scholarly journals Size Distribution of Ambient Particulate Matter and Its Constituent Chemical Species Involving Saccharides During Early Summer in a Chinese Megacity

2021 ◽  
Vol 9 ◽  
Author(s):  
Jahan Zeb Khan ◽  
Long Sun ◽  
Yingze Tian ◽  
Qili Dai ◽  
Tongxin Hu ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Size Distribution ◽  
Biomass Burning ◽  
Size Fraction ◽  
Chemical Species ◽  
Bimodal Distribution ◽  
Early Summer ◽  
Anthropogenic Sources ◽  
Formation Mechanisms ◽  
Ambient Particulate Matter

The ambient particulate matter (PM) pollution adversely influences the human health and natural environment. The size distribution of ambient PM determines the physiochemical and optical properties of ambient aerosol, whereas it reflects the variability in local and regional PM emission sources and formation mechanisms. In the present work, the size distribution and characteristics of the carbonaceous, ionic, elemental, and saccharide species were categorically investigated for the fraction-wise PM in Tianjin during 2018 early summer. The average concentrations were 32.4, 20.9, and 49.3 μg/m3 for the PM1, PM1–2.5, and PM2.5–10, respectively. The coarse PM2.5–10 accounted for most of the PM10 mass (47%), followed by the fine PM1 (33%) and intermodal PM1–2.5 (20%). The carbonaceous and ionic species exhibited bimodal distribution and were distributed mostly to the fine size fraction and then to the coarse size fraction. The elemental species exhibited unimodal distribution and were distributed mostly to the coarse size fraction. The specific saccharide species indicated the significant contribution of biomass burning and primary biogenic emissions. The bimodal mass size distribution of levoglucosan indicated the significant biomass burning contributions to the fine and coarse size fractions. The unimodal glucose, fructose, and arabitol distribution and the bimodal mannitol distribution indicated the dominant primary biogenic contributions to the coarse size fraction. The PM1/PM10, PM1–2.5/PM10, PM2.5–10/PM10, OC/EC, SOC/OC, AE/CE, NO3–/SO42–, K+/EC, and levoglucosan/K+ ratios were used to investigate the characteristics of the ambient size-fractionated PM. The anthropogenic sources (combustion processes, traffic emissions, and secondary particles, etc.) contributed mostly to the fine PM1 and intermodal PM1–2.5 fractions, whereas the natural sources (primary biogenic, marine salt, and mineral dust, etc.) contributed mostly to the coarse PM2.5–10 fraction. This work is a significant addition to the multi-size ambient PM’s size distribution and characterization studies.

scholarly journals Long-term Particulate Matter Modeling for Health Effects Studies in California – Part II: Concentrations and Sources of Ultrafine Organic Aerosols

2016 ◽  
Author(s):  
Jianlin Hu ◽  
Shantanu Jathar ◽  
Hongliang Zhang ◽  
Qi Ying ◽  
Shu-Hua Chen ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Health Effects ◽  
Waste Disposal ◽  
Size Fraction ◽  
Organic Aerosols ◽  
Epidemiological Studies ◽  
Anthropogenic Sources ◽  
Major Constituent ◽  
Spatial Distributions ◽  
Mobile Emissions

