S.12.02 Targeting VGLUT2 in dopamine neurons affects the brain reward system
Åsa Wallén‐MackenzieEmma ArvidssonE. RestrepoSonja JohannEmelie PerlandKarin NordenankarKlas KullanderJohan AlsiöRichardson N. Leão
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Aethalometer
Levoglucosan
Angstrom
Abstract. With the present demand on fast and inexpensive aerosol source apportionment methods, the Aethalometer model was evaluated for a full seasonal cycle (June 2014–June 2015) at a rural atmospheric measurement station in southern Sweden by using radiocarbon and levoglucosan measurements. By utilizing differences in absorption of UV and IR, the Aethalometer model apportions carbon mass into wood burning (WB) and fossil fuel combustion (FF) aerosol. In this study, a small modification in the model in conjunction with carbon measurements from thermal–optical analysis allowed apportioned non-light-absorbing biogenic aerosol to vary in time. The absorption differences between WB and FF can be quantified by the absorption Ångström exponent (AAE). In this study AAEWB was set to 1.81 and AAEFF to 1.0. Our observations show that the AAE was elevated during winter (1.36 ± 0.07) compared to summer (1.12 ± 0.07). Quantified WB aerosol showed good agreement with levoglucosan concentrations, both in terms of correlation (R2 = 0.70) and in comparison to reference emission inventories. WB aerosol showed strong seasonal variation with high concentrations during winter (0.65 µg m−3, 56 % of total carbon) and low concentrations during summer (0.07 µg m−3, 6 % of total carbon). FF aerosol showed less seasonal dependence; however, black carbon (BC) FF showed clear diurnal patterns corresponding to traffic rush hour peaks. The presumed non-light-absorbing biogenic carbonaceous aerosol concentration was high during summer (1.04 µg m−3, 72 % of total carbon) and low during winter (0.13 µg m−3, 8 % of total carbon). Aethalometer model results were further compared to radiocarbon and levoglucosan source apportionment results. The comparison showed good agreement for apportioned mass of WB and biogenic carbonaceous aerosol, but discrepancies were found for FF aerosol mass. The Aethalometer model overestimated FF aerosol mass by a factor of 1.3 compared to radiocarbon and levoglucosan source apportionment. A performed sensitivity analysis suggests that this discrepancy can be explained by interference of non-light-absorbing biogenic carbon during winter. In summary, the Aethalometer model offers a cost-effective yet robust high-time-resolution source apportionment at rural background stations compared to a radiocarbon and levoglucosan alternative.
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The objective of this work was to assess the yearly contribution of fossil fuel combustion (BCff) and wood burning (BCwb) to equivalent black carbon (eBC) concentrations, in Athens, Greece. Measurements were conducted at a suburban site from March 2013 to February 2014 and included absorption coefficients at seven wavelengths and PM2.5 chemical composition data for key biomass burning markers, i.e., levoglucosan, potassium (K) and elemental and organic carbon (EC, OC). A well-documented methodology of corrections for aethalometer attenuation coefficients was applied with a resulting annual dataset of derived absorption coefficients for the suburban Athens’ atmospheric aerosol. The Aethalometer model was applied for the source apportionment of eBC. An optimum Ångström exponent for fossil fuel (αff) was found, based on the combined use of the model with levoglucosan data. The measured eBC concentrations were equal to 2.4 ± 1.0 μg m−3 and 1.6 ± 0.6 μg m−3, during the cold and the warm period respectively. The contribution from wood burning was significantly higher during the cold period (21 ± 11%, versus 6 ± 7% in the warm period). BCff displayed a clear diurnal pattern with a morning peak between 8 and 10 a.m. (during morning rush hour) and a second peak during the evening and night hours, due to the shallowing of the mixing layer. Regression analysis between BCwb concentrations and biomass burning markers (levoglucosan, K and OC/EC ratio) supported the validity of the results.
