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  • Arsenic characteristics in the terrestrial environment in the vicinity of the Shimen realgar mine, China
    Sci. Total Environ. (IF 4.9) Pub Date : 2018-01-16
    Fen Yang, Shaowen Xie, Chaoyang Wei, Jinxin Liu, Hongzhi Zhang, Tao Chen, Jing Zhang
    更新日期:2018-01-17
  • 更新日期:2018-01-17
  • WRF modeling of PM2.5 remediation by SALSCS and its clean air flow over Beijing terrain
    Sci. Total Environ. (IF 4.9) Pub Date : 2018-01-16
    Qingfeng Cao, Lian Shen, Sheng-Chieh Chen, David Y.H. Pui
    更新日期:2018-01-17
  • Seasonal variations in fine particle composition from Beijing prompt oxidative stress response in mouse lung and liver
    Sci. Total Environ. (IF 4.9) Pub Date : 2018-01-16
    Michal Pardo, Fanfan Xu, Xinghua Qiu, Tong Zhu, Yinon Rudich
    更新日期:2018-01-17
  • Risk factors associated with rural water supply failure: A 30-year retrospective study of handpumps on the south coast of Kenya
    Sci. Total Environ. (IF 4.9) Pub Date : 2018-01-16
    Tim Foster, Juliet Willetts, Mike Lane, Patrick Thomson, Jacob Katuva, Rob Hope
    更新日期:2018-01-17
  • Effect of hydrogen peroxide on Microcystic aeruginosa: Role of cytochromes P450
    Sci. Total Environ. (IF 4.9) Pub Date : 2018-01-16
    Jia Wang, Zunwei Chen, Hui Chen, Yuezhong Wen
    更新日期:2018-01-17
  • 更新日期:2018-01-17
  • 更新日期:2018-01-17
  • 更新日期:2018-01-17
  • Potential factors that impact the radon level and the prediction of ambient dose equivalent rates of indoor microenvironments
    Sci. Total Environ. (IF 4.9) Pub Date : 2018-01-12
    Mohamed Yasreen Mohamed Ali, Marlia M. Hanafiah, Md Firoz Khan
    更新日期:2018-01-13
  • Land-Water-Food Nexus and indications of crop adjustment for water shortage solution
    Sci. Total Environ. (IF 4.9) Pub Date : 2018-01-12
    Dandan Ren, Yonghui Yang, Yanmin Yang, Keith Richards, Xinyao Zhou
    更新日期:2018-01-13
  • Integrating priority areas and ecological corridors into national network for conservation planning in China
    Sci. Total Environ. (IF 4.9) Pub Date : 2018-01-12
    Jie Liang, Xinyue He, Guangming Zeng, Minzhou Zhong, Xiang Gao, Xin Li, Xiaodong Li, Haipeng Wu, Chunting Feng, Wenle Xing, Yilong Fang, Dan Mo
    更新日期:2018-01-13
  • Effects of ZnO nanoparticles in the Caspian roach (Rutilus rutilus caspicus)
    Sci. Total Environ. (IF 4.9) Pub Date : 2018-01-12
    K. Khosravi-Katuli, G. Lofrano, H. Pak Nezhad, A. Giorgio, M. Guida, F. Aliberti, A. Siciliano, M. Carotenuto, E. Galdiero, E. Rahimi, G. Libralato
    更新日期:2018-01-13
  • 更新日期:2018-01-13
  • 更新日期:2018-01-13
  • Study of the evolution of gravel beaches nourished with sand
    Sci. Total Environ. (IF 4.9) Pub Date : 2018-01-12
    J.I. Pagán, M. López, I. López, A.J. Tenza-Abril, L. Aragonés
    更新日期:2018-01-13
  • 更新日期:2018-01-13
  • Bone lead levels in an environmentally exposed elderly population in shanghai, China
    Sci. Total Environ. (IF 4.9) Pub Date : 2018-01-12
    Aaron J. Specht, Yanfen Lin, Jian Xu, Marc Weisskopf, Linda H. Nie
    更新日期:2018-01-13
  • Chronic nitrogen addition induces a cascade of plant community responses with both seasonal and progressive dynamics
    Sci. Total Environ. (IF 4.9) Pub Date : 2018-01-12
    Xiaobing Zhou, Matthew A. Bowker, Ye Tao, Lin Wu, Yuanming Zhang
    更新日期:2018-01-13
  • 更新日期:2018-01-13
  • Ambient soil cation exchange capacity inversely associates with infectious and parasitic disease risk in regional Australia
    Sci. Total Environ. (IF 4.9) Pub Date : 2018-01-12
    Craig Liddicoat, Peng Bi, Michelle Waycott, John Glover, Martin Breed, Philip Weinstein
    更新日期:2018-01-13
  • Isotopic composition of nitrogen species in groundwater under agricultural areas: A review
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-23
    Olha Nikolenko, Anna Jurado, Alberto V. Borges, Kay Knӧller, Serge Brouyѐre

    This work reviews applications of stable isotope analysis to the studies of transport and transformation of N species in groundwater under agricultural areas. It summarizes evidence regarding factors affecting the isotopic composition of NO3−, NH4+ and N2O in subsurface, and discusses the use of 11B, 18O, 13C, 34S, 87Sr/86Sr isotopes to support the analysis of δ15N values. The isotopic composition of NO3−, NH4+ and N2O varies depending on their sources and dynamics of N cycle processes. The reported δ15N-NO3− values for sources of NO3− are: soil organic N – + 3‰–+8‰, mineral fertilizers – − 8‰–+7‰; manure/household waste – + 5‰ to + 35‰. For NH4+ sources, the isotopic signature ranges are: organic matter – + 2.4–+4.1‰, rainwater – − 13.4–+2.3‰, mineral fertilizers – − 7.4–+5.1‰, household waste – + 5–+9‰; animal manure – + 8–+11‰. For N2O, isotopic composition depends on isotopic signatures of substrate pools and reaction rates. δ15N values of NO3− are influenced by fractionation effects occurring during denitrification (ɛ = 5–40‰), nitrification (ɛ = 5–35‰) and DNRA (ɛ not reported). The isotopic signature of NH4+ is also affected by nitrification and DNRA as well as mineralization (ɛ = 1‰), sorption (ɛ = 1–8‰), anammox (ɛ = 4.3–7.4‰) and volatilization (ɛ = 25‰). As for the N2O, production of N2O leads to its depletion in 15N, whereas consumption – to enrichment in 15N. The magnitude of fractionation effects occurring during the considered processes depends on temperature, pH, DO, C/NO3− ratio, size of the substrate pool, availability of electron donors, water content in subsoil, residence time, land use, hydrogeology. While previous studies have accumulated rich data on isotopic composition of NO3− in groundwater, evidence remains scarce in the cases of NH4+ and N2O. Further research is required to consider variability of δ15N-NH4+ and δ15N-N2O in groundwater across agricultural ecosystems.

    更新日期:2018-01-12
  • Climatic and dam-induced impacts on river water temperature: Assessment and management implications
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-23
    Mariola Kędra, Łukasz Wiejaczka

    In a changing climate with a warming trend in air temperature, river water temperature increases as a result of heat exchange with the atmosphere. Moreover, of the different types of anthropogenic activity impacting rivers, the construction of dams appears to have multi-dimensional effects on the river environment, and it especially affects the thermal condition of rivers. The aim of the study is to identify and assess the impact of these two distinct sources of water temperature distortion in relation to the natural thermal conditions of rivers. In the study, linear trend analysis and a complex wavelet transform are used. The analysis focuses on daily river water temperature data for time periods before and after the construction of selected reservoirs in the Polish Carpathians, and on daily air temperature data for neighboring meteorological stations. Three rivers were selected for analysis: (1) Dunajec River, 22 km downstream of the Czorsztyn–Sromowce Wyżne reservoir complex, (2) Ropa River, 16 km downstream of the Klimkówka Reservoir, and (3) Wisłok River, 33 km downstream of the Besko Reservoir. Research has shown that the significant increasing trends identified for water temperature are weaker than analogous trends in air temperature. The Czorsztyn–Sromowce Wyżne and Klimkówka reservoirs appear to exert considerable influence on natural air–water temperature synchronization, because the phase difference increases 5-fold in comparison with conditions prior to the construction of the reservoirs. The weakening of the natural air–water temperature synchrony implies diminished impact of air temperature on stream water temperature. However, this creates an opportunity for preparing appropriate management practices mitigating an increasing temperature trend in order to shape more favorable (natural) thermal conditions for native aquatic biota in impounded rivers.

