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  • 701. Yan, Caiqing
    et al.
    Zheng, Mei
    Sullivan, Amy P.
    Shen, Guofeng
    Chen, Yingjun
    Wang, Shuxiao
    Zhao, Bin
    Cai, Siyi
    Desyaterik, Yury
    Li, Xiaoying
    Zhou, Tian
    Gustafsson, Örjan
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Collett, Jeffrey L.
    Residential Coal Combustion as a Source of Levoglucosan in China2018In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 52, no 3, p. 1665-1674Article in journal (Refereed)
    Abstract [en]

    Levoglucosan (LG) has been widely identified as a specific marker for biomass burning (BB) sources and frequently utilized in estimating the BB contribution to atmospheric fine particles all over the world. However, this study provides direct evidence to show that coal combustion (CC) is also a source of LG, especially in the wintertime in Northern China, based on both source testing and ambient measurement. Our results show that low-temperature residential CC could emit LG with emission factors (EF) ranging from 0.3 to 15.9 mg kg(-1). Ratios of LG to its isomers, mannosan and galactosan, differ between CC and BB emissions, and the wintertime ratios in Beijing ambient PM2.5 and source-specific tracers including carbon isotopic signatures all indicated a significant contribution from CC to ambient levoglucosan in winter in Beijing. The results suggest that LG cannot be used as a distinct source marker for biomass burning in special cases such as some cities in the northern China, where coal is still widely used in the residential and industrial sectors. Biomass burning sources could be overestimated, although such an over estimation could vary spatially and temporally.

  • 702. Yang, Cheng-En
    et al.
    Mao, Jiafu
    Hoffman, Forrest M.
    Ricciuto, Daniel M.
    Fu, Joshua S.
    Jones, Chris D.
    Thurner, Martin
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Uncertainty Quantification of Extratropical Forest Biomass in CMIP5 Models over the Northern Hemisphere2018In: Scientific Reports, ISSN 2045-2322, E-ISSN 2045-2322, Vol. 8, article id 10962Article in journal (Refereed)
    Abstract [en]

    Simplified representations of processes influencing forest biomass in Earth system models (ESMs) contribute to large uncertainty in projections. We evaluate forest biomass from eight ESMs outputs archived in the Coupled Model Intercomparison Project Phase 5 (CMIP5) using the biomass data synthesized from radar remote sensing and ground-based observations across northern extratropical latitudes. ESMs exhibit large biases in the forest distribution, forest fraction, and mass of carbon pools that contribute to uncertainty in forest total biomass (biases range from -20 Pg C to 135 Pg C). Forest total biomass is primarily positively correlated with precipitation variations, with surface temperature becoming equally important at higher latitudes, in both simulations and observations. Relatively small differences in forest biomass between the pre-industrial period and the contemporary period indicate uncertainties in forest biomass were introduced in the pre-industrial model equilibration (spin-up), suggesting parametric or structural model differences are a larger source of uncertainty than differences in transient responses. Our findings emphasize the importance of improved (1) models of carbon allocation to biomass compartments, (2) distribution of vegetation types in models, and (3) reproduction of pre-industrial vegetation conditions, in order to reduce the uncertainty in forest biomass simulated by ESMs.

  • 703. Yao, Lei
    et al.
    Garmash, Olga
    Bianchi, Federico
    Zheng, Jun
    Yan, Chao
    Kontkanen, Jenni
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. University of Helsinki, Finland.
    Junninen, Heikki
    Mazon, Stephany Buenrostro
    Ehn, Mikael
    Paasonen, Pauli
    Sipilä, Mikko
    Wang, Mingyi
    Wang, Xinke
    Xiao, Shan
    Chen, Hangfei
    Lu, Yiqun
    Zhang, Bowen
    Wang, Dongfang
    Fu, Qingyan
    Geng, Fuhai
    Li, Li
    Wang, Hongli
    Qiao, Liping
    Yang, Xin
    Chen, Jianmin
    Kerminen, Veli-Matti
    Petäjä, Tuukka
    Worsnop, Douglas R.
    Kulmala, Markku
    Wang, Lin
    Atmospheric new particle formation from sulfuric acid and amines in a Chinese megacity2018In: Science, ISSN 0036-8075, E-ISSN 1095-9203, Vol. 361, no 6399, p. 278-281Article in journal (Refereed)
    Abstract [en]

    Atmospheric new particle formation (NPF) is an important global phenomenon that is nevertheless sensitive to ambient conditions. According to both observation and theoretical arguments, NPF usually requires a relatively high sulfuric acid (H2SO4) concentration to promote the formation of new particles and a low preexisting aerosol loading to minimize the sink of new particles. We investigated NPF in Shanghai and were able to observe both precursor vapors (H2SO4) and initial clusters at a molecular level in a megacity. High NPF rates were observed to coincide with several familiar markers suggestive of H2SO4-dimethylamine (DMA)water (H2O) nucleation, including sulfuric acid dimers and H2SO4-DMA clusters. In a cluster kinetics simulation, the observed concentration of sulfuric acid was high enough to explain the particle growth to similar to 3 nanometers under the very high condensation sink, whereas the subsequent higher growth rate beyond this size is believed to result fromthe added contribution of condensing organic species. These findings will help in understanding urban NPF and its air quality and climate effects, as well as in formulating policies to mitigate secondary particle formation in China.

  • 704.
    Yin, Ge
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Stockholm University.
    Organohalogen contaminants in wildlife from the Yangtze River Delta: Development of methods and assessments of legacy and emerging persistent organic pollutants2016Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Rapid economic development has occurred during the past few decades in China with the Yangtze River Delta (YRD) area as one of the most progressive areas. The urbanization, industrialization, agricultural and aquaculture activities result in extensive production and application of chemicals. Organohalogen contaminants (OHCs) have been widely used as i.e. pesticides, flame retardants and plasticizers. They are persistent, bioaccumulative and pose a potential threat to ecosystem and human health. However, limited research has been conducted in the YRD with respect to chemicals environmental exposure.

    The main objective of this thesis is to investigate the contamination level, distribution pattern and sources of OHCs in the YRD. Wildlife from different habitats are used to indicate the environmental pollution situation, and evaluate selected matrices for use in long term biomonitoring to determine the environmental stress the contamination may cause. In addition, a method is developed for dicofol analysis. Moreover, a specific effort is made to introduce statistic power analysis to assist in optimal sampling design.

    The thesis results show extensive contamination of OHCs in wildlife in the YRD. The occurrences of high concentrations of chlorinated paraffins (CPs) are reported in wildlife, in particular in terrestrial species, (i.e. short-tailed mamushi snake and peregrine falcon). Impurities and byproducts of pentachlorophenol products, i.e. polychlorinated diphenyl ethers (PCDEs) and hydroxylated polychlorinated diphenyl ethers (OH-PCDEs) are identified and reported for the first time in eggs from black-crowned night heron and whiskered tern. High concentrations of octachlorodibenzo-p-dioxin (OCDD) are determined in these samples. The toxic equivalents (TEQs) of polychlorinated dibenzo-p-dioxin (PCDDs) and polychlorinated dibenzofurans (PCDFs) are at mean levels of 300 and 520 pg TEQ g-1lw (WHO2005 TEQ) in eggs from the two bird species, respectively. This is two orders of magnitude higher than European Union (EU) regulation limit in chicken eggs. Also, a novel pattern of polychlorinated biphenyls (PCBs) with octa- to decaCBs, contributing to as much as 20% of total PCBs therein, are reported in birds. The legacy POPs shows a common characteristic with relatively high level of organochlorine pesticides (i.e. DDT, hexacyclohexanes (HCHs) and Mirex), indicating historic applications. In contrast, rather low concentrations are shown of industrial chemicals such as PCBs and polybrominated diphenyl ethers (PBDEs).

    A refined and improved analytical method is developed to separate dicofol from its major decomposition compound, 4,4’-dichlorobenzophenone. Hence dicofol is possible to assess as such. Statistic power analysis demonstrates that sampling of sedentary species should be consistently spread over a larger area to monitor temporal trends of contaminants in a robust manner.

    The results presented in this thesis show high CPs and OCDD concentrations in wildlife. The levels and patterns of OHCs in YRD differ from other well studied areas of the world. This is likely due to the extensive production and use of chemicals in the YRD. The results strongly signal the need of research biomonitoring programs that meet the current situation of the YRD. Such programs will contribute to the management of chemicals and environment in YRD, with the potential to grow into the human health sector, and to expand to China as a whole.

  • 705.
    Yin, Ge
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Athanassiadis, Ioannis
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Swedish Toxicology Sciences Research Center, Sweden; Tongji University, China.
    Zhou, Yihui
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Tongji University, China.
    Qiu, Yanling
    Asplund, Lillemor
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    A refined method for analysis of 4,4 '-dicofol and 4,4 '-dichlorobenzophenone2017In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 24, no 15, p. 13307-13314Article in journal (Refereed)
    Abstract [en]

    The acaricide, dicofol, is a well-known pesticide and partly a substitute for dichlorodiphenyltrichloroethane (DDT). Only few reports on environmental occurrence and concentrations have been reported calling for improvements. Hence, an analytical method was further developed for dicofol and dichlorobenzophenone (DCBP) to enable assessments of their environmental occurrence. Concentrated sulfuric acid was used to remove lipids and to separate dicofol from DCBP. On-column injection was used as an alternative to splitless injection to protect dicofol from thermal decomposition. By the method presented herein, it is possible to quantify dicofol and DCBP in the same samples. Arctic cod (Gadus morhua) were spiked at two dose levels and the recoveries were determined. The mean recovery for dicofol was 65% at the low dose (1 ng) and 77% at the high dose (10 ng). The mean recovery for DCBP was 99% at the low dose (9.2 ng) and 146% at the high dose (46 ng). The method may be further improved by use of another lipid removal method, e.g., gel permeation chromatography. The method implies a step forward in dicofol environmental assessments.

