Publications by authors named "Guofeng Shen"

149 Publications

Substantial leakage into indoor air from on-site solid fuel combustion in chimney stoves.

Environ Pollut 2021 Sep 10;291:118138. Epub 2021 Sep 10.

Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China; School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen, 518055, China.

Exposure to household air pollution (HAP) from solid fuel use (SFU) causes millions of premature deaths globally. Direct leakage from stoves into indoor air is believed to be the main cause of severe HAP. However, previous laboratory-based measurements reported leakage of minimal fractions from wood fuel combustion. Using a newly developed measurement method, on-site measurements were conducted to quantitatively evaluate the leakage of gases and particulate matter from different fuel-stove combinations. The fraction of indoor leakage to the total emission (F) of the measured air pollutants varied from 23 ± 11% to 40 ± 16% for different pollutants and fuel-stove combinations, and these were significantly higher than previously lab-based results. Fuel differences overwhelmed stove differences in influencing F values, with higher values from biomass burning than from coal combustion. The particles had higher F values than gases. Fugitive emission rates (ERs) were log-normally distributed, and biomass burning had higher ERs than coal burning. Indoor PM (fine particulate matter) and CO (carbon monoxide) concentrations measured during the burning period increased by nearly 1-2 orders of magnitude compared to concentrations before or after burning, confirming substantially high indoor leakage from fuel combustion in cookstoves. High fugitive emissions in indoor cookstoves quantified from the present on-site measurements effectively explain the high HAP levels observed in rural SFU households, and call for interventions to improve indoor air quality.
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http://dx.doi.org/10.1016/j.envpol.2021.118138DOI Listing
September 2021

Proton resonance frequency-based thermometry for aqueous and adipose tissues.

Med Phys 2021 Sep 1. Epub 2021 Sep 1.

Department of Physics, Soochow University, Taipei.

Purpose: The proton resonance frequency (PRF)-based thermometry uses heating-induced phase variations to reconstruct magnetic resonance (MR) temperature maps. However, the measurements of the phase differences may be corrupted by the presence of fat due to its phase being insensitive to heat. The work aims to reconstruct the PRF-based temperature maps for tissues containing fat.

Methods: This work proposes a PRF-based method that eliminates the fat's phase contribution by estimating the temperature-insensitive fat vector. A vector in a complex domain represents a given voxel's magnetization from an acquired, complex MR image. In this method, a circle was fit to a time series of vectors acquired from a heated region during a heating experiment. The circle center served as the fat vector, which was then subtracted from the acquired vectors, leaving only the temperature-sensitive vectors for thermal mapping. This work was verified with the gel phantoms of 10%, 15%, and 20% fat content and the ex vivo phantom of porcine abdomen tissue during water-bath heating. It was also tested with an ex vivo porcine tissue during focused ultrasound (FUS) heating.

Results: A good agreement was found between the temperature measurements obtained from the proposed method and the optical fiber temperature probe in the verification experiments. In the gel phantoms, the linear regression provided a slope of 0.992 and an R of 0.994. The Bland-Altman analysis gave a bias of 0.49°C and a 95% confidence interval of ±1.60°C. In the ex vivo tissue, the results of the linear regression and Bland-Altman methods provided a slope of 0.979, an intercept of 0.353, an R of 0.947, and a 95% confidence interval of ±3.26°C with a bias of -0.14°C. In FUS tests, a temperature discrepancy of up to 28% was observed between the proposed and conventional PRF methods in ex vivo tissues containing fat.

Conclusions: The proposed PRF-based method can improve the accuracy of the temperature measurements in tissues with fat, such as breast, abdomen, prostate, and bone marrow.
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http://dx.doi.org/10.1002/mp.15203DOI Listing
September 2021

Early pregnancy loss: Do Per- and polyfluoroalkyl substances matter?

Environ Int 2021 Aug 26;157:106837. Epub 2021 Aug 26.

Reproductive Medical Center, Peking University People's Hospital, Beijing 100044, China.

Per- and poly-fluorinated substances (PFASs) with endocrine disrupting effect can efficiently transfer across the blood-follicle barrier. However, it is still controversial and attracting extensive public concern that whether PFASs can affect the human fertility potential. Therefore, we aimed to analyze the associations of women's exposure to PFASs with pregnancy loss, the relevant processes of fertilization, zygote implantation, and embryo development by using a prospective cohort study. The women undergoing in vitro fertilization-embryo transfer (IVF-ET) treatment were recruited in Beijing City (Beijing Center) and Yantai City (Yantai Center) in China during 2015-2017. A total of 305 women were recruited before the IVF-ET treatment. Twelve PFASs were measured in their serum samples collected in the day before the IVF-ET treatment, as well as in the human chorionic gonadotropin (hCG) day. The three IVF-ET outcomes were included, i.e. hCG test negative, clinical pregnancy failure (CPF), and preclinical spontaneous abortion. Nine serum PFASs had detection rate of >70% in Beijing and Yantai centers. The exposure patterns to PFASs between these two centers were overall different. For Beijing Center, we only found a positive association of perflurodecanoic acid (PFDA) with the risk of CPF [RR = 2.28 (95 %CI: 1.02-5.11)], but there is a reverse trend in Yantai Center with [RR = 0.45 (95 %CI: 0.23-0.85)]. However, the serum concentration of PFDA in Beijing Center was relatively lower than that of Yantai Center. Other significant associations of the detected PFASs with the IVF-ET outcomes, or with the relevant clinical processes, were not found. The multi-pollutant regression model of the Bayesian kernel machine regression suggested that there were no joint effects between various PFASs on the concerned outcomes. Overall, we suggest that most PFAS were not associated with early pregnancy loss at the current exposure levels. As for the PFDA, there may exist susceptibility of different populations.
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http://dx.doi.org/10.1016/j.envint.2021.106837DOI Listing
August 2021

