Fine Particulate Matter Carbon Research Articles

Ratios of organic mass to organic carbon in fine particulate matter at urban sites in China and Korea during winter and summer.

This study evaluates the composition and seasonal characteristics of fine particulate matter (PM2.5) during winter and summer through simultaneous measurements conducted at the Gwangju Institute of Science and Technology in South Korea and the Changping campus of Peking University in China. PM2.5 samples were concurrently collected at both sites, and chemical analyses were conducted to quantify various components, including carbonaceous materials, ionic species, and metals. Although the average PM2.5 concentrations were comparable between the two sites, there were distinct differences in the concentrations of major components. Organic indicator compounds were analyzed to discern the contributions of primary and secondary pollution sources. Changping displayed a mix of primary and secondary pollution, characterized by higher concentrations of primary organic carbon (POC) such as polycyclic aromatic hydrocarbons and hopanes, compared to Gwangju. In contrast, Gwangju demonstrated a higher prevalence of secondary organic carbon (SOC), particularly water-soluble organic carbon not related to biomass burning (WSOCnbb) and various polar organic compounds. The organic mass to organic carbon (OM/OC) ratios estimated using the mass balance method revealed significant differences, with Gwangju showing a higher ratio of 2.3 compared to 1.9 at Changping, indicating a greater influence of secondary pollutants at Gwangju. Additionally, both Changping and Gwangju exhibited higher OM/OC ratios in summer (Changping: 2.0, Gwangju: 2.5) compared to winter (Changping: 1.8, Gwangju: 2.2), indicating seasonal differences in organic mass contributions to PM2.5. These findings underscore the importance of accounting for spatial and seasonal variations in air pollution studies and suggest that updating commonly used OM/OC ratios could enhance the reliability of research outcomes.

Bayesian Inference Approach to Quantify Primary and Secondary Organic Carbon in Fine Particulate Matter Using Major Species Measurements.

The determination of primary organic carbon (POC) and secondary organic carbon (SOC) in fine particulate matter using ambient measurements is essential in atmospheric chemistry. A novel Bayesian inference (BI) approach is proposed to achieve such quantification using only major component measurement data and tested in two case studies. One case study composes of filter-based daily compositional data made in the Pearl River Delta region, China, during 2012, while the other uses online measurement data recorded at the Dianshan Lake monitoring site in Shanghai in wintertime 2019. Source-specific organic trace measurement data are available in both the cases so that positive matrix factorization (PMF) analysis is performed, where PMF-resolved POC and SOC are used as the best available reference values for model evaluation. Meanwhile, traditional techniques, i.e., minimum ratio value, minimum R squared, and multiple linear regression, are also employed and evaluated. For both the cases, the BI models have shown significant advantages in accurately estimating POC and SOC amounts over conventional methods. Further analysis suggests that using sulfate as the SOC tracer in BI model gives the best model performance. This methodological advance provides an improved and practical tool to derive POC and SOC levels for addressing PM-related environmental impacts.

Occurrence and sources of chromophoric organic carbon in fine particulate matter over Xi'an, China

Understanding the characteristics and sources of atmospheric chromophores is essential to assess their impact on climate change and the quality of atmospheric environment. In this work, the fine particulate matter (PM2.5) samples of Xi'an, China in 2017 were analyzed by excitation-emission matrices and parallel factor analysis (EEM-PARAFAC) method to obtain the species, content, sources and seasonal variation characteristics of atmospheric chromophores. The results showed that humic-like (HULIS) chromophores and polycyclic aromatic hydrocarbons-like (PAHs-like) chromophores were the most abundant chromophores in the samples, accounting for 42% and 33%, respectively. With the aggravation of air pollution, the relative content of low-polarity chromophores increased markedly, while the relative content of polar chromophores decreased. The concentrations of atmospheric chromophores exhibited obvious seasonal variation characteristics: high in winter and low in summer. Similarly, the relative contributions of atmospheric chromophores from each source varied with the season. In addition, special weather and human activities had a significant influence on the source of atmospheric chromophores. Dust source was an important source of atmospheric chromophores, which was susceptible to long-range incoming air masses from northwestern regions in spring. However, the chromophores from the dust source were easily removed by wet precipitation, which was the same as the chromophores from the combustion source. The chromophores from the combustion source were susceptible to human activities. The contribution of combustion source to atmospheric chromophores was reduced due to the implementation of air pollution control policies during the Chinese Spring Festival. In summer, the formation of photochemical secondary chromophores was more significant than in other seasons, and the photochemical secondary chromophores increased due to the formation of liquid phase reactions under high relative humidity conditions.

