Atmospheric degradation of volatile organic compounds
About: This article is published in Chemical Reviews.The article was published on 2003-10-29. It has received 2290 citations till now.
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TL;DR: The results suggest that, in addition to mitigating primary particulate emissions, reducing the emissions of secondary aerosol precursors from fossil fuel combustion and biomass burning is likely to be important for controlling China’s PM2.5 levels and for reducing the environmental, economic and health impacts resulting from particulate pollution.
Abstract: Rapid industrialization and urbanization in developing countries has led to an increase in air pollution, along a similar trajectory to that previously experienced by the developed nations. In China, particulate pollution is a serious environmental problem that is influencing air quality, regional and global climates, and human health. In response to the extremely severe and persistent haze pollution experienced by about 800 million people during the first quarter of 2013 (refs 4, 5), the Chinese State Council announced its aim to reduce concentrations of PM2.5 (particulate matter with an aerodynamic diameter less than 2.5 micrometres) by up to 25 per cent relative to 2012 levels by 2017 (ref. 6). Such efforts however require elucidation of the factors governing the abundance and composition of PM2.5, which remain poorly constrained in China. Here we combine a comprehensive set of novel and state-of-the-art offline analytical approaches and statistical techniques to investigate the chemical nature and sources of particulate matter at urban locations in Beijing, Shanghai, Guangzhou and Xi'an during January 2013. We find that the severe haze pollution event was driven to a large extent by secondary aerosol formation, which contributed 30-77 per cent and 44-71 per cent (average for all four cities) of PM2.5 and of organic aerosol, respectively. On average, the contribution of secondary organic aerosol (SOA) and secondary inorganic aerosol (SIA) are found to be of similar importance (SOA/SIA ratios range from 0.6 to 1.4). Our results suggest that, in addition to mitigating primary particulate emissions, reducing the emissions of secondary aerosol precursors from, for example, fossil fuel combustion and biomass burning is likely to be important for controlling China's PM2.5 levels and for reducing the environmental, economic and health impacts resulting from particulate pollution.
3,372 citations
TL;DR: Accounting for partitioning and photochemical processing of primary emissions creates a more regionally distributed aerosol and brings model predictions into better agreement with observations, attribute this unexplained secondary organic-aerosol production to the oxidation of low-volatility gas-phase species.
Abstract: Most primary organic-particulate emissions are semivolatile; thus, they partially evaporate with atmospheric dilution, creating substantial amounts of low-volatility gas-phase material. Laboratory experiments show that photo-oxidation of diesel emissions rapidly generates organic aerosol, greatly exceeding the contribution from known secondary organic-aerosol precursors. We attribute this unexplained secondary organic-aerosol production to the oxidation of low-volatility gas-phase species. Accounting for partitioning and photochemical processing of primary emissions creates a more regionally distributed aerosol and brings model predictions into better agreement with observations. Controlling organic particulate-matter concentrations will require substantial changes in the approaches that are currently used to measure and regulate emissions.
1,563 citations
TL;DR: A review of the chemistry of the formation and continuing transformation of low-volatility species in the atmosphere can be found in this article, where the primary focus is chemical processes that can change the volatility of organic compounds: oxidation reactions in the gas phase, reaction in the particle phase, and reaction in either phase over several generations.
1,411 citations
Cites background or methods from "Atmospheric degradation of volatile..."
...Atmospheric oxidation mechanisms for a wide range of VOCs have been reviewed in detail by Atkinson and Arey (2003); a generic (and highly simplified) reaction mechanism is shown in Fig....
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...The ozonolysis mechanism is described in detail elsewhere (Atkinson and Arey, 2003; Chuong et al., 2004; Docherty et al., 2005); key reactions are shown in Fig....
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...The ozonolysis mechanism is described in detail elsewhere (Atkinson and Arey, 2003; Chuong et al., 2004; Docherty et al., 2005); key reactions are shown in Fig....
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01 Jan 2007
TL;DR: The amount of primary organic aerosol (POA) depends on the gas-particle partitioning of 1000s of individual organic compounds, expressed in terms of the volatility distribution of the emissions as discussed by the authors.
Abstract: The amount of primary organic aerosol (POA) depends on the gas-particle partitioning of 1000s of individual organic compounds. This partitioning can be expressed in terms of the volatility distribution of the emissions. A volatility distribution can be constructed from speciated emissions data by lumping species with similar saturation vapor pressures. In practice, this is not possible because less than 10% of the condensed and semivolatile mass has been identified on a compound-by-compound basis (
1,344 citations
TL;DR: Adverse health effects from exposure to formaldehyde in prefabricated houses, especially irritation of the eyes and upper airways, were first reported in the mid-1960s and a guideline value of 0.1 ppm was proposed in 1977 by the former German Federal Agency of Health to limit human exposure in dwellings.
