Effects of chronic dietary exposure to environmentally relevant concentrations to 2,3,7,8-tetrachlorodibenzo- p-dioxin on survival, growth, reproduction and biochemical responses of female rainbow trout ( Oncorhynchus mykiss)

• Published in: Aquatic toxicology 2002-09, Vol.59 (1), p.35-53
• Main Authors: Giesy, John P, Jones, Paul D, Kannan, Kurunthachalam, Newsted, John L, Tillitt, Donald E, Williams, Lisa L
• Format: Article
• Language: English
• Subjects: Agnatha. Pisces; Animal, plant and microbial ecology; Animals; Applied ecology; Biological and medical sciences; Body Weight - drug effects; Diet; Dioxin; Dose-Response Relationship, Drug; Ecotoxicology, biological effects of pollution; Effects of pollution and side effects of pesticides on protozoa and invertebrates; Effects of pollution and side effects of pesticides on vertebrates; Environmental Exposure; EROD; Female; Fish; Fundamental and applied biological sciences. Psychology; Liver - chemistry; Liver - drug effects; Oncorhynchus mykiss; Oncorhynchus mykiss - growth & development; Oncorhynchus mykiss - metabolism; Oncorhynchus mykiss - physiology; Organ Size - drug effects; Ovary - chemistry; Ovary - drug effects; Ovum - chemistry; Polychlorinated Dibenzodioxins - analysis; Polychlorinated Dibenzodioxins - toxicity; Reproduction; Reproduction - drug effects; Risk
• ISSN: 0166-445X; 1879-1514
• DOI: 10.1016/S0166-445X(01)00235-1

Adult female rainbow trout were exposed to dietary 2,3,7,8-tetrachlorodibenzo- p-dioxin (TCDD) at concentrations of 1.8, 18 and 90 ng TCDD/kg (ww) food for up to 300 day. At the end of the exposure fish were spawned and the reproductive outcomes were assessed. TCDD was accumulated into tissues and eggs in a dose-dependent manner with steady state being achieved after 50–100 day of exposure. Biochemical and hematological parameters were monitored at 50, 100, 150, and 200 day after the beginning of exposure. The survival of adult female trout was reduced in a dose-dependent manner by exposure to TCDD in the diet. Fish fed 1.8 ng TCDD/kg, moist weight of diet, showed significantly reduced survival compared with those fed the control diet. TCDD also affected survival of fry from females fed 1.8 ng TCDD/kg. Observed adverse effects in adult fish were as sensitive as early life-stage endpoints. Liver EROD activity was only moderately increased in all exposure groups after 250+ day of exposure. Low rates of edema and deformities were observed in fry from all treatment groups including controls. This study has demonstrated adverse effects of TCDD to both adults and fry at concentrations comparable to current environmental concentrations. This suggests that direct adult toxicity as well as reproductive endpoints need to be incorporated in the current risk assessment paradigm for these compounds.