Volatile Organic Compounds In China Research Articles

Spatial–Temporal Characteristics, Source Apportionment, and Health Risks of Atmospheric Volatile Organic Compounds in China: A Comprehensive Review

Volatile organic compounds (VOCs) are ubiquitous in the atmosphere, posing significant adverse impacts on air quality and human health. However, current research on atmospheric VOCs mainly focuses on specific regions or industries, without comprehensive national-level analysis. In this study, a total of 99 articles on atmospheric VOCs in China published from 2015 to 2024 were screened, and data on their concentrations, source apportionment, and health risks were extracted and summarized. The results revealed that the annual average concentrations of TVOCs and their groups in China generally increased and then decreased between 2011 and 2022, peaking in 2018–2019. A distinct seasonal pattern was observed, with the highest concentrations occurring in winter, followed by autumn, spring, and summer. TVOC emissions were highly concentrated in northern and eastern China, mainly contributed by alkanes and alkenes. Source apportionment of VOCs indicated that vehicle sources (32.9% ± 14.3%), industrial emissions (18.0% ± 12.8%), and other combustion sources (13.0% ± 13.0%) were the primary sources of VOCs in China. There was a significant positive correlation (p < 0.05) between the annual mean VOC concentration and population size, and a notable negative correlation (p < 0.05) with GDP per capita. Atmospheric VOCs had no non-carcinogenic risk (HI = 0.5) but exhibited a probable carcinogenic risk (7.5 × 10−5), with relatively high values for 1,2-dibromoethane, 1,2-dichloroethane, and naphthalene. The health risk was predominantly driven by halocarbons. These findings are essential for a better understanding of atmospheric VOCs and for developing more targeted VOC control measures.

Daily Exposure to Environmental Volatile Organic Compounds Triggers Oxidative Damage: Evidence from a Large-Scale Survey in China.

Volatile organic compounds (VOCs) are ubiquitous environmental pollutants and have been implicated in adverse health outcomes. In this study, concentrations of 11 VOC metabolites (mVOCs) and three oxidative stress biomarkers (8-oxo-7,8-dihydro-2'-deoxyguanosine, 8-oxo-7,8-dihydro-guanosine, and dityrosine) were determined in 205 urine samples collected from 12 cities across mainland China. Urinary ∑11mVOC concentrations ranged from 498 to 1660 ng/mL, with a geometric mean (GM) value of 1070 ng/mL. The factorial analysis revealed that cooking, solvents, and vehicle emissions were the three primary sources of VOC exposure. A significant regional variation was clearly found in ∑11mVOC concentrations across four regions in China, with high urine VOC concentrations found in North and South China (GM: 1450 and 1340 ng/mL). The multiple linear regression model revealed that most mVOCs were significantly positively correlated with three oxidative stress markers (β range: 0.06-0.22). Mixture effect regression showed that isoprene, crotonaldehyde, acrolein, and benzene were the strongest contributors to oxidative stress. Approximately 80% of the participants have HQ values greater than 1.0 for 1,3-butadiene and benzene, suggesting that their exposure doses were close to potential adverse health effects. Our findings provide comprehensive information on human exposure and potential health risks of VOCs in China.

Indoor Volatile Organic Compounds: Concentration Characteristics and Health Risk Analysis on a University Campus.

Volatile organic compounds (VOCs) are major indoor air pollutants that contain several toxic substances. However, there are few studies on health risk assessments of indoor VOCs in China. This study aimed to determine the concentration characteristics of VOCs on college campuses by collecting VOC samples from different locations on campus during different seasons combined with the exposure times of college students in each location obtained from a questionnaire survey to assess the possible health risks. The highest total VOC concentration (254 ± 101 µg/m3) was in the dormitory. The seasonal variation of TVOC concentrations was related to the variation of emission sources in addition to temperature. Health risk assessments of VOCs were evaluated using non-carcinogenic and carcinogenic risk values, represented by hazard quotient (HQ) and lifetime cancer risk (LCR), respectively. The non-carcinogenic risks at all sampling sites were within the safe range (HQ < 1). Dormitories had the highest carcinogenic risk, whereas the carcinogenic risk in the other three places was low (with LCR < 1.0 × 10-6). Moreover, 1,2-dichloroethane was identified as a possible carcinogenic risk substance in the dormitory due to its high LCR (1.95 × 10-6). This study provides basic data on health risks in different locations on campus and a basis for formulating measures to improve people's living environments.

