Publications by authors named "James J Schauer"

194 Publications

Chemical Investigation of Household Solid Fuel Use and Outdoor Air Pollution Contributions to Personal PM Exposures.

Environ Sci Technol 2021 Nov 24. Epub 2021 Nov 24.

Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, Wisconsin 53706, United States.

In communities with household solid fuel use, transitioning to clean stoves/fuels often results in only moderate reductions in fine particulate matter (PM) exposures; the chemical composition of those exposures may help explain why. We collected personal exposure (men and women) and outdoor PM samples in villages in three Chinese provinces (Shanxi, Beijing, and Guangxi) and measured chemical components, including water-soluble organic carbon (WSOC), ions, elements, and organic tracers. Source contributions from chemical mass balance modeling (biomass burning, coal combustion, vehicles, dust, and secondary inorganic aerosol) were similar between outdoor and personal PM samples. Principal component analysis of organic and inorganic components identified analogous sources, including a regional ambient source. Chemical components of PM exposures did not differ significantly by gender. Participants using coal had higher personal/outdoor (P/O) ratios of coal combustion tracers (picene, sulfate, As, and Pb) than those not using coal, but no such trend was observed for biomass burning tracers (levoglucosan, K, WSOC). Picene and most levoglucosan P/O ratios exceeded 1 even among participants not using coal and biomass, respectively, indicating substantial indirect exposure to solid fuel emissions from other homes. Contributions of community-level emissions to exposures suggest that meaningful exposure reductions will likely require extensive fuel use changes within communities.
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http://dx.doi.org/10.1021/acs.est.1c01368DOI Listing
November 2021

Prediction of the oxidation potential of PM exposures from pollutant composition and sources.

Environ Pollut 2021 Nov 13:118492. Epub 2021 Nov 13.

Department of Anesthesiology, Pain Medicine and Critical Care Medicine, Aviation General Hospital of China Medical University, Beijing, China.

The inherent oxidation potential (OP) of atmospheric particulate matter has been shown to be an important metric in assessing the biological activity of inhaled particulate matter and is associated with the composition of PM. The current study examined the chemical composition of 388 personal PM samples collected from students and guards living in urban and suburban areas of Beijing, and assessed the ability to predict OP from the calculated metrics of carcinogenic risk, represented by ELCR (excess lifetime cancer risk), non-carcinogenic risk represented by HI (hazard index), and the composition and sources of the particulate matter using multiple linear regression methods. The correlations between calculated ELCR and HI and the measured OP were 0.37 and 0.7, respectively. HI was a better predictor of OP than ELCR. The prediction models based on pollutants (Model_1) and pollution sources (Model_2) were constructed by multiple linear regression method, and Pearson correlation coefficients between the predicted results of Model_1 and Model_2 with the measured volume normalized OP are 0.81 and 0.80, showing good prediction ability. Previous investigations in Europe and North America have developed location-specific relationships between the chemical composition of particulate matter and OP using regression methods. We also examined the ability of relationships between composition and sources, developed in Europe and North America, to predict the OP of particulate matter in Beijing from the composition and sources determined in Beijing. The relationships developed in Europe and North America provided good predictive ability in Beijing and it suggests that these relationships can be used to predict OP from the chemical composition measured in other regions of the world.
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http://dx.doi.org/10.1016/j.envpol.2021.118492DOI Listing
November 2021

Source Apportionment of Fine Organic Particulate Matter (PM) in Central Addis Ababa, Ethiopia.

Int J Environ Res Public Health 2021 11 4;18(21). Epub 2021 Nov 4.

Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, WI 53706, USA.

The development of infrastructure, a rapidly increasing population, and urbanization has resulted in increasing air pollution levels in the African city of Addis Ababa. Prior investigations into air pollution have not yet sufficiently addressed the sources of atmospheric particulate matter. This study aims to identify the major sources of fine particulate matter (PM) and its seasonal contribution in Addis Ababa, Ethiopia. Twenty-four-hour average PM mass samples were collected every 6th day, from November 2015 through November 2016. Chemical species were measured in samples and source apportionment was conducted using a chemical mass balance (CMB) receptor model that uses particle-phase organic tracer concentrations to estimate source contributions to PM organic carbon (OC) and the overall PM mass. Vehicular sources (28%), biomass burning (18.3%), plus soil dust (17.4%) comprise about two-thirds of the PM mass, followed by sulfate (6.5%). The sources of air pollution vary seasonally, particularly during the main wet season (June-September) and short rain season (February-April): From motor vehicles, (31.0 ± 2.6%) vs. (24.7 ± 1.2%); biomass burning, (21.5 ± 5%) vs. (14 ± 2%); and soil dust, (11 ± 6.4%) vs. (22.7 ± 8.4%), respectively, are amongst the three principal sources of ambient PM mass in the city. We suggest policy measures focusing on transportation, cleaner fuel or energy, waste management, and increasing awareness on the impact of air pollution on the public's health.
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http://dx.doi.org/10.3390/ijerph182111608DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8583055PMC
November 2021

Oral cavity response to air pollutant exposure and association with pulmonary inflammation and symptoms in asthmatic children.

Environ Res 2021 Oct 26:112275. Epub 2021 Oct 26.

Nicholas School of the Environment, Duke University, Durham, NC, USA; Duke Global Health Institute, Duke University, Durham, NC, USA; Duke Kunshan University, Kunshan, Jiangsu Province, China. Electronic address:

Exposure to fine particulate matter (PM) and ozone (O) may lead to inflammation and oxidative damage in the oral cavity, which is hypothesized to contribute to the worsening of airway inflammation and asthma symptoms. In this panel study of 43 asthmatic children aged 5-13 years old, each child had 4 clinic visits with a 2-week interval between two consecutive visits. At each visit, saliva samples were collected and subsequently analyzed for interleukin 6 (IL-6) and eosinophil cationic protein (ECP) as biomarkers of inflammation and malondialdehyde (MDA) as a biomarker of oxidative stress in the oral cavity. At each visit, children were measured for fractional exhaled nitric oxide (FeNO) as a marker of pulmonary inflammation. Asthma symptoms of these children were measured using the Childhood Asthma Control Test (C-ACT). We found that an interquartile range (IQR) increase in 24-h average personal exposure to PM measured 1 and 2 days prior was associated with increased salivary IL-6 concentration by 3.0% (95%CI: 0.2%-6.0%) and 4.2% (0.7%-8.0%), respectively. However, we did not find a clear association between personal O exposure and any of the salivary biomarkers, except for a negative association between salivary MDA and O exposure measured 1 day prior. An IQR increase in salivary IL-6 concentration was associated with significantly increased FeNO by 28.8% (4.3%-53.4%). In addition, we found that increasing salivary IL-6 concentrations were associated with decreased individual and total C-ACT scores, indicating the worsening of asthma symptoms. We estimated that 13.2%-22.2% of the associations of PM exposure measured 1 day prior with FeNO and C-ACT scores were mediated by salivary IL-6. These findings suggest that the induction of inflammation in the oral cavity may have played a role in linking air pollution exposure with the worsening of airway inflammation and asthma symptoms.
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http://dx.doi.org/10.1016/j.envres.2021.112275DOI Listing
October 2021

Elemental composition of fine and coarse particles across the greater Los Angeles area: Spatial variation and contributing sources.