Abstract. Organic aerosol (OA) is a major constituent of ultrafine particulate matter (PM0.1). Recent epidemiological studies have identified associations between PM0.1 OA and premature mortality and low birth weight. In this study, the source-oriented UCD/CIT model was used to simulate the concentrations and sources of primary organic aerosols (POA) and secondary organic aerosols (SOA) in PM0.1 in California for a 9-year (2000–2008) modeling period with 4 km horizontal resolution to provide more insights about PM0.1 OA for health effects studies. As a related quality control, predicted monthly average concentrations of fine particulate matter (PM2.5) total organic carbon at six major urban sites had mean fractional bias of −0.31 to 0.19 and mean fractional errors of 0.4 to 0.59. The predicted ratio of PM2.5 SOA/OA was lower than estimates derived from chemical mass balance (CMB) calculations by a factor of 2 ~ 3, which suggests the potential effects of processes such as POA volatility, additional SOA formation mechanism, and missing sources. OA in PM0.1, the focus size fraction of this study, is dominated by POA. Wood smoke is found to be the single biggest source of PM0.1 OA in winter in California, while meat cooking, mobile emissions (gasoline and diesel engines), and other anthropogenic sources (mainly solvent usage and waste disposal) are the most important sources in summer. Biogenic emissions are predicted to be the largest PM0.1 SOA source, followed by mobile sources and other anthropogenic sources, but these rankings are sensitive to the SOA model used in the calculation. Air pollution control programs aiming to reduce the PM0.1 OA concentrations should consider controlling solvent usage, waste disposal, and mobile emissions in California, but these findings should be revisited after the latest science is incorporated into the SOA exposure calculations. The spatial distributions of SOA associated with different sources are not sensitive to the choice of SOA model, although the absolute amount of SOA can change significantly. Therefore, the spatial distributions of PM0.1 POA and SOA over the 9-year study period provide useful information for epidemiological studies to further investigate the associations with health outcomes.

Size distribution and sources of humic-like substances in particulate matter at an urban site during winter

2016 ◽  
Vol 18 (1) ◽  
pp. 32-41 ◽  
Author(s):  
Seungshik Park ◽  
Se-Chang Son
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Size Distribution ◽  
Bimodal Distribution ◽  
Asian Dust ◽  
Urban Site

The highest contribution of HULIS-C to WSOC was observed to be in the particle size bins of 0.55–1.0 μm and 1.8–3.1 μm during non-Asian dust (NAD, 45 ± 6%) and Asian dust (AD, 44 ± 7%) periods, respectively. HULIS exhibited a uni-modal (@0.55 μm) distribution during the NAD and a bimodal distribution (@0.32 and 1.8 μm) during AD, respectively.

scholarly journals A Semi-automated Instrument for Cellular Oxidative Potential Evaluation (SCOPE) of Water-soluble Extracts of Ambient Particulate Matter

2021 ◽  
Author(s):  
Sudheer Salana ◽  
Yixiang Wang ◽  
Joseph Puthussery ◽  
Vishal Verma
Keyword(s):  
Particulate Matter ◽  
Chemical Species ◽  
Positive Control ◽  
Water Soluble ◽  
Ros Generation ◽  
Ambient Particulate Matter ◽  
Oxidative Potential ◽  
Cellular Assays ◽  
Potential Evaluation ◽  
Automated Instrument

Abstract. Several automated instruments exist to measure the acellular oxidative potential (OP) of ambient particulate matter (PM). However, cellular OP of the ambient PM is still measured manually, which severely limits the comparison between two types of assays. Cellular assays could provide a more comprehensive assessment of the PM-induced oxidative stress, as they incorporate more biological processes involved in the PM-catalyzed reactive oxygen species (ROS) generation. Considering this need, we developed a first of its kind semi-automated instrument for measuring the cellular OP based on a macrophage ROS assay using rat alveolar macrophages. The instrument named SCOPE – Semi-automated instrument for Cellular Oxidative Potential Evaluation, uses dichlorofluorescein diacetate (DCFH-DA) as a probe to detect the OP of PM samples extracted in water. SCOPE is capable of analyzing a batch of six samples (including one negative and one positive control) in five hours and is equipped to operate continuously for 24-hours with minimal manual intervention after every batch of analysis, i.e., after every five hours. SCOPE has a high analytical precision as assessed from both positive controls and ambient PM samples (CoV < 17 %). The results obtained from the instrument were in good agreement with manual measurements using tert-Butyl hydroperoxide (t-BOOH) as the positive control (slope = 0.83 for automated vs. manual, R2 = 0.99) and ambient samples (slope = 0.83, R2 = 0.71). We further demonstrated the ability of SCOPE to analyze a large number of both ambient and laboratory samples, and developed a dataset on the intrinsic cellular OP of several compounds, such as metals, quinones, PAHs and inorganic salts, commonly known to be present in ambient PM. This dataset is potentially useful in future studies to apportion the contribution of key chemical species in the overall cellular OP of ambient PM.