Indoor exposure levels and risk assessment of volatile organic compounds in residences, schools, and offices in China from 2000 to 2021: A systematic review.

The last two decades have witnessed rapid urbanization and economic growth accompanied by severe indoor air pollution of volatile organic compounds (VOCs) in China. However, indoor VOC pollution across China has not been well characterized and documented. This study is a systematic review of field measurements of eight target VOCs (benzene, toluene, xylenes, acetaldehyde, p-dichlorobenzene, butadiene, trichloroethylene, and tetrachloroethylene) in residences, offices, and schools in China from 2000 to 2021. The results show that indoor pollution of benzene, toluene, and xylenes has been more serious in China than in other countries. Spatiotemporal distribution shows lower indoor VOC levels in east and south-east regions and a declining trend from 2000 to 2021. Moving into a dwelling more than 1 year after decoration and improving ventilation could significantly reduce exposure to indoor VOCs. Reducing benzene exposure is urgently needed because it is associated with greater health risks (4.5 × 10-4 for lifetime cancer risk and 8.3 for hazard quotient) than any other VOCs. The present study enriches the database of indoor VOC levels and provides scientific evidence for improving national indoor air quality standards as well as estimating the attributable disease burden caused by VOCs in China.

Quantitation study on VOC emissions and their reduction potential for coking industry in China: Based on in-situ measurements on treated and untreated plants

Currently, the characteristics of volatile organic compounds (VOC) released from coking industry are still vague, and the widely used VOC emission factors (EFs) were still from the measurements of 1990s. Hence, focusing on coking industry, we conducted an in-situ measurement campaign in several typical plants, developed a set of VOC EFs for various release units, and estimated the current emission amounts and future reduction potentials of VOC in China. The measurements show that the levels of VOC in stationary units were 63.82–9563.93 μg·m−3, and those surrounding fugitive units were 111.37–1436.36 μg·m−3. VOC emissions from stationary units were directly calculated, which deducing EFs of 11.57, 15.51, 127.13, 0.28, 0.16 g·t−1 coke respectively for coke charging, coke pushing, coke oven chimney, dry quenching, and wastewater treatment processes. Meanwhile, VOC emissions from fugitive units were simulated following the inverse dispersion method, which achieving EFs of 443.34 ± 66.31, 352.12 ± 65.81, and 718.56 ± 132.69 g·t−1 coke respectively for the coke oven leakage, byproduct recovery with VOC treatment system, and byproduct recovery without VOC treatment system. Generally, the coking plants installing VOC treatment system had total VOC EF of 953.76 g·t−1 coke, about 37.1% lower than those never considering VOC treatment (1516.25 g·t−1 coke). According to these developed EFs, the VOC emission amount from coking industry in China were estimated, slightly decreasing from 623.54 to 578.17 Gg per year, although the coke production increasing from 410.86 to 418.26 Tg during 2015–2019. In future, according to the national industrial policies, regulations and standards, technical guidelines, the VOC reduction potential of this industry in China could reach 336.9 Gg, to which headstream adjustment, process improvement, and end-of-pipe control contributed about 21.4%, 31.6%, and 47.0%, respectively.

A review of whole-process control of industrial volatile organic compounds in China

Volatile organic compounds (VOCs) play an important role in the formation of ground-level ozone and secondary organic aerosol (SOA), and they have been key issues in current air pollution prevention and control in China. Considerable attention has been paid to industrial activities due to their large and relatively complex VOCs emissions. The present research aims to provide a comprehensive review on whole-process control of industrial VOCs, which mainly includes source reduction, collection enhancement and end-pipe treatments. Lower VOCs materials including water-borne ones are the keys to source substitution in industries related to coating and solvent usage, leak detection and repair (LDAR) should be regarded as an efficient means of source reduction in refining, petrochemical and other chemical industries. Several types of VOCs collection methods such as gas-collecting hoods, airtight partitions and others are discussed, and airtight collection at negative pressure yields the best collection efficiency. Current end-pipe treatments like UV oxidation, low-temperature plasma, activated carbon adsorption, combustion, biodegradation, and adsorption-combustion are discussed in detail. Finally, several recommendations are made for future advanced treatment and policy development in industrial VOCs emission control.