A critical review of pollutant emission factors from fuel combustion in home stoves.

Environ Int 2021 Aug 23;157:106841. Epub 2021 Aug 23.

School of Environmental Science and Engineering, Southern University of Science and Technology, Shenzhen 518055, China; Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.

A large population does not have access to modern household energy and relies on solid fuels such as coal and biomass fuels. Burning of these solid fuels in low-efficiency home stoves produces high amounts of multiple air pollutants, causing severe air pollution and adverse health outcomes. In evaluating impacts on human health and climate, it is critical to understand the formation and emission processes of air pollutants from these combustion sources. Air pollutant emission factors (EFs) from indoor solid fuel combustion usually highly vary among different testing protocols, fuel-stove systems, sampling and analysis instruments, and environmental conditions. In this critical review, we focus on the latest developments in pollutant emission factor studies, with emphases on the difference between lab and field studies, fugitive emission quantification, and factors that contribute to variabilities in EFs. Field studies are expected to provide more realistic EFs for emission inventories since lab studies typically do not simulate real-world burning conditions well. However, the latter has considerable advantages in evaluating formation mechanisms and variational influencing factors in observed pollutant EFs. One main challenge in field emission measurement is the suitable emission sampling system. Reasons for the field and lab differences have yet to be fully elucidated, and operator behavior can have a significant impact on such differences. Fuel properties and stove designs affect emissions, and the variations are complexly affected by several factors. Stove classification is a challenge in the comparison of EF results from different studies. Lab- and field-based methods for quantifying fugitive emissions, as an important contributor to indoor air pollution, have been developed, and priority work is to develop a database covering different fuel-stove combinations. Studies on the dynamics of the combustion process and evolution of air pollutant formation and emissions are scarce, and these factors should be an important aspect of future work.
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http://dx.doi.org/10.1016/j.envint.2021.106841DOI Listing
August 2021

Effects of comprehensive nursing on negative emotion and prognosis of patients with sepsis.

Am J Transl Res 2021 15;13(7):8221-8227. Epub 2021 Jul 15.

Department of Critical Care Medicine, Minhang Hospital, Fudan University Shanghai, China.

Objective: To explore the effect of comprehensive nursing on negative emotion and prognosis of patients with sepsis.

Methods: As a prospective study, 104 patients with sepsis were randomized into the observation group (n=52) and the control group (n=52). The patients in the control group underwent routine nursing, whereas the patients in the observation group underwent comprehensive nursing care in addition to routine nursing. The level of negative emotions, patients' prognosis, quality of life (QOL), Acute Physiology and Chronic Health Evaluation (APACHE) ll score, clinical indicators, and patient satisfaction with nursing were compared between the two groups.

Results: Compared with the control group, the observation group had lower Self-Rating Anxiety Scale score, Self-Rating Depression Scale score, and APACHE ll score (all P<0.001). The scores of physical functioning, general health perceptions, social role functioning, emotional role functioning, and mental health of the observation group were all higher than those of the control group (all P<0.01). The duration of mechanical ventilation, hospitalization expenses, and the length of stay in the Intensive Care Unit (ICU) in the observation group were lower than those in the control group (all P<0.01). Moreover, the observation group had a lower total incidence of shock, multiple organ dysfunction syndrome, and death and higher patient satisfaction with the nursing care than the control group (all P<0.05).

Conclusion: Comprehensive nursing care can alleviate anxiety and depression in patients with sepsis and can improve the prognosis and QOL of patients. Also, it can shorten the length of stay in the ICU, lower treatment costs, and improve patient satisfaction; all of which can be recommended for clinical application.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8340246PMC
July 2021

Field-based measurements of major air pollutant emissions from typical porcelain kiln in China.

Environ Pollut 2021 Jul 19;288:117810. Epub 2021 Jul 19.

Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China.