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Abstract. Airborne concentrations of the wood smoke tracers, levoglucosan and fine potassium have been measured at urban and rural sites in the United Kingdom alongside measurements with a multi-wavelength aethalometer. The UK sites, and especially those in cities, show low ratios of levoglucosan to potassium in comparison to the majority of published data. It is concluded that there may be two distinct source types, one from wood stoves and fireplaces with a high organic carbon content, best represented by levoglucosan, the other from larger, modern appliances with a very high burn-out efficiency, best represented by potassium. Based upon levoglucosan concentrations and a conversion factor of 11.2 from levoglucosan to wood smoke mass, average concentrations of wood smoke including winter and summer sampling periods are 0.23 μg m−3 in Birmingham and 0.33 μg m−3 in London, well below concentrations typical of other northern European urban areas. There may be a further contribution from sources of potassium-rich emissions amounting to an estimated 0.08 μg m−3 in Birmingham and 0.30 μg m−3 in London. Concentrations were highly correlated between two London sites separated by 4 km suggesting that a regional source is responsible. Data from the aethalometer are either supportive of these conclusions or suggest higher concentrations, depending upon the way in which the data are analysed.
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Aethalometer
Levoglucosan
TRACER
Carbon fibers
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Airborne concentrations of the wood smoke tracers,
levoglucosan and fine potassium have been measured
at urban and rural sites in the United Kingdom alongside
measurements with a multi-wavelength aethalometer. The
UK sites, and especially those in cities, show low ratios
of levoglucosan to potassium in comparison to the majority
of published data. It is concluded that there may be two
distinct source types, one from wood stoves and fireplaces
with a high organic carbon content, best represented by levoglucosan,
the other from larger, modern appliances with a
very high burn-out efficiency, best represented by potassium.
Based upon levoglucosan concentrations and a conversion
factor of 11.2 from levoglucosan to wood smoke mass, average
concentrations of wood smoke including winter and
summer sampling periods are 0.23 μgm−3 in Birmingham
and 0.33 μgm−3 in London, well below concentrations typical
of other northern European urban areas. There may be
a further contribution from sources of potassium-rich emissions
amounting to an estimated 0.08 μgm−3 in Birmingham
and 0.30 μgm−3 in London. Concentrations were highly correlated
between two London sites separated by 4 km suggesting
that a regional source is responsible. Data from the
aethalometer are either supportive of these conclusions or
suggest higher concentrations, depending upon the way in
which the data are analysed.
Levoglucosan
Aethalometer
Stove
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Abstract. Airborne concentrations of the wood smoke tracers, levoglucosan and fine potassium have been measured at urban and rural sites in the United Kingdom alongside measurements with a multi-wavelength aethalometer. The UK sites, and especially those in cities, show low ratios of levoglucosan to potassium in comparison to the majority of published data. It is concluded that there may be two distinct source types, one from wood stoves and fireplaces with a high organic carbon content, best represented by levoglucosan, the other from larger, modern appliances with a very high burn-out efficiency, best represented by potassium. Based upon levoglucosan concentrations and a conversion factor of 11.2 from levoglucosan to wood smoke mass, average concentrations of wood smoke including winter and summer sampling periods are 0.23 μg m−3 in Birmingham and 0.33 μg m−3 in London, well below concentrations typical of other northern European urban areas. There may be a further contribution from sources of potassium-rich emissions amounting to an estimated 0.08 μg m−3 in Birmingham and 0.30 μg m−3 in London. Concentrations were highly correlated between two London sites separated by 4 km suggesting that an advected regional source is responsible. Data from the aethalometer are either supportive of these conclusions or suggest higher concentrations, depending upon the way in which the data are analysed.
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Aethalometer
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Ahead of measures to incentivise wood heating, the current level of wood burning in London was assessed by two tracer methods; i) a six week campaign of daily measurements of levoglucosan along a 38 km transect across the city during winter 2010, ii) a three year (2009–2011) measurement programme of black carbon and particulate matter from wood burning using differential IR and UV absorption by Aethalometer. Mean winter levoglucosan concentrations were 160 ± 17 ng m−3 in central London and 30 ± 26 ng m−3 greater in the suburbs, with good temporal correlation (r2 = 0.68–0.98) between sampling sites. Sensitivity testing found that the aethalometer wood burning tracer method was more sensitive to the assumed value of the Ångström coefficient for fossil fuel black carbon than it was to the Ångström coefficient for wood burning PM, and that the model was optimised with Ångström coefficient for fossil fuel black carbon of 0.96. The aethalometer and levoglucosan estimates of mean PM from wood burning were in good agreement during the winter campaign; 1.8 μg m−3 (levoglucosan) and 2.0 μg m−3 (aethalometer); i.e. between 7% and 9% of mean PM10 across the London transect. Analysis of wood burning tracers with respect to wind speed suggested that wood burning PM was dominated by sources within the city. Concentrations of aethalometer and levoglucosan wood burning tracers were a greatest at weekends suggesting discretionary or secondary domestic wood burning rather than wood being used as a main heating source. Aethalometer wood burning tracers suggests that the annual mean concentration of PM10 from wood burning was 1.1 μg m−3. To put this in a policy context, this PM10 from wood burning is considerably greater than the city-wide mean PM10 reduction of 0.17 μg m−3 predicted from the first two phases of the London Low Emission Zone which was introduced to reduce PM from traffic sources.
