Vertical variability of volatile organic compound (VOC) levels in ambient air of high-rise apartment buildings with and without occurrence of surface inversion
Introduction
Many people in Korean urban areas live in high-rise apartment buildings. According to the Korea National Statistical Office, about 22 million people live in the eight largest cities and about 10 million of these live in high-rise apartment buildings (defined as apartment buildings with 10 or more stories). Since a vertical variation in the concentration of motor vehicle emitted pollutants has already been observed in a street canyon formed by five-story buildings (Ilgen et al., 2001) and many Korean high-rise apartment buildings are located near roadways, it is hypothesized that there may also be a vertical variation in the concentrations of motor vehicle emitted pollutants in the ambient air of high-rise apartment buildings. As such, a vertical variation in ambient air pollution will subject high-rise apartment residents to different exposure levels according to the floor. In fact, Fischer et al. (2000) already reported higher indoor and outdoor air concentrations of VOCs and particles for homes near high traffic than for homes near low traffic, plus the higher indoor concentrations for the homes near high traffic were primarily influenced by elevated outdoor concentrations. Therefore, this finding suggests that high-rise apartment residents may experience different indoor concentration levels according to the floor due to the penetration of different concentration levels of outdoor air pollutants into the interiors of the apartments. However, until now the vertical variation in urban air pollution concentrations has rarely been considered when evaluating residential exposure to urban ambient air pollutants, whereas the horizontal proximity of a residence location to urban pollution sources has already been well documented (Gelencser et al., 1997; Shah and Singh, 1988; Jo and Moon, 1999; Fischer et al., 2000).
The ambient aromatic VOCs and methyl-tertiary butyl ether (MTBE) found in urban residential areas are primarily emitted from motor vehicles and have received significant attention mainly due to their toxicity and prevalence in urban ambient air (Wallace, 1987; Lioy et al., 1994; Jo and Park, 1998; Ilgen et al., 2001). Therefore, the current study was designed to examine if the ambient concentrations of these compounds varied according to the apartment floor in the Daegu metropolitan area in Korea. The current investigation was performed before and after sunrise to include both surface inversion and non-surface inversion periods, as surface inversion is an important meteorological factor in the vertical distribution of urban air pollution. In the study, the ambient temperature, wind speed, and ambient air concentration levels of seven target VOCs were measured for low and high floors of high-rise apartment buildings. The target VOCs are known as markers for vehicle emissions: MTBE, benzene, toluene, ethylbenzene, o-xylene, m-xylene and p-xylene. According to the Korean Petroleum Corporation, the gasoline currently manufactured by all five Korean petroleum companies contains 6.0–8.0% MTBE, 0.8–2.3% benzene, 9–10% toluene, 2.1–3.5% ethylbenzene, and 3.8–4.5% xylenes by volume. Although its toxicity is still somewhat controversial, MTBE would appear to be acutely toxic (Bevan et al., 1997), chronic non-cancer toxic (Mehlman, 1998), and carcinogenic (Mehlman, 1996). Some aromatic target VOCs are also known or suspected carcinogens (IARC, 1987), such as benzene, where exposure can cause leukemia, while others have been associated with acute effects (Tancrede et al., 1987; US EPA, 1990).
Section snippets
Study area
The current study was conducted in Daegu, the third largest city in Korea with a population of 2.5 million and density of 2812 people per km2. About 1.1 million Daegu residents live in high-rise apartments. According to the statistical yearbook for Daegu (Daegu Metropolitan City, 1999), the number of vehicles registered in this area was as follows: about 447,000 passenger cars, 18,000 taxicabs, 50,000 buses (2800 public buses), 130,000 trucks, 120,000 motorcycles, and 800 special cars. Most of
Vertical concentration difference according to atmospheric stability
The ambient air concentrations measured for the low- and high-floor apartments are summarized in Table 1, according to the atmospheric stability and season. The current study classified the atmospheric stability into two cases: presence and absence of surface inversion. Surface inversion is typically defined as the period when the temperature at the surface increases with height. Therefore, the current study defined a surface-inversion period as when the average temperature measured during each
Conclusions
The current study evaluated whether ambient VOC concentrations vary according to the apartment floor in a Korean metropolitan area, while assessing the potential influence of the atmospheric stability and sampling period on the exposure of apartment residents. The present investigation was performed for two seasonal extremes: winter and summer. The atmospheric stability included both inversion and non-inversion periods, and the sampling included before-sunrise and after-sunrise periods. The
Acknowledgements
This study could not have been accomplished without the dedicated support of the residents of the 30 surveyed apartment buildings. The authors wish to thank four graduate students (J.W. Lee, K.H. Park, J.W. Oh, and J.K. Kim) from the Department of Environmental Engineering, Kyungpook National University, for their sample collecting and/or analyses. We would also like to thank the reviewers for their thoughtful corrections and valuable suggestions. This work was supported by a Korea Research
References (22)
- et al.