    更新日期:2018-01-12
  • Sedimentary record of antibiotic accumulation in Minnesota Lakes
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-23
    Jill F. Kerrigan, Kyle D. Sandberg, Daniel R. Engstrom, Timothy M. LaPara, William A. Arnold

    The widespread detection of antibiotics in the environment is concerning because antibiotics are designed to be effective at small doses. The objective of this work was to quantify the accumulation rates of antibiotics used by humans and animals, spanning several major antibiotic classes (sulfonamides, tetracyclines, fluoroquinolones, and macrolides), in Minnesota lake-sediment cores. Our goal was to determine temporal trends, the major anthropogenic source to these lacustrine systems, and the importance of natural production. A historical record of usage trends for ten human and/or animal-use antibiotics (four sulfonamides, three fluoroquinolones, one macrolide, trimethoprim, and lincomycin) was faithfully captured in the sediment cores. Nine other antibiotics were not detected. Ofloxacin, trimethoprim, sulfapyridine, and sulfamethazine were detected in all of the anthropogenically-impacted studied lakes. Maximum sediment fluxes reached 20.5 ng cm− 2 yr− 1 (concentration 66.1 ng/g) for ofloxacin, 1.2 ng cm− 2 yr− 1 (1.2 ng/g) for trimethoprim, 3.3 ng cm− 2 yr− 1 (11.3 ng/g) for sulfapyridine, and 1.0 ng cm− 2 yr− 1 (1.6 ng/g) for sulfamethazine, respectively. Natural production of lincomycin may have occurred in one lake at fluxes ranging from 0.4 to 1.8 ng cm− 2 yr− 1 (0.1 to 5.8 ng/g). Wastewater effluent appears to be the primary source of antibiotics in the studied lakes, with lesser inputs from agricultural activities.

    更新日期:2018-01-12
  • Assessing the environmental quality of sediments from Split coastal area (Croatia) with a battery of cell-based bioassays
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-23
    Maria Blanco, Elisabet Pérez-Albaladejo, Benjamí Piña, Grozdan Kušpilić, Vesna Milun, Roger Lille-Langøy, Odd André Karlsen, Anders Goksøyr, Cinta Porte

    A battery of cell-based bioassays, including PLHC-1 cells, zebrafish-Pxr-transfected COS-7 cells and estrogen receptor-recombinant yeast assay (ER-RYA), were applied to detect the presence of bioactive pollutants in sediments collected from Kaštela Bay and Brač Channel (Croatia). Exposure of PLHC-1 cells to the sediment extracts evidenced significant cytotoxicity and presence of CYP1A inducers in sediments collected in Kaštela Bay, near the industrial zone and cargo port of Split. Sediments from this area, which is highly contaminated with PCBs, HCB, DDTs and γ-HCH, also activated the zebrafish Pxr (zfPxr) reporter system. No evidence of estrogenicity was detected for any of the sediments extracts in the ER-RYA assay. Importantly, the battery of in vitro assays identified Kaštela Bay as the area with the higher anthropogenic impact, where sediment-bound pollutants could pose a risk to aquatic organisms. In contrast, sediments from the Brač Channel showed rather low response in the different bioassays.

    更新日期:2018-01-12
  • Arctic antibiotic resistance gene contamination, a result of anthropogenic activities and natural origin
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-22
    Lu Tan, Linyun Li, Nicholas Ashbolt, Xiaolong Wang, Yuxiao Cui, Xiao Zhu, Yan Xu, Yang Yang, Daqing Mao, Yi Luo

    The increasing global prevalence of antibiotic resistance genes (ARGs) in the environment is attributed to anthropogenic activities, particularly the misuse of antimicrobial drugs in human care and animal production. In the present study, we first examined Arctic/sub-Arctic (polar) sediments for the abundance and diversity of 30 ARGs against sulfonamide, tetracycline, aminoglycoside, quinolone, macrolide, and β-lactam antibiotics. Polar sediment ARGs were detected by qPCR at relatively low levels (10− 9 to 10− 5 copies/16S rRNA gene copies) compared to the reference sites, which were heavily impacted regions of China (the Haihe River, the Tianjin Water Park water and the Qilihai Wetland water, at 10− 8 to 10− 2 copies/16S rRNA gene copies). A human mitochondrial gene target, Hmt, was first used to aid in the identification of ARGs associated with anthropogenic activities, being relatively persistent, in high copy number and a human-specific molecular marker. Hmt was consistently present in easily quantifiable amounts in the polar sediment samples, indicating their relationship with human-impact, and it was also positively correlated with the relative abundance of ARGs and to the concentrations of modern-day antibiotics. Phylogenetic analyses of resistance sequences from both the Arctic marine sediments and a major database of human pathogens indicated that the ARGs in polar region were the result of a mix of human influence and natural origins. To our knowledge, this is the first study to show that ARGs in Arctic marine sediments appear to be a mixture of both natural origins and recent human influence. This study provides a significant reference regarding the global reach of antibiotic resistance, which is associated with anthropogenic activities.

    更新日期:2018-01-12
  • Exposure to the herbicide 2,4-D produces different toxic effects in two different phytoplankters: A green microalga (Ankistrodesmus falcatus) and a toxigenic cyanobacterium (Microcystis aeruginosa)
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-22
    Erika Berenice Martínez-Ruiz, Fernando Martínez-Jerónimo

    The extensive use of 2,4-dichlorophenoxiacetic acid (2,4-D) in agriculture is an important source of pollution to water and soil. Toxicity of commonly used herbicides to non-target, planktonic photosynthetic organisms has not been described completely yet. Therefore, we determined the effect of subinhibitory 2,4-D concentrations on the Chlorophycean alga Ankistrodesmus falcatus and on a toxigenic strain of the cyanobacterium Microcystis aeruginosa. Population growth, photosynthetic pigments, macromolecular biomarkers (carbohydrates, lipids, and protein), and antioxidant enzymes (catalase [CAT], glutathione peroxidase [GPx], and superoxide dismutase [SOD]) were quantified, and the integrated biomarker response (IBR) was calculated. Scanning electron microscope (SEM) and transmission electron microscope (TEM) observations were also performed. The 96-h median inhibitory concentration (IC50) for 2,4-D was 1353.80 and 71.20 mg L− 1 for the alga and the cyanobacterium, respectively. Under 2,4-D stress, both organisms increased pigments and macromolecules concentration, modified the activity of all the evaluated enzymes, and exhibited ultrastructural alterations. M. aeruginosa also increased microcystins production, and A. falcatus showed external morphological alterations. The green alga was tolerant to high concentrations of the herbicide, whereas the cyanobacterium exhibited sensitivity comparable to other phytoplankters. Both organisms were tolerant to comparatively high concentrations of the herbicide; however, negative effects on the assessed biomarkers and cell morphology were significant. Moreover, stimulation of the production of cyanotoxins under chemical stress could increase the risk for the biota in aquatic environments, related to herbicides pollution in eutrophic freshwater ecosystems.

    更新日期:2018-01-12
  • Assessing cover crop management under actual and climate change conditions
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-22
    María Alonso-Ayuso, Miguel Quemada, Marnik Vanclooster, Margarita Ruiz-Ramos, Alfredo Rodriguez, José Luis Gabriel

    The termination date is recognized as a key management factor to enhance cover crops for multiple benefits and to avoid competition with the following cash crop. However, the optimum date depends on annual meteorological conditions, and climate variability induces uncertainty in a decision that needs to be taken every year. One of the most important cover crop benefits is reducing nitrate leaching, a major concern for irrigated agricultural systems and highly affected by the termination date. This study aimed to determine the effects of cover crops and their termination date on the water and N balances of an irrigated Mediterranean agroecosystem under present and future climate conditions. For that purpose, two field experiments were used for inverse calibration and validation of the WAVE model (Water and Agrochemicals in the soil and Vadose Environment), based on continuous soil water content data, soil nitrogen content and crop measurements. The calibrated and validated model was subsequently used in advanced scenario analysis under present and climate change conditions. Under present conditions, a late termination date increased cover crop biomass and subsequently soil water and N depletion. Hence, preemptive competition risk with the main crop was enhanced, but a reduction of nitrate leaching also occurred. The hypothetical planting date of the following cash crop was also an important tool to reduce preemptive competition. Under climate change conditions, the simulations showed that the termination date will be even more important to reduce preemptive competition and nitrate leaching.