  • 706.
    Yin, Ge
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Athanassiadis, Ioannis
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Zhou, Yihui
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Qiu, Yanling
    Asplund, Lillemor
    A refined method for analysis of 4,4’-dicofol and 4,4’-dichlorobenzophenoneManuscript (preprint) (Other academic)
  • 707.
    Yin, Ge
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Danielsson, Sara
    Dahlberg, Anna-Karin
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Swedish University of Agricultural Sciences, Sweden.
    Zhou, Yihui
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Tongji University, China.
    Qiu, Yanling
    Nyberg, Elisabeth
    Bignert, Anders
    Sampling designs for contaminant temporal trend analyses using sedentary species exemplified by the snails Bellamya aeruginosa and Viviparus viviparus2017In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 185, p. 431-438Article in journal (Refereed)
    Abstract [en]

    Environmental monitoring typically assumes samples and sampling activities to be representative of the population being studied. Given a limited budget, an appropriate sampling strategy is essential to support detecting temporal trends of contaminants. In the present study, based on real chemical analysis data on polybrominated diphenyl ethers in snails collected from five subsites in Tianmu Lake, computer simulation is performed to evaluate three sampling strategies by the estimation of required sample size, to reach a detection of an annual change of 5% with a statistical power of 80% and 90% with a significant level of 5%. The results showed that sampling from an arbitrarily selected sampling spot is the worst strategy, requiring much more individual analyses to achieve the above mentioned criteria compared with the other two approaches. A fixed sampling site requires the lowest sample size but may not be representative for the intended study object e.g. a lake and is also sensitive to changes of that particular sampling site. In contrast, sampling at multiple sites along the shore each year, and using pooled samples when the cost to collect and prepare individual specimens are much lower than the cost for chemical analysis, would be the most robust and cost efficient strategy in the long run. Using statistical power as criterion, the results demonstrated quantitatively the consequences of various sampling strategies, and could guide users with respect of required sample sizes depending on sampling design for long term monitoring programs.

  • 708.
    Yin, Ge
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Danielsson, Sara
    Dahlberg, Anna-Karin
    Zhou, Yihui
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Qiu, Yanling
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Nyberg, Elisabeth
    Bignert, Anders
    Sampling designs for contaminant temporal trend analyses using sedentary species exemplified by the snails (Bellamya aeruginosa) and (Viviparus viviparus)Manuscript (preprint) (Other academic)
  • 709.
    Yin, Ge
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Zhou, Yihui
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Tongji University, China.
    Strid, Anna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Zheng, Ziye
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Umeå University, Sweden.
    Bignert, Anders
    Ma, Taowu
    Athanassiadis, Ioannis
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Qiu, Yanling
    Spatial distribution and bioaccumulation of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs) in snails (Bellamya aeruginosa) and sediments from Taihu Lake area, China2017In: Environmental science and pollution research international, ISSN 0944-1344, E-ISSN 1614-7499, Vol. 24, no 8, p. 7740-7751Article in journal (Refereed)
    Abstract [en]

    Taihu Lake area is one of the densest metropolitan areas in the world including diverse industrial activity. In the present study, the snail (Bellamya aeruginosa) and sediment were collected from the Taihu Lake area to investigate the contamination status, congener pattern, spatial distribution, and bioaccumulation effect of polychlorinated biphenyls (PCBs) and polybrominated diphenyl ethers (PBDEs). The samples underwent liquid extraction, lipid removal by sulfuric acid, and acidic silica gel column, and subsequently analyzed by gas chromatography-electron capture detector (GC-ECD) and gas chromatography-mass spectrometry (GC-MS). Concentration of S22PCBs ranged between 90 and 680 ng g(-1) lipid weight in the snails and between 0.018 and 0.82 ng g(-1) dry weight in the sediments. Concentration of S24PBDEs varied from 25 to 200 ng g(-1) lipid weight in the snails and from 0.62 to 67 ng g(-1) dry weight in the sediments. The levels of PCBs and PBDEs observed were in the medium to low range compared with other studies in the world. CB-153 was the predominant PCB congener in both snails and sediments whereas BDE-209 showed a low bioavailability in the snails, even if it contributed up to 70% of S24PBDEs in the sediments. The spatial distribution showed that the highest concentration of PCBs and PBDEs were detected in samples from Zhushan Lake. East Taihu Lake and Dianshan Lake showed lower concentration of PCBs and PBDEs than the other sampling sites. Biota-sediment accumulation was found between snails and sediments of most of PCB and PBDE congeners except for the highly brominated BDEs (i.e., BDE-209). Therefore, sediment is suggested to be an appropriate matrix to monitor BDE-209 while aquatic species such as the snail could be good for monitoring of PCBs and lower brominated BDE congeners. No significant correlation (Spearman correlation test, two-tailed) of CB-153 (r = 0.54, p = 0.27) or BDE-47 (r = 0.60, p = 0.21) was found between snails and sediments.

  • 710.
    Ytreberg, Erik
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Chalmers University of Technology, Sweden.
    Bighiu, Maria Alexandra
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Lundgren, Lennart
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Eklund, Britta
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    XRF measurements of tin, copper and zinc in antifouling paints coated on leisure boats2016In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 213, p. 594-599Article in journal (Refereed)
    Abstract [en]

    Tributyltin (TBT) and other organotin compounds have been restricted for use on leisure boats since 1989 in the EU. Nonetheless, release of TBT is observed from leisure boats during hull maintenance work, such as pressure hosing. In this work, we used a handheld X-ray Fluorescence analyser (XRF) calibrated for antifouling paint matrixes to measure tin, copper and zinc in antifouling paints coated on leisure boats in Sweden. Our results show that over 10% of the leisure boats (n = 686) contain >400 mu g/cm(2) of tin in their antifouling coatings. For comparison, one layer (40 mu m dry film) of a TBT-paint equals approximate to 800 mu g Sn/cm(2). To our knowledge, tin has never been used in other forms than organotin (OT) in antifouling paints. Thus, even though the XRF analysis does not provide any information on the speciation of tin, the high concentrations indicate that these leisure boats still have OT coatings present on their hull. On several leisure boats we performed additional XRF measurements by progressively scraping off the top coatings and analysing each underlying layer. The XRF data show that when tin is detected, it is most likely present in coatings close to the hull with several layers of other coatings on top. Thus, leaching of OT compounds from the hull into the water is presumed to be negligible. The risk for environmental impacts arises during maintenance work such as scraping, blasting and high pressure hosing activities. The data also show that many boat owners apply excessive paint layers when following paint manufacturers recommendations. Moreover, high loads of copper were detected even on boats sailing in freshwater, despite the more than 20 year old ban, which poses an environmental risk that has not been addressed until now.

  • 711. Ytreberg, Erik
    et al.
    Lagerström, Maria
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Chalmers University of Technology, Sweden.
    Holmqvist, Albin
    Eklund, Britta
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Elwing, Hans
    Dahlström, Magnus
    Dahl, Peter
    Dahlström, Mia
    A novel XRF method to measure environmental release of copper and zinc from antifouling paints2017In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 225, p. 490-496Article in journal (Refereed)
    Abstract [en]

    The release of copper (Cu) and zinc (Zn) from vessels and leisure crafts coated with antifouling paints can pose a threat to water quality in semi-enclosed areas such as harbors and marinas as well as to coastal archipelagos. However, no reliable, practical and low-cost method exists to measure the direct release of metals from antifouling paints. Therefore, the paint industry and regulatory authorities are obliged to use release rate measurements derived from either mathematical models or from laboratory studies. To bridge this gap, we have developed a novel method using a handheld X-Ray Fluorescence spectrometer (XRF) to determine the cumulative release of Cu and Zn from antifouling paints. The results showed a strong linear relationship between XRF Kα net intensities and metal concentrations, as determined by ICP-MS. The release of Cu and Zn were determined for coated panels exposed in harbors located in the Baltic Sea and in Kattegat. The field study showed salinity to have a strong impact on the release of Cu, i.e. the release increased with salinity. Contrary, the effect of salinity on Zn was not as evident. As exemplified in this work, the XRF method also makes it possible to identify the governing parameters to the release of Cu and Zn, e.g. salinity and type of paint formulation. Thus, the XRF method can be used to measure environmentally relevant releases of metallic compounds to design more efficient and optimized antifouling coatings.

  • 712.
    Ytreberg, Erik
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Chalmers University of Technology, Sweden.
    Lundgren, Lennart
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bighiu, Maria Alexandra
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Eklund, Britta
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    New analytical application for metal determination in antifouling paints2015In: Talanta: The International Journal of Pure and Applied Analytical Chemistry, ISSN 0039-9140, E-ISSN 1873-3573, Vol. 143, p. 121-126Article in journal (Refereed)
    Abstract [en]

    Despite the ban of applying TBT coatings on leisure boats in the late 80s, recent studies show an ongoing spread of TBT from leisure boats, particularly during hull cleaning events. Therefore, countries in EU have adopted expensive measures to clean this wash water. A more cost-efficient measure is to focus directly on the source, i.e. identify leisure boats with high concentrations of TBT and prescribe boat owners to remove the paint. We have developed a new antifouling paint application for a handheld X-ray fluorescence (XRF) analyzer to be used for identifying boats with high area concentrations (mu g/cm(2)) of Sn (indication that the hull contains TBT paint residues). Copper and zinc are also included in the application since these metals are used in the vast majority of today's paints. A blind test with up to four layers of TBT-, copper- and zinc-based paints showed good correlation between XRF-measured area concentrations and chemically analyzed concentrations. Future usage of the applications involves identification of boat hulls in particular with high Sn concentrations and also with high Cu and Zn concentrations. This method has the potential to become a useful tool in regulatory management of existence and use of toxic elements on boat hulls.

