorbtion. Histological examination of the brain, liver and kidney were also performed. The data were analyzed using Kruskal-Wallis and Mann Whitny tests.Results: Serum analysis showed no significant difference in the experimental groups in GGT, AST, ALT, T4 compared to control group (P>0.05). Also ALP, T3 and GH significantly increased compared to the control group (P<0.05). The MERCURY accumulation significantly increased retrospectively in brain, thyroid, kidney and liver with the increase in the injection dose (P<0.005). In the histopathologic study of the brain, degeneration and apoptosis were observed.Conclusion: This study showes that exposure to the low doses of induced MMC, reduces T3, growth hormone and it decreases ALP level in experimental groups compared to the control group. It may impair memory, learning and growth.

Copper (Cu) and MERCURY (Hg) enter aquatic ecosystems from different sources threatening health of aquatic organisms such as fish. As such, in this investigation, determinaing, Cu and Hg toxic concentration in Caspian roach (Rutilus rutilus caspicus), was undertaken. Acute TOXICITY of Cu and Hg were determined in fish specimen under semi-static condition. Caspian roach fry (~1 g) were exposed to Cu or Hg at 6 concentrations (0.2, 0.27, 0.39, 0.47, 0.59 and 0.66 mg L-1 total Cu and 0.22, 0.26, 0.3, 0.37, 0.44 and 0.52 mg L-1 Hg). Control fish were exposed to water with no Cu or Hg. Mortality was recorded at 24-h-intervals for 96 h. Total Cu-LC50 values found to be 0.43 mg L-1 for 24 and 48 h and 0.42 mg L-1 for 72 and 96 h. The lowest observed effect concentration (LOEC) values for total Cu were 0.39 mg L-1 for 24 and 48 h, and 0.20 mg L-1 for 72 and 96 h. On the other hand, free-Cu-LC50 values found to be 0.22 mg L-1 for 24 and 48 h and 0.21 mg L-1 for 72 and 96 h. LOEC values for free Cu were 0.20 mg L-1 for 24 and 48 h, and 0.10 mg L-1 for 72 and 96 h.24-72 h LC50 values for Hg were 0.37 mg L-1, while 96 h LC50 found to be 0.33 mg L-1. Likewise, LOEC values for Hg were 0.26 mg L-1 for 24-72 h, and 0.22 mg L-1 for 96 h. The results showed LOEC values for Cu and Hg in Caspian roach were lower than these metal concentrations in Caspian Sea water, suggesting little risk of acute TOXICITY in the sea. Chronic TOXICITY test is suggested to illustrate the effect of current levels of contamination in Caspian roach.

In most aquatic ecosystems MERCURY accumulates more in the sediment than in water column. However, due to limited eco-toxicological data, it is difficult to predict the TOXICITY of these sediments. The present study evaluated the effects of inorganic MERCURY in spiked sediment on the survival, growth, and emergence of the midge Chironomus riparius and compared the results to MERCURY concentrations reported in streams and rivers in Africa. At 3.84 mg Hg/kg dry sediment, MERCURY significantly reduced larval survival and midges emergence success in comparison to control sediment (P<0.05). The growth of the larva was significantly inhibited (P<0.05) at 2.42 mg Hg/ kg dry weight, while emergence of C .riparius midges was significantly delayed at 0.93 mg/kg dry wt. These results indicate that MERCURY inhibits C. riparius characteristics at lower concentrations than those which have been measured in sediments from watersheds impacted with MERCURY like those found around artisanal gold mining in Africa. It is therefore possible that Chironomus and probably other fauna living in these watersheds are at risk.

MERCURY (Hg) is one of the major toxic heavy metals because it bioaccumulates and biomagnifies in animal and human bodies via the food chain. To eliminate heavy metal contamination, plants are being used as removal agents of pollutants/toxic chemicals from the environment. The present study was mainly focused on elucidating the potential phytotoxic effects of Hg heavy metal ion exposure on Sesbania grandiflora seedlings. Growth of seedlings was significantly affected (56 %) at 60 mg L-1 Hg concentration. The level of chlorophyll pigment contents was increased in Hg-treated plants compared to the control. Malondialdehyde content and antioxidative enzyme activities were found to be significantly increased by increasing the concentration of Hg exposure up to 40 mg L-1 while slightly decreased at higher doses. The DNA alterations appearing in the random amplified polymorphic DNA (RAPD) profiles of leaf and root tissues following Hg heavy metal exposure included the disappearance of normal DNA bands and the appearance of new bands compared to the untreated controls. This result strongly indicated that genomic template stability was significantly affected by Hg-induced stress in S. grandiflora seedlings. It is concluded that DNA polymorphisms detected by RAPD fingerprinting analysis could be used as potential molecular markers for the evaluation of Hg heavy metal ion-induced genotoxic effects in other plant species.

The objectives of this work was to examine the toxicological effect and molecular changes caused by a heavy metal pollutant mercuric chloride (HgCl2), in fresh water snakehead Channa punctatus, locally known as Taki fish in Bangladesh. When fishes were exposed to HgCl2, it induced death of the fishes in a concentration-dependent manner. 1 mM, the highest concentration tested in this study, was found to be the deadliest and it induced death of the fishes within 35 to 40 minutes. As the concentration lowered (0.5 mM – 0.1 mM) the survival time increased dose dependently to near about five hours. HgCl2 dissolved in different types of water (such as distilled water, tap water and pond water) was found to have no effects in changing the required time of fish death. We later investigated the effect of HgCl2 on fish liver cells as liver cells are known to be mostly affected by toxic metals. HgCl2 found to decrease liver cell viability to 32% by the higher concentration (1 mM) tested. Liver cell viability increased up to 82% with decreasing concentration of HgCl2 from 0.5 mM to 0.1 mM. To characterize the mechanism of cell death induced by HgCl2, the changes in molecular level was then examined. It was found that the heavy metal induced chromosomal DNA fragmentation and expression of certain proteins.

In this article, the MERCURY-impregnated γ-alumina nanoparticles were prepared using impregnation of γ-alumina nanoparticles with MERCURY acetate into the solution of water/ isopropanol, followed by hydrolysis, washing, filtration, and drying at the room temperature. The structure of these nanoparticles were studied using X-ray diffraction (XRD) pattern. The XRD pattern was used to confirm the binding between MERCURY impregnated nanoparticles and thymine organic base in the DNA of target cell. The biological effects and TOXICITY of γ-alumina and MERCURY impregnated γ-alumina nanoparticles on the cancer cells (Hella) and bone marrow stem cells were examined using the MTT test. Based on the results, the TOXICITY of the MERCURY impregnated γ-alumina nanoparticles on Hella cancer cells was found to be higher than that of stem cells. In other words, the MERCURY impregnated γ-alumina nanoparticles had a significant effect on removing the Hella cancer cells. It was also found that in the lower concentrations, pure γ-alumina nanoparticles had lower TOXICITY than MERCURY impregnated alumina.