Octachlorodibenzo-p-dioxins OCDD

A number of toxicologically active 2,3,7,8-substituted PCDDs and PCDFs, planar PCBs and PCDD, PCDF, and PCDT homologs were measured in fish, SPMDs, and sediments. Only two target compounds exceeded the detection limits of 0.2-1 pg g in SPMD field blanks (see definition in Chapter 5). These exceptions were octachlorodibenzo-p-dioxin (OCDD) and octachlorodibenzofuran (OCDF) which were present in SPMDs at about 5 pg g However, negative... 

As discussed in the earlier survey (1), a biogenic source of polychlorinated dibenzo-p-dioxins and dibenzofurans is peroxidase-catalyzed transformation of chlorophenols as first reported by Oberg and Rappe (2041-2044). More recent studies confirm these observations (2045-2048). In addition to lactoperoxidase and horseradish peroxidase, human leukocyte myeloperoxidase catalyzes in vitro formation of dioxins and dibenzofurans from chlorophenols (2046, 2047). Formation rates are in the pmol/mol range (Scheme 3.6) demonstrating that a human biosynthesis of dioxins and furans is not only possible but also likely. These observations are reinforced by the reported in vivo (rats) conversion of the pre-dioxin nona-chloro-2-phenoxyphenol to octachlorodibenzo-p-dioxin (OCDD) (2049), and the production of hepta- and octachlorodibenzo-p-dioxin in the feces of cows fed pentachlorophenol-treated wood (Scheme 3.7) (2050, 2051). 

Information regarding adverse health effects in animals exposed to CDDs via the oral route was located for the following congeners 2-monochlorodibenzo-p-dioxin (2-MCDD), 2,3-dichlorodibenzo-/7-dioxin (2,3-DCDD), 2,7-dichlorodibenzo-p-dioxin (2,7-DCDD), 1,2,3-trichlorodibenzo-p-dioxin (1,2,3-TrCDD), l,2,3,4-tetrachlorodibenzo-/ -dioxin (1,2,3,4-TCDD), 2,3,7,8-tetrachlorodibenzo-/7-dioxin (2,3,7,8-TCDD), 1,2,3,7,8-pentachlorodibenzo-p-dioxin (1,2,3,7,8-PeCDD), 1,2,3,4,7,8-hexa-chlorodibenzo-p-dioxin (1,2,3,4,7,8-HxCDD), 1,2,4,7,8-pentachlorodibenzo-p-dioxin (1,2,4,7,8-PeCDD), 1,2,3,6,7,8-hexachlorodibenzo-p-dioxin (1,2,3,6,7,8-HxCDD), 1,2,3,7,8,9-hexachlorodibenzo-/7-dioxin (1,2,3,7,8,9-HxCDD), 1,2,3,4,6,7,8,-heptachlorodibenzo-p-dioxin (1,2,3,4,6,7,8,-HpCDD), and 1,2,3,4,6,7,8,9-octachlorodibenzo-p-dioxin (OCDD). Some of the animal studies used a mixture of 1,2,3,6,7,8-HxCDD and 1,2,3,7,8,9-HxCDD. Of all the CDD congeners, 2,3,7,8-TCDD has been the one most extensively studied. 

Octachlorodibenzo-p-dioxin OCDD Octachlorodibenzodioxin Octachloro-dibenzo[b,e](1,4)dioxin Octachlorodibenzo-p-dioxin ... 

Bimbaum LS, Couture LA. 1988. Disposition of octachlorodibenzo-p-dioxin (OCDD) in male rats. Toxicol Appl Pharmacol. 93 22-30. 

Couture LA, Elwell MR, Bimbaum LS. 1988. Dioxin-like effects observed in male rats following exposure to octachlorodibenzo-p-dioxin (OCDD) during a 13-week study. Toxicol Appl Pharmacol 93 31-46. 