Environ Pollut 2022 Jan 12;292(Pt A):118356. Epub 2021 Oct 12.

Department of Environmental Health Sciences, Jonathan and Karin Fielding School of Public Health, University of California, Los Angeles, Los Angeles, CA, 90095, USA. Electronic address:

The inorganic components of particulate matter (PM), especially transition metals, have been shown to contribute to PM toxicity. In this study, the spatial distribution of PM elements and their potential sources in the Greater Los Angeles area were studied. The mass concentration and detailed elemental composition of fine (PM) and coarse (PM) particles were assessed at 46 locations, including urban traffic, urban community, urban background, and desert locations. Crustal enrichment factors (EFs), roadside enrichments (REs), and bivariate correlation analysis revealed that Ba, Cr, Cu, Mo, Pd, Sb, Zn, and Zr were associated with traffic emissions in both PM and PM, while Fe, Li, Mn, and Ti were affected by traffic emissions mostly in PM. The concentrations of Ba, Cu, Mo, Sb, Zr (brake wear tracers), Pd (tailpipe tracer), and Zn (associated with tire wear) were higher at urban traffic sites than urban background locations by factors of 2.6-4.6. Both PM and PM elements showed large spatial variations, indicating the presence of diverse emission sources across sampling locations. Principal component analysis extracted four source factors that explained 88% of the variance in the PM elemental concentrations, and three sources that explained 86% of the variance in the PM elemental concentrations. Based on multiple linear regression analysis, the contribution of traffic emissions (27%) to PM was found to be higher than mineral dust (23%), marine aerosol (18%), and industrial emissions (8%). On the other hand, mineral dust was the dominant source of PM with 45% contribution, followed by marine aerosol (22%), and traffic emissions (19%). This study provides novel insight into the spatial variation of traffic-related elements in a large metropolitan area.
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http://dx.doi.org/10.1016/j.envpol.2021.118356DOI Listing
January 2022

Cytotoxicity and chemical composition of women's personal PM exposures from rural China.

Environ Sci Atmos 2021 Sep 27;1(6):359-371. Epub 2021 Jul 27.

Department of Earth and Planetary Sciences, Weizmann Institute of Science Rehovot Israel

Personal exposure PM samples aid in determining the sources and chemical composition of real-world exposures, particularly in settings with household air pollution. However, their use in toxicological research is limited, despite uncertainty regarding health effects in these settings and evidence of differential toxicity among PM sources and components. This study used women's PM exposure samples collected using personal exposure monitoring in rural villages in three Chinese provinces (Beijing, Shanxi, and Sichuan) during summer and winter. Water-soluble organic carbon, ions, elements, and organic tracers ( levoglucosan and polycyclic aromatic hydrocarbons [PAHs]) were quantified in water and organic PM extracts. Human lung epithelial cells (A549) were exposed to the extracts. Cell death, reactive oxygen species (ROS), and gene expression were measured. Biomass burning contributions were higher in Sichuan samples than in Beijing or Shanxi. Some PM characteristics (total PAHs and coal combustion source contributions) and biological effects of organic extract exposures (cell death, ROS, and cytokine gene expression) shared a common trend of higher levels and effects in winter than in summer for Shanxi and Beijing but no seasonal differences in Sichuan. Modulation of phase I/AhR-related genes (cyp1a1 and cyp1b1) and phase II/oxidative stress-related genes (HO-1, SOD1/2, NQO-1, and catalase) was either low or insignificant, without clear trends between samples. No significant cell death or ROS production was observed for water extract treatments among all sites and seasons, even at possible higher concentrations tested. These results support organic components, particularly PAHs, as essential drivers of biological effects, which is consistent with some other evidence from ambient PM.
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http://dx.doi.org/10.1039/d1ea00022eDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8459644PMC
September 2021

Estimation of commercial cooking emissions in real-world operation: Particulate and gaseous emission factors, activity influencing and modelling.

Environ Pollut 2021 Nov 26;289:117847. Epub 2021 Jul 26.

College of Resources and Environment, University of Chinese Academy of Sciences, Beijing, 100049, China; CAS Center for Excellence in Regional Atmospheric Environment, Chinese Academy of Sciences, Xiamen, 361021, China; Yanshan Earth Critical Zone and Surface Fluxes Research Station, University of Chinese Academy of Sciences, Beijing, 101408, China. Electronic address:

Measurements of real-world cooking emission factors (CEFs) were rarely reported in recent year's studies. However, the needs for accurately estimating CEFs to produce cooking emission inventories and further implement controlling measures are urgent. In this study, we collected cooking emission aerosols from real-world commercial location operations in Beijing, China. 2 particulate (PM, OC) and 2 gaseous (NMHC, OVOCs) CEF species were examined on influencing activity conditions of cuisine type, controlling technology, operation scales (represented by cook stove numbers), air exhausting volume, as well as location and operation period. Measured NMHC emission factors (Non-barbecue: 8.19 ± 9.06 g/h and Barbecue: 35.48 ± 11.98 g/h) were about 2 times higher than PM emission factors (Non-barbecue: 4.88 ± 3.43 g/h and Barbecue: 15.48 ± 7.22 g/h). T-test analysis results showed a significantly higher barbecued type CEFs than non-barbecued cuisines for both particulate and gaseous emission factor species. The efficacy of controlling technology was showing an average of 50 % in decreasing PM CEFs while a 50 % in increasing OC particulate CEFs. The effects of controlling equipment were not significant in removing NMHC and OVOCs exhaust concentrations. CEF variations within cook stove numbers and air exhausting volume also reflected a comprehensive effect of operation scale, cuisine type and control technology. The simulations among activity influencing factors and CEFs were further determined and estimated using hierarchical multiple regression model. The R square of this simulated model for PM CEFs was 0.80 (6.17 × 10) with standardized regression coefficient of cuisine type, location, sampling period, control technology, cook stove number (N) and N of 5.18 (0.02), 5.33 (0.02), 1.93 (0.19), 9.29 (4.18 × 10), 9.10 (1.71 × 10) and -1.18 (2.43 × 10), respectively. In perspective, our study provides ways of better estimating CEFs in real operation conditions and potentially highlighting much more importance of cooking emissions on air quality and human health.
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http://dx.doi.org/10.1016/j.envpol.2021.117847DOI Listing
November 2021

Temporal trends in the spatial-scale contributions to black carbon in a Middle Eastern megacity.

Sci Total Environ 2021 Oct 9;792:148364. Epub 2021 Jun 9.

Civil and Environmental Engineering Department, University of Wisconsin-Madison, WI, USA.

