Systemic Effects

The highest NOAEL values and all reliable representative LOAEL values for each systemic effect in each species and acute- and intermediate-duration categories for each congener tested are recorded in Table 2-1 and plotted in Figure 2-1. Respiratory Effects. Clinical observations strongly suggest that Yusho and Yu-Cheng patients experienced frequent or more severe respiratory infections (Kuratsune 1989 Rogan 1989). Chronic bronchitis accompanied by persistent cough and sputum production was...

Identification of Data Needs

Most of the existing information on health effects of CDFs in animals has been obtained in tests using congeners fully substituted in the lateral (2,3,7,8) ring positions, particularly 2,3,7,8- tetraCDF and 2,3,4,7,8-pentaCDF. Studies of 2,3,7,8-tetraCDF were generally performed due to concern for high toxicity based on knowledge of 2,3,7,8-TCDD and other CDDs. Additional testing has shown, however, that CDFs with substitutions in positions 4 and 6 as well as 2,3,7,8 lateral substitutions,...

General Population And Occupational Exposure

The general population is exposed to CDFs by inhalation, ingestion of drinking water, consumption of food, and through the use of certain consumer products. Since the concentrations of CDFs in ambient air and drinking water are low (see Section 5.4), the intake of CDFs by inhalation and ingestion of drinking water would be low. It has been shown that inhalation exposure was not a major pathway of human exposure to CDFs (Travis and Hattermer-Frey 1989). The estimate that inhalation exposure...

Immunological Effects

Clinical observations strongly suggest that Yusho and Yu-Cheng patients experienced frequent or more severe skin and respiratory infections and lowered resistance to illness (Kuratsune 1989 Rogan 1989). Various changes in immune status have been reported in Yusho and Yu-Cheng patients, including decreased serum IgA and IgM levels and lymphocyte subpopulations, diminished phagocyte complement and IgG receptors, and diminished delayed-type skin hypersensitive response (Chang et al. 1981, 1982a,...

References

*Abbott BD, Birnbaum LS, Pratt RM. 1987. TCDD-induced hyperplasia of the ureteral epithelium produces hydronephrosis in murine fetuses. Teratology 55 329-334. *Addis G, Guertin J, Pellizzari E, et al. 1989. Interlaboratory comparison of PCDF and PCDD analysis in transformers and capacitors. Chemosphere 19 97-101. *Ahlborg UG, Brouwer A, Fingerhut MA, et al. 1992. Impact of polychlorinated dibenzo-p-dioxins, dibenzofurans, and biphenyls on human and environmental health, with special emphasis on...