A biogenic volatile organic compound emission inventory for Hong Kong

Autor: Jeanie Kin-Yin Tsui, Feng Chen, Alex Guenther, Wing-Kin Yip
Rok vydání: 2009
Předmět:
Zdroj: Atmospheric Environment. 43:6442-6448
ISSN: 1352-2310
DOI: 10.1016/j.atmosenv.2008.01.027
Popis: Atmospheric Environment 43 (2009) 6442–6448 Contents lists available at ScienceDirect Atmospheric Environment journal homepage: www.elsevier.com/locate/atmosenv A biogenic volatile organic compound emission inventory for Hong Kong Jeanie Kin-Yin Tsui a , Alex Guenther b , Wing-Kin Yip a , Feng Chen a, * a b School of Biological Sciences, The University of Hong Kong, Pokfulam Road, Hong Kong, China National Center for Atmospheric Research, Atmospheric Chemistry Division, CO 80307-3000, USA a r t i c l e i n f o a b s t r a c t Article history: Received 13 August 2007 Received in revised form 14 January 2008 Accepted 14 January 2008 Biogenic volatile organic compounds (BVOCs) in the atmosphere react to form ozone and secondary organic aerosols, which deteriorate air quality, affect human health, and indirectly influence global climate changes. The present study aims to provide a preliminary assessment of BVOC emissions in Hong Kong (HKSAR). Thriteen local tree species were measured for their isoprene emission potential. Tree distribution was estimated for country park areas based on field survey data. Plant emission data obtained from measurements and the literature, tree distribution estimation data, land use information, and meteorological data were combined to estimate annual BVOC emissions of 8.610 9 g C for Hong Kong. Isoprene, monoterpenes, and other VOCs contributed about 30%, 40%, and 30% of the estimated total annual emissions, respectively. Although hundreds of plant species are found in Hong Kong country parks, the model results indicate that only 10 tree species contribute about 76% of total annual VOC emissions. Prominent seasonal and diurnal variations in emissions were also predicted by the model. The present study lays a solid foundation for future local research, and results can be applied for studying BVOC emissions in nearby southern China and Asian regions that share similar climate and plant distributions. O 2008 Elsevier Ltd. All rights reserved. Keywords: Hong Kong BVOC Isoprene Monoterpenes Emission modeling 1. Introduction Air pollution is drawing more attention than ever before from the Government as well as the general public of Hong Kong, as various negative impacts of poor air quality have been recognized, ranging from increased incidents of pulmonary diseases in the population, to its adverse effects on economy and tourism. Volatile organic compounds (VOCs) play an important role in air pollution in Hong Kong. VOC emissions from anthropogenic sources (AVOCs), such as power plant and road traffic have been well studied (e.g., Guo et al., 2007). However, little is known about VOC emissions from biogenic sources in Hong Kong. Vegetation is the primary source of biogenic volatile organic compounds (BVOCs) which include terpenoids (e.g., isoprene and monoterpenes), hexenal family compounds (hexenals, hexenols, and hexenyl esters), methanol, and acetone (Guenther et al., 2000). In the presence of sunlight and nitrogen oxides (NO x ), reaction of VOCs contributes to the formation of ozone (O 3 ) (Atkinson, 2000; Fuentes et al., 2000). The impact of BVOC on O 3 formation becomes more prominent in summer, when both photochemical activity and BVOC emissions reach the peak. * Corresponding author. Tel.: þ852 2299 0309; fax: þ852 2299 0311. E-mail address: sfchen@hkusua.hku.hk (F. Chen). 1352-2310/$ – see front matter O 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.atmosenv.2008.01.027 Tropospheric O 3 is a greenhouse gas. In addition, through its chemical impact on hydroxyl radical (OH), it modifies the lifetimes of other greenhouse gases, such as methane (CH 4 ) (IPCC, 2001). Hence, climate change is indirectly promoted by BVOC emissions. O 3 also adversely affects public health. Exposure to ozone reduces pulmonary function, causes cough and chest tightness (Abelsohn et al., 2002), and exacerbates asthma (Watson and Sheppeard, 2005). Local studies show significant association between O 3 and hospital admission due to respiratory diseases (Wong et al., 1999; Lee et al., 2006). Studies also suggest that elevated O 3 concentration would lead to increase in total, cardiovascular and respiratory mortality (Zhang et al., 2006; Zeller et al., 2006; Bell et al., 2007). Photooxidation of isoprene (Claeys et al., 2004) and mono- terpenes (Hoffmann et al., 1997; Kavouras et al., 1998) also contributes to the formation of secondary organic aerosol (SOA). Atmospheric aerosols play a critical role in climate change by modifying the radiative balance of the atmosphere by scattering or absorbing solar radiation (IPCC, 2001). It is estimated that organics contribute w20–50% of total fine aerosol mass on a global scale and as high as 90% in tropical forested areas (Andreae and Crutzen, 1997; Kanakidou et al., 2005) where biomass burning and biogenic sources dominate. Biogenic VOCs are typically more reactive than AVOCs (Abelson, 1988), and their reactivity has been estimated to be two to three times that of their counterparts from gasoline combustion (Carter, 1994).
Databáze: OpenAIRE
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