Effects of 3,3',4,4,',5-pentachlorobiphenyl and 2,3,7,8-tetrachlorodibenzo-p-dioxin injected into the yolks of double-crested cormorant (Phalacrocorax auritus) eggs prior to incubation

• Published in: Environmental toxicology and chemistry Vol. 17; no. 10; pp. 2035 - 2040
• Main Authors: Powell, D.C, Aulerich, R.J, Meadows, J.C, Tillitt, D.E, Kelly, M.E, Stromborg, K.L, Melancon, M.J, Fitzgerald, S.D, Bursian, S.J
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Periodicals, Inc 01.10.1998; SETAC
• Subjects: 2,3,7,8‐Tetrachlorodibenzo‐p‐dioxin; 8-Tetrachlorodibenzo-p-dioxin; adverse effects; Animal, plant and microbial ecology; Applied ecology; Aves; Biological and medical sciences; Cormorant; dioxins; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on vertebrates; Fundamental and applied biological sciences. Psychology; ova; Phalacrocorax; Phalacrocorax auritus; pollutants; Polychlorinated biphenyl 126; polychlorinated biphenyls; Toxic equivalency factors; toxicity; wild birds; Embryonic development; Egg; Vitellus; Mortality; Injection; Experimental study; Polychlorobiphenyl; Marine environment; Teratogenesis; Pollutant; Vertebrata; Chlorocarbon; Toxic equivalency factor; Morphological change; Biological effect; Aves; Phalacrocorax auritus
• ISSN: 0730-7268; 1552-8618
• DOI: 10.1002/etc.5620171020

Double-crested cormorant (Phalacrocorax auritus) eggs were injected with either 3.3',4,4',5-pentachlorobiphenyl (polychlorinated biphenyl [PCB] 126; 70-698 micrograms/kg egg) or 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD; 1.3-11.7 micrograms/kg egg) prior to incubation. These compounds were injected on into the yolks of cormorant eggs collected from incomplete clutches at isolated colonies on Lake Winnipegosis, Manitoba, Canada. Eggs were incubated for approximately 26 to 28 d. After hatching the brain, bursa, heart, liver, and spleen were dissected and weighed. Torsos were preserved in formalin for examination of the gonads. Median lethal doses (LD50s) calculated from mortality data at hatching were 177 and 4.0 micrograms/kg egg for PCB 126 and TCDD, respectively. No significant differences were found in the incidence of developmental abnormalities in any of the treatment groups. Bursa weights were significantly less in the greatest (11.7 micrograms/kg egg) TCDD group compared to the vehicle control group. Spleen weights were significantly less in the 349 micrograms PCB 126/kg egg and the 5.4 and 11.7 micrograms TCDD/kg egg groups when compared to the vehicle control group. No histological alterations of the gonads were found. Hepatic ethoxyresorufin-O-deethylase activity in all PCB 126 and TCDD dose groups was significantly greater compared to the control activity. The toxic equivalency factor for PCB 126 was 0.02.