scholarly journals Developing a Relative Humidity Correction for Low-Cost Sensors Measuring Ambient Particulate Matter

Sensors ◽  
2018 ◽  
Vol 18 (9) ◽  
pp. 2790 ◽  
Author(s):  
Andrea Di Antonio ◽  
Olalekan Popoola ◽  
Bin Ouyang ◽  
John Saffell ◽  
Roderic Jones
Keyword(s):  
Particle Size ◽  
Particulate Matter ◽  
Relative Humidity ◽  
Particle Size Distribution ◽  
Size Distribution ◽  
Low Cost ◽  
Monitoring Networks ◽  
Ambient Particulate Matter ◽  
Correction Algorithm ◽  
Ambient Conditions

There is increasing concern about the health impacts of ambient Particulate Matter (PM) exposure. Traditional monitoring networks, because of their sparseness, cannot provide sufficient spatial-temporal measurements characteristic of ambient PM. Recent studies have shown portable low-cost devices (e.g., optical particle counters, OPCs) can help address this issue; however, their application under ambient conditions can be affected by high relative humidity (RH) conditions. Here, we show how, by exploiting the measured particle size distribution information rather than PM as has been suggested elsewhere, a correction can be derived which not only significantly improves sensor performance but which also retains fundamental information on particle composition. A particle size distribution–based correction algorithm, founded on κ -Köhler theory, was developed to account for the influence of RH on sensor measurements. The application of the correction algorithm, which assumed physically reasonable κ values, resulted in a significant improvement, with the overestimation of PM measurements reduced from a factor of ~5 before correction to 1.05 after correction. We conclude that a correction based on particle size distribution, rather than PM mass, is required to properly account for RH effects and enable low cost optical PM sensors to provide reliable ambient PM measurements.

ELEMENTAL COMPOSITION, SIZE DISTRIBUTION AND IMAGE INTERPRETATION OF FINE PARTICULATE MATTER IN URBAN CITY ROAD SIDES, MYSORE (KARNATKA) INDIA

2017 ◽  
Vol 23 (2) ◽  
Author(s):  
S. SREENIVASA ◽  
G.V. VENKATARAMANA
Keyword(s):  
Particulate Matter ◽  
Elemental Composition ◽  
Size Distribution ◽  
Fine Particles ◽  
Fine Particulate Matter ◽  
Sampling Site ◽  
Image Interpretation ◽  
Ambient Particulate Matter ◽  
Sem Image ◽  
Urban City

The study was carried out using vacuum air pump sampler to collect particulate matter in the urban city roadsides. Elemental composition, size distribution and image interpretation of particles was analyzed using the methods of Energy Dispersive X-Ray (EDX), Dynamic Light Scattering (DLS) and Scanning Electron Microscope (SEM), respectively. Irwin road, the highly dense traffic area in Mysore city, has been selected for study purpose due to its high vehicular emissions. EDX analysis found that roadside particulate matter was dominated by black carbon (C) about 56% affected mostly by tail end pipe emissions. The samples were also rich in crustal elements like silicon (Si), iron (Fe), calcium (Ca), aluminium (Al), sodium (Na) and potassium (K) either in single elements or as chemical compounds. The results from DLS and SEM image interpretation showed that almost 90% of ambient particulate matter collected in the sampling site was in the size of fine particles (PM2.5) and around 74% of them have degree of roundness or circularity above 0.75.

Size distribution of water-soluble components in particulate matter emitted from biomass burning

2013 ◽  
Vol 73 ◽  
pp. 62-72 ◽  
Author(s):  
Seung-Shik Park ◽  
Soo Young Sim ◽  
Min-Suk Bae ◽  
James J. Schauer
Keyword(s):  
Particulate Matter ◽  
Size Distribution ◽  
Biomass Burning ◽  
Water Soluble ◽  
Soluble Components
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