The analysis of high-resolution changes in black carbon (BC) concentrations was examined to distinguish and quantify various spatial-scale contributions to BC concentrations from nearby sources within 1 km distance to ranges of emission sources distributed over a larger city scale spanning tens of kilometers. Our analysis illustrated that BC emissions on the neighborhood scale only contribute a minor fraction (~15%) to total BC concentrations in the megacity of Tehran. Approximately 62% of the total black carbon is part of the city emissions, and around 23% is transported into the city from local nearby surroundings. Our analysis in highly polluted areas, including industrial and traffic hotspots in Tehran, demonstrated that the contributions of the urban mixture were relatively smaller than the average (~56%) in highly polluted areas; however, larger local-scale (~30%) contributions were observed in these areas. Our analysis in traffic hotspot areas also demonstrated significantly smaller contributions of BC from neighborhood surroundings (~9%). These results imply that the city-scale BC emissions in Tehran are a major contributor to BC exposures even in locations with local high-emitting sources. Polar annulus analysis of BC from city-scales in Tehran showed a mixture of hotspot locations ranging from north to easterly directions implying that city-scale emissions contribute to wider pollution plume expansions and larger-scale transport and vertical mixing corresponding to mixtures of emitters located further away.
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http://dx.doi.org/10.1016/j.scitotenv.2021.148364DOI Listing
October 2021

Source attribution of air pollution using a generalized additive model and particle trajectory clusters.

Sci Total Environ 2021 Aug 23;780:146458. Epub 2021 Mar 23.

University of Wisconsin - Madison, Environmental Chemistry and Technology Program, Madison, WI, USA; Wisconsin State Laboratory of Hygiene, Madison, WI, USA.

Speciated hourly measurements of fine aerosols were made for more than two years at an urban, an industrial and a port site in Busan, Korea. A Generalized Additive Model (GAM) was designed to deconvolve factors contributing to the pollutant concentrations at multiple scales. The model yields estimates of source contributions to pollution by separately identifying the signals in the time series due to meteorology, vertical mixing, horizontal wind transport and temporal variations such as diurnal, weekly, seasonal and annual trends. The GAM model was expanded to include FLEXPART back trajectory clusters generated using fuzzy c-means clustering. This made it possible to quantify the impact of long-range transport using the Trajectory Cluster Contribution Function (TCCF). TCCF provides a development of methods such as Concentration Field Analysis and Potential Source Contribution Function by providing numerical estimates of concentration changes associated with different air mass transport patterns while accounting for possible confounding factors from meteorology. The GAM simulations identified the importance of local transport for primary pollutants and long-range transport from China for secondary pollutants. Local factors accounted for up to 72% of the variance in concentrations of NO and elemental carbon whereas large-scale/seasonal factors accounted for up to 56% of PM and 80% of inorganic species. The algorithm further identified the importance of the weekend effect and the holiday effect at the different sites in Busan. The residual from the analysis was used to estimate the impact of the COVID-19 pandemic. The signature of the pandemic was different between the pollutants as well as from site to site. The model was able to distinguish small impacts from local pollutants at the residential site; short-lived acute impacts from industrial changes; and longer-term changes due to the early pandemic response in China.
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http://dx.doi.org/10.1016/j.scitotenv.2021.146458DOI Listing
August 2021

Quantitative estimation of meteorological impacts and the COVID-19 lockdown reductions on NO and PM over the Beijing area using Generalized Additive Models (GAM).

J Environ Manage 2021 Aug 4;291:112676. Epub 2021 May 4.

Institute of Urban Meteorology, China Meteorological Administration, Beijing, China.

Unprecedented travel restrictions due to the COVID-19 pandemic caused remarkable reductions in anthropogenic emissions, however, the Beijing area still experienced extreme haze pollution even under the strict COVID-19 controls. Generalized Additive Models (GAM) were developed with respect to inter-annual variations, seasonal cycles, holiday effects, diurnal profile, and the non-linear influences of meteorological factors to quantitatively differentiate the lockdown effects and meteorology impacts on concentrations of nitrogen dioxide (NO) and fine particulate matters (PM) at 34 sites in the Beijing area. The results revealed that lockdown measures caused large reductions while meteorology offset a large fraction of the decrease in surface concentrations. GAM estimates showed that in February, the control measures led to average NO reductions of 19 μg/m and average PM reductions of 12 μg/m. At the same time, meteorology was estimated to contribute about 12 μg/m increase in NO, thereby offsetting most of the reductions as well as an increase of 30 μg/m in PM, thereby resulting in concentrations higher than the average PM concentrations during the lockdown. At the beginning of the lockdown period, the boundary layer height was the dominant factor contributing to a 17% increase in NO while humid condition was the dominant factor for PM concentrations leading to an increase of 65% relative to the baseline level. Estimated NO emissions declined by 42% at the start of the lockdown, after which the emissions gradually increased with the increase of traffic volumes. The diurnal patterns from the models showed that the peak of vehicular traffic occurred from about 12pm to 5pm daily during the strictest control periods. This study provides insights for quantifying the changes in air quality due to the lockdowns by accounting for meteorological variability and providing a reference in evaluating the effectiveness of control measures, thereby contributing to air quality mitigation policies.
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http://dx.doi.org/10.1016/j.jenvman.2021.112676DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8096144PMC
August 2021

Role of endogenous melatonin in pathophysiologic and oxidative stress responses to personal air pollutant exposures in asthmatic children.

Sci Total Environ 2021 Jun 6;773:145709. Epub 2021 Feb 6.

Nicholas School of the Environment, Duke University, Durham, NC, USA; Duke Global Health Institute, Duke University, Durham, NC, USA; Duke Kunshan University, Kunshan, Jiangsu Province, China. Electronic address:

Background: Heightening oxidative stress and inflammation is an important pathophysiological mechanism underlying air pollution health effects in people with asthma. Melatonin can suppress oxidative stress and inflammation in pulmonary and circulatory systems. However, the role of melatonin in the oxidative stress and physiological responses to air pollution exposure has not been examined in children with asthma.

Methods: In this panel study of 43 asthmatic children (5-13 years old), each child had 4 clinic visits with a 2-week interval between two consecutive visits. At each visit, urine samples were collected and subsequently analyzed for 6-sulfatoxymelatonin (aMT6s) as a surrogate of circulating melatonin and for malondialdehyde (MDA) and 8-hydroxy-2'-deoxyguanosine (8-OHdG) as two biomarkers of systemic oxidative stress. At each clinic visit, children were measured for pulmonary function and fractional exhaled nitric oxide (FeNO, a marker of pulmonary inflammation). None of the children reported to have taking melatonin supplementation. Concentrations of indoor and ambient PM and ozone (O) were combined with individual time-activity data to calculate personal air pollutant exposures.

Results: We found that interquartile range increases in urinary MDA and 8-OHdG concentrations were associated with significantly increased urinary aMT6s concentrations by 73.4% (95% CI: 52.6% to 97.0%) and 41.7% (22.8% to 63.4%), respectively. Increases in daily personal exposure to O and to PM were each associated with increased urinary aMT6s concentrations. Increasing urinary aMT6s concentrations were associated with decreased FeNO and resonant frequency, indicating improved airway inflammation and lung elasticity, respectively.

Conclusion: The results suggest that systemic oxidative stress heightened by air pollution exposure may stimulate melatonin excretion as a defense mechanism to alleviate the adverse effects.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145709DOI Listing
June 2021

Assessment of long-range oriented source and oxidative potential on the South-west shoreline, Korea: Molecular marker receptor models during shipborne measurements.

Environ Pollut 2021 Jul 23;281:116979. Epub 2021 Mar 23.