Characterization of Volatile Organic Compounds (VOCs) Using Mobile Monitoring Around the Industrial Parks in the Yangzte River Delta Region of China

Volatile organic compounds (VOCs) play important roles in the formation of ozone and fine particles in the troposphere. Industrial parks emit significant amounts of VOCs in China, while few studies have characterized them. In the present study, a mobile platform was employed to measure the levels and composition VOCs around industrial parks in the Yangzte River Delta region. The average concentration of VOCs ranged from 39 μg·m-3 (5% percentile) to 533 μg·m-3 (95% percentile) with an average of 183 μg·m-3, which was three times that of ambient concentrations. Maximum VOC concentrations ranged from 307 μg·m-3 (5% percentile) to 12006 μg·m-3 (95% percentile) with an average of 2812 μg·m-3. The frequency of abnormal peak values was as high as 64% across all the industrial parks, of which toluene (32%), xylene (18%), benzene (9%), and>C9 aromatics (19%) were the most common species. Differences in VOC characteristics were observed among the different types of industrial parks. Specifically, highest concentrations of VOCs were observed in textile industrial parks followed by chemical, painting, and petrochemical industrial parks, and VOC concentrations in electronics industrial parks were the lowest. Importantly, species measured using the mobile platform only contributed~50% of VOCs present in ambient samples, indicating that the concentrations of VOCs in the industrial parks were underestimated overall. These results can inform measures to control VOC pollution in industrial parks in China.

Emission Inventory and Emission Factors of Volatile Organic Compounds (VOCs) from Architectural Adhesives

Architectural decoration is an important anthropogenic emission source of VOCs in China, and there are few studies on the emission of VOCs from architectural adhesives. In this study, the VOCs content level and emission factors of various architectural adhesives were measured and then, a VOC emission inventory of architectural adhesives in China from 2013 to 2017 was established by a top-down emission factor method. Results showed that the comprehensive VOCs emission factor of architectural adhesives was 97.0 kg·t-1, of which 543 kg·t-1 was from solvent-based architectural adhesives, 45 kg·t-1 was from water-based architectural adhesives, and 63 kg·t-1 was from bulk architectural adhesives. The VOCs emissions from architectural adhesives were 165 kt, 181 kt, 188 kt, 201 kt, and 219 kt from 2013 to 2017 in China. The contribution of VOCs emission of various disparate architectural adhesives was 25.5%, 23.6%, and 50.9% for water-based, bulk, and solvent-based types, respectively. Shandong, Jiangsu, Zhejiang, Sichuan, Guangdong, Henan, Yunnan, and Fujian provinces contributed significant amounts, with a total emission of 120 kt in 2017, accounting for nearly 55% of the total VOCs emission for architectural adhesives.

Comprehensive characterization and health assessment of occupational exposures to volatile organic compounds (VOCs) in Xi'an, a major city of northwestern China

The personal exposure to volatile organic compounds (VOCs) was determined in five occupational groups (including printing shop employees, office workers, furniture store employees, bus and taxi drivers) in the capital city of Xi'an in northwest China. The highest personal exposure concentration (258.7 ± 10.0 μg m−3) to the 64 Air Toxics VOCs classified by the United States Environmental Protection Agency (U.S.EPA), as well as associated health risk potential, were seen in the furniture store employees. These could be attributed to off-gassing from brand new furniture and volatiles from cleaning reagents. Aromatic species were the dominant class in the personal exposure samples collected from the groups of printing shop employees, office workers, and bus and taxi drivers, with the concentrations of 49.8–74.4 μg m−3 and mass compositions of 34.8–43.2% of the sum of the 64 Air Toxics for the cases studied. The highest personal exposure to carbonyls (C≥3) of 100.4 ± 25.6 μg m−3 and composition of 38.8% were again seen in the furniture store employees. The unique VOC composition profiles represented potential indoor or in-vehicle sources in each workplace. Moreover, environmental tobacco smoke (ETS) contributed to the personal exposure to many of the Air Toxics species, especially methyl butyl ketone and 1,2-dibromoethane. The cancer risks of Class 1 carcinogens of vinyl chloride, 1,3-butadiene, and benzene, were 1.4, 12, and 5.2 times, respectively, of the threshold of carcinogenicity (1 × 10−6). Acrolein showed the highest non-cancer risk which was ~150 times the acceptable level (1.0). The results could offer a scientific basis for the government to establish the occupational air quality standards to the toxic VOCs in China.