Source apportionment of carbonaceous aerosols during haze days in Shanghai based on dual carbon isotopes

We present dual carbon isotope constrained (δ13C and Δ14C) source apportionment of organic carbon and elemental carbon in fine particulate matter (PM2.5) for five districts of Shanghai during the winter of 2013. The results show that spatial variations of the three source (biomass, liquid fossil fuel, and coal) apportionment of carbonaceous aerosol among different districts were evident. Overall, coal combustion, liquid fossil fuel combustion and biomass burning are the most important carbonaceous aerosols source in Pudong, Xuhui and Chongming, respectively. The results suggest that environmental protection policies should vary according to the functional areas of different sources in the same city.

Seasonal Variation of Black Carbon in Fine Particulate Matter (PM2.5) at the Tropical Coastal City of Mumbai, India

Black Carbon (BC) is a pollutant species primarily emitted from the combustion of fossil fuels. BC levels, associated with fine particulate matter (PM2.5), were monitored from January 2009 to December 2010 at an urban industrial area in Mumbai to study the seasonal and temporal variations and its contribution to fine particulate matter. Air particulate samples were collected in two size fractions, fine particulate matter (PM2.5) and coarse particulate matter (PM2.5-10), using a Gent air sampler. During the study period, arithmetic means of PM2.5 and PM2.5-10 were found to be 30.4 and 68.2 μg/m(3), respectively. The average value of BC in fine particulate matter was 4.0 μg/m(3), with a range of 1.0-9.4 μg/m(3). Studies carried out using Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) model indicated the contribution of BC from the northern and central part of India during days of high BC levels.

Resolving sources of water-soluble organic carbon in fine particulate matter measured at an urban site during winter.

Measurements of daily PM2.5 were carried out during winter between January 11 and February 27, 2010 in an urban area of Korea, in order to better understand the influence of sources and atmospheric processing of organic aerosols. The aerosol samples were analyzed for organic carbon and elemental carbon (OC and EC), water-soluble OC (WSOC), eight ionic species, and oxalate. The water-soluble fraction of OC was between 33 and 58% with an average of 45%. Strong correlations among WSOC, sulfate (SO 4(2-)) (R(2) = 0.69), and oxalate (R(2) = 0.82) concentrations, and between potassium (K (+)) and WSOC concentrations (R(2) = 0.81) suggest that the observed WSOC could originate from similar oxidation processes to those for SO 4(2-) and oxalate, as well as biomass burning. Also moderate correlations of the WSOC with EC and carbon monoxide (CO) indicate that there was some contribution to WSOC from primary fossil fuel combustion. Results from a principle component analysis (PCA) indicate that in addition to the biomass burning and primary non-biomass burning emissions, the observed WSOC could be formed through production pathways similar to secondary organic carbon (SOC), SO 4(2-), and oxalate. Sources of WSOC inferred, based on the correlations, were confirmed by source categories identified by the PCA. Over the study period, three haze episodes exceeding a 24 h PM 2.5 concentration of 50 μg m(-3) were identified. Of the major components in PM 2.5, EC concentrations were elevated during episode I (18-19 January), while the secondary SO 4(2-) concentrations were enhanced during episodes II (30-31 January) and III (22-23 February). However, little difference in OC concentrations among the episodes was observed. It is suggested that the aerosol particles collected during episodes II and III were more aged than those during episode I. Estimates of fossil fuel combustion, biomass burning, and SOC contributions to WSOC indicate that the fossil fuel combustion provided the highest contribution (62.3%) to WSOC in episode I, while the greatest contribution (60.6%) to WSOC from SOC was observed in episode II. The results demonstrate that the sampled aerosol particles were more aged or further processed during episodes II and III than during episode I.

Ambient Air Pollution and Infant Health: Home Monitors Make Cardiorespiratory Connections