Department of Environmental Engineering, Mokpo National University, Muan, 58554, Republic of Korea. Electronic address:

In order to determine the quantitative contributions of PM on the South-west shoreline of Korea, filter based samplings were conducted in the summertime of 2017 and 2018 (total 32 days) via shipborne measurements using both a high volume and middle volume air sampler. Water-soluble organic carbon, water-soluble ions, organic carbon and elemental carbon, elemental species, and organic molecular markers by Liquid Chromatography-tandem Mass Spectrometry were utilized to characterize the collected substrates. The current study investigates the (1) chemical characteristics of PM, (2) source apportionment using positive matrix factorization (PMF), and (3) relationship between sources and the dithiothreitol (DTT) assay during the two sampling periods. A mean PM concentration of 19.3 μg/m was observed along the entire sampling route. The ratio of water-soluble to organic carbon implies that secondary aerosol formation is dominant. The result of methanesulfonic acid (MSA) suggests the contribution of a marine-oriented biogenic source of PM. The PMF source apportionment model showed six source categories with reasonably stable profiles: 1) sulfate-rich, 2) MSA-rich, 3) nitrate-rich, 4) secondary organic, 5) continental, and 6) biomass burning sources. The PMF showed three strong events (i.e., long-range transport, mixed (ocean and long-range stay), and domestic origin events) in the contributions of sources, as well as a dependence on wind transport. Higher associations with DTT oxidative potential normalized to PM mass concentration (DTT-OP) related to long-range transport, hence, confirming the impacts of the highest intrinsic oxidative potential.
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http://dx.doi.org/10.1016/j.envpol.2021.116979DOI Listing
July 2021

Source contributions to multiple toxic potentials of atmospheric organic aerosols.

Sci Total Environ 2021 Jun 4;773:145614. Epub 2021 Feb 4.

National Institute for Environmental Studies, Tsukuba, Japan.

Fine particulate matter (PM) in the atmosphere is of high priority for air quality management efforts to address adverse health effects in human. We believe that emission control policies, which are traditionally guided by source contributions to PM mass, should also consider source contributions to PM health effects or toxicity. In this study, we estimated source contributions to the toxic potentials of organic aerosols (OA) as measured by a series of chemical and in-vitro biological assays and chemical mass balance model. We selected secondary organic aerosols (SOA), vehicles, biomass open burning, and cooking as possible important OA sources. Fine particulate matter samples from these sources and parallel atmospheric samples from diverse locations and seasons in East Asia were collected for the study. The source and atmospheric samples were analyzed for chemical compositions and toxic potentials, i.e. oxidative potential, inflammatory potential, aryl hydrocarbon receptor (AhR) agonist activity, and DNA-damage, were measured. The toxic potentials per organic carbon (OC) differed greatly among source and ambient particulate samples. The source contributions to oxidative and inflammatory potentials were dominated by naphthalene-derived SOA (NapSOA), followed by open burning and vehicle exhaust. The AhR activity was dominated by open burning, followed by vehicle exhaust and NapSOA. The DNA damage was dominated by vehicle exhaust, followed by open burning. Cooking and biogenic SOA had smaller contributions to all the toxic potentials. Regarding atmospheric OA, urban and roadside samples showed stronger toxic potentials per OC. The toxic potentials of remote samples in summer were consistently very weak, suggesting that atmospheric aging over a long time decreased the toxicity. The toxic potentials of the samples from the forest and the experimentally generated biogenic SOA were low, suggesting that toxicity of biogenic primary and secondary particles is relatively low.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145614DOI Listing
June 2021

Personal Exposure to PM Oxidative Potential in Association with Pulmonary Pathophysiologic Outcomes in Children with Asthma.

Environ Sci Technol 2021 03 8;55(5):3101-3111. Epub 2021 Feb 8.

Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States.

Fine particulate matter (PM) with a higher oxidative potential has been thought to be more detrimental to pulmonary health. We aim to investigate the associations between personal exposure to PM oxidative potential and pulmonary outcomes in asthmatic children. We measured each of the 43 asthmatic children 4 times for airway mechanics, lung function, airway inflammation, and asthma symptom scores. Coupling measured indoor and outdoor concentrations of PM mass, constituents, and oxidative potential with individual time-activity data, we calculated 24 h average personal exposures 0-3 days prior to a health outcome measurement. We found that increases in daily personal exposure to PM oxidative potential were significantly associated with increased small, large, and total airway resistance, increased airway impedance, decreased lung function, and worsened scores of individual asthma symptoms and the total symptom score. Among the PM constituents, organic matters largely of indoor origin contributed the greatest to PM oxidative potential. Given that the variability in PM oxidative potential was a stronger driver than PM mass for the variability in the respiratory health outcomes, it is suggested to reduce PM oxidative potential, particularly by reducing the organic matter constituent of indoor PM, as a targeted source control strategy in asthma management.
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http://dx.doi.org/10.1021/acs.est.0c06114DOI Listing
March 2021

Determinants of personal exposure to PM and black carbon in Chinese adults: A repeated-measures study in villages using solid fuel energy.

Environ Int 2021 01 8;146:106297. Epub 2020 Dec 8.

Department of Epidemology, Biostatistics and Occupational Health, McGill University, Montreal, Quebec, Canada; Institute for Health and Social Policy, McGill University, Montreal, Canada. Electronic address:

Exposure to air pollution is a leading health risk factor. The variance components and contributions of indoor versus outdoor source determinants of personal exposure to air pollution are poorly understood, especially in settings of household solid fuel use. We conducted a panel study with up to 4 days of repeated measures of integrated gravimetric personal exposure to PM and black carbon in 787 men and women (ages 40-79) living in peri-urban villages in northern (Beijing and Shanxi) and southern (Guangxi) China. We simultaneously measured outdoor PM and collected questionnaire data on sociodemographic characteristics and indoor pollution sources including tobacco smoking and solid fuel stove use. We obtained over 2000 days of personal exposure monitoring which showed higher exposures in the heating season (geometric mean (GM): 108 versus 65 μg/m in the non-heating season for PM) and among northern participants (GM: 90 versus 59 μg/m in southern China in the non-heating season for PM). We used mixed-effects models to estimate within- and between-participant variance components and to assess the determinants of exposures. Within-participant variance in exposure dominated the total variability (68-95%). Outdoor PM was the dominant variable for explaining within-participant variance in exposure to PM (16%). Household fuel use (PM: 8%; black carbon: 10%) and smoking status (PM: 27%; black carbon: 5%) explained the most between-participant variance. Indoor sources (solid fuel stoves, tobacco smoking) were associated with 13-30% higher exposures to air pollution and each 10 μg/m increase in outdoor PM was associated with 6-8% higher exposure. Our findings indicate that repeated measurements of daily exposure are likely needed to capture longer-term exposures in settings of household solid fuel use, even within a single season, and that reducing air pollution from both outdoor and indoor sources is likely needed to achieve measurable reductions in exposures to air pollution.
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http://dx.doi.org/10.1016/j.envint.2020.106297DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7762838PMC
January 2021

Chemical Characterization and Seasonality of Ambient Particles (PM) in the City Centre of Addis Ababa.

Int J Environ Res Public Health 2020 09 24;17(19). Epub 2020 Sep 24.

Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, WI 53706, USA.

