Legacy pesticides

While a -HCH is one of the most frequently studied chiral legacy pesticides in air and water, only limited measurements have been made of its enantiomers in soils and sediments, given its relatively low propensity to sorb to natural organic matter compared to other POPs (log Kg of 3.9 [32]). A depletion of (+)-a-HCH (EF = 0.39) was observed in surficial sediments of the North water Polynya [137]. This value was more nonracemic than the water column composition (EF = 0.45)[137],suggestingeitherpreferentialmicrobialdegradationof(+)-a-HCHasit descended in the water column [127] and/or further degradation once deposited in sediments. 

Konwick, B.J. Garrison, A.W. Black, M.C. Avants, J.K. Eisk, A.T, Bioaccumulation, biotransformation, and metabolite formation of fipronil and chiral legacy pesticides in rainbow trout Environ Sci. Technol. 2006, 40, 2930-2936. 

Impact of Transformation Products on Spatial Range and Arctic Contamination Potential of Legacy Pesticides... 

Haber s legacy, like his life, was a mix of high-minded science and nationalism gone tragically amiss. To obliterate Haber s achievements, the Nazis credited others with his nitrogen-fixation process and his chemical warfare work. Most horrifically, the Nazis used the pesticide Zyklon B—an offshoot of work begun in Haber s institute and supported by him—in concentration camp gas chambers. Among Haber s relatives, members of his stepsister s family lost their lives to Zyklon B cyanide at Auschwitz. 

Wargo, ]. (1998) Our children s toxic legacy How science and law fail to protect us from pesticides, 2nd edn, Yale University Press, 402 pp. 

Velsicol Chemical LLC, formerly Velsicol Chemical Corporation, designs, manufactures, markets and distributes high performance specialty chemicals and industrial intermediates, primarily based on benzoic acid and the organic compound cyclopentadiene. Its products include chlorendic anhydride and hexachlorocyclopentadiene (HEX). Chlorendic anhydride is corrosion resistant, fire resistant and has high UV stability, and is used in the synthesis of flame retardant polymers such as polyurethanes, unsaturated polyester and epoxy resins. HEX, a reactive intermediate used in the manufacture of agricultural pesticides in the production of flame retardants for the wire and cable industry and in the preparation of chlorendic anhydride. The company s products are produced primarily at a plant in Memphis, Tennessee Velsicol also maintains the Memphis Environmental Center (MEC), which focuses on managing legacy environmental liabilities. The firm is owned by Arsenal Capital Partners, a private equity firm. 

At the same time, the developing countries were struggling to cope with extensive intoxications from pesticides, lead and mercury poisoning, legacies of stockpiled obsolete pesticides and polychlorinated biphenyls and other issues that had to a large extent already been taken care of in the developed countries. 

Although not as well studied, nonracemic compositions of other legacy OC pesticides, as well as of a-HCH in other waters, have been observed. The Arctic Ocean was depleted in (—)-heptachlor epoxide in all regions surveyed, while cis- and tra 5-chlordane were nearly racemic [121]. Lake Ontario was also enriched in (—)-a-HCH (mean ER of 0.85), with enantiomer compositions that did not vary with depth but did vary in the presence of racemic sources such as precipitation and water from the tributary Niagara River [128]. The York River in Chesapeake Bay had microbial consortia that degraded (+)-a-HCH upstream [129, 130]. However, greater microbial activity was observed in more brackish waters... 

Bidleman, T.R Leone, A.D. Wong, R Van Vliet, L. Szeto, S. Ripley, B.D., Emission of legacy chlorinated pesticides from agricultural and orchard soils in British Columbia, Canada Environ. Toxicol Chem. 2006, 25, 1448-1457. 

A legacy of the use of an estimated 600 kg of the herbicide Agent Orange during the conflict in Vietnam has been the contamination of soil, rivers, sediment and biota with dioxins [53, 54]. Hot spots of contaminated soils in the Aluoi Valley and other former US bases where the pesticides were stored have recently been identified [53]. These sites have considerably higher dioxin levels compared with regions where dioxins were aerially sprayed. These sites, if not cleaned up, will be a continued source of dioxins to the local environment for the foreseeable future. 

GTZ Publication, Obsolete Pesticides, a Dangerous Legacy. Result of a Pilot Project on the Disposal of Obsolete Pesticides, can be found under http //www,gtz.de/chs... 

Once again, there are striking parallels in human epidemics with the development of resistant strains of viral and bacterial diseases and resistant vectors of disease. See John Wargo s discussion of malaria and its carrier, the Anopheles mosquito, in Our Children s Toxic Legacy How Science and Law Fail to Protect Us from Pesticides (New Haven Yale University Press, 1996), pp. 15-42. 

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