VOC source identification from personal and residential indoor, outdoor and workplace microenvironment samples in EXPOLIS-Helsinki, Finland
Atmospheric Environment
(2001) - et al.
Traffic-related differences in outdoor and indoor concentrations of particles and volatile organic compounds in Amsterdam
Atmospheric Environment
(2000) - et al.
Aromatic hydrocarbons in the atmospheric environmentPart I. Indoor versus outdoor sources the influence of traffic
Atmospheric Environment
(2001) - et al.
Housewives’ exposure to volatile organic compounds relative to proximity to roadside service stations
Atmospheric Environment
(1999) - et al.
The carcinogenic risk of some organic vapors indoorsa theoretical survey
Atmospheric Environment
(1987) - et al.
Review of volatile organic compound source apportionment by chemical mass balance
Atmospheric Environment
(2001) - et al.
Developmental toxicity evaluation of methyl tertiary-butyl ether (MTBE) by inhalation in mice and rabbits
Journal of Applied Toxicology
(1997) Carbon Monoxide and Non-FTP Ambient Temperature
(1981)- Daegu Metropolitan City, 1999. Statistical Yearbook of Daegu....
- et al.
Comparison of emission inventory and ambient concentration ratios of CO, NMOG, and NOx in California’s south coast air basin
Journal of the Air and Waste Management Association
(1992)
Toluene–benzene concentration ratio as a tool for characterizing the distance from vehicular emission sources
Environmental Science and Technology
Cited by (17)
Vertical profiles of biogenic volatile organic compounds as observed online at a tower in Beijing
2020, Journal of Environmental Sciences (China)An overview of the development of vertical sampling technologies for ambient volatile organic compounds (VOCs)
2019, Journal of Environmental ManagementCitation Excerpt :Therefore, various VOC air samplers have been developed as summarized briefly in Table 1. In the 1990s, the adsorbent cartridges filled with activated charcoal were employed extensively as they were attached on tethered balloons, towers and high-rise buildings (Helmig et al., 1998; Jo and Kim, 2002; Glaser et al., 2003; Jo et al., 2003; Greenberg et al., 2004; Evtyugina et al., 2006). Teflon and Tedlar bags (Andronache et al., 1994; Davis et al., 1994; Guenther et al., 1996a, 1996b, 1996c; Greenberg et al., 1999; Isebrands et al., 1999; Sangiorgi et al., 2011; Tsai et al., 2012; Yang et al., 2013; Sun et al., 2018) can be used to collect air samples, and the samples are sent to the laboratory for instrumental analysis using standard methods, e.g. TO-14A and TO-15 issued by USEPA (USEPA, 1999a, 1999b).
Vertical stratification of volatile organic compounds and their photochemical product formation potential in an industrial urban area
2018, Journal of Environmental ManagementCitation Excerpt :In this study, the inversion layer seemed to trap air pollutants emitted from the ground-level sources and accumulated at the inversion (Fig. 2a). Jo and Kim (2002) reported the inversion layer had a similar effect on vertical BTEX (benzene, toluene, ethylbenzene, and xylene) distribution in Daegu, Korea. During non-inversion periods, BTEX concentrations between high floors (56–60 m) and low floors (4–8 m) showed insignificant differences.
Vertical variation of PM<inf>2.5</inf> mass and chemical composition, particle size distribution, NO<inf>2</inf>, and BTEX at a high rise building
2018, Environmental PollutionCitation Excerpt :All the other studies were carried out in Asian countries. Jo and Kim (2002) investigated thirty apartment buildings in Korea with 10 or more storeys in both winter and summer. They found lower concentrations of BTEX (about 20%–30%) at higher floors compared to lower floors with no marked differences between seasons.
Land use regression as method to model air pollution. Previous results for Gothenburg/Sweden
2015, Procedia EngineeringAircraft measurements of BTEX compounds around Beijing city
2013, Atmospheric EnvironmentCitation Excerpt :They have already aroused concern for their negative healthy impacts on urban residents (Zhang et al., 2012a) and for their influence in atmospheric chemistry (Barletta et al., 2008), and extensive investigations of BTEX have been carried out at ground level (Zhang et al., 2012b) or indoors (Ilgen et al., 2001). A few studies also investigated the vertical distribution of BTEX on high buildings (Jo and Kim, 2002), meteorological tower (Mao et al., 2008), or by balloon (Wőhrnschimmel et al., 2006) with height below 300 m. A number of large-scale aircraft measurements on atmospheric pollutants have been carried out by some organizations such as TROZ (Fabian and Pruchniewicz, 1977), GASP (Nastrom, 1979), POLLUMET (Lehning et al., 1996), PEACAMPOT (Hatakeyama et al., 1995), Trace-P (Jacob et al., 2003), however, the vertical distribution of BTEX measured by aircraft was rarely reported.