China has been famous for its porcelains for millennia, and the combustion processes of porcelain production emit substantial amounts of air pollutants, which have not been well understood. This study provided firsthand data of air pollutant emissions from biomass porcelain kilns. The emission factor of PM was 0.95 ± 1.23 g/kg during the entire combustion cycle, lower than that of biomass burning in residential stoves and coal burning in brick kilns, attributed to the removal effects of the long-distance transport in dragon kilns. The temporal trend of particle pollutants, including particulate matters (PMs) and particulate polycyclic aromatic hydrocarbons (PAHs) (low at ignition phase and high at the end) again indicated the removal effects of the special structure, while gaseous pollutants, such as gaseous PAHs, exhibited the opposite result. The GWC was estimated as 1.4 × 10 and 0.5 × 10 kg COe/yr for the scenarios in which 50% and 100% of the wood was renewable, respectively. The GWC of dragon kilns is nearly equal to that of 745 households using wood-fueled stoves. These results indicate the necessity of pollution controls for biomass porcelain kilns to estimate the emission inventory and climate change.
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http://dx.doi.org/10.1016/j.envpol.2021.117810DOI Listing
July 2021

Direct and Inverse Reduced-Form Models for Reciprocal Calculation of BC Emissions and Atmospheric Concentrations.

Environ Sci Technol 2021 08 23;55(15):10300-10309. Epub 2021 Jul 23.

College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing 100871, China.

Atmospheric black carbon (BC) concentrations are governed by both emissions and meteorological conditions. Distinguishing these effects enables quantification of the effectiveness of emission mitigation actions by excluding meteorological effects. Here, we develop reduced-form models in both direct (RFDMs) and inverse (RFIMs) modes to estimate ambient BC concentrations. The models were developed based on outputs from multiyear simulations under three conditional scenarios with realistic or fixed emissions and meteorological conditions. We established a set of probabilistic functions (PFs) to quantify the meteorological influences. A significant two-way linear relationship between multiyear annual emissions and mean ambient BC concentrations was revealed at the grid cell scale. The correlation between them was more significant at grid cells with high emission densities. The concentrations and emissions at a given grid cell are also significantly correlated with emissions and concentrations of the surrounding areas, respectively, although to a lesser extent. These dependences are anisotropic depending on the prevailing winds and source regions. The meteorologically induced variation at the monthly scale was significantly higher than that at the annual scale. Of the major meteorological parameters, wind vectors, temperature, and relative humidity were found to most significantly affect variation in ambient BC concentrations.
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http://dx.doi.org/10.1021/acs.est.1c02174DOI Listing
August 2021

Mass Absorption Efficiency of Black Carbon from Residential Solid Fuel Combustion and Its Association with Carbonaceous Fractions.

Environ Sci Technol 2021 08 16;55(15):10662-10671. Epub 2021 Jul 16.

Laboratory for Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing 100871, People's Republic of China.

Black carbon (BC) emissions, derived primarily from incomplete fuel combustion, significantly affect the global and regional climate. Mass absorption efficiency (MAE) is one important parameter in evaluating the climate impacts of BC. Here, values and variabilities in the MAE of BC (MAE) from real-world residential emissions were investigated from a field campaign covering 163 burning events for different fuel-stove combinations. MAE (average: 12 ± 5 m/g) was normally distributed and varied greatly by 2 orders of magnitude. Statistically significant differences in MAE were found for various fuels, while no significant differences were observed among different stoves. The fuel difference explained 72 ± 7% of the MAE variation. MAE did not correlate with the modified combustion efficiency but positively correlated with the ratio of organic carbon (OC) to elemental carbon (EC) and negatively correlated with char-EC. The OC/EC ratio was not always lower in coal emissions in comparison to biomass burning emissions. Coal- and biomass-burning emissions had different profiles of carbon fractions. Char-EC, OC, OC/EC, and char-EC/soot-EC can explain 68.7% of the MAE variation, providing the potential for predicting MAE from the carbon fractions, since they are more commonly measured and available.
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http://dx.doi.org/10.1021/acs.est.1c02689DOI Listing
August 2021

Contributions of internal emissions to peaks and incremental indoor PM in rural coal use households.

Environ Pollut 2021 Jul 9;288:117753. Epub 2021 Jul 9.

Key Lab for Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing, 100871, China. Electronic address:

Indoor air quality is critically important to the human as people spend most time indoors. Indoor PM is related to the outdoor levels, but more directly influenced by internal sources. Severe household air pollution from solid fuel use has been recognized as one major risk for human health especailly in rural area, however, the issue is significantly overlooked in most national air quality controls and intervention policies. Here, by using low-cost sensors, indoor PM in rural homes burning coals was monitored for ~4 months and analyzed for its temporal dynamics, distributions, relationship with outdoor PM, and quantitative contributions of internal sources. A bimodal distribution of indoor PM was identified and the bimodal characteristic was more significant at the finer time resolution. The bimodal distribution maxima were corresponding to the emissions from strong internal sources and the influence of outdoor PM, respectively. Indoor PM was found to be correlated with the outdoor PM, even though indoor coal combustion for heating was thought to be predominant source of indoor PM. The indoor-outdoor relationship differed significantly between the heating and non-heating seasons. Impacts of typical indoor sources like cooking, heating associated with coal use, and smoking were quantitatively analyzed based on the highly time-resolved PM. Estimated contribution of outdoor PM to the indoor PM was ~48% during the non-heating period, but decreased to about 32% during the heating period. The contribution of indoor heating burning coals comprised up to 47% of the indoor PM during the heating period, while the other indoor sources contributed to ~20%. The study, based on a relatively long-term timely resolved PM data from a large number of rural households, provided informative results on temporal dynamics of indoor PM and quantitative contributions of internal sources, promoting scientific understanding on sources and impacts of household air pollution.
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http://dx.doi.org/10.1016/j.envpol.2021.117753DOI Listing
July 2021

Distribution and partitioning of pyrethroid insecticides in agricultural lands: Critical influencing factors.