    更新日期:2018-01-12
  • Shading and sediment structure effects on stream metabolism resistance and resilience to infrequent droughts
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-22
    Sanja Zlatanović, Jenny Fabian, Katrin Premke, Michael Mutz

    Perennial, temperate, low-order streams are predicted to become intermittent as a result of irregular droughts caused by global warming and increased water demand. We hypothesize that stream metabolism changes caused by irregular droughts are linked to the shading and bed sediment structure of temperate streams. We set up 16 outdoor experimental streams with low or high shade conditions and streambeds either with alternating sorted patches of gravel and sand or homogeneous gravel-sand mix sediment structures. We assessed community respiration (CR), net ecosystem production (NEP) and periphyton biomass and structure (diatoms, green algae, cyanobacteria) in the course of 6 weeks colonization, 6 weeks desiccation, and 2.5 weeks after rewetting. The heterotroph to autotroph (H:A) and fungi to bacteria (F:B) ratios in the microbial biofilm community were assessed at the end of the colonization and rewetting phases. Streams with different bed sediment structure were functionally similar; their metabolism under desiccation was controlled solely by light availability. During flow recession, all streams showed net heterotrophy. As desiccation progressed, NEP and CR decreased to zero. Desiccation altered the periphyton composition from predominantly diatoms to green algae and cyanobacteria, particularly in streams with low shade and mixed sediments. Rapid post-drought resilience of NEP was accompanied by high cyanobacteria and green algae growth in low shade, but poor total periphyton growth in high shade streams. Variable periphyton recovery was followed by increased H:A in relation to shading, and decreased F:B in relation to sediments structure. These shifts resulted in poor CR recovery compared to the colonization phase, suggesting a link between CR resilience and microbial composition changes. The links between drought effects, post-drought recovery, shading level, and streambed structure reveal the importance of low-order stream management under a changing climate and land use to mitigate the future impact of unpredictable infrequent droughts on stream metabolism in temperate ecosystems.

    更新日期:2018-01-12
  • Monitoring of aeolian desertification on the Qinghai-Tibet Plateau from the 1970s to 2015 using Landsat images
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-21
    Chun-Lai Zhang, Qing Li, Ya-Ping Shen, Na Zhou, Xue-Song Wang, Jiao Li, Wen-Ru Jia

    Aeolian desertification, one of the most serious environmental issues, has hampered socioeconomic development on the Qinghai-Tibet Plateau (QTP). However, research on aeolian desertification in this region has been limited. To develop a set of science-based preventive measures to mitigate desertification in this region, it is first necessary to clarify the status, evolution, and driving factors of aeolian desertification. In this study, based on extensive field investigations and a current classification system for aeolian desertification, we established a new system for interpreting aeolian desertified land (ADL) on the plateau using Landsat images from 1977, 1990, 2000, 2010, and 2015 and obtained the distribution of ADL through visual interpretation of the images. The results showed that ADL covered 392,914 km2 (15.1% of the study area) in 2015, including gravel ADL, sandy ADL, and aeolian monadnocks. Controlled by climate, landforms, the type of Quaternary deposit, and human activities, ADL is scattered throughout the plateau but is concentrated mostly in the western and northern parts. Aeolian desertification on the plateau expanded from 1977 to 2000 and then began to reverse. The evolution during the study period is the result of the combined effects of natural and human factors. Irrational human activities were the dominant factor responsible for the expansion of ADL prior to 2000, whereas the subsequent reversal was mainly caused by climate change combined with large ecological restoration projects.

    更新日期:2018-01-12
  • Observations of tropospheric aerosols and NO2 in Hong Kong over 5 years using ground based MAX-DOAS
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-21
    K.L. Chan, M. Wiegner, M. Wenig, D. Pöhler

    In this paper, we present long term observations of atmospheric aerosols and nitrogen dioxide (NO2) in Hong Kong using a Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS) instrument. Ground based MAX-DOAS measurements were performed over 5 years from December 2010 to November 2015. Vertical distribution profiles of aerosols and NO2 were derived from MAX-DOAS O4 and NO2 observations by applying the optimal estimation method. Retrieved MAX-DOAS measurements of aerosols and NO2 show good agreement with sun photometer observation of aerosol optical depths (AODs) and long path DOAS measurement of ground level NO2 mixing ratios. Tropospheric vertical column densities (VCDs) of NO2 derived from MAX-DOAS measurements are used to validate OMI satellite NO2 observations. Daily data show reasonably good agreement with each other with Pearson correlation coefficient R = 0.7. However, MAX-DOAS NO2 VCDs are on average higher than OMI observations by a factor of 2. Introducing aerosols in the air mass factor calculation would enhance the OMI VCDs by 7–13%, the remaining discrepancy is mainly due to the differences in spatial coverage between the two instruments. Diurnal variation patterns of aerosols and NO2 indicated significant contributions from local anthropogenic emissions. Analysis of air mass transport shows that the enhancement of surface aerosols and NO2 concentrations mainly results from accumulation of local emissions under low wind speed conditions.

    更新日期:2018-01-12
  • Vermicompost and biochar as bio-conditioners to immobilize heavy metal and improve soil fertility on cadmium contaminated soil under acid rain stress
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-21
    Ying Wang, YongAn Xu, Dan Li, BiCong Tang, ShuLei Man, YiFan Jia, Heng Xu

    This experiment was conducted to investigate the remediation effects of bio-conditioners vermicompost (VC) and biochar (BC) on cadmium contaminated soil under the threat of acid rain, individually and associatively. With the application of soil conditioners, the percentages of HOAc-extractable Cd decreased 5.2–6.8%, 9.0–13.5% and 7.9–12.1% in the groups amended with VC, BC and VC combined BC, respectively. When the pH of rain decreased from 7.0 to 4.0, the activity of acid phosphatase decreased 2.0%, 12.3%, 3.2%, 14.8% in VC, BC, VC combined BC and control groups, individually. This study affirmed that with the application of soil conditioners, the threat of heavy metal along with bioavailability of Cd was depressed, and the properties of soil biochemical indictors were enhanced. Oppositely, the bioavailability of Cd was promoted, and soil microbial viability as well as nutrient contents was inhibited with the spraying of acid rain. The findings indicated that acid deposition played a restrain effect on soil remediation process. Meanwhile, soil conditioners showed potentials to improve soil fertilities and alleviate the stress of acid rain.

    更新日期:2018-01-12
  • Riverine phytoplankton shifting along a lentic-lotic continuum under hydrological, physiochemical conditions and species dispersal
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-21
    Yueming Qu, Naicheng Wu, Björn Guse, Nicola Fohrer

    The importance of phytoplankton-based bio-assessment has been recently recognized in lowland rivers which are affected by multi-environmental factors. However, some basic questions remain unclear to date, such as: (i) spatial and temporal variations of phytoplankton, (ii) the impact of upstream lakes on downstream community, (iii) the main drivers for species composition or (iv) the regional biodiversity along a lentic-lotic continuum. To answer these questions, we collected and analyzed the fluvial phytoplankton communities along a lentic-lotic continuum from a German lowland catchment, where a well-established ecohydrological modeling predicted long-term discharges at each sampling site. Our results revealed very high spatial and temporal variations of phytoplankton community. The changes of a lake on downstream phytoplankton assemblages were significant, especially the nearest reach after the lake. However, these influences varied along with seasons and limited in a relatively short distance to the lake. Redundancy analysis and Mantel tests showed that phytoplankton composition and dissimilarities along the lentic-lotic continuum attributed more to local hydrological and physicochemical variables than species dispersal, which confirmed the suitability of lowland phytoplankton-based bioassessment. In addition, our findings highlighted the importance of flow regime in shaping phytoplankton community composition and regional beta diversities. This study emphasized the necessity to include the hydrological variables and their relationship with phytoplankton community in future bio-monitoring investigations.

    更新日期:2018-01-12
  • Supplemental feeding and other anthropogenic threats to green turtles (Chelonia mydas) in the Canary Islands
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-21
    Catalina Monzón-Argüello, Luis Cardona, Pascual Calabuig, María Camacho, José Luis Crespo-Picazo, Daniel García-Párraga, Santiago Mayans, Octavio P. Luzardo, Jorge Orós, Nuria Varo-Cruz

    Green turtles are found in the waters of the Canary Islands but little is known about the ecology and anthropogenic pressures that threaten them. Our results have revealed that juvenile green turtles, ranging in curve carapace length from 26.9–81.0 cm, are regularly found in the archipelago and originate from rookeries in both the eastern and western Atlantic. Photo-identification and satellite tracking showed high levels of site fidelity to coastal foraging grounds associated with seagrass meadows, but stable isotope analysis indicated animal-based omnivorous diets after settlement on the continental shelf, with no increase in the consumption of macrophytes as the turtles grew. Most turtles exhibited high levels of some blood biochemical markers associated with a high consumption of proteins and fat. In addition, we determined levels of some organic and inorganic pollutants. Supplemental feeding may also contribute to explain the high prevalence of hooking and boat strikes in the green turtles brought to wildlife rescue centers as compared with loggerhead turtles. Regulatory measures and surveillance should be urgently implemented in order to improve the status of the species in the archipelago.

