Effects of 3,3′,4,4′-Tetrachlorobiphenyl, 2,3,3′,4,4′-Pentachlorobiphenyl, and 3,3′,4,4′,5-Pentachlorobiphenyl on the Developing Chicken Embryo When Injected Prior to Incubation

Abstract

Great Lakes waterbird populations have experienced less-than-expected hatchability of eggs and a greater-than-expected incidence of developmental abnormalities. Such deleterious effects have been attributed to polyhalogenated hydrocarbons such as polychlorinated biphenyls (PCBs). PCBs are of primary concern since they are present in significant quantities in the environment. Specific PCB congeners, 3,3',4,4',5-pentachlorobiphenyl (IUPAC number 126), 3,3',4,4'-tetrachlorobiphenyl (IUPAC number 77), and 2,3,3',4,4'-pentachlorobiphenyl (IUPAC number 105), were injected (singly or in combination) into the yolks of White Leghorn chicken (Gallus domesticus) eggs prior to incubation. Teratogenicity was assessed in dead embryos and in hatchlings. Hatchlings were raised for 3 wk to assess body weight gain and mortality. At the end of the 3-wk period, chicks were subjected to necropsy and the brain, bursa, heart, liver, spleen, and testes were removed and weighed. All 3 congeners caused increased embryo mortality, with approximately 50% mortality occurring at 0.6, 8.8, and 5592 micrograms/kg egg for congeners 126, 77, and 105, respectively. All three congeners also produced significantly more abnormalities than the vehicle. Chicks from PCB-injected eggs had lower body weights at wk 2 and 3 of age. Congener 126 caused lower relative bursa weights, congener 77 caused greater relative spleen weights and lower relative liver weights, and all three congeners caused relative heart weights to be greater when compared to control.

Toxic Equivalency Factors (TEFs) for PCBs, PCDDs, PCDFs for Humans and Wildlife

“…Studies with chickens and wild avian species reported in vitro and in ovo effects, with REPs ranging from <0.0003 to 0.15 depending on the species (66,68,69,122,123). A value of 0.05 is recommended.…”

“…0.0001 0.0001 2',3,4,4',5-PentaCB (123) No new data are available; no revision is recommended. 0.0001 0.0001 2,3,3',4,4',5-HexaCB Recent data from semichronic studies suggest that the old value is appropriate (109).…”

Productivity of Tree Swallows (Tachycineta bicolor) Exposed to PCBs at the Kalamazoo River Superfund Site

“…Growth measurements were intended to be integrative measures of behavior, stress, efficiency of catabolism, and feeding behavior. Under a stressor such as exposure to PCBs, the energetics of animals change and growth is expected to decrease (Powell et al, 1996). PCBs have been reported to cause a number of biochemical changes, such as a decrease in vitamin A levels required for growth (Martinovic et al, 2003a).…”

Toxic Effects of Polychlorinated Biphenyls in Myogenic Cells

“…5,6) In humans, prenatal exposure to PCBs has been associated with lower body weight, 7) shorter height, and decreased total lean mass. 8) Since skeletal muscle significantly contributes to body mass and PCBs accumulate in skeletal muscle, 9) a direct toxicity of PCBs in this tissue may be hypothesized.…”