  • 713. Yu, Kuangyou
    et al.
    Xing, Zhenyu
    Huang, Xiaofeng
    Deng, Junjun
    Andersson, August
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Fang, Wenzheng
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Gustafsson, Örjan
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Zhou, Jiabin
    Du, Ke
    Characterizing and sourcing ambient PM2.5 over key emission regions in China III: Carbon isotope based source apportionment of black carbon2018In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 177, p. 12-17Article in journal (Refereed)
    Abstract [en]

    Regional haze over China has severe implications for air quality and regional climate. To effectively combat these effects the high uncertainties regarding the emissions from different sources needs to be reduced. In this paper, which is the third in a series on the sources of PM2.5 in pollution hotspot regions of China, we focus on the sources of black carbon aerosols (BC), using carbon isotope signatures. Four-season samples were collected at two key locations: Beijing-Tianjin-Hebei (BTH, part of Northern China plain), and the Pearl River Delta (PAD). We find that that fossil fuel combustion was the predominant source of BC in both BTH and PRD regions, accounting for 75 +/- 5%. However, the contributions of what fossil fuel components were dominating differed significantly between BTH and PRD, and varied dramatically with seasons. Coal combustion is overall the all-important BC source in BTH, accounting for 46 +/- 12% of the BC in BTH, with the maximum value (62%) found in winter. In contrast for the PAD region, liquid fossil fuel combustion (e.g., oil, diesel, and gasoline) is the dominant source of BC, with an annual mean value of 41 +/- 15% and the maximum value of 55% found in winter. Region- and season-specific source apportionments are recommended to both accurately assess the climate impact of carbonaceous aerosol emissions and to effectively mitigate deteriorating air quality caused by carbonaceous aerosols.

  • 714.
    Yuan, Bo
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bogdal, Christian
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Berger, Urs
    Gao, Wei
    Wang, Yawei
    de Wit, Cynthia A.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Deconvolution of Soft Ionization Mass Spectra of Chlorinated Paraffins To Resolve Congener Groups2016In: Analytical Chemistry, ISSN 0003-2700, E-ISSN 1520-6882, Vol. 88, no 18, p. 8980-8988Article in journal (Refereed)
    Abstract [en]

    We describe and illustrate a three-step data-processing approach that enables individual congener groups of chlorinated-paraffins (CPs) to be resolved in mass spectra obtained from either-of two soft ionization methods: electron capture negative-ionization mass spectrometry (ECNI-MS) or atmospheric pressure chemical ionization mass spectrometry (APCI-MS). In the first step, general fragmentation pathways of CPs are deduced from analysis of mass spectra of individual CP congeners. In the-Second step, all possible fragment ions in the general fragmentation pathways of CPs with 10 to 20 carbon atoms are enumerated and compared to mass spectra of CP mixture standards, and a deconvolution algorithm is applied to identify fragment ions that are actually observed. In the third step, isotope permutations of the observed fragment ions are calculated and used to identify isobaric overlaps, so that mass intensities of indivichial CP congener groups can be deconvolved from the unresolved isobaric ion signal intensities in mass spectra. For a specific instrument; the three steps only need to be done once to enable deconvolution of CPs in unknown samples. This approach enables congener group-level resolution of CP mixtures in environmental samples, and: it opens up the possibility, for quantification of congener group.

  • 715.
    Yuan, Bo
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bogdal, Christian
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    de Wit, Cynthia
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Modelling isotopic peak distributions of chlorinated paraffins homologue groups in high resolution mass spectrometry in soft ionization modes2015Conference paper (Other academic)
  • 716.
    Yuan, Bo
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Benskin, Jonathan P.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Chen, Chang-Er L.
    Bergman, Åke
    Determination of Chlorinated Paraffins by Bromide-Anion Attachment Atmospheric-Pressure Chemical Ionization Mass Spectrometry2018In: Environmental Science and Technology Letters, E-ISSN 2328-8930, Vol. 5, no 6, p. 348-353Article in journal (Refereed)
    Abstract [en]

    A novel method for the quantitative determination of chlorinated paraffins (CPs) was developed using bromide-anion attachment atmospheric-pressure chemical ionization mass spectrometry (APCI-MS). Bromoform was used to enhance ionization of CPs. Near exclusive formation of stable bromide adduct ions ([M + BR](-)) enabled accurate detection of individual CP congener groups (CnClm) with only a moderate-resolution quadrupole time-of-flight mass spectrometer. Furthermore, the method was free from interference commonly observed with chloride-anion attachment methods (e.g., decomposition ions [M + Cl - HCl](-)) that require deconvolution. Together with a CnClm-response-factor algorithm for quantifying short-chain CPs and a CnClm-pattern-reconstruction algorithm for quantifying medium- and long-chain CPs, method applicability was demonstrated on biota and sediment samples. These data were generated significantly faster and with improved selectivity and sensitivity versus those of conventional measurements by chloride-anion attachment APCI-MS.

  • 717.
    Yuan, Bo
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bogdal, Christian
    Berger, Urs
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Gebbink, Wouter A.
    Alsberg, Tomas
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    de Wit, Cynthia A.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Quantifying Short-Chain Chlorinated Paraffin Congener Groups2017In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 51, no 18, p. 10633-10641Article in journal (Refereed)
    Abstract [en]

    Accurate quantification of short-chain chlorinated paraffins (SCCPs) poses an exceptional challenge to analytical chemists. SCCPs are complex mixtures of chlorinated alkanes with variable chain length and chlorination level; congeners with a fixed chain length (n) and number of chlorines (m) are referred to as a congener group CnClm Recently, we resolved individual CnClm by mathematically deconvolving soft ionization high-resolution mass spectra of SCCP mixtures. Here we extend the method to quantifying CnClm by introducing CnClm specific response factors (RFs) that are calculated from 17 SCCP chain-length standards with a single carbon chain length and variable chlorination level. The signal pattern of each standard is measured on APCI-QTOF-MS. RFs of each CnClm are obtained by pairwise optimization of the normal distribution's fit to the signal patterns of the 17 chain-length standards. The method was verified by quantifying SCCP technical mixtures and spiked environmental samples with accuracies of 82-123% and 76-109%, respectively. The absolute differences between calculated and manufacturer-reported chlorination degrees were 0.9 to 1.0%Cl for SCCP mixtures of 49-71%Cl. The quantification method has been replicated with ECNI magnetic sector MS and ECNI-Q:Orbitrap-MS. CnClm concentrations determined with the three instruments were highly correlated (R-2 > 0.90) with each other.

  • 718.
    Yuan, Bo
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Brüchert, Volker
    Stockholm University, Faculty of Science, Department of Geological Sciences.
    Sobek, Anna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    de Witt, Cynthia A.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Temporal Trends of C-8-C-36 Chlorinated Paraffins in Swedish Coastal Sediment Cores over the Past 80 Years2017In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 51, no 24, p. 14199-14208Article in journal (Refereed)
    Abstract [en]

    Temporal trends of chlorinated paraffins (CPs) were analyzed in three sediment cores collected near different potential CP sources along the Swedish Baltic Sea coast. C-8-C-36 CPs were found in sediment dating back to the 1930s. The maximum CP concentrations found in proximity to a metropolitan sewage treatment plant, a wood related industrial area, and a steel factory were 48; 160, and 1400 ng/g d.w., respectively, in sediment sections dated from the early 1990s or the 2000s. The temporal trends agree with statistics on CP importation in Sweden or local industrial activities. MCCPs (C-14-C-17 CPs) and LCCPs (C->= 18 CPs) predominated, in most sediments with average percentage compositions of 47 +/- 20% and 37 +/- 20%, respectively. Concentrations of SCCPs in the three cores showed a decreasing trend in recent years. The temporal trends of MCCPs indicated that these are currently the predominant CPs in use. This study showed for the first time that LCCPs from C-18 to C-36, as well as C-8-C-17 CPs, are persistent in sediments over the last 30-80 years, indicating that CPs are persistent chemicals regaidless of alkane-chain lengths.

  • 719.
    Yuan, Bo
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Chinese Academy of Sciences, China.
    Fu, Jianjie
    Wang, Yawei
    Jiang, Guibin
    Short-chain chlorinated paraffins in soil, paddy seeds (Oryza sativa) and snails (Ampullariidae) in an e-waste dismantling area in China: Homologue group pattern, spatial distribution and risk assessment2017In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 220, p. 608-615Article in journal (Refereed)
    Abstract [en]

    Short-chain chlorinated paraffins (SCCPs) in multi-environmental matrices are studied in Taizhou, Zhejiang Province, China, which is a notorious e-waste dismantling area. The investigated matrices consist of paddy field soil, paddy seeds (Oryza sativa, separated into hulls and rice unpolished) and apple snails (Ampullariidae, inhabiting the paddy fields). The sampling area covered a 65-km radius around the contamination center. C-10 and C-11 are the two predominant homologue groups in the area, accounting for about 35.7% and 33.0% of total SCCPs, respectively. SCCPs in snails and hulls are generally higher than in soil samples (30.4-530 ng/g dw), and SCCPs in hulls are approximate five times higher than in corresponding rice samples (4.90-55.1 ng/g dw). Homologue pattern analysis indicates that paddy seeds (both hull and rice) tend to accumulate relatively high volatile SCCP homologues, especially the ones with shorter carbon chain length, while snails tend to accumulate relatively high lipophilic homologues, especially the ones with more substituted chlorines. SCCPs in both paddy seeds and snails are linearly related to those in the soil. The e-waste dismantling area, which covers a radius of approximate 20 km, shows higher pollution levels for SCCPs according to their spatial distribution in four matrices. The preliminary assessment indicates that SCCP levels in local soils pose no significant ecological risk for soil dwelling organisms, but higher risks from dietary exposure of SCCPs are suspected for people living in e-waste dismantling area.

  • 720.
    Yuan, Bo
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Strid, Anna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Darnerud, Per Ola
    de Wit, Cynthia A.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Nyström, Jessica
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Karolinska Institutet, Sweden.
    Chlorinated paraffins leaking from hand blenders can lead to significant human exposures2017In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 109, p. 73-80Article in journal (Refereed)
    Abstract [en]

    Background: Chlorinated paraffins (CPs, polychlorinated n-alkanes) are versatile, high-production-volume chemicals. A previous study indicated that hand blenders leak CPs into prepared food. & para;& para;Objectives: (1) to estimate exposure to CPs from hand blender use compared to background CP exposure from diet; (2) to assess the risk from human dietary exposure to CPs from hand blender use; (3) to investigate how hand blenders leak out CPs. & para;& para;Methods: CPs were analyzed in food market baskets, in cooking oil/water samples (1 g oil/100 mL water) mixed using 16 different hand blenders, and in dismantled components of the hand blenders. & para;& para;Results: Dietary intake of CPs from food market baskets was calculated to be 4.6 mu g/day per capita for Swedish adults. Total CP amounts in oil/water leakage samples ranged from < 0.09 to 120 mu g using the hand blenders once. CP leakage showed no decreasing levels after 20 times of hand blender usage. CP profiles in the leakage samples matched those of self-lubricating bearings and/or polymer components disassembled from the hand blenders. & para;& para;Conclusions: Usage of 75% of the hand blenders tested will lead to increased human exposure to CPs. The intake of CPs for Swedish adults by using hand blenders once a day can raise their daily dietary intake by a factor of up to 26. The 95th percentile intake of CPs via using the hand blenders once a day exceeded the TDI for Swedish infants with a body weight < 7.2 kg. CP leakage came from blender components which contain CPs. The leakage may last several hundred times of hand blender use.