    更新日期:2018-01-12
  • Toxic effects of multi-walled carbon nanotubes on bivalves: Comparison between functionalized and nonfunctionalized nanoparticles
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-20
    Lucia De Marchi, Victor Neto, Carlo Pretti, Etelvina Figueira, Federica Chiellini, Andrea Morelli, Amadeu M.V.M. Soares, Rosa Freitas

    Despite of the large array of available carbon nanotube (CNT) configurations that allow different industrial and scientific applications of these nanoparticles, their impacts on aquatic organisms, especially on invertebrate species, are still limited. To our knowledge, no information is available on how surface chemistry alteration (functionalization) of CNTs may impact the toxicity of these NPs to bivalve species after a chronic exposure. For this reason, the impacts induced by chronic exposure (28 days) to unfunctionalized MWCNTs (Nf-MWCNTs) in comparison with functionalized MWCNTs (f-MWCNTs), were evaluated in R. philippinarum, by measuring alterations induced in clams' oxidative status, neurotoxicity and metabolic capacity. The results obtained revealed that exposure to both MWCNT materials altered energy-related responses, with higher metabolic capacity and lower glycogen, protein and lipid concentrations in clams exposed to these CNTs. Moreover, R. philippinarum exposed to Nf-MWCNTs and f-MWCNTs showed oxidative stress expressed in higher lipid peroxidation and lower ratio between reduced and oxidized glutathione, despite the activation of defense mechanisms (superoxide-dismutase, glutathione peroxidase and glutathione S-transferases) in exposed clams. Additionally, neurotoxicity was observed by inhibition of Cholinesterases activity in organisms exposed to both MWCNTs.

    更新日期:2018-01-12
  • A 150-year record of polycyclic aromatic compound (PAC) deposition from high Andean Cajas National Park, southern Ecuador
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-20
    Benjamin A. Musa Bandowe, Lea Fränkl, Martin Grosjean, Wojciech Tylmann, Pablo V. Mosquera, Henrietta Hampel, Tobias Schneider

    The temporal profiles of polycyclic aromatic compounds (PACs) in lake sediments reflect past changes in emissions, transport and deposition of these pollutants and, thus, record natural and anthropogenic processes. We document fluxes of PACs [(polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (OPAHs) and azaarenes (AZAs)] deposited in two tropical high-altitude lakes in the Cajas National Park (Ecuadorian Andes, 2°50′S, 79°10′W). In remote and high elevation Laguna Fondococha (4130 m a.s.l.), the temporal fluxes of OPAHs and AZAs were similar to those of PAHs suggesting similar sources. A significant increase of PAC deposition after the 1950s reflects Ecuador's economic development. PAH fluxes were relatively low (∑ 27PAHs (without retene and perylene): 0.86–11.21 ng cm− 2 yr− 1) with a composition pattern typical for long-range atmospheric transport (high 9-fluorenone/fluorene ratios) and biomass burning (30% low molecular weight PAHs). PAHs diagnostic of high temperature combustion (industry, traffic) make up 20–25% of total PAHs. Perylene concentrations increase linearly with increasing sediment depth suggesting diagenetic in-situ production. At lower elevations (Laguna Llaviucu, 3140 m a.s.l.) and closer to urban areas, PAC fluxes in the past decades were 4–5 times higher than in the remote high-elevation lake. Laguna Llaviucu also showed higher concentrations of high molecular weight pyrogenic PAHs and a greater diversity of AZAs. Individual OPAHs and AZAs reflect mainly combustion activities. In Laguna Llaviucu, which is at a lower elevation (3140 m a.s.l.) and closer to the city, molecular ratios suggest short-range atmospheric transport and deposition of PACs. A very foggy climate (170 rainy days per year) with the precipitation maximum at 3500 m removes PACs very efficiently (by wet deposition) from the atmosphere at very short distances from emission sources. This partly explains why L. Llaviucu shows higher fluxes of PACs than the higher elevation L. Fondococha. This study presents the first historical record of organic pollutants from environmental archives in Ecuador.

    更新日期:2018-01-12
  • Deglaciation and its impact on permafrost and rock glacier evolution: New insight from two adjacent cirques in Austria
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-20
    Andreas Kellerer-Pirklbauer, Viktor Kaufmann

    Glaciers and permafrost are strongly linked to each other in mid-latitude mountain regions particularly with polythermal glaciers. This linkage is not only climatically defined but also in terms of geomorphic and glaciological processes. We studied two adjacent cirques located in the Central Austria. We focussed on the deglaciation since the Little Ice Age (LIA) maximum (c.1850 CE) and its relevance for permafrost and rock glacier evolution since then. One cirque is occupied by a glacier remnant whereas the second one is occupied by an active rock glacier which was partly overridden by a glacier during the LIA. We applied a multidisciplinary approach using field-based techniques including geoelectrics, geodetic measurements, and automatic monitoring as well as historic maps and photographs, remote sensing, and digital terrain analysis. Results indicate almost complete deglaciation by the end of the last millennium. Small-scale tongue-shaped landforms of complex origin formed during the last decades at finer-grained slope deposits below the cirque headwalls. Field evidences and geophysics results proved the existence of widespread sedimentary ice beneath a thin veneer of debris at these slopes. The variable thickness of the debris layer has a major impact on differential ablation and landform evolution in both cirques. The comparison of digital elevation models revealed clear mass losses at both cirques with low rates between 1954 and 2002 and significantly higher rates since then. The central and lower part of the rock glacier moves fast transporting sediments and ice downvalley. In contrast, the upper part of the rock glacier is characterised by low debris and ice input rates. Both effects cause a significant decoupling of the main rock glacier body from its nourishment area leading eventually to rock glacier starvation. This study demonstrates the importance of a decadal-scale and multidisciplinary research approach in determining the development of alpine landforms over both space and time.

    更新日期:2018-01-12
  • Differences in the sensitivity to Cu and ligand production of coastal vs offshore strains of Emiliania huxleyi
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-20
    Pedro Echeveste, Peter Croot, Peter von Dassow

    Copper is an essential trace metal for different physiological processes in phytoplankton, being either a limiting or toxic element depending on its bioavailability, which may induce local physiological adaptations. Atmospheric Cu deposition to the oceans can negatively impact phytoplankton growth, with the most Cu-sensitive phytoplankton exhibiting differences based on coastal vs oceanic origin. The goal of this work was to analyze sensitivity to Cu toxicity of the cosmopolitan marine calcifying phytoplankton, Emiliania huxleyi, exploring what factors determine intraspecific variability in sensitivity. We compared 17 strains isolated from coastal and open ocean waters of the Eastern South Pacific (ESP), the Mediterranean Sea, and the Tasman Sea. Offshore strains were as sensitive to Cu than coastal strains. Sensitivity to Cu was explained well by predicted depositional inputs of atmospheric Cu in the ESP both for coastal and offshore strains, but not when considered globally. The variability in Cu-sensitivity was also due to the production of organic Cu-ligands (CL), being the most productive strains the most tolerant to Cu at constitutive levels. When exposed to 100 nM Cu, E. huxleyi produced significantly higher amounts of CL, especially coastal strains, but CL production did not correlate to observed EC50s.

    更新日期:2018-01-12
  • Multivariate geostatistical analysis and source identification of heavy metals in the sediment of Poyang Lake in China
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-19
    Lijun Dai, Lingqing Wang, Lianfang Li, Tao Liang, Yongyong Zhang, Chuanxin Ma, Baoshan Xing

    Heavy metals in lake sediment have become a great concern because their remobilization has frequently occurred under hydrodynamic disturbance in shallow lakes. In this study, heavy metals (Cr, Cu, Cd, Pb, and Zn) concentrations in the surface and core sediments of the largest freshwater lake in China, Poyang Lake, were investigated. Geostatistical prediction maps of heavy metals distribution in the surface sediment were completed as well as further data mining. Based on the prediction maps, the ranges of Cr, Cu, Cd, Pb, and Zn concentrations in the surface sediments of the entire lake were 96.2–175.2, 38.3–127.6, 0.2–2.3, 22.5–77.4, and 72.3–254.4 mg/kg, respectively. A self-organizing map (SOM) was applied to find the inner element relation of heavy metals in the sediment cores. K-means clustering of the self-organizing map was also completed to define the Euclidian distance of heavy metals in the sediment cores. The geoaccumulation index (Igeo) for Poyang Lake indicated a varying degree of heavy metal contamination in the surface sediment, especially for Cu. The heavy metal contamination in the sediment profiles had similar pollution levels as those of surface sediment, except for Cd. Correlation matrix mapping and principal component analysis (PCA) were used to support the idea that Cr, Pb, and Zn may be mainly derived from both lithogenic and human activities, such as atmospheric and river inflow transportation, whereas Cu and Cd may be mainly contributed from anthropogenic sources, such as mining activities and fertilizer application.