Environ Int 2021 11 28;156:106736. Epub 2021 Jun 28.

Key Laboratory of Microbial Technology for Industrial Pollution Control of Zhejiang Province, College of Environment, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, China.

Pyrethroid insecticides are widely applied due to the broad spectrum and high efficiency in pest control and detected in various environmental media, but the key factor affecting their occurrence and distribution in agricultural lands is still not clear. Here, we measured pyrethroid residues in 644 surface soil and 630 surface water samples and quantified the impacts of various factors on the distribution and partition of pyrethroids through a large-scale field study in Southeast China during 2015-2017. The pyrethroid residues were widely detected in the studied areas, and the mean concentration of seven individual pyrethroids in surface soil and water ranged from 0.10 (cyfluthrin, (CYF)) to 12.14 ng/g (bifenthrin, (BIF)) and 0.18 (CYF) to 3.36 µg/L (BIF) respectively, which were higher than other regions in China and some other countries. Using a generalized linear model coupled with dominance analysis, we found that the crop type and season were significantly associated with pyrethroid residues in surface soil and water (p < 0.05). The crop difference dominated the variances of the distribution of pyrethroid residues in the surface soil and water with a contribution of more than 55% and followed by the factor of season difference. The findings provide new insight into the distribution and partitioning of pyrethroids in agricultural lands and insecticide control on ecological safety and public health.
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http://dx.doi.org/10.1016/j.envint.2021.106736DOI Listing
November 2021

Updated Global Black Carbon Emissions from 1960 to 2017: Improvements, Trends, and Drivers.

Environ Sci Technol 2021 06 7;55(12):7869-7879. Epub 2021 Jun 7.

College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing 100871, China.

Accurate estimation of black carbon (BC) emissions is essential for assessing the health and climate impact of this pollutant. Past emission inventories were associated with high uncertainty due to data limitations, and recent information has provided a unique updating opportunity. Moreover, understanding the drivers that cause temporal emission changes is of research value. Here, we update the global BC emission estimates using new data on the activities and emission factors (EFs). The new inventory covers 73 detailed sources at 0.1° × 0.1° spatial resolution and monthly temporal resolution from 1960 to 2017. The estimated annual emissions were 32% higher than the average of several previous inventories, which was primarily due to field-measured EFs for residential stoves and differentiated EFs for motor vehicles. In addition, the updated emissions show an inverse U-shaped temporal trend, which was mainly driven by the interaction between the positive effects of population growth, per capita energy consumption, and vehicle fleet and the negative effects of residential energy switching, stove upgrading, phasing out of beehive coke ovens, and reduced EFs for vehicles and industrial processes. Urbanization caused a significant increase in urban emissions accompanied by a more significant decline in rural emissions.
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http://dx.doi.org/10.1021/acs.est.1c03117DOI Listing
June 2021

Spatially explicit analysis identifies significant potential for bioenergy with carbon capture and storage in China.

Nat Commun 2021 05 26;12(1):3159. Epub 2021 May 26.

Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai, China.

As China ramped-up coal power capacities rapidly while CO emissions need to decline, these capacities would turn into stranded assets. To deal with this risk, a promising option is to retrofit these capacities to co-fire with biomass and eventually upgrade to CCS operation (BECCS), but the feasibility is debated with respect to negative impacts on broader sustainability issues. Here we present a data-rich spatially explicit approach to estimate the marginal cost curve for decarbonizing the power sector in China with BECCS. We identify a potential of 222 GW of power capacities in 2836 counties generated by co-firing 0.9 Gt of biomass from the same county, with half being agricultural residues. Our spatially explicit method helps to reduce uncertainty in the economic costs and emissions of BECCS, identify the best opportunities for bioenergy and show the limitations by logistical challenges to achieve carbon neutrality in the power sector with large-scale BECCS in China.
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http://dx.doi.org/10.1038/s41467-021-23282-xDOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC8154910PMC
May 2021

Coal Is Dirty, but Where It Is Burned Especially Matters.

Environ Sci Technol 2021 06 12;55(11):7316-7326. Epub 2021 May 12.

College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing 100871, China.