  • 721.
    Zabaleta, Itsaso
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. University of the Basque Country (UPV/EHU), Spain.
    Bizkarguenaga, Ekhine
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. University of the Basque Country (UPV/EHU), Spain.
    Izagirre, Urtzi
    Negreira, Noelia
    Covaci, Adrian
    Benskin, Jonathan P.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Prieto, Ailette
    Zuloaga, Olatz
    Biotransformation of 8: 2 polyfluoroalkyl phosphate diester in gilthead bream (Sparus aurata)2017In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 609, p. 1085-1092Article in journal (Refereed)
    Abstract [en]

    Polyfluoroalkyl phosphate esters (PAPs) are high production volume surfactants used in the food contact paper and packaging industry. PAPs may transform to persistent perfluoroalkyl carboxylic acids (PFCAs) under biotic conditions, but little is known about their fate and behavior in aquatic organisms. Here we report for the first time on the uptake, tissue distribution, and biotransformation of 8:2 polyfluoroalkyl phosphate diester (8:2 diPAP) in fish. Gilt-head bream (Sparus aurata) were dosed via the diet (8:2 diPAP at 29 mu g/g) for 7 days, during which time 8:2 diPAP and its transformation products were monitored in plasma, liver, muscle, gills, bile and brain. 8:2 diPAP tended to accumulate in liver, plasma and gills, and to a lesser extent in muscle, bile and brain. Several transformation products (observed previously in other organisms) were also observed inmost tissues and biofluids, including both saturated and unsaturated fluorotelomer acids (8:2 FTCA, 8:2 FTUCA, 7:3 FTCA), and perfluorooctanoic acid (PFOA). 8:2 FTCA was the major metabolite in all tissues/biofluids, except for bile, where PFOA occurred at the highest concentrations. Unexpectedly high PFOA levels (up to 3.7 ng/g) were also detected in brain. Phase 2 metabolites, which have been reported in fish following exposure to fluorotelomer alcohols, were not observed in these experiments, probably due to their low abundance. Nevertheless, the detection of PFOA indicates that exposure to PAPs may be an indirect route of exposure to PFCAs in fish.

  • 722.
    Zabaleta, Itsaso
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. University of the Basque Country (UPV/EHU), Spain.
    Bizkarguenaga, Ekhine
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. University of the Basque Country (UPV/EHU), Spain.
    Nunoo, Deborah B. O.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Schultes, Lara
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Leonel, Juliana
    Prieto, Ailette
    Zuloaga, Olatz
    Benskin, Jonathan P.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Biodegradation and Uptake of the Pesticide Sulfluramid in a Soil-Carrot Mesocosm2018In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 52, no 5, p. 2603-2611Article in journal (Refereed)
    Abstract [en]

    N-ethyl perfluorooctane sulfonamide (EtFOSA) is the active ingredient of Sulfluramid, a pesticide which is used extensively in South America for control of leaf-cutting ants. Despite being a known precursor to perfluorooctanesulfonate (PFOS), the importance of EtFOSA as a source of environmental PFOS remains unclear. In the present work, uptake, leaching, and biodegradation of EtFOSA and its transformation products were assessed over 81 days in soil-carrot (Daucus carota ssp sativus) mesocosms for the first time. Experiments performed in the presence of carrot produced PFOS yields of up to 34% using a technical EtFOSA standard and up to 277% using Grao Forte, a commercial Sulfluramid bait formulation containing 0.0024% EtFOSA. Perfluorooctane sulfonamido acetate (FOSAA), perfluorooctane sulfonamide (FOSA), and perfluorooctanoic acid (PFOA) also formed over the course of the experiments, with the latter substance attributed to the presence of perfluorooctanamide impurities. The leachate contained low levels of transformation products and a high FOSA:PFOS ratio, consistent with recent observations in Brazilian surface water. In carrots, the more hydrophilic transformation products (e.g., PFOS) occurred primarily in the leaves, while the more hydrophobic products (e.g., FOSA, FOSAA, and EtFOSA) occurred in the peel and core. Remarkably, isomer-specific analysis revealed that the linear EtFOSA isomer biodegraded significantly faster than branched isomers. These data collectively show that the application of Sulfluramid baits can lead to the occurrence of PFOS in crops and in the surrounding environment, in considerably higher yields than previously thought.

  • 723.
    Zabori, Julia
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Rastak, Narges
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Yoon, Y. J.
    Riipinen, Ilona
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Ström, Johan
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Size-resolved cloud condensation nuclei concentration measurements in the Arctic: two case studies from the summer of 20082015In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 15, no 23, p. 13803-13817Article in journal (Refereed)
    Abstract [en]

    The Arctic is one of the most vulnerable regions affected by climate change. Extensive measurement data are needed to understand the atmospheric processes governing this vulnerability. Among these, data describing cloud formation potential are of particular interest, since the indirect effect of aerosols on the climate system is still poorly understood. In this paper we present, for the first time, size-resolved cloud condensation nuclei (CCN) data obtained in the Arctic. The measurements were conducted during two periods in the summer of 2008: one in June and one in August, at the Zeppelin research station (78 degrees 54'N, 11 degrees 53'E) in Svalbard. Trajectory analysis indicates that during the measurement period in June 2008, air masses predominantly originated from the Arctic, whereas the measurements from August 2008 were influenced by mid-latitude air masses. CCN supersaturation (SS) spectra obtained on the 27 June, before size-resolved measurements were begun, and spectra from the 21 and 24 August, conducted before and after the measurement period, revealed similarities between the 2 months. From the ratio between CCN concentration and the total particle number concentration (CN) as a function of dry particle diameter (D-p) at a SS of 0.4 %, the activation diameter (D-50), corresponding to CCN / CN = 0.50, was estimated. D-50 was found to be 60 and 67 nm for the examined periods in June and August 2008, respectively. Corresponding D-50 hygroscopicity parameter (kappa) values were estimated to be 0.4 and 0.3 for June and August 2008, respectively. These values can be compared to hygroscopicity values estimated from bulk chemical composition, where kappa was calculated to be 0.5 for both June and August 2008. While the agreement between the 2 months is reasonable, the difference in kappa between the different methods indicates a size dependence in the particle composition, which is likely explained by a higher fraction of inorganics in the bulk aerosol samples.

  • 724. Zamani, Leila
    et al.
    Lundqvist, Magnus
    Zhang, Ye
    Åberg, Magnus
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Edfors, Fredrik
    Bidkhori, Gholamreza
    Lindahl, Anna
    Mie, Axel
    Mardinoglu, Adil
    Field, Raymond
    Turner, Richard
    Rockberg, Johan
    Chotteau, Veronique
    High Cell Density Perfusion Culture has a Maintained Exoproteome and Metabolome2018In: Biotechnology Journal, ISSN 1860-6768, E-ISSN 1860-7314, Vol. 13, no 10, article id 1800036Article in journal (Refereed)
    Abstract [en]

    The optimization of bioprocesses for biopharmaceutical manufacturing by Chinese hamster ovary (CHO) cells can be a challenging endeavor and, today, heavily relies on empirical methods treating the bioreactor process and the cells as black boxes. Multi-omics approaches have the potential to reveal otherwise unknown characteristics of these systems and identify culture parameters to more rationally optimize the cultivation process. Here, the authors have applied both metabolomic and proteomic profiling to a perfusion process, using CHO cells for antibody production, to explore how cell biology and reactor environment change as the cell density reaches 200x10(6)cellsmL(-1). The extracellular metabolic composition obtained in perfusion mode shows a markedly more stable profile in comparison to fed-batch, despite a far larger range of viable cell densities in perfusion. This stable profile is confirmed in the extracellular proteosome. Furthermore, the proteomics data shows an increase of structural proteins as cell density increases, which could be due to a higher shear stress and explain the decrease in cell diameter at very high cell densities. Both proteomic and metabolic results shows signs of oxidative stress and changes in glutathione metabolism at very high cell densities. The authors suggest the methodology presented herein to be a powerful tool for optimizing processes of recombinant protein production.

  • 725. Zanatta, M.
    et al.
    Gysel, M.
    Bukowiecki, N.
    Mueller, T.
    Weingartner, E.
    Areskoug, Hans
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Fiebig, M.
    Yttri, K. E.
    Mihalopoulos, N.
    Kouvarakis, G.
    Beddows, D.
    Harrison, R. M.
    Cavalli, F.
    Putaud, J. P.
    Spindler, G.
    Wiedensohler, A.
    Alastuey, A.
    Pandolfi, M.
    Sellegri, K.
    Swietlicki, E.
    Jaffrezo, J. L.
    Baltensperger, U.
    Laj, P.
    A European aerosol phenomenology-5: Climatology of black carbon optical properties at 9 regional background sites across Europe2016In: Atmospheric Environment, ISSN 1352-2310, E-ISSN 1873-2844, Vol. 145, p. 346-364Article in journal (Refereed)
    Abstract [en]

