Found 9763 publications. Showing page 209 of 391:
Trans-boundary movement of e-waste and the associated contaminants (e.g., polychlorinated biphenyls, halogenated flame retardants, metals) has emerged as an important research topic in the last decade. Several monitoring studies published in the peer-reviewed literature have documented elevated levels of various industrial-use organic contaminants (IUOCs) in the atmosphere near known or suspected e-waste receiving and processing sites in Asia. Surprisingly high concentrations of polychlorinated biphenyls in the atmosphere were also reported offshore of West Africa. Emissions of IUOCs linked to trans-boundary movement of e-waste have implications for chemical fate and exposure at local, regional and global scale. For example, the transfer of e-waste from temperate climates to tropical regions could lead to enhanced emissions simply through temperature-related increases in passive volatilization from open landfill sites. The main objective of this study is to develop emission scenarios for selected IUOCs considering the generation and transport of e-waste and simulate and compare chemical fate and transport using an evaluative modeling approach. All simulations were conducted using BETR-Global 2.0 (https://sites.google.com/site/betrglobal/), a chemical fate model which divides the globe into 288 zones (15o x 15o). This spatial resolution is deemed suitable for assessments at the regional as well as global scale. Breivik et al. (SETAC 2014) present an inventory of the global generation and trans-boundary exports of e-waste towards non-OECD countries, with an emphasis on locations in sub-tropical and tropical regions. This inventory along with the physical-chemical property data of selected IUOCs (e.g., partition coefficients, degradation rate constants) are the key inputs to the model simulations. Model output under various emission scenarios are compared in terms of overall persistence (POV) at the global scale as well as in terms of long-range transport potential (LTRP) at regional and global scale (e.g., atmospheric deposition of IUOCs in remote regions). The model outputs are also used to assess the potential implications for chemical exposure at regional and global scale under the various scenarios.
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Contaminants in Greenlandic food and chiral pesticides as indicators for selective uptake processes.
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Closing the gaps in our knowledge of the hydrological cycle over land: Conceptual problems. Space sciences series of ISSI, 46
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VOC measurements by PTR-ToF-MS at the Birkenes Observatory. A summary report. NILU OR
A high resolution proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF- MS) was used for on-line and real-time measurements of volatile organic compounds (VOCs) at the Birkenes Observatory in Southern Norway. Measurements were carried out during late spring and summer 2012 and in January and early February 2013. Here we present the obtained PTR-MS standard data product which includes volume mixing ratios of methanol, acetonitrile, acetaldehyde, acetone, dimethyl sulphide, isoprene, methacrolein plus methylvinylketone, methylethylketone, benzene, toluene, C8-alkylbenzenes, C9-alkylbenzenes and the sum of the monoterpene isomers. Exploratory data of formic acid, acetic acid, pinonaldehyde and three unidentified signals (m/z 87.080, m/z 89.060 and m/z 101.098) are also shown. PTR-ToF-MS mass spectra were dominated by oxygenated VOCs both in summer and in winter. Pure hydrocarbons were mostly aromatic hydrocarbons (benzene, toluene, C8-alkylbenzenes) in winter and biogenic hydrocarbons (monoterpenes and isoprene) in summer. The summertime data confirm that the Birkenes Observatory is an interesting site in the boreo-nemoral vegetation zone where it is possible to observe both monoterpene and isoprene emissions and their photochemical processing in the atmosphere.
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Statoil assigned NILU ¿ Norwegian Institute for Air Research to carry out a programme on "Environmental monitoring of emissions to air from the Snøhvit LNG facility". The project started on 1 February 2006. This report summarises the results of the measurement programme from 1 July 2012 to 30 June 2013. It involves the measurement of meteorological parameters on Melkøya and Fuglenesodden. Air quality parameters were measured at Fuglenesodden. Precipitation samples taken at Forsøl and Kargeneset were analysed for PAHs, inorganic ions, heavy metals and mercury. The current air quality standards are met for all compounds.
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