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Environmental Science. Processes & Impacts

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https://www.readbyqxmd.com/read/29034382/environmental-photochemistry-of-dienogest-phototransformation-to-estrogenic-products-and-increased-environmental-persistence-via-reversible-photohydration
#1
Nicholas C Pflug, Madeline K Hankard, Stephanie M Berg, Meghan O'Connor, James B Gloer, Edward P Kolodziej, David M Cwiertny, Kristine H Wammer
Potent trienone and dienone steroid hormones undergo a coupled photohydration (in light)-thermal dehydration (in dark) cycle that ultimately increases their environmental persistence. Here, we studied the photolysis of dienogest, a dienone progestin prescribed as a next-generation oral contraceptive, and used high resolution mass spectrometry and both 1D and 2D nuclear magnetic resonance spectroscopy to identify its phototransformation products. Dienogest undergoes rapid direct photolysis (t1/2 ∼ 1-10 min), forming complex photoproduct mixtures across the pH range examined (pH 2 to 7)...
October 16, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/29022620/transferring-mixtures-of-chemicals-from-sediment-to-a-bioassay-using-silicone-based-passive-sampling-and-dosing
#2
Lukas Mustajärvi, Ann-Kristin Eriksson-Wiklund, Elena Gorokhova, Annika Jahnke, Anna Sobek
Environmental mixtures of chemicals consist of a countless number of compounds with unknown identity and quantity. Yet, chemical regulation is mainly built around the assessment of single chemicals. Existing frameworks for assessing the toxicity of mixtures require that both the chemical composition and quantity are known. Quantitative analyses of the chemical composition of environmental mixtures are however extremely challenging and resource-demanding. Bioassays may therefore serve as a useful approach for investigating the combined toxicity of environmental mixtures of chemicals in a cost-efficient and holistic manner...
October 12, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28937162/experimentally-validated-mathematical-model-of-analyte-uptake-by-permeation-passive-samplers
#3
F Salim, M Ioannidis, T Górecki
A mathematical model describing the sampling process in a permeation-based passive sampler was developed and evaluated numerically. The model was applied to the Waterloo Membrane Sampler (WMS), which employs a polydimethylsiloxane (PDMS) membrane as a permeation barrier, and an adsorbent as a receiving phase. Samplers of this kind are used for sampling volatile organic compounds (VOC) from air and soil gas. The model predicts the spatio-temporal variation of sorbed and free analyte concentrations within the sampler components (membrane, sorbent bed and dead volume), from which the uptake rate throughout the sampling process can be determined...
September 22, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28933499/multi-biomarker-approach-in-the-scallop-chlamys-farreri-to-assess-pahs-pollution-in-qingdao-coastal-areas-of-china
#4
Luqing Pan, Mengyu Zhang, Qian Jin, Rongwang Ji
A multi-biomarker approach was conducted in the scallop Chlamys farreri from three sites, denoted here as S1, S2, and S3, in Qingdao coastal areas of China in March, June, September and December 2014 to assess pollution from polycyclic aromatic hydrocarbons (PAHs) and to select appropriate biomarkers. A suite of biological responses of the gills and digestive glands of the scallops was assayed, including: (i) phase I detoxification enzymes of 7-ethoxyresorufin-O-deethylase (EROD), epoxide hydrolase (EH), and dihydrodiol dehydrogenase (DD) and phase II detoxification enzymes of glutathione-S-transferase (GST) and sulfotransferase (SULT); (ii) antioxidant enzymes: catalase (CAT), superoxide dismutase (SOD), and glutathione peroxidase (GPx); (iii) oxidative damage parameters: lipid peroxidation (LPO) expressed by malondialdehyde (MDA) contents, protein carbonylation (PC) and DNA damage (F value); and (iv) the metabolism-related genes of EH, DD, GST, SULT and SOD...
September 21, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28926062/selectivity-of-solid-phase-extraction-for-dissolved-organic-matter-in-the-hypersaline%C3%A2-da-qaidam-lake-china
#5
Keli Yang, Yaoling Zhang, Yaping Dong, Wu Li
Dissolved organic matter (DOM) was isolated from the hypersaline Da Qaidam Lake using solid-phase extraction (SPE) methods with five different adsorbents: ENVI-Carb (non-porous graphitized carbon), HLB, PPL, and XAD-8 (polymer based), and ENVI-18 (silica based). Structure-selective assessments of SPE-DOM isolated using the different adsorbents were conducted using a combination of complementary analysis techniques, including dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) analysis, as well as elemental analysis, Fourier transformed infrared spectroscopy (FTIR), (1)H nuclear magnetic resonance ((1)H NMR) and pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS)...