    A reliable assessment of the optical properties of atmospheric black carbon is of crucial importance for an accurate estimation of radiative forcing. In this study we investigated the spatio-temporal variability of the mass absorption cross-section (MAC) of atmospheric black carbon, defined as light absorption coefficient (sigma(ap)) divided by elemental carbon mass concentration (m(EC)). sigma(ap) and m(EC) have been monitored at supersites of the ACTRIS network for a minimum period of one year. The 9 rural background sites considered in this study cover southern Scandinavia, central Europe and the Mediterranean. sigma(ap) was determined using filter based absorption photometers and m(EC) using a thermal-optical technique. Homogeneity of the data-set was ensured by harmonization of all involved methods and instruments during extensive intercomparison exercises at the European Center for Aerosol Calibration (ECAC). Annual mean values of sigma(ap) at a wavelength of 637 nm vary between 0.66 and 1.3 Mm(-1) in southern Scandinavia, 3.7-11 Mm(-1) in Central Europe and the British Isles, and 2.3-2.8 Mm(-1) in the Mediterranean. Annual mean values of mEC vary between 0.084 and 0.23 mu g m(-3) in southern Scandinavia, 0.28 -1.1 in Central Europe and the British Isles, and 0.22-0.26 in the Mediterranean. Both sigma(ap) and mEC in southern Scandinavia and Central Europe have a distinct seasonality with maxima during the cold season and minima during summer, whereas at the Mediterranean sites an opposite trend was observed. Annual mean MAC values were quite similar across all sites and the seasonal variability was small at most sites. Consequently, a MAC value of 10.0 m(2) g(-1) (geometric standard deviation = 133) at a wavelength of 637 nm can be considered to be representative of the mixed boundary layer at European background sites, where BC is expected to be internally mixed to a large extent. The observed spatial variability is rather small compared to the variability of values in previous literature, indicating that the harmonization efforts resulted in substantially increased precision of the reported MAC. However, absolute uncertainties of the reported MAC values remain as high as +/- 30-70% due to the lack of appropriate reference methods and calibration materials. The mass ratio between elemental carbon and non-light-absorbing matter was used as a proxy for the thickness of coatings around the BC cores, in order to assess the influence of the mixing state on the MAC of BC. Indeed, the MAC was found to increase with increasing values of the coating thickness proxy. This provides evidence that coatings do increase the MAC of atmospheric BC to some extent, which is commonly referred to as lensing effect.

  • 726.
    Zguna, Nadezda
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Mass-spectrometry based survey of BMAA sources, distribution and transfer2019Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    β-methylaminoalanine (BMAA) is a neurotoxic non-protein amino acid first isolated from cycad seeds in 1967. It is believed to be connected to neurodegenerative diseases such as Parkinson’s, Alzheimer’s and amyotrophic lateral sclerosis (ALS) and is a ubiquitous compound produced by cyanobacteria, diatoms and dinoflagellates. Consequently, elucidating natural production, distribution and routes for human exposure of BMAA are of particular importance. However, the natural function of BMAA and its mechanisms of toxicity have not been fully established yet. The contradictory results about BMAA presence in cyanobacterial cultures and food webs have been reported by different scientific groups, which required the development of more sensitive and reliable analytical methods. 

    This thesis is focused on the analytical chemistry dimension of BMAA research: covering both new method development and novel applications. New analytical methods for BMAA detection and quantification were developed, focusing on improving sensitivity, since BMAA is normally found in natural samples at low concentrations. In Paper I, a new derivatization technique was implemented, which increased sensitivity and selectivity in the analysis of BMAA and its isomers. Subsequently, this developed method was applied to determine the presence of BMAA in fat and oil matrices in Paper II, which is a step towards discovering BMAA forms other than the documented free and protein-bound BMAA species. In Paper III, a method for separation and quantification of L- and D-BMAA stereoisomers in complex biological matrix was developed and applied to determine the enantiomeric composition of BMAA in cycad seed. Studying environmental distribution of BMAA is important to evaluate potential exposure routes and health risks for humans. Part of the work was devoted to broaden assessment on environmental occurrence of BMAA by applying existing robust methodology to new samples, such as commercial seafood in Paper IV and Baltic Sea biota in Paper V. Some of the “overlooked” aspects in the existing BMAA literature (i.e., BMAA chiral analysis, possible BMAA presence in dietary oil supplements and defined food webs) were successfully addressed. 

    Overall, the thesis presents important analytical developments, which can help to further elucidate sources, distribution and transfer of BMAA.

  • 727.
    Zguna, Nadezda
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Holmbäck, Jan
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Ilag, Leopold
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Analysis of BMAA in fish oil and its vegan alternativesManuscript (preprint) (Other academic)
  • 728.
    Zguna, Nadezda
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Karlson, Agnes
    Ilag, Leopold
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Garbaras, Andrius
    Gorokhova, Elena
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Is there BMAA transfer in the pelagic and benthic food webs in the Baltic Sea?Manuscript (preprint) (Other academic)
  • 729.
    Zguna, Nadezda
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Zurita, Javier
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Andrýs, Rudolf
    Jiang, Liying
    Thorsén, Gunnar
    Ilag, Leopold L.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    LC-MS/MS for chiral separation of β-Methylamino-L-alanine (BMAA) enantiomers after (+)-1-(9-fluorenyl)-ethyl chloroformate (FLEC) derivatizationManuscript (preprint) (Other academic)
  • 730. Zhang, Haiyan
    et al.
    Vestergren, Robin
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. FRAM − High North Research Centre on Climate and the Environment, Norway.
    Wang, Thanh
    Yu, Junchao
    Jiang, Guibin
    Herzke, Dorte
    Geographical Differences in Dietary Exposure to Perfluoroalkyl Acids between Manufacturing and Application Regions in China2017In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 51, no 10, p. 5747-5755Article in journal (Refereed)
    Abstract [en]

    Emissions of perfluoroalkyl acids (PFAAs) have increased in China over the past decade, but human exposure pathways are poorly understood. Here we analyzed 15 PFAAs in commonly consumed food items and calculated body weight normalized dietary intake rates (estimated dietary intake, EDIs) in an area with ongoing PFAA production (Hubei province; n = 121) and an urbanized coastal area (Zhejiang province; n = 106). Geographical differences in concentrations were primarily observed for perfluorooctanesulfonic acid (PFOS) and perfluorohexanesulfonic acid (PFHxS) in animal food items and short chain PFAAs in vegetable food items. The average EDI of Sigma PFAAs for adults in Hubei (998 ng kg(-1) day(-1)) was more than 2 orders of magnitude higher than that in Zhejiang (9.03 ng kg-1 day(-1)). In Hubei province, the average EDI of PFOS for adults (87 ng kg(-1) day(-1)) was close to or exceeded advisory guidelines used in other countries indicating health risks for the population from long-term exposure. Yet, PFOS could only account for about 10% of the EDI of Sigma PFAAs in the Hubei province, which was dominated by short-chain PFAAs through consumption of vegetables. The large contribution of short-chain PFAAs to the total EDIs in manufacturing areas emphasize the need for improved exposure and hazard assessment tools of these substances.

  • 731. Zhang, Jin
    et al.
    Kamstra, Jorke H.
    Ghorbanzadeh, Mehdi
    Weiss, Jana M.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. VU University Amsterdam, The Netherlands.
    Hamers, Timo
    Andersson, Patrik L.
    In Silico Approach To Identify Potential Thyroid Hormone Disruptors among Currently Known Dust Contaminants and Their Metabolites2015In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, no 16, p. 10099-10107Article in journal (Refereed)
    Abstract [en]

    Thyroid hormone disrupting chemicals (THDCs) interfere with the thyroid hormone system and may induce multiple severe physiological disorders. Indoor dust ingestion is a major route of THDCs exposure in humans, and one of the molecular targets of these chemicals is the hormone transporter transthyretin (TTR). To virtually screen indoor dust contaminants and their metabolites for THDCs targeting TTR, we developed a quantitative structure activity relationship (QSAR) classification model. The QSAR model was applied to an in-house database including 485 organic dust contaminants reported from literature data and their 433 in silico derived metabolites. The model predicted 37 (7.6%) dust contaminants and 230 (53.1%) metabolites as potential TTR binders. Four new THDCs were identified after testing 23 selected parent dust contaminants in a radio-ligand TTR binding assay; 2,2',4,4'-tetrahydroxybenzophenone, perfluoroheptanesulfonic acid, 3,5,6-trichloro-2-pyridinol, and 2,4,5-trichlorophenoxyacetic acid. These chemicals competitively bind to TTR with 50% inhibition (IC50) values at or below 10 mu M. Molecular docking studies suggested that these THDCs interacted similarly with TTR via the residue Ser117A, but their binding poses were dissimilar to the endogenous ligand T4. This study identified new THDCs using an in silico approach in combination with bioassay testing and highlighted the importance of metabolic activation for TTR binding.

  • 732. Zhang, Shipeng
    et al.
    Wang, Minghuai
    Ghan, Steven J.
    Ding, Aijun
    Wang, Hailong
    Zhang, Kai
    Neubauer, David
    Lohmann, Ulrike
    Ferrachat, Sylvaine
    Takeamura, Toshihiko
    Gettelman, Andrew
    Morrison, Hugh
    Lee, Yunha
    Shindell, Drew T.
    Partridge, Daniel G.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. University of Oxford, UK.
    Stier, Philip
    Kipling, Zak
    Fu, Congbin
    On the characteristics of aerosol indirect effect based on dynamic regimes in global climate models2016In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 16, no 5, p. 2765-2783Article in journal (Refereed)
    Abstract [en]

    Aerosol-cloud interactions continue to constitute a major source of uncertainty for the estimate of climate radiative forcing. The variation of aerosol indirect effects (AIE) in climate models is investigated across different dynamical regimes, determined by monthly mean 500 hPa vertical pressure velocity (omega(500)), lower-tropospheric stability (LTS) and large-scale surface precipitation rate derived from several global climate models (GCMs), with a focus on liquid water path (LWP) response to cloud condensation nuclei (CCN) concentrations. The LWP sensitivity to aerosol perturbation within dynamic regimes is found to exhibit a large spread among these GCMs. It is in regimes of strong large-scale ascent (omega(500)aEuro-aEuro parts per thousand < aEuro-a'25 hPa day(-1)) and low clouds (stratocumulus and trade wind cumulus) where the models differ most. Shortwave aerosol indirect forcing is also found to differ significantly among different regimes. Shortwave aerosol indirect forcing in ascending regimes is close to that in subsidence regimes, which indicates that regimes with strong large-scale ascent are as important as stratocumulus regimes in studying AIE. It is further shown that shortwave aerosol indirect forcing over regions with high monthly large-scale surface precipitation rate (> 0.1 mm day(-1)) contributes the most to the total aerosol indirect forcing (from 64 to nearly 100 %). Results show that the uncertainty in AIE is even larger within specific dynamical regimes compared to the uncertainty in its global mean values, pointing to the need to reduce the uncertainty in AIE in different dynamical regimes.

