Disposition of octachlorodibenzo-p-dioxin (OCDD) in male rats*1

Toxic equivalency factors (TEFs) for PCBs, PCDDs, PCDFs for humans and wildlife.

“…However, earlier acute toxicity studies had suggested that octaCDD was essentially nontoxic, with a TEF value less than 0.000001. These subchronic studies also showed that octaCDD is extremely poorly absorbed and absorption from the gastro-intestinal tract decreased with increasing dose (143 (88,131,(144)(145)(146)(147)(148). In this respect, it should be noted that the structure-activity relationship for binding to the Ah receptor and to CYP1A2 are not identical (149).…”

Distribution of PCDDs/PCDFs and Co-PCBs in Human Maternal Blood, Cord Blood, Placenta, Milk, and Adipose Tissue: Dioxins Showing High Toxic Equivalency Factor Accumulate in the Placenta

“…In addition, intestinal absorption of dioxins might be influenced by other substances in the diet, as well as by the number of chlorine atoms. 34) Transfer of dioxins to infants via breast milk Dioxins have been identified in maternal milk. 14,18) In general, it is thought that they are excreted from the body through lactation and hence that the dioxin content of breast milk decreases with time.…”

Balance of Intake and Excretion of 20 Congeners of Polychlorinated Dibenzo-p-dioxin, Polychlorinated Dibenzofuran and Coplanar Polychlorinated Biphenyl in Healthy Japanese Men.

“…Octachlorodibenzo-p-dioxin (OCDD), 2,3,7,3,7, and 3,3′,4,4′-tetrachlorobiphenyl (3,3′,4,4′-TCB) were well absorbed from intestine and excreted at more than 100% of intake, mainly from the sebum. In contrast, 1,2,3,4,7,2,3,4,7,2,3,7,8,2,3,7,8, were excreted at relatively low levels from sebum, although well absorbed from the intestine, and the excretion ratios were lowest among the 20 congeners. It was suggested that 80.5-85.2% TEQ of each congener-group might be absorbed from the intestine, after taking bile excretion into consideration.…”

“…8 ± 5.6 pg TEQ, respectively, indicating 22% the daily intake of dioxins from meals is excreted from feces and 29% from sebum. 1,2,3,7,8-Pentachlorodibenzo-p-dioxin (1,2,3,7,2,3,4,7,3,4,7, and 3,3′,4,4′,5-pentachlorobiphenyl (3,3′, 4,4′,5-PeCB) were most abundant in TEQ, in meals, feces, sebum and blood. Co-PCBs were most efficiently excreted among three congener groups in TEQ, especially from sebum.…”