A gridded emission inventory of semi-volatile and intermediate volatility organic compounds in China

An emission inventory of precursors is a prerequisite for the simulation of secondary organic aerosol (SOA), which could provide valuable information on the evolution of precursors, formation of SOA, and its influence on fine particle (PM2.5) abundance, oxidative capacity, and climate change. However, an emission inventory of semi-volatile and intermediate volatility organic compounds (S/IVOCs), the key precursor of SOA, particularly the gridded inventory that is appropriate for input into regional air quality models, remains limited in China, leading to an incomplete understanding of S/IVOCs sources and roles in SOA formation and the atmospheric environment. Therefore, a gridded emission inventory of S/IVOCs in China for 2016 was developed based on ample source-specific measured data on emission ratios of S/IVOCs to primary organic aerosols (POA) from literatures. The total emission of S/IVOCs was estimated to be 9.6 Tg, and industry and residential sectors were major sources of S/IVOCs, with contributions of 48.0% and 30.2%, respectively. The spatial variations suggested that S/IVOC emissions were mainly distributed in the highly industrialized and urbanized regions in China, such as Beijing–Tianjin–Hebei (BTH), the Yangtze River Delta (YRD), the Pearl River Delta (PRD), and the Sichuan–Chongqing (SC) regions, though the contributions and temporal patterns varied between different regions. Furthermore, uncertainty of the emission inventory was estimated to be within the range of −66%–153%, which was mainly attributed to emission ratios of IVOCs/POA for industry, transportation, and power plants. The gridded emission inventory developed in this study can be used to estimate the emissions of S/IVOCs in different regions, and can be applied to different models for a better understanding of the environmental effects of S/IVOCs.

Volatile Organic Compound Emission Characteristics of Furniture Manufacturing Enterprises and the Influence on the Atmospheric Environment

The furniture manufacturing industry is a typical industry with high pollution, low added value, relatively outdated technology and low levels of pollution control. The process of furniture manufacturing uses a large number of paints and adhesives, which emit a great quantity of volatile organic compounds (VOCs). The furniture manufacturing industry is a key industry for the control of VOCs in China. The VOCs emission characteristics and environmental impact of the furniture manufacturing industry has been studied in this work, which could be helpful for the Chinese government when formulating VOCs pollution control policy for this industry. In this study, a typical furniture manufacturing enterprise was chosen as the object. The emission concentration level and source profile of VOCs in a typical enterprise was obtained, and an assessment of the environmental impact of furniture manufacturing was developed. The results showed that the concentration of VOCs in the workshop ranged from 9.18 to 181.58 mg·m-3, the concentration of VOCs in the stack was 30.64-155.94 mg·m-3, and the treatment efficiency was 7.43%-67.14%. The main species of VOCs in the workshop were aromatic hydrocarbons, esters, and aldehydes and ketones; the main species of VOCs in the stack are esters and aromatic hydrocarbons, followed by alkanes, and the main VOCs in the industry are sec-butyl acetate, toluene, m-xylene, methylal and ethylbenzene. The average ozone generation potential (OFP) of workshop and stack VOCs was 258.01 and 289.14 mg·m-3, respectively, and the average secondary organic aerosol generation potential (SOAFP) of workshop and stack VOCs was 148.66 and 165.31 mg·m-3, respectively. The most important contribution to the OFP and SOAFP in each emission sector is aromatic hydrocarbons. The OFP and SOAFP in the edge-sealing workshop are large and the VOCs should be controlled. The main malodorous substances at the shop boundary are sec-butyl acetate, m-xylene, butyl acetate, p-xylene, ethylbenzene, 1-ethyl-3-methylbenzene, o-xylene, and toluene; the VOCs at the factory boundary produce almost no odor pollution. Targeted enhanced control of aromatic hydrocarbons and esters should be adopted to achieve effective emission reduction of VOCs in furniture manufacturing.

