RESUMEN
The wastewater contamination of urban rivers is a concern for biodiversity and a consequence from poor urban conservation policies. In the current study, the impact of urban and industrial activities was investigated in Iguaçu river (Southern Brazil) using juvenile Oreochromis niloticus, after trophic and chronic exposure (25, 50 and 100 %), over 81 days. After exposure liver, gills, gonads, brain, muscle, and blood were sampled for chemical, biochemical, histopathological, genotoxic and molecular analyses. Water levels of persistent organic pollutants such as polychlorinated biphenyls, organochlorine pesticides, polycyclic aromatics hydrocarbon (PAHs) and metals were investigated. The redox unbalance, histopathological and increase in vitellogenin expression in fish revealed both the bioavailability of micropollutants and their harmful effects. According to the results, the level of Iguaçu river pollution negatively impacts the health of O. niloticus revealing and highlighting the risk of this pollution exposure to biota and human populations.
Asunto(s)
Cíclidos , Contaminantes Químicos del Agua/toxicidad , Acetilcolinesterasa/metabolismo , Animales , Encéfalo/efectos de los fármacos , Encéfalo/metabolismo , Brasil , Catalasa/metabolismo , Cíclidos/sangre , Cíclidos/metabolismo , Femenino , Branquias/efectos de los fármacos , Branquias/patología , Glutatión Transferasa/metabolismo , Gónadas/efectos de los fármacos , Gónadas/patología , Hidrocarburos Clorados/análisis , Hidrocarburos Clorados/toxicidad , Hígado/efectos de los fármacos , Hígado/metabolismo , Hígado/patología , Masculino , Metales Pesados/análisis , Metales Pesados/toxicidad , Músculos/efectos de los fármacos , Músculos/metabolismo , Hidrocarburos Policíclicos Aromáticos/análisis , Hidrocarburos Policíclicos Aromáticos/toxicidad , Carbonilación Proteica/efectos de los fármacos , Ríos , Vitelogeninas/sangre , Contaminantes Químicos del Agua/análisisRESUMEN
The presence of 2,4,6-Tribromophenol (TBP) in the environment increased the risk of exposure to aquatic organisms affecting the animal development or metabolism. The current study investigated the low, subchronic and trophic effect of TBP in both, male and female adult of Oreochromis niloticus. The fish were exposed to 0.5 or 50 ng g-1 of TBP every ten days for 70 days. Then, hepatosomatic (HSI) and gonadosomatic (GSI) indexes, erythrocyte parameters (hemoglobin content, nuclear morphology and morphometrical abnormalities), biochemical endpoints (glutathione S-Transferase and catalase activities, non-protein thiols, lipid peroxidation and protein carbonylation levels in the liver; and acetylcholinesterase activity in the brain and muscle), histopathological analysis (liver) and vitellogenin levels (plasma) were considered. TBP affected the HSI in male and female fish, but not the GSI. Principal Component Analysis revealed that erythrocytes from males are more sensitive to TBP exposure. Likewise, TBP induced the expression of vitellogenin, CAT activity and liver lesion in male fish comparatively with control group, but GST and NPT were influenced only by sex. Finally, the results showed that the antioxidant mechanism and cholinesterase activity effects were more pronounced in male than in female. The current data shows evidences of estrogenic endocrine disruption and toxicity in O. niloticus exposed to TBP, revealing the risk of exposure to biota.
Asunto(s)
Cíclidos , Contaminantes Químicos del Agua , Animales , Catalasa/metabolismo , Cíclidos/metabolismo , Femenino , Peroxidación de Lípido , Hígado/metabolismo , Masculino , Estrés Oxidativo , Fenoles/metabolismo , Fenoles/toxicidad , Superóxido Dismutasa/metabolismo , Contaminantes Químicos del Agua/metabolismo , Contaminantes Químicos del Agua/toxicidadRESUMEN
The 2,4,6-tribromophenol (TBP) is an environmental persistent pollutant widely used as flame retardant, antimicrobial and insecticide agent in wood preservation and plastic production. Currently, TBP is found in environmental compartments such as soil, freshwater, groundwater, sewage sludge and domestic dust, but the effects to biota and the risk of exposure to aquatic vertebrates are still scarce. In the present study, Rhamdia quelen fish embryos (8â¯h post-fertilization - hpf) were exposed to 0.3 and 3.0⯵gâ¯L-1 of TBP until 96 hpf. Biochemical biomarkers, hatching, survival and larvae/embryo malformations were evaluated after exposure. Additionally, a mathematical model was proposed to evaluate the effects along further generations. The results showed that TBP decreased the survival level but did not cause significant difference in the hatching rates. After 72 and 96 hpf, individuals from the highest tested concentration group showed more severe malformations than individuals from control and the lower concentrations groups. The deformities were concentrated on the embryos facial region where the sensorial structures related to fish behavior are present. The biochemical biomarkers revealed both oxidative stress and neurotoxicity signs after exposure to the contaminant, while the application of the mathematical model showed a decrease of population in both tested TBP concentrations. In conclusion, the current results demonstrated that TBP is toxic to R. quelen embryos and represents a risk to population after early life stage exposure.
Asunto(s)
Bagres , Embrión no Mamífero/efectos de los fármacos , Desarrollo Embrionario/efectos de los fármacos , Larva/efectos de los fármacos , Fenoles/toxicidad , Contaminantes Químicos del Agua/toxicidad , Animales , Conducta Animal/efectos de los fármacos , Bagres/anomalías , Embrión no Mamífero/anomalías , Femenino , Larva/crecimiento & desarrollo , Masculino , Modelos Teóricos , América del Sur , Análisis de SupervivenciaRESUMEN
In this study, we investigated the use of branchial carbonic anhydrase activity in a sessile filter feeding species, the oyster Crassostrea rhizophorae, as a biomarker. The oysters were collected in three human impacted Brazilian estuaries, following a crescent latitudinal gradient: in Pernambuco state (Itamaracá), in Espírito Santo state (Piraquê), and in Paraná state (Paranaguá), in August/2003 (Winter in the southern hemisphere) and February/2004 (Summer). Three sites were chosen in each estuary for oyster sampling: Reference (R), Contaminated 1 (C1, close to industrial/harbor contamination), and Contaminated 2 (C2, near to sewage discharges). Comparing to values in oysters sampled in reference sites, there was apparent inhibition in carbonic anhydrase activity (CAA) in gills of oysters from C1 of Itamaracá and from C2 of Piraquê, both cases in Summer. On the other hand, increased CAA was noted in C2 oysters of Itamaracá in winter, and of Paranaguá, in both seasons. Branchial CAA in C. rhizophorae was thus very responsive to coastal contamination. Data are consistent with its usefulness as a supporting biomarker for inexpensive and rapid analysis in the assessment of estuaries using a sessile osmoconformer species, but preferably allied to other biomarkers and with knowledge on the suite of contaminants present.