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371.
Concentrations of polychlorinated biphenyls (PCBs) in blubber of female common dolphins and harbour porpoises from the Atlantic coast of Europe were frequently above the threshold at which effects on reproduction could be expected, in 40% and 47% of cases respectively. This rose to 74% for porpoises from the southern North Sea. PCB concentrations were also high in southern North Sea fish. The average pregnancy rate recorded in porpoises (42%) in the study area was lower than in the western Atlantic but that in common dolphins (25%) was similar to that of the western Atlantic population. Porpoises that died from disease or parasitic infection had higher concentrations of persistent organic pollutants (POPs) than animals dying from other causes. Few of the common dolphins sampled had died from disease or parasitic infection. POP profiles in common dolphin blubber were related to individual feeding history while those in porpoises were more strongly related to condition.  相似文献   
372.
Oliveira M  Pacheco M  Santos MA 《Chemosphere》2007,66(7):1284-1291
This study represents a first approach to short-term effects of phenanthrene (Phe) in fish. The teleost Liza aurata was exposed to 0.1-2.7microM Phe during 16h. CYP1A induction was assessed as liver ethoxyresorufin-O-deethylase (EROD) activity. Genotoxicity was evaluated in gill and liver as DNA integrity (by alkaline unwinding), whereas in blood the erythrocytic nuclear abnormalities (ENA) frequency was determined. Stress responses were determined as cortisol, glucose and lactate plasma levels. Liver EROD activity was significantly increased by Phe 0.3-2.7microM. Phe genotoxicity in gill was not found, whereas liver DNA integrity significantly decreased after exposure to Phe 0.1 and 0.9microM demonstrating its genotoxicity which did not correlate with liver CYP1A induction. Phe genotoxicity in blood was demonstrated by a significant ENA increase from 0.1 up to 2.7microM. In terms of stress responses, plasma cortisol was significantly increased by Phe 0.3-2.7microM, though plasma glucose was only significantly increased by Phe 0.9 and 2.7microM. The Phe observed effects on L. aurata detected at different levels demonstrate a physiological unbalance and a probable ecological risk to ichthyofauna.  相似文献   
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This work presents a liquid disposal monitoring originated from uranium enrichment process at Aramar Experimental Center from 1990 to 1998. Assessment of uranium, fluorides, ammoniacal nitrogen, chemical oxygen demand, and pH measurements were made in water samples and compared with results achieved in other countries, as North America and India. The liquid disposal evaluation, generated by uranium enrichment process, showed low levels, considering most parameters established by Federal and State Legislation, aiming environmental pollution control. However, uranium levels were above the limits established by Conselho Nacional do Meio Ambiente, Environment Protection Agency and mainly by the World Health Organization.  相似文献   
376.
We hypothesize that floating debris leaving polluted coastal bays accumulate on nearby pristine beaches. We examined composition, quantities and distribution of marine debris along approximately 150 km of relatively undeveloped, tropical beaches in Costa do Dendê (Bahia, Brazil). The study site is located south of Salvador City, the largest urban settlement from NE Brazil. Strong spatial variations were observed. Plastics accounted for 76% of the sampled items, followed by styrofoam (14%). Small plastic fragments resultant from the breakdown of larger items are ubiquitous all over the area. Because the dominant littoral drift in Bahia is southward, average beach debris densities (9.1 items/m) along Costa do Dendê were threefold higher than densities previously observed north of Salvador City. River-dominated and stable beaches had higher debris quantities than unstable, erosional beaches. Areas immediately south of the major regional embayments (Camamu and Todos os Santos) were the preferential accumulation sites, indicating that rivers draining populous areas are the major source of debris to the study site. Our results provide baseline information for future assessments. Management actions should focus on input prevention at the hydrographic basin level rather than on cleaning services on beaches.  相似文献   
377.
The impact of drilling oil activities in the Brazilian Bonito Field/Campos Basin (Rio de Janeiro) shell drilling (300 m) using nonaqueous fluids (NAFs) was investigated with respect to Al, Fe, Mn, Ba, Co, Pb, Cu, As, Hg, Cr, Ni, Zn, Cd, V, and aliphatic and polynuclear aromatic hydrocarbons concentrations in the sediment. Sampling took place in three different times during approximately 33 months. For the metals Al, As, Co, Cr, Cu, Cd, Fe, Ni, Mn, V, and Zn, no significant variation was observed after drilling activities in most of the stations. However, an increase was found in Ba concentration—due to the drilling activity—without return to the levels found 22 months after drilling. High Ba contents was already detected prior to well drilling, probably due to drilling activities in other wells nearby. Hydrocarbon contents also suggest previous anthropogenic activities. Aliphatic hydrocarbon contents were in the range usually reported in other drilling sites. The same behavior was observed in the case of polyaromatic hydrocarbons. Nevertheless, the n-alkane concentration increased sharply after drilling, returning almost to predrilling levels 22 months after drilling activities.  相似文献   
378.
A simple and sensitive method was developed for determination of trace copper by direct precipitation preconcentration and detection with Flame Atomic Absorption Spectrometry (FAAS). The reagent 2-[2'-(6-methyl-benzothiazolylazo)]-4-aminophenol (Me-BTAP) was used as precipitating agent. The experimental conditions for the quantitative precipitation of copper, such as pH, amount of reagents, temperature and the effect of diverse ions on the precipitation have been investigated. It was found that copper is quantitatively extracted (> or =95%) and the method provides a sensitivity enhancement of 40-fold for a 10 ml sample volume with a detection limit of 0.5 microg l(-1). The proposed method was successfully applied for the determination of trace copper in water, urine and biological samples.  相似文献   
379.
Textile industry wastes raise a great concern due to their strong coloration and toxicity. The objective of the present work was to characterize the degradation and mineralization of textile effluents by advanced oxidative processes using either TiO2 or TiO2/H2O2 and to monitor the toxicity of the products formed during 6-h irradiation in relation to that of the in natura effluent. The results demonstrated that the TiO2/H2O2 association was more efficient in the mineralization of textile effluents than TiO2, with high mineralized ion concentrations (NH 4 + , NO 3 ? , and SO 4 2? ) and significantly decreased organic matter ratios (represented by the chemical oxygen demand and total organic carbon). The toxicity of the degradation products after 4-h irradiation to Artemia salina L. was not significant (below 10 %). However, the TiO2/H2O2 association produced more toxicity under irradiation than the TiO2 system, which was attributed to the increased presence of oxidants in the first group. Comparatively, the photogenerated products of both TiO2 and the TiO2/H2O2 association were less toxic than the in natura effluent.  相似文献   
380.
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