Source apportionment of summertime ozone in China using a source-oriented chemical transport model

Contributions of industries, power plants, residential, transportation, open burning, and biogenic sectors to summertime ozone (O3) in China in August 2013 are quantified using an improved O3 source apportionment method implemented in a source-oriented Community Multiscale Air Quality (CMAQ) model. The new O3 source apportionment method attributes in-situ O3 formed in each time step to nitrogen oxides (NOx) and volatile organic compounds (VOCs) with a new attribution scheme that considers NOx-VOC-O3 formation sensitivity in NOx-limited, transition, and VOC-limited regimes (three regimes, 3R). This represents an improvement from the traditional O3 source apportionment models, in which O3 formation sensitivity is divided into two-regimes (2R), either NOx-limited or VOC-limited. An expanded source-oriented gas phase chemical mechanism is developed to concurrently track NOx and primary VOCs and their oxidation products from different sources. The source-resolved NO2 photolysis rates and the NO to NO2 conversion rates by peroxy radicals from the source-oriented chemical mechanism are then used to apportion O3 to NOx (O3_NOx) and VOCs (O3_VOC) from different emission sources.Industries, transportation, power plants and biogenic sources are the major emission sectors to O3. High industrial O3_NOx (8–15 ppb; 20–25% of total O3) is mainly located in north and northeast China, the Yantze River Delta (YRD) and part of the Sichuan Basin (SCB). Transportation O3_NOx accounts for 10–15% of total O3 in most urban areas. Power plants’ contributions to O3_NOx (10–15%) are mostly located in Shanxi, Shaanxi, Ningxia and part of Shandong and Jiangsu. The contribution of soil NOx to O3_NOx is highest in regions in west, central and south China with less direct anthropogenic emission influences. VOC-limited grid cells are mostly located at urban cores and large city clusters in the YRD and Pearl River Delta (PRD) regions. Biogenic and industrial sectors are the most important emission sectors that contribute to O3_VOC, accounting for more than 85% of the O3_VOC in China. In north and east provinces, more than 50% of the O3 is non-background, with the provinces in north China having higher overall O3. The Beijing-Tianjin-Hebei (BTH) region has an area-averaged 8-hr O3 of 75 ppb in August 2013 and about half is non-background. Contributions of industries, transportation, power and biogenic sources to non-background O3 are 37%, 22%, 13% and 23%, respectively. The relative contribution of biogenic emissions to non-background O3 is lower on high 8-hr O3 days. The 2R and 3R approaches show significant differences in assessing the relative importance of O3_NOx and O3_VOC, with the 2-regime approach predicting lower O3_NOx but higher O3_VOC. The new source allocation method for O3_VOC can lead to up to 10% differences for industrial and biogenic sectors.

Tropospheric volatile organic compounds in China

Photochemical smog, characterized by high concentrations of ozone (O3) and fine particles (PM2.5) in the atmosphere, has become one of the top environmental concerns in China. Volatile organic compounds (VOCs), one of the key precursors of O3 and secondary organic aerosol (SOA) (an important component of PM2.5), have a critical influence on atmospheric chemistry and subsequently affect regional and global climate. Thus, VOCs have been extensively studied in many cities and regions in China, especially in the North China Plain, the Yangtze River Delta and the Pearl River Delta regions where photochemical smog pollution has become increasingly worse over recent decades. This paper reviews the main studies conducted in China on the characteristics and sources of VOCs, their relationship with O3 and SOA, and their removal technology. This paper also provides an integrated literature review on the formulation and implementation of effective control strategies of VOCs and photochemical smog, as well as suggestions for future directions of VOCs study in China.

Ambient volatile organic compounds pollution in China

Owing to rapid economic and industrial development, China has been suffering from degraded air quality and visibility. Volatile organic compounds (VOCs) are important precursors to the formation of ground-level ozone and hence photochemical smog. Some VOCs adversely affect human health. Therefore, VOCs have recently elicited public concern and given new impetus to scientific interest. China is now implementing a series of polices to control VOCs pollution. The key to formulating policy is understanding the ambient VOCs pollution status. This paper mainly analyzes the species, levels, sources, and spatial distributions of VOCs in ambient air. The results show that the concentrations of ambient VOCs in China are much higher than those of developed countries such as the United States and Japan, especial benzene, which exceeds available standards. At the same time, the ozone formation potential (OFP) and secondary organic aerosol formation potential (SOAFP) of various VOCs are calculated. Aromatics and alkenes have much higher OFPs, while aromatics have higher SOAFP. The OFPs of ambient VOCs in the cities of Beijing, Guangzhou and Changchun are very high, and the SOAFP of ambient VOCs in the cities of Hangzhou, Guangzhou and Changchun are higher.