    更新日期:2018-01-12
  • Association between degradation of pharmaceuticals and endocrine-disrupting compounds and microbial communities along a treated wastewater effluent gradient in Lake Mead
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-19
    Susanna M. Blunt, Joshua D. Sackett, Michael R. Rosen, Mark J. Benotti, Rebecca A. Trenholm, Brett J. Vanderford, Brian P. Hedlund, Duane P. Moser

    The role of microbial communities in the degradation of trace organic contaminants in the environment is little understood. In this study, the biotransformation potential of 27 pharmaceuticals and endocrine-disrupting compounds was examined in parallel with a characterization of the native microbial community in water samples from four sites variously impacted by urban run-off and wastewater discharge in Lake Mead, Nevada and Arizona, USA. Samples included relatively pristine Colorado River water at the upper end of the lake, nearly pure tertiary-treated municipal wastewater entering via the Las Vegas Wash, and waters of mixed influence (Las Vegas Bay and Boulder Basin), which represented a gradient of treated wastewater effluent impact. Microbial diversity analysis based on 16S rRNA gene censuses revealed the community at this site to be distinct from the less urban-impacted locations, although all sites were similar in overall diversity and richness. Similarly, Biolog EcoPlate assays demonstrated that the microbial community at Las Vegas Wash was the most metabolically versatile and active. Organic contaminants added as a mixture to laboratory microcosms were more rapidly and completely degraded in the most wastewater-impacted sites (Las Vegas Wash and Las Vegas Bay), with the majority exhibiting shorter half-lives than at the other sites or in a bacteriostatic control. Although the reasons for enhanced degradation capacity in the wastewater-impacted sites remain to be established, these data are consistent with the acclimatization of native microorganisms (either through changes in community structure or metabolic regulation) to effluent-derived trace contaminants. This study suggests that in urban, wastewater-impacted watersheds, prior exposure to organic contaminants fundamentally alters the structure and function of microbial communities, which in turn translates into greater potential for the natural attenuation of these compounds compared to more pristine sites.

    更新日期:2018-01-12
  • Representativeness of environmental impact assessment methods regarding Life Cycle Inventories
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-19
    Antoine Esnouf, Éric Latrille, Jean-Philippe Steyer, Arnaud Helias

    Life Cycle Assessment (LCA) characterises all the exchanges between human driven activities and the environment, thus representing a powerful approach for tackling the environmental impact of a production system. However, LCA practitioners must still choose the appropriate Life Cycle Impact Assessment (LCIA) method to use and are expected to justify this choice: impacts should be relevant facing the concerns of the study and misrepresentations should be avoided. This work aids practitioners in evaluating the adequacy between the assessed environmental issues and studied production system. Based on a geometrical standpoint of LCA framework, Life Cycle Inventories (LCIs) and LCIA methods were localized in the vector space spanned by elementary flows. A proximity measurement, the Representativeness Index (RI), is proposed to explore the relationship between those datasets (LCIs and LCIA methods) through an angular distance. RIs highlight LCIA methods that measure issues for which the LCI can be particularly harmful. A high RI indicates a close proximity between a LCI and a LCIA method, and highlights a better representation of the elementary flows by the LCIA method. To illustrate the benefits of the proposed approach, representativeness of LCIA methods regarding four electricity mix production LCIs from the ecoinvent database are presented. RIs for 18 LCIA methods (accounting for a total of 232 impact categories) were calculated on these LCIs and the relevance of the methods are discussed. RIs prove to be a criterion for distinguishing the different LCIA methods and could thus be employed by practitioners for deeper interpretations of LCIA results.

    更新日期:2018-01-12
  • Evaluation of genotoxic potential in the Velika Morava River Basin in vitro and in situ
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-19
    Jovana Jovanović, Stoimir Kolarević, Aleksandra Milošković, Nataša Radojković, Vladica Simić, Biljana Dojčinović, Margareta Kračun-Kolarević, Momir Paunović, Jovana Kostić, Karolina Sunjog, Jovana Timilijić, Jelena Djordjević, Zoran Gačić, Bojana Žegura, Branka Vuković-Gačić

    The Velika Morava River is the greatest national Serbian river and the significant tributary of the Danube River. The major problems in the Velika Morava River Basin (VMRB) represent untreated industrial and municipal wastewaters. In this study, the level of genotoxic potential at the sites along the VMRB was evaluated by parallel in vitro and in situ approach. Within in vitro testing, genotoxicity of native water samples collected from the sites in VMRB was evaluated by SOS/umuC test on Salmonella typhimurium TA1535/pSK1002 and by the comet assay on HepG2 cells. DNA damage in situ was assessed in bleak (Alburnus alburnus) erythrocytes by the comet (alkaline and Fpg-modified comet) and micronucleus assays. Additionally, the concentration of heavy metals in fish tissue was measured and this data, compiled with the data of the physico-chemical parameters measured in water, was used as a measure of the pollution pressure at the sites. Results showed that applied in vitro tests with native water samples are less sensitive in comparison with in situ tests and should be taken with precaution when making predictions on the status of the ecosystem. Within applied battery of in situ assays differential sensitivity of assays was observed where alkaline comet assay showed the highest potential in differentiation of the sites based on genotoxic potential. Integrated biomarker response showed that usage of the battery of bioassays provides better insight in a genotoxic effects in animals, and consequently, that the holistic approach is more suitable for this type of study.

    更新日期:2018-01-12
  • Different methods of incorporating ciprofloxacin in soil affect microbiome and degradation of ciprofloxacin residue
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-19
    Longyong Liu, Jiandui Mi, Yan Wang, Yongde Zou, Baohua Ma, Xindi Liao, Juan Boo Liang, Yinbao Wu

    Antibiotic residues in swine manure when entered the soil would most likely affect the complex composition and functions of the soil microbiome, which is also responsible for degrading these antibiotics. Three different methods of adding ciprofloxacin (CIP), a common antibiotic used in the swine industry, to the soil were used to investigate the effects of CIP on the soil microbiome and the degradation of CIP. Results of the study showed that the microbiome could promote the degradation of CIP in the soil when CIP was incorporated into the soil together with manure. However, the CIP degradation time was prolonged when adding the manure of swine fed with diet containing CIP in the soil. All treatments did not affect the copy number of the resistance genes, except for aac(6′)-Ib-cr, as compared with the initial numbers of each treatment. MiSeq Illumina sequencing and Biolog-ECO microplates results showed that CIP had a significant effect on the abundance, structure, and function of the soil microbiome, but different addition methods resulted in distinct effects. Results of the present study demonstrated that the microbiome and fate of CIP responded differently to the different methods of adding CIP to the soil.

    更新日期:2018-01-12
  • Assessment of ecosystem productivity damage due to land use
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-19
    Piyanon Kaenchan, Jeroen Guinée, Shabbir H. Gheewala

    Land use can affect ecosystems on land and their services. Because land use has mainly local effects, damage to ecosystem productivity due to land use should be modelled spatially dependent. Unfortunately, even though land use of impacts are particular importance for countries whose economies are highly agriculture-based, ecosystem productivity damage due to land use has not yet been assessed in Thailand so far. This study presents the method for assessing the damage to ecosystem productivity due to land use (land occupation and land transformation) in Thailand. Ecosystem productivity damage is expressed through net primary production (NPP). To convert the damage into monetary units, this study performs an economic valuation of NPP using the production function approach. The results show that the value of marginal product of NPP is around 10–15 Thai baht (THB) (1 USD ≈ 36 THB), per tonne dry weight biomass. The results are applied to the case of biodiesel production. The method presented in this paper could be a guideline for future land use impact assessment research. In addition, converting the NPP damage results into monetary units facilitates integration of impact assessment and economic analysis results for supporting decision support tools such as cost benefit analysis.

    更新日期:2018-01-12
  • Aqueous Hg(II) immobilization by chitosan stabilized magnetic iron sulfide nanoparticles
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-19
    Mingyang Sun, Guanghuan Cheng, Xinlei Ge, Mindong Chen, Cheng Wang, Liping Lou, Xinhua Xu

    Stabilized iron sulfide (FeS) nanoparticles have been proven effective in the adsorption of Hg from the water environment. However, previous work with these nanoparticles determined that the separation from the treated water was difficult and time-consuming. In this study, nanoscale FeS-Fe3O4 nanocomposites were firstly synthesized with chitosan as the stabilizer (CTO-MFeS). Then, the Hg adsorption capacity and mechanism were studied. Results showed that the size of the prepared nanoparticles was about 20 nm and the specific surface area was 21.3 m2/g. Hg removal by the CTO-MFeS nanoparticles involved both adsorption and precipitation. Further investigation with XPS showed that Hg2 + was adsorbed on the surface of the CTO-MFeS nanoparticles and reacted with CTO-MFeS to form HgS and [Fe(1 − x)Hgx]S. It was also found as pH decreased below 4, the adsorption capacity of CTO-MFeS was significantly reduced that might be due to the dissolving of Fe. Additionally, the presence of Cl− resulted in the transformation of Hg2 + to HgClx2-x (x = 1, 2, 3, 4) that competed with OH in solution for Hg2 + and therefore inhibited the adsorption of Hg. Our findings provide additional information that may be useful for a theoretical basis for Hg treatment in water environment.

