Matches in SemOpenAlex for { <https://semopenalex.org/work/W4243671566> ?p ?o ?g. }
- W4243671566 abstract "Abstract. The Kathmandu Valley in Nepal suffers from severe wintertime air pollution. Volatile organic compounds (VOCs) are key constituents of air pollution, though their specific role in the Valley is poorly understood due to insufficient data. During the SusKat-ABC (Sustainable Atmosphere for the Kathmandu Valley-Atmospheric Brown Clouds) field campaign conducted in Nepal in the winter of 2012–2013, a comprehensive study was carried out to characterize the chemical composition of ambient Kathmandu air, including the determination of speciated VOCs by deploying a Proton Transfer Reaction Time of Flight Mass Spectrometer (PTR-TOF-MS)–the first such deployment in South Asia. 71 ion peaks (for which measured ambient concentrations exceeded the 2 σ detection limit) were detected in the PTR-TOF-MS mass scan data, highlighting the chemical complexity of ambient air in the Valley. Of the 71 species, 37 were found to have campaign average concentrations greater than 200 ppt and were identified based on their spectral characteristics, ambient diel profiles and correlation with specific emission tracers as a result of the high mass resolution (m/Δm > 4200) and temporal resolution (1 min) of the PTR-TOF-MS. The highest average VOC mixing ratios during the measurement period were (in rank order): acetaldehyde (8.8 ppb), methanol (7.4 ppb), acetone (4.2 ppb), benzene (2.7 ppb), toluene (1.5 ppb), isoprene (1.1 ppb), acetonitrile (1.1 ppb), C8-aromatics (~ 1 ppb), furan (~ 0.5 ppb), and C9-aromatics (0.4 ppb). Distinct diel profiles were observed for the nominal isobaric compounds isoprene (m/z = 69.070) and furan (m/z = 69.033). Comparison with wintertime measurements from several locations elsewhere in the world showed mixing ratios of acetaldehyde (~ 9 ppb), acetonitrile (~ 1 ppb) and isoprene (~ 1 ppb) to be among the highest reported till date. Two new ambient compounds namely, formamide (m/z = 46.029) and acetamide (m/z = 60.051), which can photochemically produce isocyanic acid in the atmosphere, are reported in this study along with nitromethane (a tracer for diesel exhaust) which has only recently been detected in ambient studies. Two distinct periods were selected during the campaign for detailed analysis: the first was associated with high wintertime emissions of biogenic isoprene, and the second with elevated levels of ambient acetonitrile, benzene and isocyanic acid from biomass burning activities. Emissions from biomass burning and biomass co-fired brick kilns were found to be the dominant sources for compounds such as propyne, propene, benzene and propanenitrile which correlated strongly with acetonitrile (r2 > 0.7), a chemical tracer for biomass burning. The calculated total VOC OH reactivity was dominated by acetaldehyde (24.0 %), isoprene (20.2 %) and propene (18.7 %), while oxygenated VOCs and isoprene collectively contributed to more than 68 % of the total ozone production potential. Based on known SOA yields and measured ambient concentrations in the Kathmandu Valley, the relative SOA production potential of VOCs were: benzene > naphthalene > toluene > xylenes > monoterpenes > trimethyl-benzenes > styrene > isoprene. The first ambient measurements from any site in South Asia of compounds with significant health effects such as isocyanic acid, formamide, acetamide, naphthalene and nitromethane have been reported in this study. Our results suggest that mitigation of intense wintertime biomass burning activities, in particular point sources such biomass co-fired brick kilns, would be important to reduce the emission and formation of toxic VOCs (such as benzene and isocyanic acid) in the Kathmandu Valley and improve its air quality." @default.
- W4243671566 created "2022-05-12" @default.
- W4243671566 creator A5008074499 @default.
- W4243671566 creator A5012147883 @default.
- W4243671566 creator A5017324798 @default.
- W4243671566 creator A5039858148 @default.
- W4243671566 creator A5053994402 @default.
- W4243671566 creator A5062583827 @default.
- W4243671566 creator A5064486546 @default.
- W4243671566 creator A5080894480 @default.
- W4243671566 creator A5083426573 @default.
- W4243671566 date "2015-09-15" @default.
- W4243671566 modified "2023-10-03" @default.