Ambient air pollution is a growing public health concern in major African cities, including Addis Ababa (Ethiopia), where little information is available on fine particulate matter (PM, with aerodynamic diameter <2.5 µm) pollution. This paper aims to characterize annual PM, including bulk composition and seasonal patterns, in Addis Ababa. We collected 24-h PM samples in the central city every 6 days from November 2015 to November 2016. The mean (±SD) daily PM concentration was 53.8 (±25.0) µg/m, with 90% of sampled days exceeding the World Health Organization's guidelines. Principal components were organic matter (OM, 44.5%), elemental carbon (EC, 25.4%), soil dust (13.5%), and SNA (sulfate, nitrate, and ammonium ions, 8.2%). Higher PM concentrations were observed during the heavy rain season, while crustal dust concentrations ranged from 2.9 to 37.6%, with higher levels during dry months. Meteorological variables, vehicle emissions, biomass fuels, unpaved roads, and construction activity contribute to poor air quality. Compared to the Air Quality Index (AQI), 31% and 36% of observed days were unhealthy for everyone and unhealthy for sensitive groups, respectively. We recommend adopting effective prevention strategies and pursuing research on vehicle emissions, biomass burning, and dust control to curb air pollution in the city.
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http://dx.doi.org/10.3390/ijerph17196998DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7579520PMC
September 2020

Children's microenvironmental exposure to PM and ozone and the impact of indoor air filtration.

J Expo Sci Environ Epidemiol 2020 11 22;30(6):971-980. Epub 2020 Sep 22.

Duke University, Civil and Environmental Engineering, 121 Hudson Hall, Box 90287, Durham, NC, 27708, USA.

Background: In highly polluted urban areas, personal exposure to PM and O occur daily in various microenvironments. Identifying which microenvironments contribute most to exposure can pinpoint effective exposure reduction strategies and mitigate adverse health impacts.

Methods: This work uses real-time sensors to assess the exposures of children with asthma (N = 39) in Shanghai, quantifying microenvironmental exposure to PM and O. An air cleaner was deployed in participants' bedrooms where we hypothesized exposure could be most efficiently reduced. Monitoring occurred for two 48-h periods: one with bedroom filtration (portable air cleaner with HEPA and activated carbon filters) and the other without.

Results: Children spent 91% of their time indoors with the majority spent in their bedroom (47%). Without filtration, the bedroom and classroom environments were the largest contributors to PM exposure. With filtration, bedroom PM exposure was reduced by 75% (45% of total exposure). Although filtration status did not impact O, the largest contribution of O exposure also came from the bedroom.

Conclusions: Actions taken to reduce bedroom PM and O concentrations can most efficiently reduce total exposure. As real-time pollutant monitors become more accessible, similar analyses can be used to evaluate new interventions and optimize exposure reductions for a variety of populations.
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http://dx.doi.org/10.1038/s41370-020-00266-5DOI Listing
November 2020

Malondialdehyde in Nasal Fluid: A Biomarker for Monitoring Asthma Control in Relation to Air Pollution Exposure.

Environ Sci Technol 2020 09 3;54(18):11405-11413. Epub 2020 Sep 3.

Nicholas School of the Environment, Duke University, Durham, North Carolina 27708, United States.

Fine particulate matter (PM) and ozone (O) may exert oxidative damage in the nose, which is hypothesized to be associated with worsened asthma symptoms. This study, hence, is to explore whether an oxidative stress biomarker, malondialdehyde (MDA) in the nasal fluid, has the potential to aid personalized asthma control. In a panel study of 43 asthmatic children, 5-13 years old, each child was measured 4 times with a 2-week interval between consecutive clinic visits. At each visit, nasal fluid and urine samples were collected, and fractional exhaled nitric oxide (FeNO) was measured as a biomarker of pulmonary inflammation. In addition to nasal MDA, urinary MDA and 8-hydroxy-2'-deoxyguanosine (8-OHdG) were measured as biomarkers of systemic oxidative stress. We also assessed asthma symptoms using the Childhood Asthma-Control Test (C-ACT). We found that interquartile range (IQR) increases in 24 h average personal PM exposure (22.2-33.5 μg/m), estimated 0 to 5 days prior to a clinic visit, were associated with increased nasal MDA concentrations by 38.6-54.9%. Similarly, IQR increases in 24 h average personal O exposure (7.7-8.2 ppb) estimated 2 to 4 days prior were associated with increased nasal MDA by 22.1-69.4%. Only increased PM exposure was associated with increased FeNO. Increased nasal MDA concentration was associated with decreased total and individual C-ACT scores, indicating worsening of asthma symptoms. However, no significant associations were observed between urinary MDA or 8-OHdG and C-ACT scores. The results confirm that oxidative stress plays an important role in linking air pollution exposure and adverse respiratory health effects. These findings support that MDA in the nasal fluid may serve as a useful biomarker for monitoring asthma status, especially in relation to PM and O exposures, two known risk factors of asthma exacerbation.
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http://dx.doi.org/10.1021/acs.est.0c02558DOI Listing
September 2020

Investigating Cumulative Exposures among 3- to 4-Year-Old Children Using Wearable Ultrafine Particle Sensors and Language Environment Devices: A Pilot and Feasibility Study.

Int J Environ Res Public Health 2020 07 21;17(14). Epub 2020 Jul 21.

Human Development and Family Studies Department, School of Human Ecology, University of Wisconsin-Madison, Madison, WI 53706, USA.

Interdisciplinary approaches are needed to measure the additive or multiplicative impacts of chemical and non-chemical stressors on child development outcomes. The lack of interdisciplinary approaches to environmental health and child development has led to a gap in the development of effective intervention strategies. It is hypothesized that a broader systems approach can support more effective interventions over time. To achieve these goals, detailed study protocols are needed. Researchers in child development typically focus on psychosocial stressors. Less attention is paid to chemical and non-chemical stressors and how the interaction of these stressors may impact child development. This feasibility study aims to bridge the gap between child development and environmental epidemiology research by trialing novel methods of gathering ultrafine particle data with a wearable air sensor, while simultaneously gathering language and noise data with the Language Environment Analysis (LENA) system. Additionally, psychosocial data (e.g., parenting quality, caregiver depression, and household chaos) was gathered from parent reports. Child participants (age 3-4 years) completed cognitive tasks to assess self-regulation and receptive language skills, and provided a biospecimen analyzed for inflammatory biomarkers. Data collection was completed at two time points, roughly corresponding to fall and spring. Twenty-six participants were recruited for baseline data, and 11 participants completed a follow-up session. Preliminary results indicate that it is feasible to gather personal Particulate Matter (PM2.5), language, and noise data, cognitive assessments, and biospecimens from our sample of 3-4-year-old children. While there are obstacles to overcome when working with this age group, future studies can benefit from adapting lessons learned regarding recruitment strategies, study design, and protocol implementation.
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http://dx.doi.org/10.3390/ijerph17145259DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7400160PMC
July 2020

Real-time measurements of PM and ozone to assess the effectiveness of residential indoor air filtration in Shanghai homes.

Indoor Air 2021 01 27;31(1):74-87. Epub 2020 Jul 27.

Civil and Environmental Engineering, Duke University, Durham, NC, USA.