    更新日期:2018-01-12
  • No increase in marine microplastic concentration over the last three decades – A case study from the Baltic Sea
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-19
    Sabrina Beer, Anders Garm, Bastian Huwer, Jan Dierking, Torkel Gissel Nielsen

    Microplastic is considered a potential threat to marine life as it is ingested by a wide variety of species. Most studies on microplastic ingestion are short-term investigations and little is currently known about how this potential threat has developed over the last decades where global plastic production has increased exponentially. Here we present the first long-term study on microplastic in the marine environment, covering three decades from 1987 to 2015, based on a unique sample set originally collected and conserved for food web studies. We investigated the microplastic concentration in plankton samples and in digestive tracts of two economically and ecologically important planktivorous forage fish species, Atlantic herring (Clupea harengus) and European sprat (Sprattus sprattus), in the Baltic Sea, an ecosystem which is under high anthropogenic pressure and has undergone considerable changes over the past decades. Surprisingly, neither the concentration of microplastic in the plankton samples nor in the digestive tracts changed significantly over the investigated time period. Average microplastic concentration in the plankton samples was 0.21 ± 0.15 particles m− 3. Of 814 fish examined, 20% contained plastic particles, of which 95% were characterized as microplastic (< 5 mm) and of these 93% were fibres. There were no significant differences in the plastic content between species, locations, or time of day the fish were caught. However, fish size and microplastic in the digestive tracts were positively correlated, and the fish contained more plastic during summer than during spring, which may be explained by increased food uptake with size and seasonal differences in feeding activity. This study highlights that even though microplastic has been present in the Baltic environment and the digestive tracts of fishes for decades, the levels have not changed in this period. This underscores the need for greater understanding of how plastic is cycled through marine ecosystems. The stability of plastic concentration and contamination over time observed here indicates that the type and level of microplastic pollution may be more closely correlated to specific human activities in a region than to global plastic production and utilization as such.

    更新日期:2018-01-12
  • Use of multi-criteria decision analysis to identify potentially dangerous glacial lakes
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-19
    Ioannis Kougkoulos, Simon J. Cook, Vincent Jomelli, Leon Clarke, Elias Symeonakis, Jason M. Dortch, Laura A. Edwards, Myriam Merad

    Glacial Lake Outburst Floods (GLOFs) represent a significant threat in deglaciating environments, necessitating the development of GLOF hazard and risk assessment procedures. Here, we outline a Multi-Criteria Decision Analysis (MCDA) approach that can be used to rapidly identify potentially dangerous lakes in regions without existing tailored GLOF risk assessments, where a range of glacial lake types exist, and where field data are sparse or non-existent. Our MCDA model (1) is desk-based and uses freely and widely available data inputs and software, and (2) allows the relative risk posed by a range of glacial lake types to be assessed simultaneously within any region. A review of the factors that influence GLOF risk, combined with the strict rules of criteria selection inherent to MCDA, has allowed us to identify 13 exhaustive, non-redundant, and consistent risk criteria. We use our MCDA model to assess the risk of 16 extant glacial lakes and 6 lakes that have already generated GLOFs, and found that our results agree well with previous studies. For the first time in GLOF risk assessment, we employed sensitivity analyses to test the strength of our model results and assumptions, and to identify lakes that are sensitive to the criteria and risk thresholds used. A key benefit of the MCDA method is that sensitivity analyses are readily undertaken. Overall, these sensitivity analyses lend support to our model, although we suggest that further work is required to determine the relative importance of assessment criteria, and the thresholds that determine the level of risk for each criterion. As a case study, the tested method was then applied to 25 potentially dangerous lakes in the Bolivian Andes, where GLOF risk is poorly understood; 3 lakes are found to pose ‘medium’ or ‘high’ risk, and require further detailed investigation.

    更新日期:2018-01-12
  • From headwaters to estuary: Distribution and fate of halogenated flame retardants (HFRs) in a river basin near the largest HFR manufacturing base in China
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-18
    Xiaomei Zhen, Jianhui Tang, Lin Liu, Xinming Wang, Yanan Li, Zhiyong Xie

    With the gradual phasing out of polybrominated diphenyl ethers (PBDEs), market demands for alternative halogenated flame retardants (HFRs) are increasing. The Laizhou Bay area is the biggest manufacturing base for brominated flame retardants (BFRs) in China, and the Xiaoqing River is the largest and most heavily contaminated river in this region. Water and sediment samples were collected from the headwaters to the estuary of the Xiaoqing River to investigate the distribution and fate of HFRs [i.e., PBDEs, alternative brominated flame retardants (aBFRs) and dechlorane plus (DPs). In the water samples, DPs was the most abundant flame retardant (median: 11.7 ng/L), followed by decabromodiphenylethane (DBDPE) (5.92 ng/L). In the sediment samples, DBDPE was the predominant flame retardant (39.5 ng/g dw), followed by decabromodiphenyl ether (BDE 209) (2.81 ng/g dw). The levels of DBDPE exceeded those of BDE 209 in most samples, indicating the overwhelming replacement of BDE 209 by DBDPE in this area. In the river section of this study, point source and atmospheric deposition followed by land runoff were the major factors influencing the distribution of HFRs, whereas in the estuary, riverine discharge, the estuarine maximum turbidity zone (MTZ), and hydrodynamic parameters played more important roles. Manufacturing is a significant source of contamination of the Xiaoqing River basin through atmospheric deposition and wastewater discharge.

    更新日期:2018-01-12
  • Impacts of rapid urbanization on the water quality and macroinvertebrate communities of streams: A case study in Liangjiang New Area, China
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-18
    Kun Luo, Xuebin Hu, Qiang He, Zhengsong Wu, Hao Cheng, Zhenlong Hu, Asit Mazumder

    Rapid urbanization in China has dramatically deteriorated the water quality of streams and threatening aquatic ecosystem health. This study aims to 1) assess the impacts of urbanization on water quality and macroinvertebrate composition and 2) address the question of how urbanization affects macroinvertebrate distribution patterns. Environmental variables over multispatial scales and macroinvertebrate community data were collected on April (dry season) and September (wet season) of 2014 and 2015 at 19 sampling sites, of which nine had a high urbanization level (HUL), six had moderate urbanization level (MUL) and four had low urbanization level (LUL), in the Liangjiang New Area. The results of this study showed that macroinvertebrate assemblages significantly varied across the three urbanization levels. The sensitive species (e.g., EPT taxa) were mainly centralized at LUL sites, whereas tolerant species, such as Tubificidae (17.3%), Chironomidae (12.1%), and Physidae (4.61%), reached highest relative abundance at LUL sites. The values of family biotic index (FBI) and biological monitoring working party (BMWP) indicated the deterioration of water quality along urbanization gradient. Seasonal and inter – annual changes in macroinvertebrate communities were not observed. The results of variation partitioning analyses (CCAs) showed that habitat scale variables explained the major variation in macroinvertebrate community composition. Specifically, the increased nutrient concentrations favored tolerant species, whereas high water flow and substrate coarseness benefitted community taxa richness, diversity and EPT richness. Considering the interactions between scale-related processes, the results of this study suggested that urbanization resulted in less diverse and more tolerant stream macroinvertebrate assemblages mainly via increased nutrient concentrations and reduced substrate coarseness.

    更新日期:2018-01-12
  • Apportioning source of erosion-induced organic matter in the hilly-gully region of loess plateau in China: Insight from lipid biomarker and isotopic signature analysis
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-18
    Chun Liu, Zhongwu Li, Xiaofeng Chang, Xiaodong Nie, Lin Liu, Haibing Xiao, Danyang Wang, Hao Peng, Guangming Zeng

    Understanding the dynamics of organic matter (OM) at global and local scales is one of the challenges in the environmental sciences and i.e. terrestrial biogeochemistry. The accurate identification of OM is an essential element to achieve this goal. In our study, a novel application for quantitatively apportioning sources of eroded sedimentary OM from an eco-geomorphologic perspective was shown successfully via a coupled molecular n-alkane biomarkers and stable isotopic signatures (13C and 15N) along with elemental compositions (TOC and TN) using a Bayesian mixing model (SIAR). Soil source samples were collected from different land use types (i.e., forests, grassland, cropland, and fallow) and gully, which were probably transported downstream along the steep terrain. Meanwhile, three soil profiles with a total of 90 sediment samples were also sampled in check dam. The results indicated that cropland was the main sedimentary OM source in this catchment, contributing 29.5%, whereas the forests, grassland, fallow and gully contributed 12.17%, 15.39%, 21.53% and 21.85%, respectively. Although the molecular biomarker as a tracer was not valid solely, the combined approaches of n-alkanes biomarker and bulk parameters were efficient complements in tracing OM source in a hilly-gully region on the Loess Plateau of China.