Coal abatement actions for pollution reduction often target total coal consumption. The health impacts of coal uses, however, vary extensively among sectors. Here, we modeled the sectorial contributions of coal uses to emissions, outdoor and indoor PM (particulate matter with an aerodynamic diameter of less than 2.5 mm) concentrations, exposures, and health outcomes in China from 1970 to 2014. We show that in 2014, residential coal accounted for 2.9% of total energy use but 34% of premature deaths associated with PM exposure, showing that effects were magnified substantially along the causal path. The number of premature deaths attributed to unit coal consumption in the residential sector was 40 times higher than that in the power and industrial sectors. Emissions of primary PM were more important than secondary aerosol precursors in terms of health consequences, and indoor exposure accounted for 97% and 91% of total premature deaths attributable to PM from coal combustion in 1974 and 2014, respectively. Our assessment raises a critical challenge in the switching of residential coal uses to effectively mitigate PM exposure in the Chinese population.
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http://dx.doi.org/10.1021/acs.est.1c01148DOI Listing
June 2021

Emission factors of environmentally persistent free radicals in PM from rural residential solid fuels combusted in a traditional stove.

Sci Total Environ 2021 Jun 6;773:145151. Epub 2021 Feb 6.

Stockbridge School of Agriculture, University of Massachusetts, Amherst, MA 01003, United States.

Emission factors (EFs) are crucial for establishing emission inventory and subsequent health risk assessment of pollutants. However, the EFs of environmentally persistent free radicals (EPFRs) in PM have not been well investigated. We measured EPFRs in PM from burning of different solid fuels in a traditional stove widely used in rural China and calculated the EFs of EPFRs (EF). The characteristics of EPFRs varied greatly with PM depending on the feedstock, and the EF of crop residue, firewood and bitumite was 2.13 ± 1.04, 1.40 ± 0.76 and 1.08 ± 0.39 (10 spins·kg), respectively. The estimated results of EPFRs emission associated with PM showed that the crop residue was the main contributor to the top four provinces with high EPFRs emissions in China in 2010. A wide range (0.03-4.89 cig·person·day) of equivalent cigarette number converted by inhaling EPFRs in PM was observed. Provinces with higher equivalent cigarette number were mainly agricultural provinces, because the rural residents tend to use readily available fuels. Additionally, EPFRs in collected PM during 2 - month photoaging were more stable in particles with higher organic carbon contents. Our findings provided a new insight into the risk assessment of PM from different sources by taking EPFRs into consideration.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145151DOI Listing
June 2021

Associations of Dietary Exposure to Organochlorine Pesticides from Plant-Origin Foods with Lipid Metabolism and Inflammation in Women: A Multiple Follow-up Study in North China.

Bull Environ Contam Toxicol 2021 Aug 17;107(2):289-295. Epub 2021 Apr 17.

Institute of Reproductive and Child Health, Peking University/Key Laboratory of Reproductive Health, National Health Commission of the People's Republic of China, Beijing, 100191, People's Republic of China.

This study explored effects of dietary OCP intake from plant-origin foods (cereals, fruits, and vegetables) consumption on lipid metabolism and inflammation of women using a multiple follow-up study. The results showed that dietary intake of p,p'-dichlorodiphenyltrichloroethane (DDT) [β = - 10.11, 95% confidence interval (95%CI): - 17.32, - 2.905] and o,p'-dichlorodiphenyldichloroethylene (DDE) (β = - 6.077, 95%CI: - 9.954, - 2.200) were overall negatively associated with serum high-density lipoprotein cholesterol (HDL), whereas other OCPs were not. Serum interleukin (IL)-8 was positively associated with intake of dieldrin (β = 0.390, 95%CI: 0.105, 0.674), endosulfan-β (β = 0.361, 95%CI: 0.198, 0.523), total endosulfan (β = 0.136, 95%CI: 0.037, 0.234), and total OCPs (β = 0.084, 95%CI: 0.016, 0.153), and negatively correlated with intake of p,p'-DDE (β = - 2.692, 95%CI: - 5.185, - 0.198). We concluded that dietary intake of some individual DDT-, DDE- dieldrin-, and endosulfan-class chemicals from plant-origin foods may interfere with lipid metabolism and inflammation responses.
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http://dx.doi.org/10.1007/s00128-021-03224-5DOI Listing
August 2021

Hydrogen sulfide reduces pyroptosis and alleviates ischemia-reperfusion-induced acute kidney injury by inhibiting NLRP3 inflammasome.

Life Sci 2021 Mar 31;284:119466. Epub 2021 Mar 31.

Department of Critical Care Medicine, Minhang Hospital, Fudan University, Shanghai 201199, China. Electronic address:

Aims: Ischemia-reperfusion (I/R)-induced acute kidney injury (AKI) shows high mortality. Hydrogen sulfide (HS) is essential for regulating kidney function. This study explored the role and mechanism of HS in I/R-induced AKI.

Materials And Methods: I/R-induced mouse model and hypoxia/reoxygenation (H/R)-induced HK2 cell model of AKI were established and treated with NaHS (HS donor), MCC950 (NLRP3 inhibitor) or DL-Propargylglycine (PAG, CSE inhibitor). Serum creatinine (Cr) and blood urea nitrogen (BUN) were measured to evaluate kidney function. The pathological changes of kidney tissues were detected. HS level and HS synthetase activity in kidney tissues were detected. Pyroptosis was assessed by pyroptotic cell numbers and pyroptosis-related protein levels determination. HK-2 cell viability and apoptosis were measured. NLRP3 protein level was detected. The role of NLRP3/Caspase-1 was verified in vivo and in vitro after MCC950 or PAG intervention.