  • 733.
    Zhou, Yihui
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Tongji University, China.
    Asplund, Lillemor
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Yin, Ge
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Athanassiadis, Ioannis
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Wideqvist, Ulla
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bignert, Anders
    Qiu, Yanling
    Zhu, Zhiliang
    Zhao, Jianfu
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Swedish Toxicology Sciences Research Center (Swetox), Sweden; Tongji University, China.
    Extensive organohalogen contamination in wildlife from a site in the Yangtze River Delta2016In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 554, p. 320-328Article in journal (Refereed)
    Abstract [en]

    The environmental and human health concerns for organohalogen contaminants (OHCs) extend beyond the 23 persistent organic pollutants (POPs) regulated by the Stockholm Convention. The current, intense industrial production and use of chemicals in China and their bioaccumulation makes Chinese wildlife highly suitable for the assessment of legacy, novel and emerging environmental pollutants. In the present study, six species of amphibians, fish and birds were sampled from paddy fields in the Yangtze River Delta (YRD) were screened for OHCs. Some extensive contamination was found, both regarding number and concentrations of the analytes, among the species assessed. High concentrations of chlorinated paraffins were found in the snake, Short-tailed mamushi (range of 200-340 mu g g(-1) lw), Peregrine falcon (8-59 mu g g(-1) lw) and Asiatic toad (97 mu g g(-1) lw). Novel contaminants and patterns were observed; octaCBs to decaCB made up 20% of the total polychlorinated biphenyls (PCBs) content in the samples and new OHCs, substituted with 5-8 chlorines, were found but are not yet structurally confirmed. In addition, Dechlorane 602 (DDC-DBF) and numerous other OHCs (DDTs, hexachlorocyclohexanes (HCHs), polybrominated diphenyl ethers (PBDEs), hexbromocyclododecane (HBCDD), chlordane, heptachlor, endosulfan and Mirex) were found in all species analyzed. These data show extensive chemical contamination of wildlife in the YRD with a suite of OHCs with both known and unknown toxicities, calling for further indepth studies.

  • 734.
    Zhou, Yihui
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Tongji University, China.
    Chen, Qiaofeng
    Du, Xinyu
    Yin, Ge
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Qiu, Yanling
    Ye, Lu
    Zhu, Zhiliang
    Zhao, Jianfu
    Occurrence and trophic magnification of polybrominated diphenyl ethers (PBDEs) and their methoxylated derivatives in freshwater fish from Dianshan Lake, Shanghai, China2016In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 219, p. 932-938Article in journal (Refereed)
    Abstract [en]

    In this study, polybrominated diphenyl ethers (PBDEs) and methoxylated polybrominated diphenyl ethers (MeO-PBDEs) were analyzed in eleven freshwater fish species from Dianshan Lake, Shanghai, China. The highest concentrations of PBDEs and MeO-PBDEs were found in snakehead, with mean values of 38 ng g(-1) lw and 4.2 ng g(-1) lw, respectively. BDE-47 was the predominant congener of PBDEs, followed by BDE-154. Congener pattern variation of PBDEs was observed among different fish species, implying differences in biotransformation potential among fish. Yellow catfish showed highest concentrations of BDE-99, -153 and -183, suggesting that it is more resistant to debromination than any other fish analyzed in the present study. Trophic magnification factors were in the range of 1.35-1.81 for all the PBDE congeners, but not for 2'-MeO-BDE-68. Negative relationship was observed between PBDEs concentration and sample size (length and weight), indicating fish size dilution effect.

  • 735.
    Zhou, Yihui
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Tongji University, China.
    Yin, Ge
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Asplund, Lillemor
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Qiu, Yanling
    Bignert, Anders
    Zhu, Zhiliang
    Zhao, Jianfu
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Swedish Toxicology Sciences Research Center, Sweden; Tongji University, China.
    A novel pollution pattern: Highly chlorinated biphenyls retained in Black-crowned night heron (Nycticorax nycticorax) and Whiskered tern (Chlidonias hybrida) from the Yangtze River Delta2016In: Chemosphere, ISSN 0045-6535, E-ISSN 1879-1298, Vol. 150, p. 491-498Article in journal (Refereed)
    Abstract [en]

    Contamination of organochlorine pesticides (OCPs), polychlorinated diphenyls (PCBs), polybrominated diphenyl ethers (PBDEs), hydroxylated polybrominated diphenyl ethers (OH-PBDEs) and their methylated counterparts (MeO-PBDEs) were determined in Black-crowned night heron (Nycticorax nycticorax) and Whiskered tern (Chlidonias hybrida) from two drinking water sources, e.g. Tianmu lake and East Tai lake in Yangtze River Delta, China. A novel PCBs contamination pattern was detected, including 11% and 6.9% highly chlorinated biphenyls (PCBs with eight to ten chlorines) in relation to total PCB concentrations in the Black-crowned night heron and Whiskered tern eggs, respectively. The predominating OCPs detected in the present study were 4,4'-DDE, with concentration range 280-650 ng g(-1) lw in Black crowned night heron and 240-480 ng g(-1) lw in Whiskered tern, followed by beta-HCH and Mirex. 6MeO-BDE-90 and 6-MeO-BDE-99 are the two predominant congeners of MeO-PBDEs whereas 6-OH-BDE-47 contributes mostly to the OH-PBDEs in both species. Contamination level was considered as median or low level compared global data.

  • 736.
    Zhou, Yihui
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Yin, Ge
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Asplund, Lillemor
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Stewart, Kathryn
    Rantakokko, Panu
    Bignert, Anders
    Ruokojärvi, Päivi
    Kiviranta, Hannu
    Qiu, Yanling
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Ma, Zhijun
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    High concentrations of OCDD and related chemicals in heron and tern eggs from Yangtze River Delta indicating PCP originArticle in journal (Other academic)
  • 737.
    Zhou, Yihui
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Tongji University, China.
    Yin, Ge
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Asplund, Lillemor
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Stewart, Kathryn
    Rantakokko, Panu
    Bignert, Anders
    Ruokojärvi, Päivi
    Kiviranta, Hannu
    Qiu, Yanling
    Ma, Zhijun
    Bergman, Åke
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. Tongji University, China; Karolinska Institute, Sweden.
    Human exposure to PCDDs and their precursors from heron and tern eggs in the Yangtze River Delta indicate PCP origin2017In: Environmental Pollution, ISSN 0269-7491, E-ISSN 1873-6424, Vol. 225, p. 184-192Article in journal (Refereed)
    Abstract [en]

    Polychlorinated dibenzo-p-dioxins (PCDDs) and polychlorinated dibenzofurans (PCDFs) are highly toxic to humans and wildlife. In the present study, PCDD/Fs were analyzed in the eggs of whiskered terns (Chlidonias hybrida), and genetically identified eggs from black-crowned night herons (Nycticorax nycticorax) sampled from two lakes in the Yangtze River Delta area, China. The median toxic equivalent (TEQ) of PCDD/Fs were 280 (range: 95-1500) and 400 (range: 220-1100) pg TEQ g(-1) lw (WHO, 1998 for birds) in the eggs of black-crowned night heron and whiskered tern, respectively. Compared to known sources, concentrations of PCDDs relative to the sum of PCDD/Fs in bird eggs, demonstrated high abundance of octachlorodibenzo-p-dioxin (OCDD), 1,2,3,4,6,7,8-heptaCDD and 1,2,3,6,7,8-hexaCDD indicating pentachlorophenol (PCP), and/or sodium pentachlorophenolate (Na-PCP) as significant sources of the PCDD/Fs. The presence of polychlorinated diphenyl ethers (PCDEs), hydroxylated and methoxylated polychlorinated diphenyl ethers (OH-and Me0-PCDEs, known impurities in PCP products), corroborates this hypothesis. Further, significant correlations were found between the predominant congener CDE-206, 3'-OH-CDE-207, 2'-MeO-CDE-206 and OCDD, indicating a common origin. Eggs from the two lakes are sometimes used for human consumption. The WHO health-based tolerable intake of PCDD/Fs is exceeded if eggs from the two lakes are consumed regularly on a weekly basis, particularly for children. The TEQs extensively exceed maximum levels for PCDD/Fs in hen eggs and egg products according to EU legislation (2.5 pg TEQ g(-1)/w). The results suggest immediate action should be taken to manage the contamination, and further studies evaluating the impacts of egg consumption from wild birds in China. Likewise, studies on dioxins and other POPs in common eggs need to be initiated around China.

  • 738. Zhou, Yihui
    et al.
    Yin, Ge
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Du, Xinyu
    Xu, Maoying
    Qiu, Yanling
    Ahlqvist, Patrik
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Chen, Qiaofeng
    Zhao, Jianfu
    Short-chain chlorinated paraffins (SCCPs) in a freshwater food web from Dianshan Lake: Occurrence level, congener pattern and trophic transfer2018In: Science of the Total Environment, ISSN 0048-9697, E-ISSN 1879-1026, Vol. 615, p. 1010-1018Article in journal (Refereed)
    Abstract [en]

    Short-chain chlorinated paraffins (SCCPs) are new group of persistent organic pollutants (POPs) listed in the Stockholm Convention. The Yangtze River Delta is among the industrially most developed areas in China, supporting a large production and consumption of chlorinated paraffins (CPs). Despite this, there is very limited data on the environmental exposure of SCCPs from the region. This study analyzed SCCPs in 14 wild aquatic organisms from Dianshan Lake, Shanghai, China. The concentrations of total SCCPs ranged from 10 to 1300 mu g g(-1) lipid weight, with significantly higher levels (p < 0.05) in benthic (benthic fish and invertebrates) than in non-benthic species (pelagic and mesopelagic fish). The abundance of C-10 congeners was much higher in the benthic species compared to in the non-benthic species. The calculated trophic magnification factors (TMFs) of SCCP congeners varied from 1.19 (C10H12Cl10) to 1.57 (C13H20Cl8). The TMFs were significantly correlated (p < 0.01) with carbon-chain length in a positive linear relationship and with Log K-ow in a parabolic curve relationship. Considering the high concentrations of SCCPs in wild aquatic organisms and the trophic magnification observed in the freshwater food web, further studies should be undertaken to assess the environmental fate of SCCPs and the public health risk in the Yangtze River Delta.