WagenaarWJ, Boelhouwers EJ, de Kok HAM, Groen CP, Govers HAJ, Olie K, de Gerlache J, de Rooij CG (1995), Chemosphere 31 2983-2992. A comparative study of the photolytic degradation of octachlorodibenzofuran (OCDF) and octachlorodibenzo-p-dioxin (OCDD) ... 

In Table 4, the equation to predict the bioaccumulation factor (BAFl) of relatively persistent chemicals in human (fat) is also presented [191, 192]. This equation is only valid for chemicals which are not or only minimal metabolized in human. It is also important to note that for super-hydrophobic chemicals, such as octachlorodibenzo-p-dioxin (OCDD) and Mirex, no steady-state BAF value is reached during the whole life. 

Table 9. Physico-chemical properties, bioconcentration factors on a wet weight basis (BCF ) and on a lipid basis (BCFl), and estrogenic or anti-estro-genic effects of 2,3,7,8-Tetrachlorodibenzo-p-dioxin (TCDD) and Octachlorodibenzo-p-dioxin (OCDD)... 

The general increase in concentration with increasing degree of chlorination can be observed, with OCDD (octachlorodibenzo-p-dioxin) as the predominant congener. This is consistent with previously reported data for sewage sludge in other countries. 

Abbreviations PnCDD, pentachlorodibenzo-p-dioxin HxCDD, hexachlorodibenzo-p-dioxin HpCDD, heptachlorodibenzo-p-dioxin OCDD, octachlorodibenzo-/i-dioxin PnCDF, pentachlorodibenzofuran HxCDF, hexachlorodibenzofuran HpCDF, heptachlorodibenzofuran OCDF, octachlorodibenzofliran TCB, tetrachlorobiphenyl PnCB, pentachlorobiphenyl HxCB, hexachlorobiphenyl HpCB, heptachlorobiphenyl. 

DCDD1 = 2,7-dichlorodibenzo-p-dioxin HCDD5 = unspecified mixture of hexachlorodibenzo-p-dioxins LOAEL = lowest-observable-adverse-effect level NOAEL = no-observable-adverse-effect level NS = not specified OCDD = octachlorodibenzo-p-dioxin... 

CDD = chlorinated dibenzo-p-dioxin HpCDD = heptachlorodibenzo-p-dioxin HxCDD = hexachlorodibenzo-p-dioxin NPL = National Priorities List OCDD = octachlorodibenzo-p-dioxin PeCDD = pentachlorodibenzo-p-dioxin TCDD = tetrachlorodibenzo-p-dioxin... 

Fig. 9. Relationship between the steady-state bioconcentration factors on a lipid basis (BCFl) of chemicals in different fish species and the n-octanol/water partition coefficient (Kqw) (log/log scale). ( ) Solid circles are chemicals with known endocrine-disrupting properties. Abbreviations of the chemicals p,p -DDT 2,2-bis-(p-chlorophenyl)-l,l,l-trichloroethane. OCDD octachlorodibenzo-p-dioxin. TCDD tetrachlorodibenzo-p-dioxin. HCB hexachloro-benzene. PCA pentachloroanisole. PeCB pentachlorobenzene. MX musk xylene. TeCB tetrachlorobenzene. NP nonylphenol. TCB tetrachlorobenzene. y-HCH y-hexachlorocyclo-hexane (Lindane). PCP pentachlorophenol. DCB dichlorobenzene. BPA bisphenol-A. PCBs polychlorinated biphenyls...

In the following sections, the physico-chemical properties and the bioconcentration of selected super-hydrophobic persistent organic pollutants (POPs) such as 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD),octachlorodibenzo-p-dio-xin (OCDD), Mirex, and Toxaphene in fish and other animals will be discussed. 

SYNS NCI-C03678 OCDD OCTACHLORO-DIBENZO(b,e)(l,4)DIOXIN OCTACffl-ORODIBENZO-p-DIOXIN 1,2.3,4,6,7,8,9-OCTACHLORODIBENZO-DIOXIN... 

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