Chlordane in sediment

Chlordanes in sediments usually were highest in those sediments with the hipest organic... 

Marine clams and worms tended to underrepresent chlordane concentrations in the ambient sediments. Concentration factors were less than 0.2 for clams and 0.6 for worms (Ray et al. 1983). Similarly, chlordane concentrations in clams from the Shatt al-Arab River in Iraq closely reflected chlordane concentrations in water particulates when compared to levels in water columns or in sediments (DouAbul et al. 1988). 

Heptachlors were spread into the environment either as an agrochemical or as impurities of technical chlordanes. In Japan, technical chlor-dane was used not only for agrochemicals but also for termite control, especially in south-west part where termite tends to damage houses more actively due to high temperature and humidity. Apparently the technical chlordanes used in Japan had been quite homogeneous, for chlordanes composition (proportions of trans-chlordane, cA-chlordane, trans-nonachlor, cA-nonachlor and oxychlordane) in air, and also in water, are quite similar to each other among the same media irrespective of the sampling locations. It is also expected that proportions of heptachlors in technical chlordanes were also stable in fact, similar heptachlors/ chlordanes ratios have been observed in many places in Japan in air, water and sediments, and majority of the data plots on chlordanes (X)... 

Figure 1.10. Chlordanes vs. heptachlors in sediment samples (FY2004).

Figure 4.11 Enantiomer fractions ofcis-chlorclane and trans-chlordane in air samples from the Arctic (AA), southern Sweden (RA), historical atmospheric deposition samples from 1971-1973 (AD), and in sediment cores of Lake DV-09, Devon Island, Canada). Error bars are a. (Reproduced with permission from Atmospheric Environment, Chiral signatures of chlordanes Indicate changing sources to the atmosphere over the past 30 years, by Terry F. Bidleman, Fiona Wong et al., 38(35), 5963-5970. Copyright (2004) Elsevier)...

As with chlordanes, toxaphene can be nonracemic in sediments, but predominantly from in situ microbial degradation. Several chlorobornane enantiomers were quantified in a 1992 sediment core from Hanson Lake, Yukon, Canada, treated with toxaphene as a piscicide in 1963 [149]. Two hexachlorinated congeners, B6-923 and an unidentified congener, were... 

While agricultural soils now have nonracemic OC pesticide residues and emit these nonracemic compositions to the atmosphere, this was not necessarily always the case. Archived extracts of air samples collected in Sweden, Slovakia, and Iceland between in the early 1970s had racemic cis- and fra 5-chlordane [138]. This observation suggests that those residues were released either from fresh emissions, as these compounds were in active use at the time, and/or they were volatilized from racemic residues in soil. The former hypothesis is more likely, given the EFs of these compounds in sediment cores, which were racemic in the 1950s but less so after that point, including the 1970s [138, 139]. 

Li, X. Yang, L. Jans, U. Melcer, M.E. Zhang, R, Lack of enantioselective microbial degradation of chlordane in Long Island Sound sediment Environ. Sci. Technol. 2007, 41, 1635-1640. 

Wood, L.W., P.A. Jones, and A. Richards. 1986. Possible sediment scavenging of chlordane and contamination of the aquatic biota in Belmont Lake, New York. Bull. Environ. Contam. Toxicol. 36 159-167. 

Soil The actinomycete Nocardiopsis sp. isolated from soil extensively degraded pure cis- and /ra/3s-chlordane to dichlorochlordene, oxychlordane, heptachlor, heptachlor e/ c/o-epoxide, chlordene chlorohydrin, and 3-hydroxy-traas-chlordane. Oxychlordane slowly degraded to 1-hydroxy-2-chlorochlordene (Beeman and Matsumura, 1981). In Hudson River, NY sediments, the presence of adsorbed chlordane suggests it is very persistent in this environment (Bopp et al., 1982). The reported half-life in soil is approximately 1 yr (Hartley and Kidd, 1987). 

In aquatic sediments, chlordane was nearly complete after 6 d (Oloffs et al, 1972, 1973). 

Below-grade bioremediation is an ex situ technology designed to treat soil, sludge, and sediment impacted with chlorinated cyclodiene insecticides such as chlordane and heptachlor. Naturally occurring fungi are added to pesticide-contaminated soil, which is then treated in a below-grade actively aerated bioremediation cell. 

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