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Predictors of pesticide concentrations in freshwater trout – The role of life history
2016
Scholes, Rachel C. | Hageman, Kimberly J. | Closs, Gerry | Stirling, Claudine H. | Reid, Malcolm R. | Gabrielsson, Rasmus | Augspurger, Jason M.
Concentrations of halogenated pesticides in freshwater fish can be affected by age, size, trophic position, and exposure history. Exposure history may vary for individual fish caught at a single location due to different life histories, e.g. they may have hatched in different tributaries before migrating to a specific lake. We evaluated correlations of pesticide concentrations in freshwater brown trout (Salmo trutta) from the Clutha River, New Zealand, with potential predictors including capture site, age, length, trophic level, and life history. Life history was determined from otolith (fish ear bone) strontium isotope signatures, which vary among tributaries in the region of our study. Variability in pesticide concentrations between individual fish was not well explained by capture site, age, length, or trophic level. However, hexachlorobenzene (HCB) and chlorpyrifos concentrations were distinct in lake-based trout with different life histories. Additionally, one of the riverine life histories was associated with relatively high concentrations of total endosulfans. Linear models that included all potential predictor variables were evaluated and the resulting best models for HCB, chlorpyrifos, and total endosulfans included life history. These findings show that in cases where otolith isotope signatures vary geographically, they can be used to help explain contaminant concentration variations in fish caught from a single location.
Показать больше [+] Меньше [-]Environmental impact of non-certified versus certified (ASC) intensive Pangasius aquaculture in Vietnam, a comparison based on a statistically supported LCA
2016
Nhu, Trang T. | Schaubroeck, Thomas | Henriksson, Patrik J.G. | Bosma, Roel | Sorgeloos, Patrick | Dewulf, Jo
Pangasius production in Vietnam is widely known as a success story in aquaculture, the fastest growing global food system because of its tremendous expansion by volume, value and the number of international markets to which Pangasius has been exported in recent years. While certification schemes are becoming significant features of international fish trade and marketing, an increasing number of Pangasius producers have followed at least one of the certification schemes recognised by international markets to incorporate environmental and social sustainability practices in aquaculture, typically the Pangasius Aquaculture Dialogue (PAD) scheme certified by the Aquaculture Stewardship Council (ASC). An assessment of the environmental benefit of applying certification schemes on Pangasius production, however, is still needed. This article compared the environmental impact of ASC-certified versus non-ASC certified intensive Pangasius aquaculture, using a statistically supported LCA. We focused on both resource-related (water, land and total resources) and emissions-related (global warming, acidification, freshwater and marine eutrophication) categories. The ASC certification scheme was shown to be a good approach for determining adequate environmental sustainability, especially concerning emissions-related categories, in Pangasius production. However, the non-ASC certified farms, due to the large spread, the impact (e.g., water resources and freshwater eutrophication) was possibly lower for a certain farm. However, this result was not generally prominent. Further improvements in intensive Pangasius production to inspire certification schemes are proposed, e.g., making the implementation of certification schemes more affordable, well-oriented and facilitated; reducing consumed feed amounts and of the incorporated share in fishmeal, especially domestic fishmeal, etc. However, their implementation should be vetted with key stakeholders to assess their feasibility.
Показать больше [+] Меньше [-]Experimental examination of effectiveness of vegetation as bio-filter of particulate matters in the urban environment
2016
Chen, Lixin | Liu, Chenming | Zou, Rui | Yang, Mao | Zhang, Zhiqiang
Studies focused on pollutants deposition on vegetation surfaces or aerodynamics of vegetation space conflict in whether vegetation planting can effectively reduce airborne particulate matter (PM) pollution. To achieve a more comprehensive understanding of the conflict, we conducted experiments during 2013 and 2014 in Beijing, China to evaluate the importance of vegetation species, planting configurations and wind in influencing PM concentration at urban and street scales. Results showed that wind field prevailed over the purification function by vegetation at urban scale. All six examined planting configurations reduced total suspended particle along horizontal but not vertical direction. Shrubs and trees–grass configurations performed most effectively for horizontal PM2.5 reduction, but adversely for vertical attenuation. Trapping capacity of PMs was species-specific, but species selection criteria could hardly be generalized for practical use. Therefore, design of planting configuration is practically more effective than tree species selection in attenuating the ambient PM concentrations in urban settings.
