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Mercury Toxicity
Published in Edgardo R. Donati, Heavy Metals in the Environment, 2018
Mohammed H. Abu-Dieyeh, Kamal Usman, Haya Alduroobi, Mohammad Al-Ghouti
Complexation is crucial to mercury cycle in the environment and the most common complexing agent is methylation of mercury (Gabriel and Williamson, 2004). Methylation of mercury is generally believed to be facilitated by microorganisms, while abiotic factors are more likely to influence organic contaminants (Zhang et al., 2012). The production of methyl mercury is not as simple as a factor of total concentration mercury in the entire system, but a function of several environmental determinants; diversity of bacterial community, temperature, redox potential and persistence, as well as organic and inorganic complexing substances which together interact to determine methyl mercury formation (Randall and Chattopadhyay, 2013). Naturally occurring organic matter are known to be composed of a heterogeneous mixture of organic compounds that are widely distributed in the environment (Wang et al., 2012b). The natural organic matter binds strongly to heavy metals and influences their speciation, solubility, transport, and subsequent environmental toxicity (Buffle, 1988).
Chemical health risks
Published in Blanca Jiménez, Joan Rose, Urban Water Security: Managing Risks, 2009
Inés Navarro, Francisco J. Zagmutt
Atmospheric deposition of elemental mercury from both natural and anthropogenic sources is identified as an indirect source of mercury to surface waters (WHO, 2003). The greatest releases of anthropogenic mercury to the environment are from combustion of fuel containing trace amounts of mercury; industrial processes that use mercury; and disposal of products that contain mercury either as an intentional constituent or as an impurity. Most of this waste was either incinerated or placed in landfills. It is estimated that one-third of anthropogenic emissions are deposited through wet and dry sedimentation around the releases sites; while the remaining two-thirds are transported outside the sites and enter the global mercury cycle (US EPA, 1999).
Emissions Sources
Published in Winston Chow, Katherine K. Connor, Peter Mueller, Ronald Wyzga, Donald Porcella, Leonard Levin, Ramsay Chang, Managing Hazardous Air Pollutants, 2020
William P. Peel, Charles E. Schmidt
Hg° has a relatively long atmospheric half-life (≈1 year)7 and so is relatively well mixed in the global atmosphere before being deposited as a function of atmospheric oxidation-reduction reactions and precipitation.8,9 By contrast, ionic mercury should have a much shorter atmospheric residence time and so will more effectively be scavenged and deposited locally, near the source.10 Thus, in assessing the impact of emissions and emission-reduction strategies on the mercury cycle, it is vital that high-quality speciation information be obtained.
Fate of mercury in a terrestrial biological lab process using Polypogon monspeliensis and Cyperus odoratus
Published in International Journal of Phytoremediation, 2019
Héctor Daniel García-Mercado, Georgina Fernández-Villagómez, Marco Antonio Garzón-Zúñiga, María del Carmen Durán-Domínguez-de-Bazúa
Many authors have used the biological process for the treatment of contaminated sites as bioremediation, artificial wetlands, phytoremediation, and biofilters to understand the mercury cycle (de-Jesús-García 2007; Millán et al.2007; Moreno-Jímenez et al. 2007; Kumar et al.2008; Sas-Nowosielska et al. 2008; Chen et al. 2009; Freitas et al. 2009; López-Domínguez 2009). Some studies reported as P. monspeliensis mercury concentrations accumulated 6.27–13.35 mg g−1 in leaves at 5 days (de-Souza et al. 1999). Another report (Higueras et al. 2007) indicates mercury concentrations of 9–750 mg g−1 in roots, 6–525 mg g−1 in the stem, and 3–1500 mg g−1 in leaves for the same vegetal specie. While C. odoratus accumulated, in the root zone, 0.63 mg kg−1 of Cd and 22.9 mg kg−1 of Cr and the translocation factor was 1.51 (Nazareno and Bout 2015).