Method to establish the emission inventory of anthropogenic volatile organic compounds in China and its application in the period 2008–2012

Abstract A method was developed to establish a comprehensive anthropogenic VOC emission inventory in China, in which a four-level source categorization was proposed, and an emission factor determination system together with a reference database were developed. And this was applied to establish VOC emission inventories for the period 2008–2012. Results show China's anthropogenic VOC emissions increased from 22.45 Tg in 2008 to 29.85 Tg in 2012 at an annual average rate of 7.38%, with Shandong, Guangdong, Jiangsu, Zhejiang and Hebei provinces being the largest emitters. Industrial processes, transportation and solvent utilization were the key sources, accounting for 39.3%, 25.6%, and 14.9% of the total emissions in 2012, respectively. Passenger cars, biofuel combustion, coke production, field burning of biomass, and raw chemical manufacturing were the primary VOC sources nationwide. The key sources for each province were different because of the disparate industry and energy structure. China's VOC emissions displayed remarkable spatial variation, with emissions in the east and southeast regions being much larger than in the northwest, and the high emission areas mainly centered in the Bohai Economic Rim, the Yangtze River Delta, the Pearl River Delta and the Sichuan Basin. The size of high emission areas expanded over the period 2008–2012, with heavily polluted city clusters gradually emerging.

Impacts of land use and land cover changes on biogenic emissions of volatile organic compounds in China from the late 1980s to the mid-2000s: implications for tropospheric ozone and secondary organic aerosol

Based on the MEGAN (Model of Emissions of Gases and Aerosols from Nature) module embedded within the global chemical transport model (GEOS-Chem), we estimate the changes in emissions of biogenic volatile organic compounds (BVOCs) and their impacts on surface-layer O3 and secondary organic aerosols (SOA) in China between the late 1980s and the mid-2000s by using the land cover dataset derived from remote sensing images and land use survey. The land cover change in China from the late 1980s to the mid-2000s can be characterised by an expansion of urban areas (the total urban area in the mid-2000s was four times that in the late 1980s) and a reduction in total vegetation coverage by 4%. Regionally, the fractions of land covered by forests exhibited increases in southeastern and northeastern China by 10–30 and 5–15%, respectively, those covered by cropland decreased in most regions except that the farming–pastoral zone in northern China increased by 5–20%, and the factions of grassland in northern China showed a large reduction of 5–30%. With changes in both land cover and meteorological fields, annual BVOC emission in China is estimated to increase by 11.4% in the mid-2000s relative to the late 1980s. With anthropogenic emissions of O3 precursors, aerosol precursors and aerosols fixed at year 2005 levels, the changes in land cover and meteorological parameters from the late 1980s to the mid-2000s are simulated to change the seasonal mean surface-layer O3 concentrations by −4 to +6 ppbv (−10 to +20%) and to change the seasonal mean surface-layer SOA concentrations by −0.4 to +0.6 µg m−3 (−20 to +30%) over China. We find that the decadal changes in meteorological parameters had larger collective effects on BVOC emissions and surface-layer concentrations of O3 and SOA than those in land cover and land use alone. We also perform a sensitivity simulation to compare the impacts of changes in anthropogenic emissions on concentrations of O3 and SOA with those of the changes in meteorological parameters and land cover.

Historical industrial emissions of non-methane volatile organic compounds in China for the period of 1980–2010

This paper presents a new classification of industrial sector on basis of a source-tracing method for the historical industrial emissions of non-methane volatile organic compounds (NMVOCs). The industrial sources were divided into four major source categories: production of NMVOCs, storage and transport, industrial processes using NMVOCs as raw materials, and processes using NMVOCs-containing products. Multiyear emission inventories of NMVOCs from industrial sources were established for the period of 1980–2010 in China, covering 98 contributing industrial sources. The inventories were developed by the emission factor method, and further gridded at a spatial resolution of 50 km × 50 km based on GIS methodology, using population data as spatial surrogate. The result showed that China's industrial NMVOCs emissions had increased by 11.6 times at an average annual rate of 8.5% from 1.15 Tg in 1980 to 13.35 Tg in 2010. The four major source categories generated 19.6% (2.63 Tg, production of NMVOCs), 9.6% (1.295 Tg, storage and transport), 13.2% (1.769 Tg, industrial processes using NMVOCs as raw materials), and 57.4% (7.662 Tg, processes using NMVOCs-containing products) of the total emissions from China in 2010. Moreover, the top four industrial emissions sources were oil refinery, architectural decoration, machinery equipment and printing, accounted for 48.3% all together. With respect to the spatial distribution, the emissions mostly occurred in the eastern, northern and southern parts of China, all being much higher than that in the western part. The top four emission provinces were Shandong, Jiangsu, Guangdong, and Zhejiang, accounting for 38.3% of the national emissions. As for the past 30 years, the national industrial NMVOCs emissions increased year-by-year, being in pace with the accelerated industrialization process and the sharp economic growth, especially the rapid expansion of the high-emission industries. Particularly, the oil refinery, product oil and solvent distribution, architectural decoration, and mechanical equipment manufacture became the four largest contributors, accounting for 15.9–34.3%, 6.5–10.2%, 7–8%, and 6–7% of national industrial NMVOCs.