Portable air cleaners are increasingly used in polluted areas in an attempt to reduce human exposure; however, there has been limited work characterizing their effectiveness at reducing exposure. With this in mind, we recruited forty-three children with asthma from suburban Shanghai and deployed air cleaners (with HEPA and activated carbon filters) in their bedrooms. During both 2-week filtration and non-filtration periods, low-cost PM and O air monitors were used to measure pollutants indoors, outdoors, and for personal exposure. Indoor PM concentrations were reduced substantially with the use of air cleaners, from 34 ± 17 to 10 ± 8 µg/m , with roughly 80% of indoor PM estimated to come from outdoor sources. Personal exposure to PM was reduced from 40 ± 17 to 25 ± 14 µg/m . The more modest reductions in personal exposure and high contribution of outdoor PM to indoor concentrations highlight the need to reduce outdoor PM and/or to clean indoor air in multiple locations. Indoor O concentrations were generally low (mean = 8±4 ppb), and no significant difference was seen by filtration status. The concentrations of pollutants and the air cleaner effectiveness were highly variable over time and across homes, highlighting the usefulness of real-time air monitors for understanding individual exposure reduction strategies.
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http://dx.doi.org/10.1111/ina.12716DOI Listing
January 2021

Source Apportionment of Coarse Particulate Matter (PM) in Yangon, Myanmar.

Int J Environ Res Public Health 2020 06 10;17(11). Epub 2020 Jun 10.

Occupational and Environmental Health Division, Department of Public Health, Ministry of Health and Sports, Nay Pyi Taw, Myanmar.

The Republic of the Union of Myanmar is one of many developing countries facing concerns about particulate matter (PM). Previously, a preliminary study of PM in 2018 suggested that the main source of PM in Yangon, the former capital, was vehicle emissions. However, this suggestion was not supported by any chemical composition data. In this study, to fill that gap, we quantitatively determined source contributions to coarse particulate matter (PM) in Yangon, Myanmar. PM samples were collected in Yangon from May 2017 to April 2018 and chemically analyzed to determine composition. Chemical composition data for these samples were then used in the Chemical Mass Balance (CMB) model to identify the major sources of particulate matter in this area. The results indicate that PM composition varies seasonally according to both meteorological factors (e.g., precipitation and temperature) and human activities (e.g., firewood and yard waste burning). The major sources of PM in Yangon annually were dust, secondary inorganic aerosols (SIA), and secondary organic aerosols (SOA), while contributions from biomass burning were more important during the winter months.
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http://dx.doi.org/10.3390/ijerph17114145DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7312491PMC
June 2020

Associations between source-resolved PM and airway inflammation at urban and rural locations in Beijing.

Environ Int 2020 06 12;139:105635. Epub 2020 May 12.

Department of Anesthesiology, Pain Medicine and Critical Care Medicine, Aviation General Hospital of China Medical University, Beijing, China.

Background: A large number of research studies have explored the health effects of exposure to atmospheric particulate matter. However, limited quantitative evidence has linked specific sources of personal PM directly to adverse health effects. This study was conducted in order to examine the association between airway inflammation and personal exposure to PM mass, components, and sources among two healthy cohorts living in both urban and rural areas of Beijing, China.

Methods: We conducted a follow-up study during the summer of 2016 and the winter of 2016/2017 among 92 students and 43 guards. 24-h personal and ambient exposure to PM and fractional exhaled nitric oxide (FeNO) were measured at least twice for each participant. Chemical components of 385 personal PM exposure samples were analyzed, and pollution sources were resolved by a positive matrix factorization (PMF) receptor model. We have constructed linear mixed effect models to evaluate the association between ambient/personal PM mass, chemical constituents, and source specific PM with FeNO after controlling for temperature, relative humidity, sites, season, and potential individual confounders.

Results: Interquartile range (IQR) increase in household heating sources was associated with increased FeNO (2.72%; 95% CI = 1.26-4.17%) across two sites. IQR increase in roadway transport was associated with increased FeNO (9.84%; 95% CI = 2.69-17%) in urban areas; IQR increase in Secondary inorganic sources and Industrial/Combustion sources were associated with increased FeNO (7.96%; 95% CI = 1.47-14.4%% and 7.85%; 95% CI = 0.0676-15.6%, respectively) in rural areas. Personal exposure to EC, OC, and some trace elements (Se, Pb, Bi, Cs) were also estimated to be significantly associated with the increase of FeNO. In addition, there was no significant difference (P > 0.05) between the effects of ambient and personal PM mass.

Conclusions: Although personal PM mass was not significantly associated with the health effects, airway inflammation can be linked to source-resolved exposures.
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http://dx.doi.org/10.1016/j.envint.2020.105635DOI Listing
June 2020

Association Between Bedroom Particulate Matter Filtration and Changes in Airway Pathophysiology in Children With Asthma.

JAMA Pediatr 2020 06;174(6):533-542

Nicholas School of the Environment, Duke University, Durham, North Carolina.

Importance: Fine particles (particulate matter 2.5 μm [PM2.5]), a ubiquitous air pollutant, can deposit in the small airways that play a vital role in asthma. It appears to be unknown whether the use of a PM2.5 filtration device can improve small airway physiology and respiratory inflammation in children with asthma.

Objective: To discover what pathophysiological changes in the small airways are associated with using a PM2.5-removing device in the bedrooms of children with asthma.

Design, Setting, And Participants: Children with mild or moderate asthma were enrolled in this double-blind, crossover study. The participants used a true filtration device and a sham filtration device in their bedrooms in a random order for 2 weeks each with a 2-week washout interval. The study was conducted in a suburb of Shanghai, China, during a low-ozone season.

Exposures: Ozone and PM2.5 were measured inside bedrooms and outside a window.

Main Outcomes And Measures: Impulse oscillometry, spirometry, and fractional exhaled nitric oxide were measured at the beginning and the end of each intervention. Peak expiratory flow was measured twice daily at home.

Results: Forty-three children (5-13 years old; 26 boys [60%]) participated. Outdoor 24-hour mean PM2.5 concentrations were moderately high, ranging from 28.6 to 69.8 μg/m3 (median, 53 μg/m3). During true filtration, bedroom PM2.5 concentrations were a mean (SD) of 63.4% (35.9%) lower than during sham filtration. Compared with sham filtration, true filtration was significantly associated with improved airway mechanics, reflected in a 24.4% (95% CI, 11.8%-37.1%) reduction in total airway resistance, a 43.5% (95% CI, 13.7%-73.3%) reduction in small airway resistance, a 22.2% (95% CI, 2.2%-42.2%) reduction in resonant frequency, and a 73.1% (95% CI, 0.3%-145.8%) increase in airway reactance. True filtration was also associated with significant improvements in fractional exhaled nitric oxide (a 27.6% [95% CI, 8.9%-42.4%] reduction) and peak expiratory flow (a 1.6% [95% CI, 0.8%-2.5%] increase). These improvements were significantly associated with bedroom PM2.5 reduction. Improvements in small airway function were nonsignificant (8.4% [95% CI, -1.4% to 18.3%]) in all participants but significant (13.2% [95% CI, 1.2%-25.1%]) in participants without eosinophilic airway inflammation at baseline. No improvements were observed for forced vital capacity, forced expiratory volume during the first second, and the ratio of these in all participants or subgroups.