September 19, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28920987/mechanisms-of-distinct-activated-carbon-and-biochar-amendment-effects-on-petroleum-vapour-biofiltration-in-soil
#6
Khaled M Bushnaf, George Mangse, Paola Meynet, Russell J Davenport, Olaf A Cirpka, David Werner
We studied the effects of two percent by weight activated carbon versus biochar amendments in 93 cm long sand columns on the biofiltration of petroleum vapours released by a non-aqueous phase liquid (NAPL) source. Activated carbon greatly enhanced, whereas biochar slightly reduced, the biofiltration of volatile petroleum hydrocarbons (VPHs) over 430 days. Sorbent amendment benefitted the VPH biofiltration by retarding breakthrough during the biodegradation lag phase. Subsequently, sorbent amendment briefly reduced the mineralization of petroleum hydrocarbons by limiting their bioavailability...
October 18, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28892110/hexabromocyclododecane-and-tetrabromobisphenol-a-in-tree-bark-from-different-functional-areas-of-shanghai-china-levels-and-spatial-distributions
#7
Tao Han, Ming-Hong Wu, Chao Zang, Rui Sun, Liang Tang, Ning Liu, Jian-Qiu Lei, Hai-Yang Shao, Jian-Zhong Gu, Gang Xu
The concentrations and spatial distributions of hexabromocyclododecane (HBCDD) and tetrabromobisphenol A (TBBPA) were measured in tree bark from different functional areas of Shanghai. ΣHBCDD (sum of α-, β-, and γ-HBCDD) concentrations ranged from 1.2 × 10(2) to 6.6 × 10(3) ng g(-1) lw (median 5.7 × 10(2) ng g(-1) lw) and TBBPA concentrations ranged from 48 to 7.2 × 10(4) ng g(-1) lw (median 2.8 × 10(2) ng g(-1) lw). The concentrations of ΣHBCDD and TBBPA all followed the order of industrial areas > commercial areas > residential areas...
October 18, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28891564/standardisation-of-a-european-measurement-method-for-organic-carbon-and-elemental-carbon-in-ambient-air-results-of-the-field-trial-campaign-and-the-determination-of-a-measurement-uncertainty-and-working-range
#8
Richard J C Brown, Sonya Beccaceci, David M Butterfield, Paul G Quincey, Peter M Harris, Thomas Maggos, Pavlos Panteliadis, Astrid John, Aleksandra Jedynska, Thomas A J Kuhlbusch, Jean-Philippe Putaud, Angeliki Karanasiou
The European Committee for Standardisation (CEN) Technical Committee 264 'Air Quality' has recently produced a standard method for the measurements of organic carbon and elemental carbon in PM2.5 within its working group 35 in response to the requirements of European Directive 2008/50/EC. It is expected that this method will be used in future by all Member States making measurements of the carbonaceous content of PM2.5. This paper details the results of a laboratory and field measurement campaign and the statistical analysis performed to validate the standard method, assess its uncertainty and define its working range to provide clarity and confidence in the underpinning science for future users of the method...
October 18, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28879355/rare-earth-elements-in-freshwater-marine-and-terrestrial-ecosystems-in-the-eastern-canadian-arctic
#9
Gwyneth Anne MacMillan, John Chételat, Joel P Heath, Raymond Mickpegak, Marc Amyot
Few ecotoxicological studies exist for rare earth elements (REEs), particularly field-based studies on their bioaccumulation and food web dynamics. REE mining has led to significant environmental impacts in several countries (China, Brazil, U.S.), yet little is known about the fate and transport of these contaminants of emerging concern. Northern ecosystems are potentially vulnerable to REE enrichment from prospective mining projects at high latitudes. To understand how REEs behave in remote northern food webs, we measured REE concentrations and carbon and nitrogen stable isotope ratios (∂(15)N, ∂(13)C) in biota from marine, freshwater, and terrestrial ecosystems of the eastern Canadian Arctic (N = 339)...