Vol. 119, No. 9 News | Science SelectionsOpen AccessAmbient Air Pollution and Infant Health: Home Monitors Make Cardiorespiratory Connectionsis accompanied byAmbient Air Pollution and Apnea and Bradycardia in High-Risk Infants on Home Monitors Kellyn S. Betts Kellyn S. Betts Search for more papers by this author Published:1 September 2011https://doi.org/10.1289/ehp.119-a398aCited by:1AboutSectionsPDF ToolsDownload CitationsTrack Citations ShareShare onFacebookTwitterLinked InReddit Children are particularly susceptible to the health effects of air pollution because they spend more time outdoors, have higher respiratory rates, and breathe in a greater volume of air relative to their body weights. Babies may be especially sensitive to the effects of air pollution because their immune, respiratory, and central nervous systems are not fully developed. To date, infants’ respiratory responses to air pollution have been studied much less extensively than those of older children. A new study now links ambient air pollution to an increased risk for apnea (prolonged pauses in breathing) and bradycardia (decreases in heart rate) in babies at high risk for these conditions [EHP 119(9):1321–1327; Peel et al.].The study involved 4,277 infants living in the Atlanta area (about 80 square miles) between 1998 and 2002 whose heart rates and respiration were recorded on home cardiorespiratory monitors. Most of the infants were being monitored because of previous apnea events related to premature birth; others, including some full-term infants, were being monitored for reasons such as gastroesophageal reflux disease. Concentrations of ground-level ozone, nitrogen dioxide, sulfur dioxide, carbon monoxide, oxygenated hydrocarbons, and particulate matter were measured at a centrally located monitoring site.Home cardiorespiratory monitors shed light on health events related to ambient air pollution.Joseph Tart/EHPThe team of researchers documented 8,960 apnea events (in which the child stopped breathing for at least 20 seconds) and 29,450 bradycardia events (in which the child’s heart rate fell below a value determined by his or her age and prematurity status) recorded on the monitors. They examined associations between these events and the 2-day average levels of air pollution, recorded the same day as and the day before each event.The researchers found significant associations between bradycardia and increases in 8-hour levels of ozone and 1-hour levels of nitrogen dioxide. The relationship between ozone and apnea was similar but not statistically significant. In general, stronger associations were observed for full-term infants with normal birth weights than for premature infants with low birth weights—a surprising but not unprecedented finding. There also was an association between apnea events and increased concentrations of organic carbon in fine particulate matter for full-term, normal-birth-weight infants.These findings are consistent with previous studies linking air pollution with respiratory symptoms, related hospital admissions, and increased mortality in infants. Although the underlying causes of apnea and bradycardia are unclear, some evidence suggests that immaturity in the autonomic control of the nervous and/or respiratory systems may be involved, which makes a link with increased vulnerability to the effects of air pollution plausible.FiguresReferencesRelatedDetailsCited by Pshybelsky V, Zhuravlov O, Shevchuk T and Zhuravlova O (2018) INDICATORS OF RESPIRATORY SYSTEM IN CONDITIONS OF CHRONIC ACTION OF HARMFUL ENVIRONMENTAL FACTORS WITH TYPE OF BODY CONSTITUTION, EUREKA: Health Sciences, 10.21303/2504-5679.2018.00691, 4, (34-41), Online publication date: 31-Jul-2018. Related articlesAmbient Air Pollution and Apnea and Bradycardia in High-Risk Infants on Home Monitors29 March 2011Environmental Health Perspectives Vol. 119, No. 9 September 2011Metrics About Article Metrics Publication History Originally published1 September 2011Published in print1 September 2011 Financial disclosuresPDF download License information EHP is an open-access journal published with support from the National Institute of Environmental Health Sciences, National Institutes of Health. All content is public domain unless otherwise noted. Note to readers with disabilities EHP strives to ensure that all journal content is accessible to all readers. However, some figures and Supplemental Material published in EHP articles may not conform to 508 standards due to the complexity of the information being presented. If you need assistance accessing journal content, please contact [email protected]. Our staff will work with you to assess and meet your accessibility needs within 3 working days.

Fossil and nonfossil carbon in fine particulate matter: A study of five European cities

[1] Fossil carbon in particulate matter comes from anthropogenic use and combustion of fossil fuels, while nonfossil carbon may originate from both biogenic (e.g., pollen, plant debris, fungal spores, and biogenic secondary organic aerosol (SOA)) and anthropogenic sources (e.g., cooking and residential wood combustion). We investigated the relative contributions of fossil and nonfossil sources to fine carbonaceous aerosols in five European cities by radiocarbon analysis of aerosol samples collected at four types of sites in 2002–2004. The average fraction of nonfossil carbon was 43 ± 11%, with the lowest fraction, 36 ± 7%, at urban curbside sites and the highest fraction, 54 ± 11%, at rural background sites, farthest away from the impact of man-made emissions. Generally, fossil carbon concentrations at urban curbside sites are elevated in comparison to background sites, which is expected because of their proximity to vehicular emissions. Contrary to what might be expected, the concentration of nonfossil carbon is also higher at curbside than at background sites. This may be attributable to differences between site categories in levels of primary biological aerosols, brake and tire wear in resuspended road dust, biofuels, emissions from cooking and residential wood combustion, or processes such as anthropogenic enhancement of biogenic SOA and increased partitioning of semivolatile compounds into the aerosol phase at urban sites. The exact causes should be investigated by future detailed source analyses.

