Observational insights into the compound environmental effect for 2-methyltetrols formation under humid ambient conditions.

Laboratory experiments suggest acid-catalyzed aqueous-phase production can promote the formation of isoprene SOA, i.e., 2-methyltetrols.

Chemical speciation, including polycyclic aromatic hydrocarbons (PAHs), and toxicity of particles emitted from meat cooking operations.

We assessed the chemical properties and oxidative stress of particulate matter (PM) emissions from underfired charbroiled meat operations with and without the use of aftertreatment control technologies. Cooking emissions concentrations showed a strong dependence on the control technology utilized, with all emission rates showing decreases with the control technologies compared to the baseline testing. The organic acids profile was dominated by the saturated nonanoic, myristic, palmitic, and stearic acids, and the unsaturated oleic, elaidic, and palmitoleic acids.

Chemical characterization and sources of personal exposure to fine particulate matter (PM) in the megacity of Guangzhou, China.

Concurrent ambient and personal measurements of fine particulate matter (PM) were conducted in eight districts of Guangzhou during the winter of 2011. Personal-to-ambient (P-C) relationships of PM chemical components were determined and sources of personal PM exposures were evaluated using principal component analysis and a mixed-effects model. Water-soluble inorganic ions (e.

Biomarkers as indicators of fungal biomass in the atmosphere of São Paulo, Brazil.

The biogenic aerosol contribution to atmospheric particulate matter (PM) mass concentration is usually neglected due to the difficulty in identifying its components, although it can be significant. In the Metropolitan Area of São Paulo (MASP)-Brazil, several studies have been performed to identify sources for PM, revealing vehicular emissions and soil re-suspension as the main identified sources. The organic fraction has been related primarily to biomass burning (BB) and fuel combustion, although there is significant presence of green areas in the city which render biogenic emissions as an additional source of organic carbon (OC).

Brown and black carbon in Beijing aerosol: Implications for the effects of brown coating on light absorption by black carbon.

Brown carbon (BrC) is increasingly included in climate models as an emerging category of particulate organic compounds that can absorb solar radiation efficiently at specific wavelengths. Water-soluble organic carbon (WSOC) has been commonly used as a surrogate for BrC; however, it only represents a limited fraction of total organic carbon (OC) mass, which could be as low as about 20% in urban atmosphere. Using methanol as the extraction solvent, up to approximately 90% of the OC in Beijing aerosol was isolated and measured for absorption spectra over the ultraviolet-to-visible wavelength range.

Seasonal variations and source estimation of saccharides in atmospheric particulate matter in Beijing, China.

Saccharides are important constituents of atmospheric particulate matter (PM). In order to better understand the sources and seasonal variations of saccharides in aerosols in Beijing, China, saccharide composition was measured in ambient PM samples collected at an urban site in Beijing. The highest concentrations of total saccharides in Beijing were observed in autumn, while an episode with abnormal high total saccharide levels was observed from 15 to 23 June, 2011, due to extensive agricultural residue burning in northern China during the wheat harvest season.

[Composition and Source Apportionments of Saccharides in Atmospheric Particulate Matter in Beijing].

Based on the newly established high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), the saccharides in PM2.5 and PM10 in Beijing from 2011 - 2012 were quantified. Fourteen saccharides were synchronously detected in the aerosols samples in Beijing, which can be divided into three categories, i.

The characteristics of Beijing aerosol during two distinct episodes: impacts of biomass burning and fireworks.

The chemical composition of Beijing aerosol was measured during summer and winter. Two distinct episodes were identified. Water-soluble potassium (K(+)) increased significantly during the firework episode in winter with an episode to non-episode ratio of 4.

Organosulfates in humic-like substance fraction isolated from aerosols at seven locations in East Asia: a study by ultra-high-resolution mass spectrometry.

Humic-like substances (HULIS) in ambient aerosols collected at seven locations in East Asia were analyzed using electrospray ionization (ESI) coupled with an ultra-high-resolution mass spectrometer (UHRMS). Locations included a 3 km high mountaintop site in Taiwan, rural, suburban, and urban locations in the Pearl River Delta (PRD), South China, and in Taiwan. Organosulfates (OS) in the HULIS fraction were tentatively identified through accurate mass measurements and MS/MS spectra interpretation.

Observation of elevated fungal tracers due to biomass burning in the Sichuan Basin at Chengdu City, China.