  • 739.
    Ziarrusta, Haizea
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. University of the Basque Country (UPV/EHU), Spain.
    Mijangos, Leire
    Izagirre, Urtzi
    Plassmann, Merle M.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Benskin, Jonathan P.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Anakabe, Eneritz
    Olivares, Maitane
    Zuloaga, Olatz
    Bioconcentration and Biotransformation of Amitriptyline in Gilt-Head Bream2017In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 51, no 4, p. 2464-2471Article in journal (Refereed)
    Abstract [en]

    Extensive global use of the serotonin norepinephrine reuptake inhibitor Amitriptyline (AMI) for treatment of mental health problems has led to its common occurrence in the aquatic environment. To assess AMI bioconcentration factors, tissue distribution, and metabolite formation in fish, we exposed gilt-head bream (Sparus aurata) to AMI in seawater for 7 days at two concentrations (0.2 mu g/L and 10 mu g/L). Day 7 proportional bioconcentration factors (BCFs) ranged from 6 (10 mu g/L dose, muscle) to 127 (0.2 mu g/L dose, brain) and were consistently larger at the low dose level. The relative tissue distribution of AMI was consistent at both doses, with concentrations decreasing in the order brain approximate to gill > liver > plasma > bile >> muscle. Using a suspect screening workflow based on liquid chromatography-high resolution (Orbitrap) mass spectrometry we identified 33 AMI metabolites (both Phase I and Phase II), occurring mostly in bile, liver and plasma. Ten structures are reported for the first time. Remarkably, all 33 metabolites retained the tricyclic ring structure common to tricyclic antidepressants, which may be toxicologically relevant. Collectively these data indicate that, in addition to AMI, a broad suite of metabolites should be included in biomonitoring campaigns in order to fully characterize exposure in aquatic wildlife.

  • 740.
    Zieger, Paul
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Aalto, P. P.
    Aaltonen, V.
    Aijala, M.
    Backman, J.
    Hong, J.
    Komppula, M.
    Krejci, Radovan
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry. University of Helsinki, Finland.
    Laborde, M.
    Lampilahti, J.
    de Leeuw, G.
    Pfuller, A.
    Rosati, B.
    Tesche, Matthias
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Tunved, Peter
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Vaananen, R.
    Petaja, T.
    Low hygroscopic scattering enhancement of boreal aerosol and the implications for a columnar optical closure study2015In: Atmospheric Chemistry And Physics, ISSN 1680-7316, E-ISSN 1680-7324, Vol. 15, no 13, p. 7247-7267Article in journal (Refereed)
    Abstract [en]

    Ambient aerosol particles can take up water and thus change their optical properties depending on the hygroscopicity and the relative humidity (RH) of the surrounding air. Knowledge of the hygroscopicity effect is of crucial importance for radiative forcing calculations and is also needed for the comparison or validation of remote sensing or model results with in situ measurements. Specifically, particle light scattering depends on RH and can be described by the scattering enhancement factor f(RH), which is defined as the particle light scattering coefficient at defined RH divided by its dry value (RH < 30-40 %). Here, we present results of an intensive field campaign carried out in summer 2013 at the SMEAR II station at Hyytiala, Finland. Ground-based and airborne measurements of aerosol optical, chemical and microphysical properties were conducted. The f(RH) measured at ground level by a humidified nephelometer is found to be generally lower (e.g. 1.63 +/- 0.22 at RH = 85% and lambda = 525 nm) than observed at other European sites. One reason is the high organic mass fraction of the aerosol encountered at Hyytiala to which f(RH) is clearly anti-correlated (R-2 approximate to 0.8). A simplified parametrization of f(RH) based on the measured chemical mass fraction can therefore be derived for this aerosol type. A trajectory analysis revealed that elevated values of f(RH) and the corresponding elevated inorganic mass fraction are partially caused by transported hygroscopic sea spray particles. An optical closure study shows the consistency of the ground-based in situ measurements. Our measurements allow to determine the ambient particle light extinction coefficient using the measured f(RH). By combining the ground-based measurements with intensive aircraft measurements of the particle number size distribution and ambient RH, columnar values of the particle extinction coefficient are determined and compared to columnar measurements of a co-located AERONET sun photometer. The water uptake is found to be of minor importance for the column-averaged properties due to the low particle hygroscopicity and the low RH during the daytime of the summer months. The in situ derived aerosol optical depths (AOD) clearly correlate with directly measured values of the sun photometer but are substantially lower compared to the directly measured values (factor of similar to 2-3). The comparison degrades for longer wavelengths. The disagreement between in situ derived and directly measured AOD is hypothesized to originate from losses of coarse and fine mode particles through dry deposition within the canopy and losses in the in situ sampling lines. In addition, elevated aerosol layers (above 3 km) from long-range transport were observed using an aerosol lidar at Kuopio, Finland, about 200 km east-northeast of Hyytiala. These elevated layers further explain parts of the disagreement.

  • 741.
    Zieger, Paul
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Vaisanen, O.
    Corbin, J. C.
    Partridge, Dan G.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Bastelberger, S.
    Mousavi-Fard, M.
    Rosati, B.
    Gysel, M.
    Krieger, U. K.
    Leck, Caroline
    Stockholm University, Faculty of Science, Department of Meteorology .
    Nenes, A.
    Riipinen, Ilona
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Virtanen, A.
    Salter, Matthew E.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Revising the hygroscopicity of inorganic sea salt particles2017In: Nature Communications, ISSN 2041-1723, E-ISSN 2041-1723, Vol. 8, article id 15883Article in journal (Refereed)
    Abstract [en]

    Sea spray is one of the largest natural aerosol sources and plays an important role in the Earth's radiative budget. These particles are inherently hygroscopic, that is, they take-up moisture from the air, which affects the extent to which they interact with solar radiation. We demonstrate that the hygroscopic growth of inorganic sea salt is 8-15% lower than pure sodium chloride, most likely due to the presence of hydrates. We observe an increase in hygroscopic growth with decreasing particle size (for particle diameters <150 nm) that is independent of the particle generation method. We vary the hygroscopic growth of the inorganic sea salt within a general circulation model and show that a reduced hygroscopicity leads to a reduction in aerosol-radiation interactions, manifested by a latitudinal-dependent reduction of the aerosol optical depth by up to 15%, while cloud-related parameters are unaffected. We propose that a value of kappa(s) = 1.1 (at RH = 90%) is used to represent the hygroscopicity of inorganic sea salt particles in numerical models.

  • 742.
    Zou, Hongyan
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    The measurement of chemical persistence in the field by benchmarking: Theory and Experiment2015Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Persistence is one of the core criteria in chemical exposure and hazard assessment. It is often defined as the half-life for the removal of a chemical from a specified environment by transformation. Chemicals with long transformation half-lives may pose high risks for wildlife or humans and be subject to long-range transport to remote areas. It is challenging to measure persistence directly in the field in view of the complexity of the natural environment and spatial and temporal variability in environmental conditions that may affect degradation.

    The mass balance approach is the most commonly used method for field measurement of persistence. In this thesis an alternative to the traditional mass balance approach that uses benchmarking is proposed and evaluated using models and field application. The benchmarking approach compares the relative behavior of chemicals, rather than measuring the absolute value of a property. The unknown property (persistence in this thesis) of test chemicals can be estimated by comparison against another chemical for which this property is known.

    In Paper I, the potential of benchmarking to measure persistence in the field was evaluated by modeling. A framework for applying benchmarking to measure persistence in the field was developed. Lake systems with hydraulic residence times of the order of months were identified as appropriate field sites to measure the persistence of chemicals that are close to the regulatory thresholds, which are also on the scale of months. Field studies in two Swedish lakes were conducted. Both are shallow lakes, whereas Norra Bergundasjön (Paper II) has a longer residence time (four months) than Boren (one to two months; Paper III). In Paper II the benchmarking approach was tested to measure the persistence of a group of chemicals that were expected to stay in the water phase. Acesulfame K (artificial sweetener) without observable degradation in the lake was used as the benchmark chemical. The persistence of 9 pharmaceuticals and one X-ray contrast agent was measured to range from <1-2 days (ketoprofen) to 580-5700 days (carbamazepine). The results obtained using the benchmarking approach agreed well with the mass balance approach, indicating that the benchmarking approach can be a valid and useful method to measure persistence in the field. In Paper III the seasonality in chemical persistence was investigated by benchmarking. The seasonal difference in chemical persistence was found to be largest between spring and autumn. The persistence of 5 chemicals in spring were lower than in autumn, mainly attributed to lower temperature and less sunlight in autumn. The spatial variation of the persistence of chemicals was observed by comparing the persistence of chemicals in spring in the two lakes. Thus benchmarking is a useful tool to study the temporal and spatial variation of persistence in the real environment.  

    Paper IV explores the potential of benchmarking thoroughly and the application of benchmarking in a regulatory context. Benchmarking could facilitate more field measurements of persistence, leading to a better understanding of the temporal and spatial variability of persistence in various environments and a basis for lab-to-field extrapolation. Besides quantitative estimation of persistence in the field, benchmarking can be applied to determine the relative magnitude of persistence, called threshold benchmarking which could be a valuable tool in regulatory processes.

  • 743.
    Zou, Hongyan
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Radke, Michael
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Kierkegaard, Amelie
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    MacLeod, Matthew
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    McLachlan, Michael S.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Using Chemical Benchmarking to Determine the Persistence of Chemicals in a Swedish Lake2015In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, no 3, p. 1646-1653Article in journal (Refereed)
    Abstract [en]

    It is challenging to measure the persistence of chemicals under field conditions. In this work, two approaches for measuring persistence in the field were compared: the chemical mass balance approach, and a novel chemical benchmarking approach. Ten pharmaceuticals, an X-ray contrast agent, and an artificial sweetener were studied in a Swedish lake. Acesulfame K was selected as a benchmark to quantify persistence using the chemical benchmarking approach. The 95% confidence intervals of the half-life for transformation in the lake system ranged from 780-5700 days for carbamazepine to <1-2 days for ketoprofen. The persistence estimates obtained using the benchmarking approach agreed well with those from the mass balance approach (1-21% difference), indicating that chemical benchmarking can be a valid and useful method to measure the persistence of chemicals under field conditions. Compared to the mass balance approach, the benchmarking approach partially or completely eliminates the need to quantify mass flow of chemicals, so it is particularly advantageous when the quantification of mass flow of chemicals is difficult. Furthermore, the benchmarking approach allows for ready comparison and ranking of the persistence of different chemicals.

