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α-Lindane
Published in Philip H. Howard, Edward M. Michalenko, William F. Jarvis, Dipak K. Basu, Gloria W. Sage, William M. Meylan, Julie A. Beauman, D. Anthony Gray, Handbook of Environmental FATE and EXPOSURE DATA, 2017
Philip H. Howard, Edward M. Michalenko, William F. Jarvis, Dipak K. Basu, Gloria W. Sage, William M. Meylan, Julie A. Beauman, D. Anthony Gray
Artificial Sources: Pesticidal use of technical hexachlorocyclohexane, a 65:7:14:4:10 mixture of the α, β, γ, epsilon and other isomers, respectively [33], constitutes the major release of α-HCH to the environment. α-HCH occurs as a byproduct of the production of lindane from benzenehexachloride [33]. Lindane may undergo sunlight induced isomerization to α-HCH to a small extent [43]. Based on α-HCH concentrations in sedimenting particles and contaminant down-fluxes, 9.4 kg/day of α-HCH were estimated to enter Lake Ontario [48]. Loading of α-HCH from rain and snow into Lake Superior was estimated to be 860 kg/yr based on α-HCH concentrations in rain [68]. Loadings of α-HCH to Lake Ontario in 1979-1981 from the Niagara River by suspended sediments and raw water were estimated to be 7 and 1940 kg/yr, respectively [36]. The loadings of α-HCH in metric tons per year by deposition from the atmosphere to each of the Great Lakes were estimated to be: Lake Superior 3.3, Lake Michigan 2.3, Lake Erie 1.1, and Lake Ontario 0.77 [21]. Mean loadings from treated wastewater in kg/day were: coal mining 0.0056, aluminum forming 0.0086, foundries 0.017, and non-ferrous metals manufacturing 0.0008 [74].
Biological stabilisation of sludge
Published in Bhola R. Gurjar, Vinay Kumar Tyagi, Sludge Management, 2017
Bhola R. Gurjar, Vinay Kumar Tyagi
In many countries, the use of lindane, the p-isomer of hexachlorocyclohexane (HCH), is still made as an insecticide for use in agriculture and forestry, which leads to many environmental problems (Hernandez et al., 1991; Johri et al., 1996). Consequently, since the early 1970s, the microbiological transformation of HCH has been extensively studied, both under aerobic and anaerobic conditions (Middeidorp et al., 1996; Sahu et al., 1995). In most cases, the 13-isomer of HCH was found to be least susceptible to microbial dechlorination. This is probably due to the spatial (all equatorial) arrangement of the chlorine atoms as was postulated by Beurskens et al. (1991). In soils contaminated with HCH, rapid degradation of the a- and y-isomer of HCH was found under aerobic conditions by the microbial population naturally present (Nagasawa et al., 1993; Sahu et al., 1995). Further, in anaerobic (flooded) soils, a- and y-HCH are almost always transformed, whereas the 13-isomer is mostly found to be persistent under methanogenic conditions (Sahu et al., 1992; Senoo & Wada, 1990; Van Eekert et al., 1998a).
Assessment of Some Hazards Associated with Dangerous Chemicals
Published in Rouf Ahmad Bhat, Moonisa Aslam Dervash, Khalid Rehman Hakeem, Khalid Zaffar Masoodi, Environmental Biotechnology, 2022
Organochlorinated insecticides, namely, those based on HCH (hexachlorocyclohexane) and DDT (pp’–dichlordiphenyl–trichloroethane) were introduced in use in the 1940s and have long been used to protect agricultural crops against vector insects of certain diseases. Organochlorinated insecticides HCH and DDT (isomers and metabolites) are very persistent, accumulating in the soil; the half-life in soils being 2 years for HCH and decades for DDT.
Hexachlorocyclohexane phytoremediation using Eucalyptus dunnii of a contaminated site in Argentina
Published in International Journal of Phytoremediation, 2020
M. J. Gotelli, A. Lo Balbo, G. M. Caballero, C. A. Gotelli
From the 1950s to the 1980s, 1,2,3,4,5,6-hexachlorocyclohexane (HCH) was one of the most used pesticides for worldwide agriculture. A total of eight HCH isomers have been described; but, only the α- , β- , γ- , δ-, and ε-isomers are stable and these are the ones commonly identified in technical formulations. Of these isomers, only the γ isomer (lindane) has insecticidal properties. However, the production of lindane is inefficient: for each ton of lindane, 8–12 tons of other HCH isomers are produced (Vijgen et al.2006). Other authors calculated that during lindane manufacture only 14% of the HCH formed was the γ isomer; the remaining 86% consists of mainly of α-HCH (ca 70%), β-HCH (ca 7%), and δ-HCH (ca 7%) (Doelman et al.1990). These isomers remained as by-products and finally became hazardous waste which was dumped uncontrolled at many sites around the world, usual practice of those years. This malpractice led to a global environmental issue since organochlorine pesticides (OCPs) are pollutants with high resistance to biological, chemical, and physical degradation (Weber et al.2013), and are also suspected to have endocrine disrupting and carcinogenic properties (Ogbeide et al.2016). Due to its high lipid solubility and hydrophobicity, lindane and its isomers can bioaccumulate easily in the food chain and rapidly bioconcentrate in microorganisms, invertebrates, fish, birds, and mammals. Remediation of HCH contaminated soils is thus needed in order to limit the dispersion of these pollutants into the surroundings avoiding its eventual accumulation into human food resources. In May 2001, the United Nations Environment Program (UNEP) adopted the Stockholm Convention on Persistent Organic Pollutants, a global treaty which emphasized the necessity to regulate the production and use of persistent OCPs to control the global contamination produced by these toxic environmental chemicals for protecting human health and the environment. The convention was signed to regulate and ban the use of a preliminary list of 12 chemicals that showed high persistence and bioaccumulation in fatty tissues. In the following years, 11 more chemicals, including lindane and its isomers, were added to the list (Haffner and Schecter 2014). From those years on, OCPs remediation has become a key topic for environmental science and technology. For the removal of organic contaminants in soils, there are several physical or chemical processes available (Rubinos et al.2007; Morillo and Villaverde 2017; Wacławek et al.2019), but OCPs bioremediation (Salam et al.2013) and phytoremediation (Nurzhanova et al.2013) processes has been also proposed as cost efficient and environmental-friendly alternatives. The application of phytoremediation technique results in reduction and/or removal of contaminants without the need of excavation and hence is a relatively low cost technology compared with the other methods. By definition, phytoremediation is a technology that makes use of plants, fungi, or algae to eliminate and control contaminants and to stimulate contaminant breakdown by rhizospheric microorganisms (McCutcheon and Schnoor 2003). In particular, the role of phytoremediation to remove OCPs from contaminated environments has been discussed in a recent review (Singh and Singh 2017).