Key Findings: I/R-induced mice showed elevated levels of serum Cr and BUN, and obvious pathological changes, including severe tubular dilatation, tubular cell swelling, tubular epithelial cell abscission, tubular cell necrosis and inflammatory cell infiltration. HS level and HS synthetase activity were decreased. Increasing the level of HS by NaHS improved the pathological changes of kidney tissues and limited the number of pyroptotic cells. In vitro, NaHS could reverse H/R-induced cell injury. HS suppressed cell pyroptosis and kidney injury via inhibiting the NLRP3/Caspase-1 axis.

Significance: We highlighted that HS prevented cell pyroptosis via suppressing the NLRP3/Caspase-1 axis, thereby inhibiting I/R-induced AKI. These findings may confer novel insights for the clinical management of I/R-induced AKI.
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http://dx.doi.org/10.1016/j.lfs.2021.119466DOI Listing
March 2021

Intermediate Volatile Organic Compound Emissions from Residential Solid Fuel Combustion Based on Field Measurements in Rural China.

Environ Sci Technol 2021 05 2;55(9):5689-5700. Epub 2021 Apr 2.

Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.

Residential solid fuel combustion (RSFC) is a key cause of air pollution in China. In these serial studies, field measurements of RSFC from 166 rural households in eastern China were conducted to update the database of emission factors (EFs) and chemical profiles of gaseous and particulate organic pollutants, and the present study focuses on the intermediate volatile organic compounds (IVOCs), which are precursors of secondary organic aerosol (SOA). The results show that the averaged EFs of IVOCs (EF) for crop straw, fuelwood, and coal are 550.7 ± 397.9, 416.1 ± 249.5, and 361.9 ± 308.0 mg/kg, respectively, which are among the EF of gasoline vehicle, diesel vehicle, non-road machinery, and heavy fuel oil vessel, and are significantly affected by fuel, stove, and combustion efficiency. The percentages of normal alkanes (-alkanes), branched alkanes (-alkanes), polycyclic aromatic hydrocarbons (PAHs), and unresolved complex mixture from RSFC are 3.5 ± 1.6, 8.0 ± 3.7, 17.6 ± 6.7, and 70.9 ± 8.1%, respectively, and the compositions are featured by lower b-alkanes and higher PAHs than those of vehicle sources. The proportions of some individual n-alkanes and PAHs (such as -C--C, naphthalene, and its alkyl substituents) can be used as indicators to differentiate RSFC from vehicle sources, while methoxyphenols can be used to distinguish biomass burning from coal combustion. Based on China's energy statistics, the total IVOC emissions from RSFC in 2014 were 175.9 Gg. These data will help to update the IVOC emission inventory and improve the estimates of SOA production in China.
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http://dx.doi.org/10.1021/acs.est.0c07908DOI Listing
May 2021

Organochlorine Pesticide Ban Facilitated Reproductive Recovery of Chinese Striped Hamsters.

Environ Sci Technol 2021 05 2;55(9):6140-6149. Epub 2021 Apr 2.

State Key Laboratory of Integrated Management on Pest Insects and Rodents in Agriculture, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China.

Organochlorine pesticides (OCPs) have been used worldwide on an enormous scale over the last century but are banned globally due to environmental persistence and ecotoxicity in recent decades. The long-term effects of OCP ban for agricultural use in China since 1983 on the reproductive health of small terrestrial mammals have never been evaluated in the field. We examined the residue dynamics of OCPs and the reproductive performance of Chinese striped hamsters () in North China Plain during 1983-2010 and concluded that the exposure levels of OCPs in hamsters drastically decreased from 2900 ± 740 to 25.2 ± 6.88 ng/g with an average half-life of 5.08 yrs, coinciding with the observed reproductive recovery of hamsters. The population-based reproductive performance of hamsters was significantly and negatively associated with OCP exposure levels after adjusting the contributions from climate and population density factors, indicating that the ban of OCPs has facilitated the reproductive recovery of hamsters by up to 81% contribution. Our findings suggest that the OCP ban is effective to restore reproduction of small terrestrial mammals. Integration of population biology and environmental science is essential to assess the impacts of persistent organic pollutants on ecological safety and biodiversity loss under accelerated global change.
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http://dx.doi.org/10.1021/acs.est.1c00167DOI Listing
May 2021

Bioaccessibility and public health risk of heavy Metal(loid)s in the airborne particulate matter of four cities in northern China.

Chemosphere 2021 Aug 19;277:130312. Epub 2021 Mar 19.

MOE Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.