- W4243671566 title "Overview of VOC emissions and chemistry from PTR-TOF-MS measurements during the SusKat-ABC campaign: high acetaldehyde, isoprene and isocyanic acid in wintertime air of the Kathmandu Valley" @default.
- W4243671566 cites W1482944906 @default.
- W4243671566 cites W1508940303 @default.
- W4243671566 cites W1563424411 @default.
- W4243671566 cites W1907185040 @default.
- W4243671566 cites W1938107539 @default.
- W4243671566 cites W1967258436 @default.
- W4243671566 cites W1968049169 @default.
- W4243671566 cites W1969189555 @default.
- W4243671566 cites W1969537981 @default.
- W4243671566 cites W1971140043 @default.
- W4243671566 cites W1976604902 @default.
- W4243671566 cites W1976887766 @default.
- W4243671566 cites W1978848700 @default.
- W4243671566 cites W1980087779 @default.
- W4243671566 cites W1983803283 @default.
- W4243671566 cites W1985009809 @default.
- W4243671566 cites W1987173854 @default.
- W4243671566 cites W1988963778 @default.
- W4243671566 cites W1989095231 @default.
- W4243671566 cites W1993945141 @default.
- W4243671566 cites W1994941127 @default.
- W4243671566 cites W1995286282 @default.
- W4243671566 cites W1995896410 @default.
- W4243671566 cites W2001022079 @default.
- W4243671566 cites W2002570697 @default.
- W4243671566 cites W2004661833 @default.
- W4243671566 cites W2005801777 @default.
- W4243671566 cites W2007004709 @default.
- W4243671566 cites W2008568527 @default.
- W4243671566 cites W2008711911 @default.
- W4243671566 cites W2008715801 @default.
- W4243671566 cites W2009106452 @default.
- W4243671566 cites W2013287304 @default.
- W4243671566 cites W2013356945 @default.
- W4243671566 cites W2014277839 @default.
- W4243671566 cites W2017686486 @default.
- W4243671566 cites W2021984751 @default.
- W4243671566 cites W2029825309 @default.
- W4243671566 cites W2031675844 @default.
- W4243671566 cites W2033230301 @default.
- W4243671566 cites W2034573983 @default.
- W4243671566 cites W2037319789 @default.
- W4243671566 cites W2040407162 @default.
- W4243671566 cites W2044499383 @default.
- W4243671566 cites W2047457654 @default.
- W4243671566 cites W2048131657 @default.
- W4243671566 cites W2053745186 @default.
- W4243671566 cites W2054861009 @default.
- W4243671566 cites W2056399136 @default.
- W4243671566 cites W2061528753 @default.
- W4243671566 cites W2068302976 @default.
- W4243671566 cites W2068780477 @default.
- W4243671566 cites W2069641008 @default.
- W4243671566 cites W2069700009 @default.
- W4243671566 cites W2070543664 @default.
- W4243671566 cites W2070896820 @default.
- W4243671566 cites W2071625349 @default.
- W4243671566 cites W2071706389 @default.
- W4243671566 cites W2072831875 @default.
- W4243671566 cites W2073363749 @default.
- W4243671566 cites W2075275228 @default.
- W4243671566 cites W2076745781 @default.
- W4243671566 cites W2078877451 @default.
- W4243671566 cites W2087592052 @default.
- W4243671566 cites W2098757498 @default.
- W4243671566 cites W2101564492 @default.
- W4243671566 cites W2107842672 @default.
- W4243671566 cites W2109962412 @default.
- W4243671566 cites W2110066415 @default.
- W4243671566 cites W2111155943 @default.
- W4243671566 cites W2113212697 @default.
- W4243671566 cites W2114601739 @default.
- W4243671566 cites W2117135487 @default.
- W4243671566 cites W2119705547 @default.
- W4243671566 cites W2120339371 @default.
- W4243671566 cites W2122574093 @default.
- W4243671566 cites W2123314968 @default.
- W4243671566 cites W2124640426 @default.
- W4243671566 cites W2125782074 @default.
- W4243671566 cites W2129460250 @default.
- W4243671566 cites W2132709466 @default.
- W4243671566 cites W2132921883 @default.
- W4243671566 cites W2136206546 @default.
- W4243671566 cites W2140674562 @default.
- W4243671566 cites W2140869764 @default.
- W4243671566 cites W2141955911 @default.