Показать больше [+] Меньше [-]Thyroid hormone-disrupting activity and ecological risk assessment of phosphorus-containing flame retardants by in vitro, in vivo and in silico approaches
2016
Zhang, Quan | Ji, Chenyang | Yin, Xiaohui | Yan, Lu | Lu, Meiya | Zhao, Meirong
In recent years, phosphorus-containing flame retardants (PFRs) have been frequently detected in various environmental media and biota - and in humans - as the result of steady increase in global usage of PFRs. However, studies on the potential health and ecological risks of PFRs are still scarce. In this study, we investigated the thyroid hormone-disrupting activity and ecological risk of nine frequently detected PFRs by in vitro, in vivo and in silico approaches. Results from the dual-luciferase reporter gene assay showed that tributyl phosphate (TNBP), tricresyl phosphate (TMPP), tris(2-chloroisopropyl)phosphate (TCIPP) and tris(2-chloro-1-(chloromethyl)ethyl)phosphate (TDCIPP) exerted thyroid receptor β (TRβ) antagonistic activity, with the values of RIC20 of 5.2 × 10−7, 2.7 × 10−7, 1.2 × 10−6 and 6.8 × 10−6 M, respectively. Molecular docking platform simulations suggested that the observed effects may be attributed to direct binding of PFRs to TR. Results from the T-screen assay indicated that TNBP and TMPP showed T3 antagonistic activity and thus significantly decreased the viability of GH3 cell lines in the presence of T3. The exposure assay using Xenopus tropicalis embryos revealed the potential teratogenic effect of TNBP, TMPP, TCIPP and TDCIPP. In conclusion, our studies revealed that some PFRs were potential thyroid hormone disruptors and may cause health and ecological risks. However, the mode of action of PFRs on TR remains uncertain. The correlation between the predicted affinity and the amplitude of the effect observed in cell based assay is encouraging, but not decisive. Further in vitro binding experiments of TR and PFRs are required. At the same time, the results provided here also demonstrated that multi-model approaches are of great importance to comprehensively evaluate the potential risks of emerging contaminants.
Показать больше [+] Меньше [-]Changes of concentrations and possibility of accumulation of bisphenol A and alkylphenols, depending on biomass and composition, in zooplankton of the Southern Baltic (Gulf of Gdansk)
2016
Staniszewska, Marta | Nehring, Iga | Mudrak-Cegiołka, Stella
The focus of the present study was to find the relationship between concentrations of bisphenol A (BPA), 4-tert-octylphenol (OP) and 4-nonylphenol (NP) in zooplankton and seasonal changes in the composition and biomass of particular zooplankton taxa in the Gulf of Gdansk (Southern Baltic) in the years 2011–2012. Assays of BPA, OP and NP in water and zooplankton samples were performed using the HPLC/FL system. High mean concentrations of the studied compounds, determined in spring (405.9 (BPA); 25.7 (OP); 111.2 (NP) ng g−1 dw), can be linked to the high proportion of meroplankton in that season. Rotifera also had an influence on the rise in concentrations of the studied compounds but to a lesser degree, while the lowest concentrations (determined in summer) can be associated with the high participation of Copepoda and Cladocera in zooplankton biomass. It was also observed that juvenile forms can be more susceptible to accumulating endocrine disrupting compounds (EDCs). This is indicated by the positive correlation between BPA concentration in zooplankton and the proportion of Copepoda nauplii biomass in spring (r = 0.90; p < 0.05). In most cases, greater zooplankton biomass accumulated higher concentrations and loads of the studied compounds. With biomass growth (to 123.32 μg m−3), the bioconcentration factor also rose (to max 46.1·103), demonstrating that unlike typical hydrophobic compounds the studied EDCs do not become “diluted” in zooplankton biomass. The highest BPA concentrations from all compounds may be connected with anthropogenic sources located in the coastal zone.