    更新日期:2018-01-12
  • WW LCI v2: A second-generation life cycle inventory model for chemicals discharged to wastewater systems
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-18
    Pradip P. Kalbar, Ivan Muñoz, Morten Birkved

    We present a second-generation wastewater treatment inventory model, WW LCI 2.0, which on many fronts represents considerable advances compared to its previous version WW LCI 1.0. WW LCI 2.0 is a novel and complete wastewater inventory model integrating WW LCI 1.0, i.e. a complete life cycle inventory, including infrastructure requirement, energy consumption and auxiliary materials applied for the treatment of wastewater and disposal of sludge and SewageLCI, i.e. fate modelling of chemicals released to the sewer. The model is expanded to account for different wastewater treatment levels, i.e. primary, secondary and tertiary treatment, independent treatment by septic tanks and also direct discharge to natural waters. Sludge disposal by means of composting is added as a new option. The model also includes a database containing statistics on wastewater treatment levels and sludge disposal patterns in 56 countries. The application of the new model is demonstrated using five chemicals assumed discharged to wastewater systems in four different countries. WW LCI 2.0 model results shows that chemicals such as diethylenetriamine penta (methylene phosphonic acid) (DTPMP) and Diclofenac, exhibit lower climate change (CC) and freshwater ecotoxicity (FET) burdens upon wastewater treatment compared to direct discharge in all country scenarios. Results for Ibuprofen and Acetaminophen (more readily degradable) show that the CC burden depends on the country-specific levels of wastewater treatment. Higher treatment levels lead to lower CC and FET burden compared to direct discharge. WW LCI 2.0 makes it possible to generate complete detailed life cycle inventories and fate analyses for chemicals released to wastewater systems. Our test of the WW LCI 2.0 model with five chemicals illustrates how the model can provide substantially different outcomes, compared to conventional wastewater inventory models, making the inventory dependent upon the atomic composition of the molecules undergoing treatment as well as the country specific wastewater treatment levels.

    更新日期:2018-01-12
  • Feed additives shift gut microbiota and enrich antibiotic resistance in swine gut
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-18
    Yi Zhao, Jian-Qiang Su, Xin-Li An, Fu-Yi Huang, Christopher Rensing, Kristian Koefoed Brandt, Yong-Guan Zhu

    Antibiotic resistance genes (ARGs) are emerging environmental contaminants posing a threat to public health. Antibiotics and metals are widely used as feed additives and could consequently affect ARGs in swine gut. In this study, high-throughput quantitative polymerase chain reaction (HT-qPCR) based ARG chip and next-generation 16S rRNA gene amplicon sequencing data were analyzed using multiple statistical approaches to profile the antibiotic resistome and investigate its linkages to antibiotics and metals used as feed additives and to the microbial community composition in freshly collected swine manure samples from three large-scale Chinese pig farms. A total of 146 ARGs and up to 1.3 × 1010 total ARG copies per gram of swine feces were detected. ARGs conferring resistance to aminoglycoside, macrolide-lincosamide-streptogramin B (MLSB) and tetracycline were dominant in pig gut. Total abundance of ARGs was positively correlated with in-feed antibiotics, microbial biomass and abundance of mobile genetic elements (MGEs) (P < 0.05). A significant correlation between microbial communities and ARG profiles was observed by Procrustes analysis. Network analysis revealed that Bacteroidetes and Firmicutes were the most dominant phyla co-occurring with specific ARGs. Partial redundancy analysis indicated that the variance in ARG profiles could be primarily attributed to antibiotics and metals in feed (31.8%), gut microbial community composition (23.3%) and interaction between feed additives and community composition (16.5%). These results suggest that increased levels of in-feed additives could aggravate the enrichment of ARGs and MGEs in swine gut.

    更新日期:2018-01-12
  • Estimation of intake and uptake of bisphenols and triclosan from personal care products by dermal contact
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-18
    Shaoyou Lu, Yuling Yu, Lu Ren, Xiaolan Zhang, Guihua Liu, Yingxin Yu

    Increasing concern has been raised in respect of exposure to bisphenols and triclosan (TCS) due to their widespread use. However, little is known about their occurrence in personal care products (PCPs) or, particularly, their dermal uptake following daily application. It is therefore necessary to evaluate the human health risk of bisphenols and TCS via dermal absorption. In this study, 150 PCPs, covering 11 different categories, were collected in China. The concentrations of seven bisphenol analogues and TCS were measured, and the associated human health risks by dermal contact were estimated. High detection frequencies of TCS (46.7%) and bisphenol AF (38.7%) were found in the PCPs. The highest mean concentration of Σ7BPs (sum concentration of all seven bisphenols) was 77.8 ng g− 1 found in masks, and the highest mean concentration of TCS was 86.7 ng g− 1 in hand sanitizers. The bisphenol composition profiles varied among different categories. Bisphenol A and bisphenol F generally showed higher concentrations. Combining the concentrations of the target substances with the daily usage quantities of PCPs and other parameters, the total estimated dermal intakes and uptakes of Σ7BPs and TCS were calculated. The results showed that the former (12.1 and 1.06 ng·kg− 1bw day− 1) were markedly higher than the latter (1.21 and 9.58 × 10− 2 ng·kg− 1bw day− 1), which included dermal absorption rates of the chemicals in the estimation. Although diet is the main source, and oral ingestion is the main route, for human BPA exposure, the results of the estimated dermal uptakes of BPA in the present study combined with those from a European study show that dermal contact is the main route with thermal paper being the main contributor when both unconjugated and conjugated BPA in the human body are considered. The present study also showed that exposure to BPA in PCPs following dermal contact should not be ignored.

    更新日期:2018-01-12
  • The toxicity of ionic liquid 1-decylpyridinium bromide to the algae Scenedesmus obliquus: Growth inhibition, phototoxicity, and oxidative stress
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-18
    Dingdong Liu, Huijun Liu, Shengtao Wang, Jiazheng Chen, Yilu Xia

    Although ionic liquids (ILs) are unlikely to act as air contaminants, their high solubility and slow degradation make them a potential threat to the aquatic environment. The IL 1-decylpyridinium bromide ([DPy]Br) is a common type of pyridine IL, which has varied applications such as in extraction, separation, and catalytic synthesis. Herein, the toxicity of [DPy]Br to S. obliquus is determined. Growth was inhibited by high-concentration [DPy]Br, whereas it had a hormetic effect at low concentrations. The IC50–96 h was approximately 0.06 mg/L. The cell membrane permeability of S. obliquus increased with [DPy]Br concentration, indicating that [DPy]Br can cause damage to the algae cell structure. Chlorophyll content decreased at high [DPy]Br concentration; chlorophyll fluorescence parameters, such as the maximum effective quantum yield of PSII (Fv/Fm), potential activity of PSII (Fv/F0), yield of the photochemical quantum [Y(II)], and the non-photochemical quenching coefficient (NPQ) were affected, suggesting that [DPy]Br can damage PSII. The ROS fluorescent images revealed that the morphology of cells changed gradually from fusiform to round. High ROS levels were observed with high concentrations of [DPy]Br, indicating that [DPy]Br induced oxidative stress on S. obliquus. The SOD and CAT activities increased when the concentration was lower than IC50, whereas they decreased when the concentration was higher than IC50. The relative ROS content was significantly correlated with growth inhibition rate, cell membrane permeability, chlorophyll content, and SOD and CAT activities. The increase of ROS content in algal cells is an important toxicological mechanism of [DPy]Br to S. obliquus.

    更新日期:2018-01-12
  • Association of serum levels of perfluoroalkyl substances (PFASs) with the metabolic syndrome (MetS) in Chinese male adults: A cross–sectional study
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-18
    Qiaoyun Yang, Xiaoli Guo, Pengling Sun, Yujiao Chen, Wei Zhang, Ai Gao

    As extensively used chemicals in a variety of consumer products, perfluoroalkyl substances (PFASs) are ubiquitous and could bring significant risk to human health. However, the effect of PFASs on metabolic syndrome (MetS) is not fully understood. In 2015, a preliminary cross-sectional study was undertaken. A total of 148 male subjects including 81 affected by MetS and 67 non–MetS participants as the reference were recruited from Physical Examination Center affiliated to Capital Medical University, China. Serum levels of perfluorohexane sulfonic acid (PFHxS), perfluorooctanoic acid (PFOA) and perfluorononanoic acid (PFNA) were significantly higher in the subjects with MetS. Logistic regression results showed that concentration of PFNA in serum was associated with 10.9–fold [95% confidence interval (CI), 2.00–59.1] increased risk of MetS. Moreover, increased serum PFNA concentrations were associated with high blood pressure [both for systolic and diastolic blood pressure (SBP and DBP); odds ratio (OR) 7.52 (95%CI, 1.34–42.1) for SBP and 7.27 (95%CI, 1.17–45.1) for DBP], hypertriglyceridemia [13.2 (95%CI, 2.34–74.2)] and obesity [13.3 (95%CI, 2.38–74.4)], respectively. After adjustment by age in logistic regression models, serum levels of PFOA were associated with 29.4–fold (95%CI, 2.90–299.7) increased risk of MetS. Increased PFOA levels were also correlated with MetS [29.4 (95%CI, 2.9–299.7)], SBP [10.8 (95%CI, 1.31–90.0)], hypertriglyceridemia [16.6 (95%CI, 1.92–147.1)], and obesity [46.7 (95%CI, 4.47–487.7)] with adjustment for age. This study suggests bodily retention of PFASs and its association with MetS. Further clinical and animal studies are warranted to clarify the putative causal relationship.