Simulation of the interannual variations of biogenic emissions of volatile organic compounds in China: Impacts on tropospheric ozone and secondary organic aerosol

We use the MEGAN (Model of emissions of Gases and Aerosols from Nature) module embedded within the global three-dimensional Goddard Earth Observing System chemical transport model (GEOS-Chem) to simulate the interannual variations in biogenic volatile organic compound (BVOC) emissions and concentrations of ozone and secondary organic aerosols (SOA) in China over years 2001–2006. To have better representation of biogenic emissions, we have updated in the model the land cover and leaf area index in China using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite measurements, and we have developed a new classification of vegetation with 21 plant functional types. Estimated annual BVOC emission in China averaged over 2001–2006 is 18.85 Tg C yr−1, in which emissions of isoprene, monoterpenes, and other reactive volatile organic compounds account for 50.9%, 15.0%, and 34.1%, respectively. The simulated BVOC emissions in China have large interannual variations. The values of regionally averaged absolute percent departure from the mean (APDM) of isoprene emissions are in the range of 21–42% in January and 15–28% in July. The APDM values of monoterpene emissions are 14–32% in January and 10–21% in July, which are generally smaller than those of isoprene emissions. Model results indicate that the interannual variations in isoprene emissions are more dependent on variations in meteorological fields, whereas the interannual variations in monoterpene emissions are more sensitive to changes in vegetation parameters. With fixed anthropogenic emissions, as a result of the variations in both meteorological parameters and vegetation, simulated O3 concentrations show interannual variations of 0.8–5 ppbv (or largest APDM values of 4–15%), and simulated SOA shows APDM values of 5–15% in southwestern China in January as well as 10–25% in southeastern and 20–35% in northeastern China in July. On a regional mean basis, the interannual variations in BVOCs alone can lead to 2–5% differences in simulated O3 and SOA in summer.

Comparison of receptor models for source apportionment of volatile organic compounds in Beijing, China

Identifying the sources of volatile organic compounds (VOCs) is key to reducing ground-level ozone and secondary organic aerosols (SOAs). Several receptor models have been developed to apportion sources, but an intercomparison of these models had not been performed for VOCs in China. In the present study, we compared VOC sources based on chemical mass balance (CMB), UNMIX, and positive matrix factorization (PMF) models. Gasoline-related sources, petrochemical production, and liquefied petroleum gas (LPG) were identified by all three models as the major contributors, with UNMIX and PMF producing quite similar results. The contributions of gasoline-related sources and LPG estimated by the CMB model were higher, and petrochemical emissions were lower than in the UNMIX and PMF results, possibly because the VOC profiles used in the CMB model were for fresh emissions and the profiles extracted from ambient measurements by the two-factor analysis models were "aged".

Anthropogenic emissions of non-methane volatile organic compounds in China

Inventories of emissions of non-methane volatile organic compounds (NMVOC) in China are reported for the years 1990, 1995, 2000, 2010, and 2020. For 1990 and 1995, historical activity data were assembled for more than 70 processes that lead to the release of NMVOC. Appropriate emission factors were developed, based on Western, Asian and Chinese experience. It is estimated that emissions were 11.1 Tg in 1990 and 13.1 Tg in 1995, principally from the combustion of biofuels and coal in small combustors. All emissions are presented at provincial level. Using appropriate growth factors derived from anticipated economic, population, and lifestyle changes, and factoring in regulatory changes and technology improvements, we estimate that emissions could grow to 15.6 Tg in 2000, 17.2 Tg in 2010, and 18.2 Tg in 2020. Though activity growth rates are much higher than these increases would imply, technology improvements mediate the increases. Emissions from solvent use, paint use, and transport become increasingly important as time goes on. The sectoral distribution and per capita level of China's emissions are compared with those of other countries. Finally, gridded NMVOC emission fields are presented at 1°×1° resolution, and speciation of the emissions into 16 chemical types is reported.