Atmospheric coarse particulate matter (PM) enriched with heavy metal(loid)s could pose potentially significant health risk to humans, while accurate health risk assessment calls for characterization of their bioaccessibility, besides the total contents. The health risk of major toxic heavy metal(loid)s in the PM from four large cities in northern China via inhalation was investigated based on their total contents and bioaccessibility. The annual mean concentrations of PM-bound Zn, As, Pb, and Mn in the atmosphere of the four cities were 650, 305, 227, and 177 ng⋅m, respectively. The levels of heavy metal(loid)s in the PM were generally higher in winter but lower in summer in all four cities, which resulted primarily from the emissions associated with coal combustion for district and household heating and the unfavorable meteorological conditions in winter. The bioaccessibility of heavy metal(loid)s in the PM ranged from 0.9 to 48.7%, following the general order of Mn > Co > Ni > Cd > Cu > As > Cr > Zn > Pb. Based on their total contents in the PM, most heavy metal(loid)s posed significant public health risk via inhalation exposure in the four cities. However, after accounting for the bioaccessibility of metal(loid)s, the non-carcinogenic risk of most metal(loid)s was negligible, except for As in the PM of Jinzhong, while only the carcinogenic risk posed by Cr and As in the PM exceeded the acceptable level. These findings demonstrate the importance of characterizing the bioaccessibility of airborne PM-bound heavy metal(loid)s in health risk assessment and could guide the on-going efforts on reducing the public health risk of PM in northern China.
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http://dx.doi.org/10.1016/j.chemosphere.2021.130312DOI Listing
August 2021

Spatially Resolved Emission Factors to Reduce Uncertainties in Air Pollutant Emission Estimates from the Residential Sector.

Environ Sci Technol 2021 04 15;55(8):4483-4493. Epub 2021 Mar 15.

Laboratory for Earth Surface Process, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.

The residential sector is a major source of air pollutant emission inventory uncertainties. A nationwide field emission measurement campaign was conducted in rural China to evaluate the variabilities of realistic emission factors (EFs) from indoor solid fuel combustion. For a total of 1313 burning events, the overall average EFs (±standard deviation) of PM were 8.93 ± 6.95 and 7.33 ± 9.01 g/kg for biomass and coals, respectively, and 89.3 ± 51.2 and 114 ± 87 g/kg for CO. Higher EFs were found from burning of uncompressed straws, while lower EFs were found from processed biomass pellets, coal briquettes, and relatively clean anthracite coals. Modified combustion efficiency was found to be the most significant factor associated with variations in CO EFs, whereas for PM, fuel and stove differences determined its variations. Weak correlations between PM and CO indicated high uncertainties in using CO as a surrogate for PM. EFs accurately fit log-normal distributions, and obvious spatial heterogeneity was observed attributed to different fuel-stove combinations across the country. Emission estimation variabilities, which are determined by the interquartile ranges divided by the median values, were notably reduced when spatially resolved EFs were adopted in the inventory.
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http://dx.doi.org/10.1021/acs.est.0c08568DOI Listing
April 2021

A mechanistic study on removal efficiency of four antibiotics by animal and plant origin precursors-derived biochars.

Sci Total Environ 2021 Jun 30;772:145468. Epub 2021 Jan 30.

Laboratory for Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China. Electronic address:

Extensive research has been performed on the utilization of biochar for pollutant removal via sorption. Additionally, the relationship between sorption strength of organic pollutants by organic matter and nanomaterials and their sorption site energy distribution has been studied. However, the linkage between removal efficiency of organic pollutants and the sorption site energy distribution on biochars is unknown. As a first attempt to address this knowledge gap, three biochars were derived from two plant-origin precursors (corn straw-CS; birch sawdust-BS) and one animal-origin precursor (meat and bone meal-MBM) at 500 °C (CS-500, BS-500, and MBM-500). In addition, two biochars were prepared with CS at 300 and 800 °C (CS-300 and CS-800) to examine the relationship between their site energy distribution and removal efficiency of antibiotics including sulfadiazine (SDZ), sulfamethoxazole (SMX), tetracycline (TC) and ciprofloxacin (CFX) by these materials. Our findings showed that the antibiotic-biochar interactions can be well interpreted with site energy distribution and XPS analysis results. Polar interactions between CS-300, CS-500, and CS-800 and SDZ and SMX occurring at the high-energy sites dominated their removal. However, TC and CFX removal by these biochars was driven by their polar interactions occurring at high-energy sites and π-π interactions at low-energy sites. The π-π stacking mechanism tended to dominate their removal with increasing charring temperature. Abundance of polar functionalities on CS-500, BS-500, and MBM-500 and TC removal efficiency of these materials consistently followed an order of MBM-500 > CS-500 > BS-500, highlighting importance of precursors for making biochars and polar interactions in its removal.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145468DOI Listing
June 2021

Impacts of Chinese spring festival on household PM pollution and blood pressure of rural residents.

Indoor Air 2021 Jul 11;31(4):1072-1083. Epub 2021 Feb 11.

College of Environment, Research Centre of Environmental Science, Zhejiang University of Technology, Hangzhou, China.

Background: Household air pollution (HAP) from residential combustion considerably affects human health in rural China. Large-scale population migration and rural lifestyle changes during the Spring Festival are supposed to change the household air pollution and health risks; however, limited field study has determined its impacts on HAP and short-term health outcomes.

