169 research outputs found

    Long-term observations of the background aerosol at Cabauw, The Netherlands

    Get PDF
    Long-term measurements of PM2.5 mass concentrations and aerosol particle size distributions from 2008 to 2015, as well as hygroscopicity measurements conducted over one year (2008-2009) at Cabauw, The Netherlands, are compiled here in order to provide a comprehensive dataset for understanding the trends and annual variabilities of the atmospheric aerosol in the region. PM2.5 concentrations have a mean value of 14.4 mu g m(-3) with standard deviation 2.1 mu g m(-3), and exhibit an overall decreasing trend of -0.74 mu g m(-3) year(-1). The highest values are observed in winter and spring and are associated with a shallower boundary layer and lower precipitation, respectively, compared to the rest of the seasons. Number concentrations of particles smaller than 500 nm have a mean of 9.2 x 10(3) particles cm(-3) and standard deviation 4.9x10(3) particles cm(-3), exhibiting an increasing trend between 2008 and 2011 and a decreasing trend from 2013 to 2015. The particle number concentrations exhibit highest values in spring and summer (despite the increased precipitation) due to the high occurrence of nucleation-mode particles, which most likely are formed elsewhere and are transported to the observation station. Particle hygroscopicity measurements show that, independently of the air mass origin, the particles are mostly externally mixed with the more hydrophobic mode having a mean hygroscopic parameter kappa of 0.1 while for the more hydrophilic mode kappa is 0.35. The hygroscopicity of the smaller particles investigated in this work (i.e., particles having diameters of 35 nm) appears to increase during the course of the nucleation events, reflecting a change in the chemical composition of the particles. (C) 2017 Elsevier B.V. All rights reserved.Peer reviewe

    21. Environmental disclosure in Japanese wood-related companies for 2005 and 2010

    Get PDF
    Environmental and sustainability reports by private sectors are primarily aimed at information disclosure for individual entities. Comparison of such reports in two different years, provide us with unique opportunity to explore underpinning changes. This article compares Japanese wood-related sectors in 2005 and in 2010. During this half-decade, the economy was sluggish, with a number of dramatic meltdowns symbolized by the “Lehman shock” in 2008. The period also experience upheaval of environmental movements with a major UN COP on biodiversity taking place in Nagoya in 2010, making comparison of these two years more interesting. Environmental disclosure from 51 companies mainly from 7 wood related sectors was reviewed. The trends in disclosed information was reviewed based on the following criteria: publishing of environmental reports, reference to illegal logging, definition of sustainable forest management, and membership to the Global Compact. The results indicated an increase in many of the indicators for large size companies, particularly for trading companies, while the majority of small and mid-size companies did not conduct basic activities such as publishing reports.[Book Chapter]: 21. Environmental disclosure in Japanese wood-related companies for 2005 and 2010, Part V. Ecosystem Service and Socioeconomic Aspects with Special Reference to Biodiversity, Integrative Observations and Assessments (Ecological Research Monographs / Asia-Pacific Biodiversity Observation Network), edited by Shin-ichi Nakano(中野 伸一), Tetsukazu Yahara(矢原 徹一), Tohru Nakashizuka(浅野 透), DOI:10.1007/978-4-431-54783-

    Measurement report : Molecular composition and volatility of gaseous organic compounds in a boreal forest - from volatile organic compounds to highly oxygenated organic molecules

    Get PDF
    The molecular composition and volatility of gaseous organic compounds were investigated during April- July 2019 at the Station for Measuring Ecosystem - Atmosphere Relations (SMEAR) II situated in a boreal forest in Hyytiala, southern Finland. In order to obtain a more complete picture and full understanding of the molecular composition and volatility of ambient gaseous organic compounds (from volatile organic compounds, VOCs, to highly oxygenated organic molecules, HOMs), two different instruments were used. A Vocus proton-transfer-reaction time-of-flight mass spectrometer (Vocus PTR-ToF; hereafter Vocus) was deployed to measure VOCs and less oxygenated VOCs (i.e., OVOCs). In addition, a multi-scheme chemical ionization inlet coupled to an atmospheric pressure interface time-of-flight mass spectrometer (MION API-ToF) was used to detect less oxygenated VOCs (using Br- as the reagent ion; hereafter MION-Br) and more oxygenated VOCs (including HOMs; using NO3- as the reagent ion; hereafter MION-NO3). The comparison among different measurement techniques revealed that the highest elemental oxygen-to-carbon ratios (O : C) of organic compounds were observed by the MION-NO3 (0.9 +/- 0.1, average +/- 1 standard deviation), followed by the MION-Br (0.8 +/- 0.1); lowest O : C ratios were observed by Vocus (0.2 +/- 0.1). Diurnal patterns of the measured organic compounds were found to vary among different measurement techniques, even for compounds with the same molecular formula, suggesting contributions of different isomers detected by the different techniques and/or fragmentation from different parent compounds inside the instruments. Based on the complementary molecular information obtained from Vocus, MION-Br, and MION-NO3, a more complete picture of the bulk volatility of all measured organic compounds in this boreal forest was obtained. As expected, the VOC class was the most abundant (about 53.2 %), followed by intermediate-volatility organic compounds (IVOCs, about 45.9 %). Although condensable organic compounds (low-volatility organic compounds, LVOCs; extremely low volatility organic compounds, ELVOCs; and ultralow-volatility organic compounds, ULVOCs) only comprised about 0.2 % of the total gaseous organic compounds, they play an important role in new particle formation as shown in previous studies in this boreal forest. Our study shows the full characterization of the gaseous organic compounds in the boreal forest and the advantages of combining Vocus and MION API-ToF for measuring ambient organic compounds with different oxidation extents (from VOCs to HOMs). The results therefore provide a more comprehensive understanding of the molecular composition and volatility of atmospheric organic compounds as well as new insights into interpreting ambient measurements or testing/improving parameterizations in transport and climate models.Peer reviewe

    A Protein Diet Score, Including Plant and Animal Protein, Investigating the Association with HbA1c and eGFR-The PREVIEW Project

    Get PDF
    Higher-protein diets have been advocated for body-weight regulation for the past few decades. However, the potential health risks of these diets are still uncertain. We aimed to develop a protein score based on the quantity and source of protein, and to examine the association of the score with glycated haemoglobin (HbA1c) and estimated glomerular filtration rate (eGFR). Analyses were based on three population studies included in the PREVIEW project (PREVention of diabetes through lifestyle Intervention and population studies in Europe and around the World): NQplus, Lifelines, and the Young Finns Study. Cross-sectional data from food-frequency questionnaires (n = 76,777 subjects) were used to develop a protein score consisting of two components: 1) percentage of energy from total protein, and 2) plant to animal protein ratio. An inverse association between protein score and HbA1c (slope -0.02 +/- 0.01 mmol/mol, p <0.001) was seen in Lifelines. We found a positive association between the protein score and eGFR in Lifelines (slope 0.17 +/- 0.02 mL/min/1.73 m(2), p <0.0001). Protein scoring might be a useful tool to assess both the effect of quantity and source of protein on health parameters. Further studies are needed to validate this newly developed protein score.Peer reviewe
    • …
    corecore