Conclusions And Relevance: Per these results, indoor PM2.5 filtration can be a practical method to improve air flow in an asthmatic lung through improved airway mechanics and function as well as reduced inflammation. This warrants a clinical trial to confirm.

Trial Registration: ClinicalTrials.gov Identifier: NCT03282864.
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http://dx.doi.org/10.1001/jamapediatrics.2020.0140DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7136863PMC
June 2020

Changes in ozone photochemical regime in Fresno, California from 1994 to 2018 deduced from changes in the weekend effect.

Environ Pollut 2020 Aug 20;263(Pt A):114380. Epub 2020 Mar 20.

University of Wisconsin - Madison, Environmental Chemistry and Technology Program, Madison, WI, USA; Wisconsin State Laboratory of Hygiene, Madison, WI, USA.

Significant progress has been made in reducing emissions of air pollutants in the San Joaquin Valley in California. Nevertheless, from May to October, the valley still experiences numerous exceedances of the ozone health standard. As the standards are tightened, it is becoming harder to design policies to attain them. To better understand historical emissions reductions in the context of necessary future control efforts, we analyze 25 years of hourly measurements of ozone and nitrogen oxides concentrations for the hottest one third of days in Fresno using multiple linear regression analysis. We then analyze the changing dynamics of the weekend effect over the years in order to evaluate the growing importance of day-to-day carryover on ozone concentrations. A simplified model of the day-of-week pattern of ozone concentrations is used to explore the impact of same-day and previous-day concentrations. In addition to ozone, O (O + NO) is used to distinguish reductions of atmospheric oxidants from short-duration exchanges between O and NO. The analysis shows that there has been a significant increase in the importance of day-to-day carryover on ozone levels, and that consequently the ozone weekend effect in Fresno has changed over the last 25 years. In the 1990s, lower NO on the weekend led to increased ozone on Saturdays and Sundays but levels of O remained constant. In the 2010s, lower weekend NO led to reduced ozone on Saturdays, Sundays and Mondays showing that reductions in primary pollutants are sufficient to yield immediate decreases in secondary pollutants. Overall, the photochemical regime in the atmosphere has evolved such that carryover and regional pollution will be increasingly important in determining local ozone concentrations. Policies will therefore need to pay greater attention to regional emissions as local reductions may not be sufficient to meet the health standard.
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http://dx.doi.org/10.1016/j.envpol.2020.114380DOI Listing
August 2020

Associations of personal exposure to air pollutants with airway mechanics in children with asthma.

Environ Int 2020 05 13;138:105647. Epub 2020 Mar 13.

Nicholas School of the Environment and Duke Global Health Institute, Duke University, Durham, NC, USA; Duke Global Health Institute, Duke University, Durham, NC, USA; Global Health Research Center, Duke Kunshan University, Kunshan, Jiangsu Province, China. Electronic address:

Background: The importance of airway mechanics has been increasingly recognized in pediatric asthma. However, no studies have examined responses of airway mechanics to air pollution exposure in asthmatic children.

Methods: In this panel study involving indoor air filtration manipulation that created a large gradient of personal exposure to PM, the airway mechanics and lung function of 43 asthmatic children 5-13 years old in a suburb of Shanghai were measured four times within 3 consecutive months. Concentrations of indoor and outdoor PM and ozone were coupled with individual time-activity data to calculate personal exposures. Linear mixed effects models were used to examine the relationships of personal exposure with indicators of airway mechanics and lung function, respectively.

Results: An interquartile range (IQR) increase in 24-hour average PM personal exposure (30.3 µg/m) in the prior day was associated with significant increases in small airway resistance (R-R) of 15.8%, total airway resistance (R) of 6.3%, and airway inflammation (FeNO) of 9.6%. These associations were stronger in children with lower blood eosinophil counts (<450/µL). No significant associations were found between personal PM exposure and lung function. Low-level ozone exposure (daily maximum 8-hour exposure range 1.1-56.4 ppb) was not significantly associated with any of the outcomes.

Conclusion: Changes in personal PM exposure, partly enhanced by air filtration, were associated with significant changes in airway resistance and inflammation in children with asthma. These findings suggest the importance of reducing PM exposure, via personal air quality management, in improving airflow limitation in the airways, especially the small airways.
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http://dx.doi.org/10.1016/j.envint.2020.105647DOI Listing
May 2020

Impacts of Sources on PM Oxidation Potential during and after the Asia-Pacific Economic Cooperation Conference in Huairou, Beijing.

Environ Sci Technol 2020 03 10;54(5):2585-2594. Epub 2020 Feb 10.

College of Resources and Environment, University of Chinese Academy of Sciences, Beijing 100049, China.

To illustrate the major sources responsible for the redox activity of ambient fine particles during the 2014 Asia-Pacific Economic Cooperation (APEC) conference in Beijing, 3 months of daytime (8:00-19:30 LST) and nighttime (20:00-7:30 LST) particulate kmatter (PM) was collected in Huairou, Beijing from November 3, 2014 through January 31, 2015. PM compositions were analyzed, including elements, organic carbon, elemental carbon, water-soluble ions, organics, and redox activities measured by both the dithiothreitol and the macrophage reactive oxygen species (ROS) assays. The mass-normalized redox activity was approximately constant during the noncontrol period (NCP) and control period (CP). The absolute value of the volume-normalized redox activity was about 4 times higher during NCP than that during CP, indicating the effectiveness of the control measures. The statistical analysis results showed that an interquartile range increase in PM mass, chemicals, and sources (μg/m) was associated with the 1-3% increase in redox activity, indicating that the successful control did make a significant reduction in redox activity but did not elucidate that some source controls (i.e., vehicle emissions) could be more effective at reducing redox activity than other control programs (i.e., dust source). This study demonstrated that combustion particles from both solid fuels and liquid fuels could contribute to ROS generation. Furthermore, ROS could be formed in the atmosphere via photochemical reactions, which highlights the need to further research on their formation pathways. A better understanding of the relevant mechanistic pathways and different source contributors to ROS will help to guide strategies for targeted mitigation of the atmospheric oxidation potential and will also help to reduce the great disease stress caused by exposure to air pollution.
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http://dx.doi.org/10.1021/acs.est.9b05468DOI Listing
March 2020

Occurrence of estrogens, androgens and progestogens and estrogenic activity in surface water runoff from beef and dairy manure amended crop fields.

Sci Total Environ 2020 Mar 20;710:136247. Epub 2019 Dec 20.

University of Wisconsin - Madison, Environmental Chemistry and Technology, 680 North Park Street, Madison, WI 53706, United States of America; Wisconsin State Laboratory of Hygiene, Environmental Health Division, 2601 Agriculture Drive, Madison, WI 53718, United States of America.