Показать больше [+] Меньше [-]Drospirenone intake alters plasmatic steroid levels and cyp17a1 expression in gonads of juvenile sea bass
2016
Blanco, María | Fernandes, Denise | Medina, Paula | Blázquez, Mercedes | Porte, Cinta
Drospirenone (DRO) is one of the most widely used progestins in contraceptive treatments and hormone replacement therapies. The pharmacokinetics and potential toxicological effects of DRO were investigated in juvenile sea bass (Dicentrarchus labrax) exposed through the diet (0.01–10 μg DRO/g) for up to 31 days. DRO was detected in the blood (4–27 ng/mL) of fish exposed to the highest concentration, with no significant bioaccumulation over time and no alteration of hepatic metabolizing enzymes, namely, CYP1A and CYP3A-catalysed activities and UDP-glucuronyltransferase (UGT). Pregnenolone (P5), progesterone (P4), 17α-hydroxyprogesterone (17P4), 17α-hydroxypregnenolone (17P5), androstenedione (AD) and testosterone (T) were determined in plasma and gene expression of cyp17a1, cyp19a1a and cyp11β analysed by qRT-PCR in gonads. The significant increase in plasmatic levels of 17P5, 17P4 and AD detected after 31 days exposure to 10 ng DRO/g together with the increased expression of cyp17a1 in females evidence the ability of DRO to alter steroid synthesis at low intake concentrations (7 ng DRO/day). However, the potential consequences of this steroid shift for female reproduction remain to be investigated.
Показать больше [+] Меньше [-]Positive associations of serum perfluoroalkyl substances with uric acid and hyperuricemia in children from Taiwan
2016
Qin, Xiao-Di | Qian, Zhengmin | Vaughn, Michael G. | Huang, Jin | Ward, Patrick | Zeng, Xiao-Wen | Zhou, Yang | Zhu, Yu | Yuan, Bing | Li, Meng | Bai, Zhipeng | Paul, Gunther | Hao, Yuan-Tao | Chen, Wen | Chen, Pau-Chung | Dong, Guang-Hui | Lee, Yungling Leo
To investigate the risk of hyperuricemia in relation to Perfluoroalkyl substances (PFASs) in children from Taiwan, 225 Taiwanese children aged 12–15 years were recruited from 2009 to 2010. Linear and logistic regression models were employed to examine the influence of PFASs on serum uric acid levels. Findings revealed that eight of ten PFASs analyses were detected in >94% of the participants' serum samples. Multivariate linear regression models revealed that perfluorooctanic acid (PFOA) was positively associated with serum uric acid levels (β = 0.1463, p < 0.05). Of all the PFASs analyses, only PFOA showed a significant effect on elevated levels of hyperuricemia (aOR = 2.16, 95%CI: 1.29–3.61). When stratified by gender, the association between serum PFOA and uric acid levels was only evident among boys (aOR = 2.76, 95%CI: 1.37–5.56). In conclusion, PFOA was found to be associated with elevated serum levels of uric acid in Taiwanese children, especially boys. Further research is needed to elucidate these links.
Показать больше [+] Меньше [-]Mechanisms of cadmium accumulation (adsorption and absorption) by the freshwater bivalve Corbicula fluminea under hydrodynamic conditions
2016
Nan, Geng | Peifang, Wang | Zhao, Wang | Jun, Hou | Jin, Qian | Lingzhan, Miao
Many heavy metals in sediments and water have potential adverse effects on aquatic organisms such as Corbicula fluminea (O.F. Müller, 1774), a bivalve species frequently used as a biomonitor for metal pollution. Studies over the past decades examining the heavy metal uptake by C. fluminea, very few has investigated the effect of hydrodynamic conditions on accumulation of heavy metal by C. fluminea. Therefore, in this study, to investigate the mechanism of intracellular and extracellular accumulation of metal, individuals of C. fluminea were exposed to cadmium (Cd)-treated water under three different hydrodynamic conditions. These included exposures in two set ups: three rates of rotation (500, 350, 200 r/min) in beakers for 10 days, and then exposure to Cd-treated sediment under two naturally turbulent water conditions (14 cm/s and 3.2 cm/s) in experimental flumes for 23 days. Hydrodynamic force increased the burrowing rate but decreased the activity of C. fluminea. After 10 days of exposure, the extracellular concentrations of Cd in the tissues of C. fluminea in the sand group were significantly higher than that in the gravel groups. The intracellular and extracellular concentrations of Cd in the tissues of C. fluminea dramatically increased in the Cd-treated sediment test. Moreover, the concentration of the extracellular Cd adsorbed on the tissues of C. fluminea in the 14 cm/s and 3.2 cm/s groups was significantly higher than that in the control group, whereas the effect of hydrodynamic force on absorption of Cd by C. fluminea was not obvious. These results suggest that hydrodynamic condition plays an important role in extracellular accumulation of Cd by C. fluminea. In future study, when using C. fluminea to assess Cd pollution in aquatic environment, extracellular Cd adsorbed on the tissue should be removed to avoid the influence of hydrodynamics.
