In the last few years many concerns have been raised regarding the environmental safety of alkylphenol polyethoxylate surfactants (APnEOs).They are widely used in detergents, paints, herbicides and many other formulated products. It has been estimated that 60% of APnEOs end up in the aquatic environment; they are biodegradable and transformed into alkylphenols, such as nonylphenol and octylphenol that are hydrophobic and tend to accumulate. In the present study, acute and chronic aquatic toxicity and the estrogenic activity of the following eight alkylphenols were assessed: 4-nonylphenol, 4-octylphenol, 4-nonylphenol-10-ethoxylate, 4-tert-octylphenol, POE (1 to 2)-nonylphenol, POE (6)-nonylphenol, POE (3)-tert-octylphenol and POE (9 to 10)-tert-octylphenol. The toxic potential was measured on the crustaceans Daphnia magna and Ceriodaphnia dubia, while the estrogenic activity was determined by using the YES-test with the strain Saccharomyces cerevisiae RMY326. The results showed that the exposure of crustaceans to the eight xenoestrogens investigated caused both acute and chronic effects. The EC50 values found for C. dubia at 48 h were compared to D. magna at 24h and, gave a first indication about the toxic activity of the compounds investigated, that is better expressed in the long-term. In fact, chronic data showed a strong increase in toxicity with EC50 values one or two orders of magnitude lower than the acute values. The results of the YES-test showed that nonylphenol, octylphenol and 4-tert-octylphenol were the most estrogenic and the bioassay was able to detect their estrogenicity at very low concentrations (ng-microg/l). 相似文献
The use of psychoactive substances, including illegal drugs, drugs of abuse and psychiatric pharmaceuticals, is a major health and environmental issue. In particular, drugs are found in urban sewage and water ecosystems. The analysis of drugs in wastewater is challenging because drugs occur at trace levels in complex organo-mineral media, calling for advanced analytical methods. Here we review recent methods developped to analyze drugs in sludge, sediments, soils and biota. Extraction methods include solid–liquid extraction, sonication, microwave, and quick, easy, cheap, effective, rugged and safe extraction (QuEChERS). We compare and discuss advantages and disadvantages of each analytical step for various sample types.
Seed dispersal is a crucial component of plant population dynamics. Human landscape modifications, such as habitat destruction and fragmentation, can alter the abundance of fruiting plants and animal dispersers, foraging rates, vector movement, and the composition of the disperser community, all of which can singly or in concert affect seed dispersal. Here, we quantify and tease apart the effects of landscape configuration, namely, fragmentation of primary forest and the composition of the surrounding forest matrix, on individual components of seed dispersal of Heliconia acuminata, an Amazonian understory herb. First we identified the effects of landscape configuration on the abundance of fruiting plants and six bird disperser species. Although highly variable in space and time, densities of fruiting plants were similar in continuous forest and fragments. However, the two largest-bodied avian dispersers were less common or absent in small fragments. Second, we determined whether fragmentation affected foraging rates. Fruit removal rates were similar and very high across the landscape, suggesting that Heliconia fruits are a key resource for small frugivores in this landscape. Third, we used radiotelemetry and statistical models to quantify how landscape configuration influences vector movement patterns. Bird dispersers flew farther and faster, and perched longer in primary relative to secondary forests. One species also altered its movement direction in response to habitat boundaries between primary and secondary forests. Finally, we parameterized a simulation model linking data on fruit density and disperser abundance and behavior with empirical estimates of seed retention times to generate seed dispersal patterns in two hypothetical landscapes. Despite clear changes in bird movement in response to landscape configuration, our simulations demonstrate that these differences had negligible effects on dispersal distances. However, small fragments had reduced densities of Turdus albicollis, the largest-bodied disperser and the only one to both regurgitate and defecate seeds. This change in Turdus abundance acted together with lower numbers of fruiting plants in small fragments to decrease the probability of long-distance dispersal events from small patches. These findings emphasize the importance of foraging style for seed dispersal and highlight the primacy of habitat size relative to spatial configuration in preserving biotic interactions. 相似文献
Environmental Science and Pollution Research - Coal mining and burning activities in coal-fired power plants are among the most polluting activities in developing countries. In Brazil, the Candiota... 相似文献
Environmental Science and Pollution Research - Sentinel lymph node (SLN) sampling is important for evaluating the nodal stage of breast cancer when the axillary nodes are clinically free of... 相似文献
Environmental Science and Pollution Research - Coal exploration and burning activities are among the activities with the greatest potential to cause atmospheric pollution due to the combustion... 相似文献
An isocratic High Performance Liquid Chromatographic (HPLC) method was optimized for 3-phenoxybenzyl (1RS)-cis-trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-cyclopropanecarboxylate (permethrin) residues identification and quantification in wine matrix. Analytical reverse phase (RP) C-18 column was used (25 cm × 4 mm i.d., 5 μ m) with mobile phase consisting of acetonitrile and water in ratio 70 %/30 % (v v?1), flow-rate 2.0 mL min?1, UV-detection at 215 nm and controlled oven temperature at 25°C. The peaks of isomers were identified with the retention times as compared to standard cis-/trans- mixture and confirmed with characteristic spectra using photodiode array detector. Under these conditions, permethrin isomers were well separated with resolution 2.8 and no interference with the naturally present wine compounds was observed. The method was validated for linearity, precision, accuracy, limit of detection (LOD) and limit of quantification (LOQ). Linear regression analysis data proved a good linear relationship (correlation coefficients, r2, for cis- and trans-isomer are: 0.9995 and 0.9997, respectively) between response of the detector and concentration of permethrin isomers over a wide concentration range for both isomers (0.55 mg L?1 ?4.40 mg L?1). Experimental data showed mean recoveries between 93.95% and 96.58% with RSD values in range: 0.89% ?3.69%. The effect of ethanol content in the solvent on permethrin isomers peak areas was also studied and 60% v v?1 ethanol was found to be optimal for sample preparation. The method was successfully tested on 20 commercial wine samples from the market in which no permethrin was detected. Thus, it was proved that it is suitable for routine permethrin residues analysis. The proposed method is suitable for routine analysis because of the simple sample preparation, acceptable run-time, low cost and its applicability with conventional instruments. 相似文献
Several investigations were carried out on biotic and abiotic samples to determine the difference between Chernobyl and preChernobyl environmental radiocontamination of the Adriatic Sea. Special emphasis was put on the determination of 137Cs which resulted in the most abundant radionuclide in a wide variety of samples (sea water, sediment, pelagic and benthic species). Attention was also given to the neutron activation products 110mAg and 134Cs that were first discovered in the Adriatic ecosystem after the Chernobyl event in particular, although the 110Ag fallout deposition over the area was neglected in comparison to that of 137Cs, its bioaccumulation in macroalgae and molluscs was much higher suggesting some particular physiological accumulation mechanism. 相似文献