RESUMO
The effects of 17α-ethinylestradiol (EE2) on sex ratio, gonopodium morphology, and gonadal histology of C. decemmaculatus were assessed by a full-lifecycle exposure experiment. Newborn fish were waterborne exposed to 30, 100, and 300 ng EE2/L for 90 d, using 50 fish per treatment. Additionally, in December of 2016, a field survey was conducted on a C. decemmaculatus population inhabiting the Girado Creek downstream of the Chascomus city wastewater effluent discharge. After 90 d of exposure, EE2 was able to histologically skew the sex ratio toward females and inhibit the full gonopodium development since the lowest tested concentration (LOEC = 30 ng/L). At higher concentrations, EE2 was toxic, inducing mortality in a concentration-dependent fashion (90 d-LC50 = 109.9 ng/L) and altering the gonadal histoarchitecture, causing neither testes nor ovaries discernible histologically (LOEC = 100 ng/L). In addition, a novel response, perianal hyperpigmentation, was discovered been induced by the EE2 exposure in a concentration-dependent fashion (90 d-EC50 = 39.3 ng/L). A higher proportion of females and perianal hyperpigmentation were observed in wild fish collected from the Girado Creek. The major reached conclusions are: i) EE2 induce different effects on the sexual traits of C. decemmaculatus when exposed from early-life or adult stages. ii) The most sensitive effects observed in the laboratory occur in a creek receiving wastewater effluent. iii) The perianal hyperpigmentation comes-up as a promising biomarker of exposure to estrogenic compounds.
Assuntos
Ciprinodontiformes/crescimento & desenvolvimento , Disruptores Endócrinos/toxicidade , Etinilestradiol/toxicidade , Gônadas/efeitos dos fármacos , Hiperpigmentação/induzido quimicamente , Poluentes Químicos da Água/toxicidade , Animais , Relação Dose-Resposta a Droga , Feminino , Gônadas/crescimento & desenvolvimento , Gônadas/patologia , Humanos , Estágios do Ciclo de Vida/efeitos dos fármacos , Masculino , Ovário/efeitos dos fármacos , Ovário/crescimento & desenvolvimento , Ovário/patologia , Fenótipo , Razão de Masculinidade , Testículo/efeitos dos fármacos , Testículo/crescimento & desenvolvimento , Testículo/patologiaRESUMO
The aim of the present study was to assess the responses of the gonopodium morphology and the gonadal and liver histology of adult male Cnesterodon decemmaculatus to sublethal long-term exposure concentrations of 17α-ethinylestradiol (EE2). Two experiments were conducted exposing the fish to waterborne concentrations of EE2 ranging from 20 ng/L to 200 ng/L for 8 wk, 12 wk, and 16 wk. Intersex gonads were observed after 8 wk and 16 wk in fish exposed to 200 ng EE2/L and 100 ng EE2/L, respectively. Oocytes' development from testis germ cells and replacement of the efferent duct periodic acid-Schiff-positive secretion surrounding spermatozeugmata by parenchymal tissue and duct structure alterations were the major observed changes in the gonads. In contrast, no response was observed in the gonopodium morphology. Liver histology was also altered, showing increasing steatosis, single-cell necrosis to generalized necrosis, and disruption of acinar organization from 100 ng EE2/L to 200 ng EE2/L. In summary, the present results showed that although EE2 was not able to alter the morphology of a developed gonopodium, it was capable of inducing development of testicular oocytes in adult male C. decemmaculatus at environmentally relevant concentrations. Thus, externally normal but intersex C. decemmaculatus males would be expected in the wastewater-receiving streams that the species inhabits. According to the literature, the present study would be the first indicating estrogen-induced intersex in adult male poeciliid. Environ Toxicol Chem 2017;36:1738-1745. © 2016 SETAC.
Assuntos
Ciprinodontiformes/crescimento & desenvolvimento , Transtornos do Desenvolvimento Sexual/etiologia , Etinilestradiol/toxicidade , Gônadas/efeitos dos fármacos , Fígado/efeitos dos fármacos , Células Acinares/efeitos dos fármacos , Células Acinares/patologia , Animais , Ciprinodontiformes/fisiologia , Transtornos do Desenvolvimento Sexual/patologia , Transtornos do Desenvolvimento Sexual/veterinária , Fígado Gorduroso/etiologia , Fígado Gorduroso/veterinária , Feminino , Gônadas/crescimento & desenvolvimento , Gônadas/patologia , Fígado/metabolismo , Fígado/patologia , Masculino , Necrose , Oócitos/efeitos dos fármacos , Oócitos/crescimento & desenvolvimento , Oócitos/patologia , Testículo/efeitos dos fármacos , Testículo/crescimento & desenvolvimento , Testículo/patologiaRESUMO
Both raw and composted poultry manure is applied as soil amendment. The aims of this study were: (1) to develop phytotoxicity indexes for organic wastes and composts, and (2) to assess the correlation among phytotoxicity indexes, ecotoxicological endpoints and stability and physicochemical parameters during passive composting of poultry manure. Six 2-m(3) composting piles were constructed and four parameter groups (physicochemical and microbiological parameters, ecotoxicological endpoints, and biological activity) were determined at four sampling times during 92days. Extracts were used to carry out acute toxicity tests on Daphnia magna, Lactuca sativa and Raphanus sativus. Composting decreased average toxicity 22.8% for the 3 species and D. magna was the most sensitive species. The static respiration index decreased from 1.12 to 0.46mgO2gOMh(-1) whilst organic matter reduced by 64.1% at the end of the process. Escherichia coli colonies remained higher than values recommended by international guidelines. The D. magna immobilization test allowed the assessment of possible leachate or run-off toxicity. The new phytotoxicity indexes (RGIC0.8 and GIC80%), proposed in this study, as well as salinity, proved to be good maturity indicators. Hence, these phytotoxicity indexes could be implemented in monitoring strategies as useful ecotoxicological tools. Multivariate analyses demonstrated positive correlations between ecotoxicological endpoints (low toxicity) and biological activity (stability). These two parameter groups were associated at the final sampling time and showed negative correlations with several physicochemical parameters (organic and inorganic contents). The final poultry manure compost was rendered stable, but immature and, thus, unsuitable for soil amending.
Assuntos
Poluentes Ambientais/toxicidade , Esterco/análise , Eliminação de Resíduos/métodos , Testes de Toxicidade/normas , Animais , Carbono , Ecotoxicologia , Poluentes Ambientais/normas , Nitrogênio , Aves Domésticas , TemperaturaRESUMO
Effluents generated during the process of anaerobic digestion should be treated before their disposal into the environment. The aim of this study was evaluating the effectiveness of the effluent treatment system from an anaerobic bioreactor, assessing the toxicity reduction with the Lactuca sativa seed germination and root elongation inhibition test. Three sampling points were selected along the effluent treatment system: inflow into the first treatment pond, outflow from the third pond and recirculated flow to the bioreactor. Effluent dilutions tested for each sampling point were 25% and 50% (v/v), undiluted sample and controls. The pH, conductivity, temperature, dissolved oxygen, BOD5 and COD were measured. The decrease in the organic and inorganic loads was correlated with a reduction in the phytotoxicity. The use of the seed toxicity test allows evaluating the quality and effectiveness of the studied effluent treatment system.