October 18, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28876016/bioaccumulation-of-hexachlorobutadiene-in-pumpkin-seedlings-after-waterborne-exposure
#10
Xingwang Hou, Haiyan Zhang, Yanlin Li, Miao Yu, Jiyan Liu, Guibin Jiang
Hexachlorobutadiene (HCBD) has been listed as a persistent organic pollutant (POP) in the Stockholm Convention, and is now drawing more and more research interest. However, the understanding of its bioaccumulation, especially in plants, is still very limited. In this work, the behavior of HCBD in aqueous solution and pumpkin seedlings was studied through in-lab hydroponic exposure experiments. It was found that 69% of HCBD volatilized from water to the atmosphere after one day of exposure, and only 1% remained in the solution after four days...
October 18, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28871292/emerging-investigator-series-as-v-in-magnetite-incorporation-and-redistribution
#11
Brittany L Huhmann, Anke Neumann, Maxim I Boyanov, Kenneth M Kemner, Michelle M Scherer
Exposure to As in groundwater negatively impacts millions of people around the globe, and As mobility in groundwater is often controlled by Fe mineral dissolution and precipitation. Additionally, trace elements can be released from and incorporated into the structure of Fe oxides in the presence of dissolved Fe(ii). The potential for As to redistribute between sorbed on the magnetite surface and incorporated in the magnetite structure, however, remains unclear. In this study, we use selective chemical extraction and X-ray absorption spectroscopy (XAS) to distinguish magnetite-sorbed and incorporated As(v) and to provide evidence for As(v) incorporation during magnetite precipitation...
October 18, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28861557/diesel-particulate-matter-and-polycyclic-aromatic-hydrocarbons-in-fire-stations
#12
Raymond C Bott, Katherine M Kirk, Michael B Logan, Damien A Reid
Firefighters are known to be exposed to a wide variety of combustion products during operational and training firefighting activities. However, the potential for exposure to diesel exhaust emissions, recently classified as carcinogenic to humans by the International Agency for Research on Cancer, also exists within the fire station environment. In this study, concentrations of diesel particulate matter and polycyclic aromatic hydrocarbons have been measured in the engine bays, duty offices and dormitory areas of eight fire stations in Queensland, Australia...
October 18, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28858346/response-of-the-phytoplankton-community-to-water-quality-in-a-local-alpine-glacial-lake-of-xinjiang-tianchi-china-potential-drivers-and-management-implications
#13
Xiaotian Lu, Shuai Song, Yonglong Lu, Tieyu Wang, Zhaoyang Liu, Qifeng Li, Meng Zhang, Sarvajayakesavalu Suriyanarayanan, Alan Jenkins
Eutrophication has become one of the most serious threats to aquatic ecosystems in the world. With the combined drivers of climate change and human activities, eutrophication has expanded from warm shallow lakes to cold-water lakes in relatively high latitude regions and has raised greater concerns over lake aquatic ecosystem health. A two-year field study was carried out to investigate water quality, phytoplankton characteristics and eutrophication status in a typical alpine glacial lake of Tianchi, a scenic area and an important drinking water source in the Xinjiang Autonomous Region of China, in 2014 and 2015...
October 18, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28858343/comparison-of-indoor-air-sampling-and-dust-collection-methods-for-fungal-exposure-assessment-using-quantitative-pcr
#14
Jennie Cox, Reshmi Indugula, Stephen Vesper, Zheng Zhu, Roman Jandarov, Tiina Reponen
Evaluating fungal contamination indoors is complicated because of the many different sampling methods utilized. In this study, fungal contamination was evaluated using five sampling methods and four matrices for results. The five sampling methods were a 48 hour indoor air sample collected with a Button™ inhalable aerosol sampler and four types of dust samples: a vacuumed floor dust sample, newly settled dust collected for four weeks onto two types of electrostatic dust cloths (EDCs) in trays, and a wipe sample of dust from above floor surfaces...