    更新日期:2018-01-12
  • Assessing the potential impacts of a revised set of on-farm nutrient and sediment ‘basic’ control measures for reducing agricultural diffuse pollution across England
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-18
    A.L. Collins, J.P. Newell Price, Y. Zhang, R. Gooday, P.S. Naden, D. Skirvin

    The need for improved abatement of agricultural diffuse water pollution represents cause for concern throughout the world. A critical aspect in the design of on-farm intervention programmes concerns the potential technical cost-effectiveness of packages of control measures. The European Union (EU) Water Framework Directive (WFD) calls for Programmes of Measures (PoMs) to protect freshwater environments and these comprise ‘basic’ (mandatory) and ‘supplementary’ (incentivised) options. Recent work has used measure review, elicitation of stakeholder attitudes and a process-based modelling framework to identify a new alternative set of ‘basic’ agricultural sector control measures for nutrient and sediment abatement across England. Following an initial scientific review of 708 measures, 90 were identified for further consideration at an industry workshop and 63 had industry support. Optimisation modelling was undertaken to identify a shortlist of measures using the Demonstration Test Catchments as sentinel agricultural landscapes. Optimisation selected 12 measures relevant to livestock or arable systems. Model simulations of 95% implementation of these 12 candidate ‘basic’ measures, in addition to business-as-usual, suggested reductions in the national agricultural nitrate load of 2.5%, whilst corresponding reductions in phosphorus and sediment were 11.9% and 5.6%, respectively. The total cost of applying the candidate ‘basic’ measures across the whole of England was estimated to be £450 million per annum, which is equivalent to £52 per hectare of agricultural land. This work contributed to a public consultation in 2016.

    更新日期:2018-01-12
  • Nitrogen removal by thiosulfate-driven denitrification and plant uptake in enhanced floating treatment wetland
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-18
    Lei Gao, Weili Zhou, Suqing Wu, Shengbing He, Jungchen Huang, Xu Zhang

    This study investigated the potential of thiosulfate-driven autotrophic enhanced floating treatment wetland (AEFTW) in removing nitrogen from the secondary effluent at the relatively short hydraulic retention times and low S/N ratios. Simultaneous autotrophic and heterotrophic denitrification was observed in AEFTW. The peak TN removal rate (15.3 g m− 2 d− 1) exceeded most of the reported floating treatment wetlands. Based on the kinetic model results, low mean temperature coefficient and high k20 verified that the excellent performance in AEFTW diminished the microbial dependence on temperature. Nitrogen removal performance of enhanced floating treatment wetland (EFTW) and floating treatment wetland (FTW) were similar and highly sensitive to temperature. The interaction of sulfur transformation on the nitrogen, carbon uptake of plants was studied. Thiosulfate addition significantly raised sulfur content in the shoots and further enhanced the uptake of nitrogen and carbon, and increased the plant biomass at the same time. Higher composition of autotrophic and heterotrophic denitrifiers in AEFTW interpreted the occurrence of mixotrophic denitrification during summer. Thiosulfate induced mutual promotion of nitrogen removal by plant uptake and microbial denitrification in AEFTW.

    更新日期:2018-01-12
  • Legionella - A threat to groundwater: Pathogen transport in recharge basin
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-18
    Lauren R. McBurnett, Nathan T. Holt, Absar Alum, Morteza Abbaszadegan

    This study elucidates the potential risk posed by Legionella during aquifer recharge practices. Experiments were conducted using pilot-scale column simulating infiltration of bacterial surrogate and pathogen, E. coli and Legionella pneumophila, under central Arizona recharge basin conditions. A column was packed with a loamy sand media collected from a recharge basin and was fitted with six sampling ports at soil depths of 15, 30, 60, 92, 122 cm and acclimated for a month with tertiary treated wastewater. Transport of Legionella appeared to be delayed compared to E. coli. The breakthrough of E. coli and Legionella at 122 cm depth occurred at 3 and 24 h, respectively. Slow transport of Legionella is consistent with its pleomorphic nature and variation in size and shape under low nutrient conditions. Legionella persisted for a longer time in the column, but at lower concentrations. Given the novel results of this study, the transport of Legionella into groundwater aquifers can occur through engineering recharge basin conditions creating a potential public health risk.

    更新日期:2018-01-12
  • Importance of sediment organic matter to methane ebullition in a sub-tropical freshwater reservoir
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-18
    Alistair Grinham, Matthew Dunbabin, Simon Albert

    This paper summarises the results of an extensive field campaign which demonstrates that high sediment organic matter is the primary driver of methane ebullition in a sub-tropical, freshwater reservoir. Methane emissions from freshwater reservoirs represent an important global methane source. Whilst diffusive methane fluxes are commonly used for predicting total emissions, recent studies show that the under-reported ebullitive fluxes can vary by over three orders of magnitude within an individual system and have a greater relative contribution compared to diffusion. Key to predicting this variability in emission rates is to better understand the primary drivers of different emission pathways, and in particular ebullition. Zones of catchment derived organic material as well as elevated water column chlorophyll a concentration have been associated with increased rates of ebullition. Little Nerang Dam (LND), a subtropical freshwater reservoir in Queensland Australia, consistently experiences high rates of ebullition adjacent to major inflow arms that are both deposition zones of catchment organic material as well as areas with elevated water column chlorophyll a concentration. A year-long study of emission rates was undertaken on LND during which water column chlorophyll a concentration, bottom water temperature and sediment organic matter content were assessed for methane ebullition potential. This included a transect with high-spatial sampling (259 sites) from the dam wall to the ebullition zones to explore the relationship between water column chlorophyll a concentration, sediment organic matter content and methane ebullition. These results showed that ebullition was associated with the large forest litter deposits adjacent to major inflow sites where sediment organic matter content was significantly higher compared with the main body of the reservoir.

    更新日期:2018-01-12
  • Catalytic dehydrochlorination of lindane by nitrogen-containing multiwalled carbon nanotubes (N-MWCNTs)
    Sci. Total Environ. (IF 4.9) Pub Date : 2017-10-18
    Jirui Yang, Feng Shen, Mo Qiu, Xinhua Qi

    This paper reports a nonreductive dechlorination pathway (dehydrochlorination) of lindane in the presence of N-MWCNTs (CNT-N1 and CNTN2) under environmentally relevant conditions. The enhanced catalytic dehydrochlorination at mild pH values (7.0–9.0) was mainly attributed to the Lewis base nature of nitrogen functional groups on the surface of N-MWCNTs, based on FT-IR spectra, X-ray photoelectron spectroscopy and CO2-TPD profile. Amine and pyridinic nitrogen species were inferred as the main basic sites that were responsible for the dehydrochlorination of lindane. The concentration of lindane was unchanged in homogenous alkaline aqueous solutions at pH 7.0 and 8.0 within 6 d, and up to 89.5% of lindane remained at pH 9.0. In sharp contrast, the reaction rate constant (kobs) increased from 0.024 to 0.876 d− 1 with the increasing pH from 7.0 to 9.0 when CNT-N2 catalyst was used. All lindane was transformed in the presence of CNT-N2 at pH 9.0, leading to a much greater kobs as compared to that obtained in homogenous solution (0.876 vs 0.019 d− 1). Even at neutral pH condition, the kobs obtained in the presence of CNT-N2 was higher than that observed in weakly alkaline solution (0.024 d− 1 at pH 7.0 vs 0.019 d− 1 at pH 9.0). γ-1,3,4,5,6-pentachlorocyclohexene and trichlorobenzene isomers were detected as the intermediate and final products, respectively. It might be inferred that amine and pyridinic nitrogen species could attack the hydrogen atom attached to the β‑carbon, and the dehydrochlorination of lindane followed a β-elimination mechanism. This study provides an alternative dechlorination way for making lindane less toxic and better biodegradable under mild conditions, which is beneficial for complete mineralization of lindane when coupled with microbial degradation.

    更新日期:2018-01-12
Some contents have been Reproduced with permission of the American Chemical Society.
Some contents have been Reproduced by permission of The Royal Society of Chemistry.
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