Fungal material (i.e., spores and fragments) is an important component of atmospheric aerosols.

Stable carbon isotope ratio analysis of anhydrosugars in biomass burning aerosol particles from source samples.

A new method for stable carbon isotope ratio analysis of anhydrosugars from biomass burning aerosol particle source filter samples was developed by employing Thermal Desorption--2 Dimensional Gas Chromatography--Isotope Ratio Mass Spectrometry (TD-2DGC-IRMS). Compound specific isotopic measurements of levoglucosan, mannosan, and galactosan performed by TD-2DGC-IRMS in a standard mixture show good agreement with isotopic measurements of the bulk anhydrosugars, carried out by Elemental Analyzer--Isotope Ratio Mass Spectrometry (EA-IRMS). The established method was applied to determine the isotope ratios of levoglucosan, mannosan, and galactosan from source samples collected during combustion of hard wood, softwood, and crop residues.

Levoglucosan and carbonaceous species in the background aerosol of coastal southeast China: case study on transport of biomass burning smoke from the Philippines.

Introduction: Levoglucosan and carbonaceous species in the background aerosol of coastal southeast China were measured at Jianfengling (JFL), a background mountain site in a National Reserve Park on Hainan Island, and at Hok Tsui (HT), a rural site on the southern coast of Hong Kong from April to May of 2004 during an intensive field study.

Methods: We integrated the information from field study, satellite and backward trajectory model to examine the long-range transport of biomass burning smoke from the Philippines and assess its impact on background aerosol in coastal southeast China.

Results And Discussion: The average levoglucosan concentrations were 42 and 30 ng m(-3) at JFL and HT, respectively, while the organic and elemental carbon concentrations were 3.

Observations of ozone and carbon monoxide at Mei-Feng mountain site (2269 m a.s.l.) in Central Taiwan: seasonal variations and influence of Asian continental outflow.

Continuous measurements of ozone (O(3)) and carbon monoxide (CO) were carried out at Mei-Feng (24.05°N, 120.10°E, 2269 m above sea level), a remote mountain site in central Taiwan, to investigate the influence of long-range transported air pollution on O(3) and CO variations in the subtropical Pacific region.

Evaluating real-time air-quality data as earthquake indicator.

A catastrophic earthquake, namely the 921-earthquake, occurred with a magnitude of M(L)=7.3 in Taiwan on September 21, 1999, causing severe disaster. The evaluation of real-time air-quality data, obtained by the Taiwan Environmental Protection Administration (EPA), revealed a staggering increase in ambient SO(2) concentrations by more than one order of magnitude across the island several hours prior to the earthquake, particularly at background stations.

Change of air quality and its impact on atmospheric visibility in central-western Pearl River Delta.

Ambient air quality data, including atmospheric visibility, of Foshan city, a highly polluted city in the Pearl River Delta (PRD), and data obtained by the On-line Air Pollutant Exhaust Monitoring Network (OAPEMN), recently established by the National Emission Monitoring and Control Network for major industrial enterprises, were analyzed and are reported here for the first time, revealing the change in air pollution patterns and its impact on visibility degradation in the last decade. Reduced visibility of less than 8 km (after elimination of rainy and foggy periods) was found 22% of the time from 1998 to 2008, accompanied by elevated levels of pollutants, especially SO₂ and PM₁₀, in comparison with that of other developed cities. However, PM₁₀ showed a steady decreasing trend (0.

Particle size distributions of organic aerosol constituents during the 2002 Yosemite Aerosol Characterization Study.

The Yosemite Aerosol Characterization Study (YACS) was conducted in the summer of 2002 to investigate sources of regional haze in Yosemite National Park. Organic carbon and molecular source marker species size distributions were investigated during hazy and clear periods. More than 75% of the organic carbon mass was associated with submicron aerosol particles.

Determination of levoglucosan from smoke samples using microchip capillary electrophoresis with pulsed amperometric detection.

Separation and detection of native anhydrous carbohydrates derived from the combustion of biomass using an electrophoretic microchip with pulsed amperometric detection (PAD) is described. Levoglucosan represents the largest single component of the water extractable organics in smoke particles and can be used to trace forest fires or discriminate urban air pollution sources. Detection of levoglucosan and other sugar anhydrides in both source and ambient aerosol samples is typically performed by gas chromatographic (GC) separation with mass spectrometric (MS) detection.