Показать больше [+] Меньше [-]Predicting total dissolved solids release from central Appalachian coal mine spoils
2016
Daniels, W. L. | Zipper, C. E. | Orndorff, Z. W. | Skousen, J. | Barton, C. D. | McDonald, L. M. | Beck, M. A.
Appalachian USA surface coal mines face public and regulatory pressure to reduce total dissolved solids (TDS) in discharge waters, primarily due to effects on sensitive macroinvertebrates. Specific conductance (SC) is an accurate surrogate for TDS and relatively low levels of SC (300–500 μS cm−1) have been proposed as regulatory benchmarks for instream water quality. Discharge levels of TDS from regional coal mines are frequently >1000 μS cm−1. The primary objectives of this study were to (a) determine the effect of rock type and weathering status on SC leaching potentials for a wide range of regional mine spoils; (b) to relate leachate SC from laboratory columns to actual measured discharge SC from field sites; and (c) determine effective rapid lab analyses for SC prediction of overburden materials. We correlated laboratory unsaturated column leaching results for 39 overburden materials with a range of static lab parameters such as total-S, saturated paste SC, and neutralization potential. We also compared column data with available field leaching and valley fill discharge SC data. Leachate SC is strongly related to rock type and pre-disturbance weathering. Fine-textured and non-weathered strata generally produced higher SC and pose greater TDS risk. High-S black shales produced the highest leachate SC. Lab columns generated similar range and overall SC decay response to field observations within 5–10 leaching cycles, while actual reduction in SC in the field occurs over years to decades. Initial peak SC can be reliably predicted (R2 > 0.850; p < 0.001) by simple lab saturated paste or 1:2 spoil:water SC procedures, but predictions of longer-term SC levels are less reliable and deserve further study. Overall TDS release risk can be accurately predicted by a combination of rock type + S content, weathering extent, and simple rapid SC lab measurements.
Показать больше [+] Меньше [-]In situ passive sampling of sediments in the Lower Duwamish Waterway Superfund site: Replicability, comparison with ex situ measurements, and use of data
2016
Apell, Jennifer N. | Gschwend, P. M.
Superfund sites with sediments contaminated by hydrophobic organic compounds (HOCs) can be difficult to characterize because of the complex nature of sorption to sediments. Porewater concentrations, which are often used to model transport of HOCs from the sediment bed into overlying water, benthic organisms, and the larger food web, are traditionally estimated using sediment concentrations and sorption coefficients estimated using equilibrium partitioning (EqP) theory. However, researchers have begun using polymeric samplers to determine porewater concentrations since this method does not require knowledge of the sediment's sorption properties. In this work, polyethylene passive samplers were deployed into sediments in the field (in situ passive sampling) and mixed with sediments in the laboratory (ex situ active sampling) that were contaminated with polychlorinated biphenyls (PCBs). The results show that porewater concentrations based on in situ and ex situ sampling generally agreed within a factor of two, but in situ concentrations were consistently lower than ex situ porewater concentrations. Imprecision arising from in situ passive sampling procedures does not explain this bias suggesting that field processes like bioirrigation may cause the differences observed between in situ and ex situ polymeric samplers.
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