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- Hedberg Larsson, E, et al.
(författare)
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Is Levoglucosan a Suitable Quantitative Tracer for Wood Burning? - Comparison with Receptor Modeling on Trace Elements in Lycksele, Sweden
- 2006
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Ingår i: Journal of the Air and Waste Management Association. - 1096-2247. ; 56:12, s. 1669-1678
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Tidskriftsartikel (refereegranskat)abstract
- Particle emissions from residential wood combustion in small communities in Northern Sweden can sometimes increase the ambient particle concentrations to levels comparable to densely trafficked streets in the center of large cities. The reason for this is the combination of increased need for domestic heating during periods of low temperatures, leading to higher emission rates, and stable meteorological conditions. In this work, the authors compare two different approaches to quantify the wood combustion contribution to fine particles in Northern Sweden: a multivariate source-receptor analysis on inorganic compounds followed by multiple linear regression (MLR) of fine particle concentrations and levoglucosan used as a tracer. From the receptor model, it can be seen that residential wood combustion corresponds with 70% of modeled particle mass. Smaller contributions are also seen from local nonexhaust traffic particles, road dust, and brake wear (each contributing 14%). Of the mass, 1.5% is explained by long-distance transported particles, and 2% derives from a regional source deriving from either oil combustion or smelter activities. In samples collected in ambient air, a significant linear correlation was found between wood burning particles and levoglucosan. The levoglucosan fraction in the ambient fine particulate matter attributed to wood burning according to the multivariate analysis ranged from < 2% to 50%. This is much higher than the fraction found in the emission from the boilers expected to be responsible for most emissions at this site (between 3% and 6%). A laboratory emission study of wood and pellet boilers gave 0.3%(wt) to 22%(wt) levoglucosan to particle mass, indicating that the levoglucosan fraction may be highly dependent on combustion conditions, making it uncertain to use it as a quantitative tracer under real-world burning conditions. Thus, quantitative estimates of wood burning contributions will be very uncertain using solely levoglucosan as a tracer.
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| 2. |
- Bidleman, TF, et al.
(författare)
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Chiral signatures of chlordanes indicate changing sources to the atmosphere over the past 30 years
- 2004
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310. ; 38:35, s. 5963-5970
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Tidskriftsartikel (refereegranskat)abstract
- Chlordane was used as an insecticide for half a century until its withdrawal from the world market in 1997. Trans- and cis-chlordane (TC, CC) are racemic in the technical product, but undergo enantio selective degradation in soil to leave nonracemic residues. In most cases, the (+) enantiomer of TC and the (-) enantiomer of CC are depleted, leading to enantiomer fractions, EF = (+)/[(+) + (-)], that are < 0.500 for TC and > 0.500 for CC. Nonracemic EFs of TC and CC, showing the same degradation preference as soils, were found in 1998-2001 air samples from stations in Arctic Canada and Finland, and on the west coast of Sweden. Environmental samples representing different time periods of chlordane history were also examined in: (a) archived atmospheric deposition samples collected in Sweden, Slovakia and Iceland in 1971-1973, (b) soils from southern Sweden sampled in 2001 and (c) a laminated lake sediment core from the Canadian Arctic representing similar to50 years of accumulation. TC and CC were racemic or nearly so in the historical atmospheric deposition samples and nonracemic in the Swedish soils. The EF of TC in the dated take sediment core decreased from nearly racemic in the past to nonracemic in recent times. These observations suggest that sources of chlordane to the atmosphere have changed over time and are now influenced to a greater extent by emission from soils.
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| 3. |
- Magnusson, Kerstin, 1957, et al.
(författare)
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Contamination and correlation with toxicity of sediment samples from the Skiagerrak and Kattegat
- 1996
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Ingår i: Journal of Sea Research. - 1385-1101. ; 35:1-3, s. 223-234
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Tidskriftsartikel (refereegranskat)abstract
- The pollution state in the Skagerrak and Kattegat was investigated by determination of pollutant concentrations and toxicity of sediment samples from 11 stations in the area. A comparison was made with the sediment from a reference site near the Faroe Islands. Polycyclic aromatic hydrocarbons (PAH) and organochlorines were determined in whole sediment and heavy metals and ammonia were analysed in filtered pore water. Toxicity was bioassayed in whole sediment with Nitocra spinipes and Daphnia magna, in pore water with Mytilus edulis larvae and in solvent extracts from sediment with tests measuring etoxyresorufin-O-deethylase (EROD) activity in Oncorhyncus mykiss and rate of denitrification. Sites close to Goteborg and in an area from the Oslo fjord to the Norwegian Trench were most polluted. Sediment from the Faroe Islands was least polluted and also least toxic. Multivariate statistical analysis indicates that the different tests were sensitive to different kinds of pollutants. Effects on mussel larvae correlated strongest with the occurrence of ammonia, manganese, cadmium and PAHs, Nitocra with alpha-hexachlorocyclohexane (HCH) and p,p'-DDD, Daphnia with arsenic and gamma-HCH, fish EROD activity with benzo[ghi]perylene and unknown compounds associated with organic carbon, and denitrification with chlordanes, dieldrin and a few PAHs. The results indicate that sampling sites close to Goteborg are so polluted that harmful effects on the ecosystem probably occur.
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