Abstract: 1.1. History
Formaldehyde was described in the year 1855 by the Russian scientist Alexander Michailowitsch Butlerow. The technical synthesis by dehydration of methanol was achieved in 1867 by the German chemist August Wilhelm von Hofmann. The versatility that makes it suitable for use in various industrial applications was soon discovered, and the compound was one of the first to be indexed by Chemical Abstracts Service (CAS). In 1944, Walker published the first edition of his classic work Formaldehyde.(1) Between 1900 and 1930, formaldehyde-based resins became important adhesives for wood and wood composites. The first commercial particle board was produced during World War II in Bremen, Germany. Since 1950, particle board has become an attractive alternative to solid wood for the manufacturing of furniture. Particle board and other wood-based panels were subsequently also used for the construction of housing. Adverse health effects from exposure to formaldehyde in prefabricated houses, especially irritation of the eyes and upper airways, were first reported in the mid-1960s. Formaldehyde emissions from particle boards bonded with urea formaldehyde resin were soon identified as the cause of the complaints. As a consequence, a guideline value of 0.1 ppm was proposed in 1977 by the former German Federal Agency of Health to limit human exposure in dwellings. Criteria for the limitation and regulation of formaldehyde emissions from wood-based materials were established in 1981 in Germany and Denmark. The first regulations followed in the United States in 1985 or thereabouts. In Germany and the United States, large-scale test chambers were used for the evaluation of emissions. Although the chamber method is very reliable, it is also time-consuming and expensive. This meant there was a strong demand for simple laboratory test methods.(2)
1,253 citations
References
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TL;DR: In this article, the authors developed a global model to estimate emissions of volatile organic compounds from natural sources (NVOC), which has a highly resolved spatial grid and generates hourly average emission estimates.
Abstract: Numerical assessments of global air quality and potential changes in atmospheric chemical constituents require estimates of the surface fluxes of a variety of trace gas species. We have developed a global model to estimate emissions of volatile organic compounds from natural sources (NVOC). Methane is not considered here and has been reviewed in detail elsewhere. The model has a highly resolved spatial grid (0.5° × 0.5° latitude/longitude) and generates hourly average emission estimates. Chemical species are grouped into four categories: isoprene, monoterpenes, other reactive VOC (ORVOC), and other VOC (OVOC). NVOC emissions from oceans are estimated as a function of geophysical variables from a general circulation model and ocean color satellite data. Emissions from plant foliage are estimated from ecosystem specific biomass and emission factors and algorithms describing light and temperature dependence of NVOC emissions. Foliar density estimates are based on climatic variables and satellite data. Temporal variations in the model are driven by monthly estimates of biomass and temperature and hourly light estimates. The annual global VOC flux is estimated to be 1150 Tg C, composed of 44% isoprene, 11% monoterpenes, 22.5% other reactive VOC, and 22.5% other VOC. Large uncertainties exist for each of these estimates and particularly for compounds other than isoprene and monoterpenes. Tropical woodlands (rain forest, seasonal, drought-deciduous, and savanna) contribute about half of all global natural VOC emissions. Croplands, shrublands and other woodlands contribute 10–20% apiece. Isoprene emissions calculated for temperate regions are as much as a factor of 5 higher than previous estimates.
3,859 citations
TL;DR: The present status of knowledge of the gas phase reactions of inorganic Ox, Hox and NOx species and of selected classes of volatile organic compounds (VOCs) and their degradation products in the troposphere is discussed in this paper.
2,722 citations
TL;DR: The most recent review and evaluation of Atkinson [J. Phys. Chem. Ref. Data, 26, No. 3 (1997) and as mentioned in this paper concerning the gas phase reactions of alkanes and alkenes (including isoprene and monoterpenes) leading to their first generation products are reviewed and evaluated for tropospheric conditions.
Abstract: Literature data (through mid-1996) concerning the gas-phase reactions of alkanes and alkenes (including isoprene and monoterpenes) leading to their first generation products are reviewed and evaluated for tropospheric conditions. The recommendations of the most recent IUPAC evaluation [J. Phys. Chem. Ref. Data, 26, No. 3 (1997)] are used for the ⩽C3 organic compounds, unless more recent data necessitates reevaluation. The most recent review and evaluation of Atkinson [J. Phys. Chem. Ref. Data, Monograph 2, 1 (1994)] concerning the kinetics of the reactions of OH radicals, NO3 radicals, and O3 is also updated for these two classes of volatile organic compounds.
1,228 citations
TL;DR: In this article, the kinetics, products and mechanisms of the tropospheric reactions of biogenic organic compounds are presented and briefly discussed, and the results of the reactions are discussed.
1,185 citations
TL;DR: In this paper, two modes of seasonal behavior are noted for surface ozone at mid-latitudes: a broad summer maximum within a few hundred km of industrial/urban areas in Europe and the U.S., and a minimum in summer or autumn in sparcely populated regions that are remote from industrial activity.
Abstract: In the present analysis of tropospheric ozone data, attention is given to spatial and temporal variations. Two modes of seasonal behavior are noted for surface ozone at mid-latitudes: a broad summer maximum within a few hundred km of industrial/urban areas in Europe and the U.S., and a minimum in summer or autumn in sparcely populated regions that are remote from industrial activity. These and limited historical data indicate that summertime concentrations of ozone near the surface in the rural areas of Europe and the U.S. may have increased between 20 and 100 percent since the 1940s. It is suggested that the summer maximum in ozone and other observed trends are due to photochemical production associated with anthropogenic emissions of NO(x), hydrocarbons, and CO from fossil fuel combustion.
997 citations