  • 744.
    Zou, Hongyan
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Radke, Michael
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Kierkegaard, Amelie
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    McLachlan, Michael S.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Temporal Variation of Chemical Persistence in a Swedish Lake Assessed by Benchmarking2015In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, no 16, p. 9881-9888Article in journal (Refereed)
    Abstract [en]

    Chemical benchmarldng was used to investigate the temporal variation of the persistence of chemical contaminants in a Swedish lake. The chemicals studied included 12 pharmaceuticals, an artificial sweetener, and an X-ray contrast agent. Measurements were conducted in late spring, late autumn, and winter. The transformation half-life in the lake could be quantified for 7 of the chemicals. It ranged from several days to hundreds of days. For 5 of the chemicals (bezafibrate, climbazole, diclofenac, furosemide, and hydrochlorothiazide), the measured persistence was lower in late spring than in late autumn. This may have been caused by lower temperatures and/or less irradiation during late autumn. The seasonality in chemical persistence contributed to changes in chemical concentrations in the lake during the year. The impact of seasonality of persistence was compared with the impact of other important variables determining concentrations in the lake: chemical inputs and water flow/dilution. The strongest seasonal variability in chemical concentration in lake water was observed for hydrochlorothiazide (over a factor of 10), and this was attributable to the seasonality in its persistence.

  • 745.
    Zurita, Javier
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Amino acids with relevance to health, climate and the environment: Development of mass spectrometric methods2018Doctoral thesis, comprehensive summary (Other academic)
    Abstract [en]

    Amino acids play vital roles in health, either in their native form or chemically modified. Some studies have linked certain non-proteinogenic amino acids to neurodegenerative diseases, such as in the case of β-methylaminoalanine (BMAA). Various environmental pollutants, including carcinogenic polycyclic aromatic compounds, are able to react forming adducts with blood proteins. Amino acids may also be essential in chemical ecology as constituents of flower nectar, potentially used by common feeders as butterflies to synthesize pheromones. Additionally, proteinaceous materials have been detected in aerosols with an apparent potential to influence climate, possibly having a role in cloud formation.

    The determination of amino acids presents many challenges, due to the fact that they are most often constituents of complex sample matrices that contain a high level of chemical interferences. In this respect, mass spectrometry (MS) is a selective and sensitive analytical tool that can be used to measure amino acids in biological samples.

    In this work, several analytical methods based on MS were developed. (i) First, derivatization with a permanently charged N-hydroxysuccinimide ester of N-butylnicotinic acid (C4-NA-NHS) was used to increase the sensitivity and selectivity for amino acids. This strategy was applied to localize BMAA in both visceral and non-visceral parts of blue mussels. (ii) Moreover, a method was developed to separate and determine L- and D- BMAA in cycad seeds by derivatization with a chiral reagent, (+)-1-(9-fluorenyl) ethyl chloroformate (FLEC). Together with L-BMAA, appreciable amounts of D-BMAA (50.13 ± 0.05 and 4.08 ± 0.04 µg BMAA/g Cycas micronesica, wet weight, respectively) were detected for the first time after enzymatic digestion, suggesting D-BMAA may be bound to proteins or may be a conjugate and released only after hydrolysis. (iii) Derivatization with C4-NA-NHS was applied as well for the determination of amino acids in nectar of Bunias orientalis. The presence of tryptophan and phenylalanine, purportedly used to synthesize anti-aphrodisiac pheromones by nectar feeders (adult male butterflies), could then be observed. (iv) Furthermore, the profiling of amino acids in Arctic aerosols was carried out and was used to measure the contribution of free and polyamino acids in aerosol formation. Levels detected were in the range of 0.02-2914 pmol/m3 sampled air. For the first time the measurement of polyamino acids in the Arctic atmosphere was reported. Additionally, possible anthropogenic and marine sources were suggested. The results support the hypothesis that proteinaceous materials act as cloud condensation nuclei over the Arctic. (v) Finally, a method was developed employing selective chromatography/high-resolution MS to identify histidine and lysine adducts in serum albumin of mice exposed to the carcinogen benzo(a)pyrene, as well as in human samples in vivo. Adduct isomers from diol epoxide metabolites could be detected in serum albumin from human samples at attomole/mg levels. This work shows the possibility of future exposure measurements from these compounds in different groups of the population.

    This thesis presents the development of improved analytical methodologies for detecting and identifying trace levels of amino acids, to investigate their relevance in health, climate and the environment.

  • 746.
    Zurita, Javier
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Motwani, Hitesh V.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Ilag, Leopold L.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Souliotos, Vassilis L
    Kyrtopoulos, Soterios A
    Nilsson, Ulrika
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Törnqvist, Margareta
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Detection of benzo[a]pyrene diol epoxide adducts to histidine and lysine in serum albumin in vivo by high-resolution-tandem mass spectrometryManuscript (preprint) (Other academic)
  • 747.
    Zurita, Javier
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Zguna, Nadezda
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Andrýs, Rudolf
    Strzelczak, Anna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Jiang, Liying
    Thorsen, Gunnar
    Ilag, Leopold L.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Chiral separation of beta-Methylamino-alanine (BMAA) enantiomers after (+)-1-(9-fluorenyl)-ethyl chloroformate (FLEC) derivatization and LC-MS/MS2019In: Analytical Methods, ISSN 1759-9660, E-ISSN 1759-9679, Vol. 11, p. 432-442Article in journal (Refereed)
    Abstract [en]

    β-Methylamino-L-alanine, a neurotoxin first isolated from the seeds of cycad tree Cycas circinalis, is widely spread in a variety of environments. New sensitive techniques and robust methodologies are needed to detect its presence in complex biological samples and to further understand its biochemical properties. In this context, the determination of the enantiomeric composition of natural BMAA is of great importance. In this study, a simple and easily implemented LC-ESI-MS/MS method was developed to determine the presence of both D- and L-BMAA enantiomers in samples of cycad seed (Cycas micronesica). The samples were subjected to enzymatic hydrolysis to avoid racemization that occurs during strong acid hydrolysis. Derivatization with (+)-1-(9-fluorenyl)-ethyl chloroformate (FLEC) was performed prior to LC-ESI-MS/MS to produce chromatographically separable derivatives of D- and L-BMAA. Together with the retention time, two MRM transitions and their peak area ratios were used to identify the compounds. The LOQ obtained was 0.3 μg BMAA per g wet weight for each enantiomer. Method repeatability was within 3 RSD% both intraday and interday and accuracy was 98–108%. An accurate enantiomeric composition was obtained from the samples of cycad seed, where L- and D-BMAA were detected at 50.13 ± 0.05 and 4.08 ± 0.04 μg BMAA per g wet weight respectively (n = 3).

  • 748.
    Ågerstrand, Marlene
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    In Response: Reporting recommendations to ensure reliability and reproducibility of ecotoxicity studies—A tripartite initiative2016In: Environmental Toxicology and Chemistry, ISSN 0730-7268, E-ISSN 1552-8618, Vol. 35, no 5, p. 1072-1073Article in journal (Other academic)
  • 749.
    Ågerstrand, Marlene
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Berg, Cecilia
    Björlenius, Berndt
    Breitholtz, Magnus
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Brunström, Björn
    Fick, Jerker
    Gunnarsson, Lina
    Larsson, D. G. Joakim
    Sumpter, John P.
    Tysklind, Mats
    Rudén, Christina
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Improving Environmental Risk Assessment of Human Pharmaceuticals2015In: Environmental Science and Technology, ISSN 0013-936X, E-ISSN 1520-5851, Vol. 49, no 9, p. 5336-5345Article in journal (Refereed)
    Abstract [en]

    This paper presents 10 recommendations for improving the European Medicines Agency's guidance for environmental risk assessment of human pharmaceutical products. The recommendations are based on up-to-date, available science in combination with experiences from other chemical frameworks such as the REACH-legislation for industrial chemicals. The recommendations concern: expanding the scope of the current guideline; requirements to assess the risk for development of antibiotic resistance; jointly performed assessments; refinement of the test proposal; mixture toxicity assessments on active pharmaceutical ingredients with similar modes of action; use of all available ecotoxicity studies; mandatory reviews; increased transparency; inclusion of emission data from production; and a risk management option. We believe that implementation of our recommendations would strengthen the protection of the environment and be beneficial to society. Legislation and guidance documents need to be updated at regular intervals in order to incorporate new knowledge from the scientific community. This is particularly important for regulatory documents concerning pharmaceuticals in the environment since this is a research field that has been growing substantially in the last decades.

  • 750.
    Ågerstrand, Marlene
    et al.
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Beronius, Anna
    Stockholm University, Faculty of Science, Department of Environmental Science and Analytical Chemistry.
    Weight of evidence evaluation and systematic review in EU chemical risk assessment: Foundation is laid but guidance is needed2016In: Environment International, ISSN 0160-4120, E-ISSN 1873-6750, Vol. 92-93, p. 590-596Article, review/survey (Refereed)
    Abstract [en]

    The aim of this review was to investigate if and how the application of weight of evidence (WoE) evaluation or systematic review (SR) in chemical risk assessment is promoted within different regulatory frameworks in the European Union. Legislative and relevant guidance documents within nine regulatory frameworks were scrutinized and compared. WoE evaluation or SR is promoted in seven of the investigated frameworks but sufficient guidance for how to perform these processes is generally lacking. None of the investigated frameworks give enough guidance for generating robust and reproducible WoE evaluations or SRs. In conclusion, the foundation for use of WoE evaluation and SR is laid-in the majority of the investigated frameworks, but there is a need to provide more structured and detailed guidance. In order to make the process of developing guidance as efficient as possible, and to ensure smooth transfer of risk assessment's between frameworks if a chemical is risk assessed both as, for example, a biocide and an industrial chemical, it is recommended that guidance is developed jointly by the European regulatory agencies.

1213141516 701 - 750 of 755
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