October 18, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28848957/epoxide-formation-from-heterogeneous-oxidation-of-benzo-a-pyrene-with-gas-phase-ozone-and-indoor-air
#15
Shouming Zhou, Leo W Y Yeung, Matthew W Forbes, Scott Mabury, Jonathan P D Abbatt
The formation of two classes of epoxide products from the heterogeneous reaction of benzo[a]pyrene (BaP) with gas-phase ozone was demonstrated. BaP was coated on a Pyrex glass tube and oxidized with different concentrations of ozone. After oxidation, the epoxide products were derivatized by N-acetylcystein (NAC) and then analyzed by liquid chromatography-tandem mass spectrometry (LC-MS/MS). The results show that in addition to mono-epoxides, diol-epoxides were also formed. BaP exposed to genuine indoor air also produces mono- and diol-epoxides, having similar chromatograms to those produced by oxidation of BaP by low concentrations of ozone...
October 18, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28840207/minor-methane-emissions-from-an-alpine-hydropower-reservoir-based-on-monitoring-of-diel-and-seasonal-variability
#16
Sébastien Sollberger, Bernhard Wehrli, Carsten J Schubert, Tonya DelSontro, Werner Eugster
We monitored CH4 emissions during the ice-free period of an Alpine hydropower reservoir in the Swiss Alps, Lake Klöntal, to investigate mechanisms responsible for CH4 variability and to estimate overall emissions to the atmosphere. A floating eddy-covariance platform yielded total CH4 and CO2 emission rates at high temporal resolution, while hydroacoustic surveys provided no indication of CH4 ebullition. Higher CH4 fluxes (2.9 ± 0.1 mg CH4 per m(2) per day) occurred during the day when surface water temperatures were warmer and wind speeds higher than at night...
October 18, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28825440/source-tracing-of-natural-organic-matter-bound-mercury-in-boreal-forest-runoff-with-mercury-stable-isotopes
#17
Martin Jiskra, Jan G Wiederhold, Ulf Skyllberg, Rose-Marie Kronberg, Ruben Kretzschmar
Terrestrial runoff represents a major source of mercury (Hg) to aquatic ecosystems. In boreal forest catchments, such as the one in northern Sweden studied here, mercury bound to natural organic matter (NOM) represents a large fraction of mercury in the runoff. We present a method to measure Hg stable isotope signatures of colloidal Hg, mainly complexed by high molecular weight or colloidal natural organic matter (NOM) in natural waters based on pre-enrichment by ultrafiltration, followed by freeze-drying and combustion...
October 18, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28805852/the-effect-of-sub-zero-temperature-on-the-formation-and-composition-of-secondary-organic-aerosol-from-ozonolysis-of-alpha-pinene
#18
K Kristensen, L N Jensen, M Glasius, M Bilde
This study presents a newly constructed temperature controlled cold-room smog chamber at Aarhus University, Denmark. The chamber is herein utilized to study the effect of sub-zero temperature on the formation and chemical composition of secondary organic aerosol (SOA) from ozone initiated oxidation of α-pinene. The chemical composition of α-pinene SOA formed from dark ozonolysis of α-pinene at 293 K and 258 K was investigated using High-Resolution Time-of-Flight Aerosol Mass Spectrometry (HR-ToF-AMS) and Ultra-High Performance Liquid Chromatography/Electrospray Ionization Quadrupole Time-of-Flight Mass Spectrometry (UHPLC/ESI-qToF-MS)...
October 18, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28799617/long-range-transport-clusters-and-positive-matrix-factorization-source-apportionment-for-investigating-transboundary-pm2-5-in-gothenburg-sweden
#19
Peter Molnár, Lin Tang, Karin Sjöberg, Janine Wichmann
Source apportionment studies of particulate matter are common and have been performed either as source region analyses using air mass back trajectories or by source type using source apportionment techniques. By combining the two approaches, it is possible to estimate the relative importance of emitters in different regions. PM2.5 samples were collected in Gothenburg between September 2008 and September 2009. The mean daily PM2.5 level was 6.1 μg m(-3) (range 0.79-30.91 μg m(-3)). Elemental analyses were done using Energy dispersive X-ray fluorescence (EDXRF) spectroscopy...
October 18, 2017: Environmental Science. Processes & Impacts
https://www.readbyqxmd.com/read/28879349/the-necessity-of-bioanalytical-tools-for-advancing-water-and-sediment-quality-assessment
#20
EDITORIAL
Edward P Kolodziej, Kyungho Choi, Ruth Marfil-Vega, Bryan W Brooks
No abstract text is available yet for this article.
September 20, 2017: Environmental Science. Processes & Impacts
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