[Analysis of Water Soluble Organic Aerosol in Spring PM with Soot Particle Aerosol Mass Spectrometry (SP-AMS)].

To investigate the chemical composition and pollution characteristics of spring fine particles (PM) in Changzhou, a total of 84 PM samples were collected from March 1st to May 30th, 2017. We measured and analyzed conventional components, such as water-soluble ions (WSIIs) and carbonaceous components (OC and EC). The water-soluble organic aerosol (WSOA) was also analyzed by an aerodyne soot particle aerosol mass spectrometer (SP-AMS).

Secondary organic aerosol formation from C-initiated oxidation of 4-ethylguaiacol in atmospheric aqueous-phase.

In this study, we investigated aqueous-phase triplet excited states (C)-induced photo-degradation of 4-ethylguaiacol (EG) under both simulated sunlight and ultraviolet (UV) light irradiations. Through quencher experiments, the relative contributions of reactive oxygen species (ROS, such as O/O/·OH) and C were calculated and results showed three reactive species, e.g.

[Secondary Organic Aerosol Mass Yield and Characteristics from 4-ethylguaiacol Aqueous·OH Oxidation: Effects of Initial Concentration].

Aqueous-phase chemical processing, as an essential formation pathway of secondary organic aerosol (SOA), has attracted widespread attention from within atmospheric chemistry fields. Due to the complicated reaction nature, reaction mechanisms, and product characteristics of aqueous-phase chemical processing, its contribution to the SOA budget is still not fully understood. In this work, we investigate how the initial concentration (0.

Characteristics, sources and health risks of toxic species (PCDD/Fs, PAHs and heavy metals) in PM during fall and winter in an industrial area.

Particulate toxic species, such as polychlorinated dibenzo-p-dioxins and polychlorinated dibenzofurans (PCDD/Fs), polycyclic aromatic hydrocarbons (PAHs) and heavy metals may have significant health risks. This study investigated characteristics, sources and health risks of all three classes of toxic species in PM (particles with aerodynamic diameter ≤2.5 μm) samples collected at an industrial area in Changzhou, a big city in the Yangtze Delta region of China.

A comprehensive investigation of aqueous-phase photochemical oxidation of 4-ethylphenol.

Secondary organic aerosol (SOA) species formed in atmospheric aqueous phases is recently recognized as an important contributor to fine aerosols, which is known to be a prominent human health risk factor internationally. This work, for the first time, systematically investigated aqueous-phase photochemical oxidation of 4-ethylphenol (4-EP) - a model compound from biomass burning and a surrogate of intermediate volatility organic compounds, under both ultraviolet (UV) (Hg lamp) and simulated sunlight (Xe lamp). We found that 4-EP could degrade upon hydroxal radical (OH) oxidation under UV light nearly 15 times faster than that under simulated sunlight, but large aqueous SOA (aqSOA) yields (108%-122%) were observed under both situations.

[Day-night Characteristics of Humic-like Substances in PM During Winter in Changzhou].

To investigate the characteristics of diurnal variation of humic-like substances (HULIS) in atmospheric aerosols during winter in Changzhou, a total of 64 fine particle (PM) samples were collected from January 1 to February 28, 2017. In this study, the concentration as well as light absorption parameters of humic-like substances of carbon (HULIS-C) were examined. The results showed that the average day PM and HULIS-C concentrations were 122.

Chemical characterization of PM from a southern coastal city of China: applications of modeling and chemical tracers in demonstration of regional transport.

An intensive sampling campaign of airborne fine particles (PM) was conducted at Sanya, a coastal city in Southern China, from January to February 2012. Chemical analyses and mass reconstruction were used identify potential pollution sources and investigate atmospheric reaction mechanisms. A thermodynamic model indicated that low ammonia and high relative humidity caused the aerosols be acidic and that drove heterogeneous reactions which led to the formation of secondary inorganic aerosol.

Morphologies and elemental compositions of local biomass burning particles at urban and glacier sites in southeastern Tibetan Plateau: Results from an expedition in 2010.

Many studies indicate that the atmospheric environment over the southern part of the Tibetan Plateau is influenced by aged biomass burning particles that are transported over long distances from South Asia. However, our knowledge of the particles emitted locally (within the plateau region) is poor. We collected aerosol particles at four urban sites and one remote glacier site during a scientific expedition to the southeastern Tibetan Plateau in spring 2010.

Atmospheric levels and cytotoxicity of polycyclic aromatic hydrocarbons and oxygenated-PAHs in PM in the Beijing-Tianjin-Hebei region.