Contributions of resuspended soil and road dust to organic carbon in fine particulate matter in the Midwestern US

Considerable uncertainty still exists regarding the contribution of resuspended soil and road dust to PM2.5 organic carbon (OC) in US urban areas. Contributing factors are the limited knowledge of the OC content of resuspended soils and road dusts, and the variability of the ratio of OC to traditional soil markers such as silicon and aluminum. This study investigates the composition of resuspended soils and road dusts in the Midwestern US, and the contributions of these soils to atmospheric PM2.5 OC. Paved road dust and soil samples were resuspended in a residence chamber from which PM2.5 size fractions were collected and analyzed to generate source profiles. Differences significant to 1 standard deviation were observed in the mass ratios between OC, and silicon and aluminum across different soil types which were larger between soil types within each city (61–97%), than between samples of the same soil type collected in different cities (29–57%). CMB 8.2 source apportionment results revealed large biases in soil apportionments, but these did not greatly affect the overall OC apportionments in six Midwest cities due to the small contributions of soil to total OC (ranging between 0.01 and 0.1 μg m−3). Apportionments of total PM2.5 mass were more greatly affected: biases up to 0.7 μg m−3 for total PM2.5 masses ranging between 7 and 14 μg m−3 were observed when soil profiles were interchanged.

Tracking sources and behaviors of water-soluble organic carbon in fine particulate matter measured at an urban site in Korea

PM 2.5 water-soluble organic carbon (WSOC) was measured over 24-h periods with organic carbon and elemental carbon (OC and EC) at an urban site in Gwangju, Korea, during summer (1 June–22 August 2008) and winter (26 November 2008–27 February 2009). The average mass concentrations of OC and WSOC were 5.0 ± 2.9 μg C m −3 and 2.8 ± 1.6 μg C m −3 during summer, respectively, and 8.4 ± 4.6 μg C m −3 and 3.7 ± 2.5 μg C m −3 during winter, respectively. The WSOC/EC and WSOC/OC ratios were 1.74 ± 0.60 and 0.55 ± 0.10 in summer, and 1.30 ± 0.70 and 0.43 ± 0.11 in winter, respectively. According to the results of air mass backward trajectory analysis, high fractions of WSOC to OC in the study region, compared to those reported in many other urban sites, could be explained by the atmospheric transport of water-soluble organic species from upwind regions, i.e., large-scale Steel Works and national industrial complexes located in the southeastern and eastern directions of the sampling site and northeastern regions (Beijing, Shenyang, and Shanghai) of China in the summer, and the northeastern regions of China in the winter. The secondary OC concentrations, estimated using the EC-tracer method, accounted for 26.9 ± 19.1% (0.0–65.0%) and 24.3 ± 19.5% (0.0–73.5%) of the measured OC in summer and winter, respectively. Higher correlation between secondary OC and WSOC was found in the summer ( R 2 = 0.78) than in the winter ( R 2 = 0.34), reflecting a high fraction of secondary WSOC in the summer. The entire winter sampling period was separated into two periods, i.e., winter periods “A” (Nov 26 2008–Jan 8 2009) and “B” (Jan 19–Feb 27 2009), due to the existence of open burning activities around the sampling site. Highly enriched behaviors of potassium ion (K + ) and WSOC concentrations during the winter “A” period are in accordance with the fact that open burning of wood and vegetation debris at a construction working place near the sampling site was occasionally observed. The moderate correlations between water- soluble K + and WSOC concentrations suggest that some of the WSOC observed during summer and winter could be attributed to the impact of biomass burning.

Sources of organic carbon in fine particulate matter in northern European urban air

Abstract. A major fraction of fine particle matter consists of organic carbon (OC) but its origin is still inadequately known. In this study the sources of OC were investigated in the northern European urban environment in Helsinki, Finland. Measurements were carried out over one year and they included both filter (PM1) and online methods. From the filter samples OC, elemental carbon (EC), water-soluble OC (WSOC), levoglucosan and major ions were analyzed. Filter data together with the concentrations of inorganic gases were analyzed by Positive matrix factorization (PMF) in order to find the sources of OC (and WSOC) on an annual as well as on a seasonal basis. In order to study the diurnal variation of sources, OC and EC were measured by a semicontinuous OC/EC analyzer and major ions were determined by a Particle-into-Liquid Sampler coupled to ion chromatographs. According to PMF, OC concentrations were impacted by four sources: biomass combustion, traffic, long-range transport and secondary production. On an annual basis the OC concentration was dominated by secondary organic aerosol (SOA). Its contribution to OC was as high as 64% in summer, which besides anthropogenic sources may also result from the large biogenic volatile organic carbon (VOC) emissions in the boreal region. In winter biomass combustion constituted the largest fraction in OC due to domestic wood combustion for heating purposes. Traffic contributed to OC from 15 to 27%. Regarding the diurnal variation, the contribution from traffic was higher from 08:00 to 18:00 on weekdays than on weekends. The contribution from long-range transport to OC was 24% on average. All four sources also influenced the WSOC concentrations, however, the contribution of SOA was significantly larger for WSOC than OC.