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Levoglucosan
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Abstract. With the present demand on fast and inexpensive aerosol source apportionment methods, the aethalometer model was evaluated for a full seasonal cycle (June 2014–June 2015) at a rural atmospheric measurement station in southern Sweden by using radiocarbon and levoglucosan measurements. By utilizing differences in absorption of UV and IR, the aethalometer model apportions carbon mass into wood burning (WB) and fossil fuel combustion (FF) aerosol. In this study, a small modification in the model in conjunction with carbon measurements from thermal-optical analysis allowed apportioned non-light absorbing biogenic aerosol to vary in time. The absorption differences between WB and FF can be quantified by the absorption Ångström exponent (AAE). In this study AAEWB was set to 1.81 and AAEFF to 1.0. Our observations show that AAE was elevated during winter (1.36 ± 0.07) compared to summer (1.12 ± 0.07). Quantified WB aerosol showed good agreement with levoglucosan concentrations, both in terms of correlation (R2 = 0.70) and in comparison to reference emission inventories. WB aerosol showed strong seasonal variation with high concentrations during winter (0.65 µg m−3, 56 % of total carbon) and low concentrations during summer (0.07 µg m−3, 6 % of total carbon). FF aerosol showed less seasonal dependence, however black carbon (BC) FF showed clear diurnal patterns corresponding to traffic rush hour peaks. The presumed non-light absorbing biogenic carbonaceous aerosol concentration was high during summer (1.04 µg m−3, 72 % of total carbon) and low during winter (0.13 µg m−3, 8 % of total carbon). Aethalometer model results were further compared to radiocarbon and levoglucosan source apportionment results. The comparison displayed good agreement in apportioned mass of WB and biogenic carbonaceous aerosol but discrepancies were found for FF aerosol mass. The aethalometer model overestimated FF aerosol mass by a factor of 1.3 compared to radiocarbon and levoglucosan source apportionment. This discrepancy may possibly be explained by a relatively low R2 value in the fit of FF aerosol light absorption to carbon mass concentration. In summary, the aethalometer model offers a cost-effective, yet robust high-time resolution source apportionment at rural background stations compared to a radiocarbon and levoglucosan alternative.
Aethalometer
Levoglucosan
Apportionment
Seasonality
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Citations (11)
We characterized residential biomass burning contributions to fine particle concentrations via multiple methods at Fyfe Elementary School in Las Vegas, Nevada, during January 2008: with levoglucosan on quartz fiber filters; with water soluble potassium (K+) measured using a particle-into-liquid system with ion chromatography (PILS-IC); and with the fragment C2H4O2+ from an Aerodyne High Resolution Aerosol Mass Spectrometer (HR-AMS). A Magee Scientific Aethalometer was also used to determine aerosol absorption at the UV (370 nm) and black carbon (BC, 880 nm) channels, where UV-BC difference is indicative of biomass burning (BB). Levoglucosan and AMS C2H4O2+ measurements were strongly correlated (r2 = 0.92); K+ correlated well with C2H4O2+ (r2 = 0.86) during the evening but not during other times. While K+ may be an indicator of BB, it is not necessarily a unique tracer, as non-BB sources appear to contribute significantly to K+ and can change from day to day. Low correlation was seen between UV-BC difference and other indicators, possibly because of an overwhelming influence of freeway emissions on BC concentrations. Given the sampling location—next to a twelve-lane freeway—urban-scale biomass burning was found to be a surprisingly large source of aerosol: overnight BB organic aerosol contributed between 26% and 33% of the organic aerosol mass.
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Las vegas
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