The chemical composition of PM and cellular effects from exposure to fine aerosol extracts were studied for samples collected in Beijing, Tianjin, Shijiazhuang, and Hengshui, China in winter 2015. Effects of priority polycyclic aromatic hydrocarbons (PAHs) and their oxygenated derivatives (OPAHs) in PM on cell cultures were a major focus of the study. Total quantified PAHs and OPAHs at Shijiazhuang and Hengshui were higher than at Beijing and Tianjin, and benz(a)anthracene, chrysene and 1,8-naphthalic anhydride were the most abundant species.

Spectral dependence of aerosol light absorption at an urban and a remote site over the Tibetan Plateau.

We present a study of aerosol light absorption by using a 7-wavelength Aethalometer model AE33 at an urban site (Lhasa) and a remote site (Lulang) in the Tibetan Plateau. Approximately 5 times greater aerosol absorption values were observed at Lhasa (53±46Mm at 370nm and 20±18Mm at 950nm, respectively) in comparison to Lulang (15±19Mm at 370nm and 4±5Mm at 950nm, respectively). Black carbon (BC) was the dominant light absorbing aerosol component at all wavelengths.

Variation in Day-of-Week and Seasonal Concentrations of Atmospheric PM-Bound Metals and Associated Health Risks in Bangkok, Thailand.

While effective analytical techniques to promote the long-term intensive monitoring campaign of particulate heavy metals have been well established, efforts to interpret these toxic chemical contents into policy are lagging behind. In order to ameliorate the interpretation of evidence into policies, environmental scientists and public health practitioners need innovative methods to emphasize messages concerning adverse health effects to state and local policymakers. In this study, three different types of health risk assessment models categorized by exposure pathways.

Characteristics of surface O₃ over Qinghai Lake area in Northeast Tibetan Plateau, China.

Surface O3 was monitored continuously during Aug. 12, 2010 to Jul. 21, 2011 at a high elevation site (3,200 m above sea level) in Qinghai Lake area (36°58'37″N, 99°53'56″E) in Northeast Tibetan Plateau, China.

Day-night differences and seasonal variations of chemical species in PM₁₀ over Xi'an, northwest China.

To investigate day-night differences and seasonal variations of PM10 and its chemical composition in an urban environment in Xi'an, northwest China, day- and nighttime PM10 mass and its chemical components including water-soluble ions (Na(+), NH4 (+), K(+), Mg(2+), Ca(2+), F(-), Cl(-), NO3 (-), and SO4 (2-)), organic carbon (OC), elemental carbon, and water-soluble organic carbon (WSOC) were measured on selected representative days from 20 December 2006 to 12 November 2007. Annual mean PM10 concentration in this city was five times of the China Ambient Air Quality Standard for annual average (70 μg m(-3)). Carbonaceous fractions and water-soluble ions accounted for nearly one third and 12.

Comparison and implications of PM₂.₅ carbon fractions in different environments.

The concentrations of PM₂.₅ carbon fractions in rural, urban, tunnel and remote environments were measured using the IMPROVE thermal optical reflectance (TOR) method. The highest OC1 and EC1 concentrations were found for tunnel samples, while the highest OC2, OC3, and OC4 concentrations were observed for urban winter samples, respectively.

Chemical composition, sources, and deposition fluxes of water-soluble inorganic ions obtained from precipitation chemistry measurements collected at an urban site in northwest China.

Precipitation samples were collected at an urban site in Xi'an, northwest China during March to November in 2009 and were then analyzed to determine the pH and concentrations of water-soluble inorganic ions (Na(+), NH(4)(+), K(+), Mg(2+), Ca(2+), SO(4)(2-), NO(3)(-), Cl(-), and F(-)) in precipitation. The pH of precipitation ranged from 4.1 to 7.

Molecular distribution and stable carbon isotopic composition of dicarboxylic acids, ketocarboxylic acids, and α-dicarbonyls in size-resolved atmospheric particles from Xi'an City, China.

Size-resolved airborne particles (9-stages) in urban Xi'an, China, during summer and winter were measured for molecular distributions and stable carbon isotopic compositions of dicarboxylic acids, ketocarboxylic acids, and α-dicarbonyls. To our best knowledge, we report for the first time the size-resolved differences in stable carbon isotopic compositions of diacids and related compounds in continental organic aerosols. High ambient concentrations of terephthalic (tPh, 379 ± 200 ng m(-3)) and glyoxylic acids (ωC(2), 235 ± 134 ng m(-3)) in Xi'an aerosols during winter compared to those in other Chinese cities suggest significant emissions from plastic waste burning and coal combustions.