Hormone contamination of aquatic systems has been shown to cause reproductive impairment of aquatic organisms. To assess to what extent beef and dairy farms represent a source of hormones to the aquatic environment, surface water runoff samples from three beef and dairy farms that utilize best manure management practices were evaluated for hormone concentrations (estrogens, androgens, progestogens) and estrogenic activity. Runoff was collected from weirs at the edge of each of six study fields from March 2008 to March 2010 and was analyzed for hormone concentrations using liquid chromatography with tandem mass spectrometry and for estrogenic activity using the E-screen bioassay. The majority of runoff events occurred in February and March when the soil was frozen. Progesterone and 4-androstenedione were the most frequently detected hormones (63% and 50%, respectively) and occurred at event loads up to 49,000 μg/ha and 26,000 μg/ha, respectively. Progesterone, 4-androstenedione, 17α-estradiol had the highest event load concentrations and were found at the field that sustained dairy cattle grazing during the winter and were likely due to application of excreta on frozen soil. The high progesterone event loads could lead to concentrations in receiving streams that exceed the lowest observable effects concentrations for fish. There was a consistent association with the elevated zearalenone presence and corn production. The synthetic hormones, 17α-trenbolone and 17β-trenbolone, were not detected in runoff from the beef farm that utilized trenbolone acetate implants, which is likely due to their short half lives. Estrogenic activity in runoff samples ranged from 0.09 to 133 ng/L estradiol equivalents, with 39% of runoff events exceeding the 2 ng/L predicted-no-effect-concentration for fish. These results indicate that grazing cattle and application of manure to frozen fields present the greatest risk to elevated hormones in runoff and that progesterone is the primary hormone of concern from beef and dairy operations.
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http://dx.doi.org/10.1016/j.scitotenv.2019.136247DOI Listing
March 2020

Impacts of stove/fuel use and outdoor air pollution on chemical composition of household particulate matter.

Indoor Air 2020 03 13;30(2):294-305. Epub 2020 Jan 13.

Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, WI, USA.

Biomass combustion for cooking and heating releases particulate matter (PM ) that contributes to household air pollution. Fuel and stove types affect the chemical composition of household PM, as does infiltration of outdoor PM. Characterization of these impacts can inform future exposure assessments and epidemiologic studies, but is currently limited. In this study, we measured chemical components of PM (water-soluble organic matter [WSOM], ions, black carbon, elements, organic tracers) in rural Chinese households using traditional biomass stoves, semi-gasifier stoves with pelletized biomass, and/or non-biomass stoves. We distinguished households using one stove type (traditional, semi-gasifier, or LPG/electric) from those using multiple stoves/fuels. WSOM concentrations were higher in households using only semi-gasifier or traditional stoves (31%-33%) than in those with exclusive LPG/electric stove (13%) or mixed stove use (12%-22%). Inorganic ions comprised 14% of PM in exclusive LPG/electric households, compared to 1%-5% of PM in households using biomass. Total PAH content was much higher in households that used traditional stoves (0.8-2.8 mg/g PM) compared to those that did not (0.1-0.3 mg/g PM). Source apportionment revealed that biomass burning comprised 27%-84% of PM in households using biomass. In all samples, identified outdoor sources (vehicles, dust, coal combustion, secondary aerosol) contributed 10%-20% of household PM .
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http://dx.doi.org/10.1111/ina.12636DOI Listing
March 2020

Source apportionment of fine particulate matter in a Middle Eastern Metropolis, Tehran-Iran, using PMF with organic and inorganic markers.

Sci Total Environ 2020 Feb 21;705:135330. Epub 2019 Nov 21.

Laboratory of Atmospheric Chemistry, Paul Scherrer Institute (PSI), 5232 Villigen-PSI, Switzerland. Electronic address:

With over 8 million inhabitants and 4 million motor vehicles on the streets, Tehran is one of the most crowded and polluted cities in the Middle East. Frequent exceedances of national daily PM limit have been reported in this city during the last decade, yet, the chemical composition and sources of fine particles are poorly determined. In the present study, 24-hour PM samples were collected at two urban sites during two separate campaigns, a one-year period from 2014 to 2015 and another three-month period at the beginning of 2017. Concentrations of organic carbon (OC), elemental carbon (EC), inorganic ions, trace metals and specific organic molecular markers were measured by chemical analysis of filter samples. The dominant mass components were organic matter (OM), sulfate and EC. With a 20% water-soluble organic carbon (WSOC) fraction, the predominance of primary anthropogenic sources (i.e. fossil fuel combustion) was anticipated. A positive matrix factorization (PMF) analysis using the ME-2 (Multilinear Engine-2) solver was then applied to this dataset. 5 factors were identified by Marker-PMF, named as traffic exhaust (TE), biomass burning (BB), industries (Ind.), nitrate-rich and sulfate-rich. Another 4 factors were identified by Metal-PMF, including, dust, vehicles (traffic non-exhaust, TNE), industries (Ind.) and heavy fuel combustion (HFC). Traffic exhaust was the dominant source with 44.5% contribution to total quantified PM mass. Sulfate-rich (24.2%) and nitrate-rich (18.4%) factors were the next major contributing sources. Dust (4.4%) and biomass burning (6.7%) also had small contributions while the total share of all other factors was < 2%. Investigating the correlations of different factors between the two sampling sites showed that traffic emissions and biomass burning were local, whereas dust, heavy fuel combustion and industrial sources were regional. Results of this study indicate that gas- and particle-phase pollutants emitted from fossil fuel combustion (mobile and stationary) are the principal origin of both primary and secondary fine aerosols in Tehran.
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http://dx.doi.org/10.1016/j.scitotenv.2019.135330DOI Listing
February 2020

The impact of household air cleaners on the oxidative potential of PM and the role of metals and sources associated with indoor and outdoor exposure.

Environ Res 2020 02 13;181:108919. Epub 2019 Nov 13.

Environmental Chemistry and Technology Program, University of Wisconsin-Madison, Madison, WI, 53706, USA; Wisconsin State Laboratory of Hygiene, University of Wisconsin-Madison, Madison, WI, 53718, USA. Electronic address:

The health effects associated with human exposure to airborne fine particulate matter (PM) have been linked to the ability of PM to facilitate the production of excess cellular reactive oxygen species (oxidative potential). Concern about the adverse human health impacts of PM has led to the increased use of indoor air cleaners to improve indoor air quality, which can be an important environment for PM exposure. However, the degree to which the oxidative potential of indoor and personal PM can be influenced by an indoor air cleaner remains unclear. In this study we enrolled 43 children with physician diagnosed asthma in suburban Shanghai, China and collected two paired-sets of 48-h indoor, outdoor, and personal PM exposure samples. One set of samples was collected under "real filtration" during which a functioning air cleaner was installed in the child's bedroom, and the other ("false filtration") with an air cleaner without internal filters. The PM samples were characterized by inductively coupled plasma mass spectroscopy for elements, and by an alveolar macrophage assay for oxidative potential. The sources of metals contributing to our samples were determined by the EPA Positive Matrix Factorization model. The oxidative potential was lower under real filtration compared to sham for indoor (median real/sham ratio: 0.260) and personal exposure (0.813) samples. Additionally, the sources of elements in PM that were reduced indoors and personal exposure samples by the air cleaner (e.g. regional aerosol and roadway emissions) were found by univariate multiple regression models to be among those contributing to the oxidative potential of the samples. An IQR increase in the regional aerosol and roadway emissions sources was associated with a 107% (95% CI: 80.1-138%) and 38.1% (17.6-62.1%) increase in measured oxidative potential respectively. Our results indicate that indoor air cleaners can reduce the oxidative potential of indoor and personal exposure to PM, which may lead to improved human health.
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http://dx.doi.org/10.1016/j.envres.2019.108919DOI Listing
February 2020
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