Methods: A field study was conducted in rural areas of Southern China before and during the Spring Festival to explore the associations between HAP and blood pressure considering different factors such as cooking fuel, heating fuel, and smoking. Stationary real-time PM monitors were used to measure PM concentrations of the kitchen, living room, and yard of 156 randomly selected households. Personal exposure to PM was calculated based on the results of stationary samplers and corresponding time local residents spent in different microenvironments, and one adult resident was recruited of each family for the blood pressure measurement.

Results: Both personal exposure to PM and blood pressures of local residents increased during Spring Festival compared to the days before the holiday. Based on generalized linear model coupled with dominance analysis approach, it was found that personal PM exposure was positively associated with the factors of population size and the types of cooking and heating fuels with the relative contributions of approximately 82%, and systolic blood pressure (SBP, 100-120 mmHg as normal range for adults) was positively and significantly associated with personal PM exposures with the relative contribution of 11%.

Conclusion: The findings in this study demonstrated that Spring Festival can give rise to increase of HAP and hypertension risks, also related to tremendous solid fuel use, suggesting further policy making on promoting cleaner energy in rural areas and more attention on large population migration during national holidays.
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http://dx.doi.org/10.1111/ina.12795DOI Listing
July 2021

Chemical composition, structures, and light absorption of N-containing aromatic compounds emitted from burning wood and charcoal in household cookstoves.

Atmos Chem Phys 2020 Nov;20(22):14077-14090

State Key Laboratory of Pollution Control and Resource Reuse, Nanjing University, Nanjing 210023, China.

N-containing aromatic compounds (NACs) are an important group of light-absorbing molecules in the atmosphere. They are often observed in combustion emissions, but their chemical formulas and structural characteristics remain uncertain. In this study, red oak wood and charcoal fuels were burned in cookstoves using the standard water boiling test (WBT) procedure. Submicron aerosol particles in the cookstove emissions were collected using quartz (Q ) and polytetrafluoroethylene (PTFE) filter membranes positioned in parallel. A back-up quartz filter (Q ) was also installed downstream of the PTFE filter to evaluate the effect of sampling artifact on NACs measurements. Liquid chromatography-mass spectroscopy (LC-MS) techniques identified seventeen NAC chemical formulas in the cookstove emissions. The average concentrations of total NACs in Q samples (0.37 ± 0.31 - 1.79 ± 0.77 μg m) were greater than 50% of those observed in the Q samples (0.51 ± 0.43 - 3.91 ± 2.06 μg m), and the Q to Q mass ratios of individual NACs had a range of 0.02 - 2.71, indicating that the identified NACs might have substantial fractions remaining in the gas-phase. In comparison to other sources, cookstove emissions from red oak or charcoal fuels did not exhibit unique NAC structural features, but had distinct NACs composition. However, before identifying NACs sources by combining their structural and compositional information, the gas-particle partitioning behaviors of NACs should be further investigated. The average contributions of total NACs to the light absorption of organic matter at λ = 365 nm (1.10 - 2.57%) in Q and Q samples (10.7 - 21.0%) are up to 10 times larger than their mass contributions (Q 0.31 - 1.01%, Q 1.08 - 3.31%), so the identified NACs are mostly strong light absorbers. To explain more sample extracts absorption, future research is needed to understand the chemical and optical properties of high molecular weight (e.g., MW > 500 Da) entities in particulate matter.
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http://dx.doi.org/10.5194/acp-20-14077-2020DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7863623PMC
November 2020

Combined analyses of hygroscopic properties of organic and inorganic components of three representative black carbon samples recovered from pyrolysis.

Sci Total Environ 2021 Jun 27;771:145393. Epub 2021 Jan 27.

State Key Laboratory of Pollution Control and Resource Reuse, School of the Environment, Nanjing University, Jiangsu 210046, China; School of Urban and Environmental Sciences, Key Laboratory of the Ministry of Education for Earth Surface Processes, Peking University, Beijing 100871, China. Electronic address:

Hygroscopicity of black carbon (BC) aerosols is a key factor determining their climate forcing effect and atmospheric lifetime. However, the compositional dependence of BC hygroscopicity is not well understood. Here, a variety of different compositional components were separated from three representative BC samples recovered from pyrolysis (grass and wheat straw derived BC, household soot), including water extracted fraction of BC (WEBC, 9-21 wt%), residue fraction of BC after water extraction (R-WEBC, 79-91 wt%), water extracted minerals (WEM, 9-18 wt%), alkali extracted organic carbon (OC, 1-9 wt%), and elemental carbon (EC, 37-48 wt%). The bulk BC and separated BC components were analyzed in detail by elemental analysis and combined spectroscopic analyses. Their equilibrium hygroscopicity was measured by gravimetric method over a range of relative humidity (RH) levels (10-94%). Compared with the two organic components (OC and EC), the inorganic component (WEM) exhibited much stronger water uptake at all RH levels. At 94% RH level, WEM accounted for 16-139% of the overall water uptake by BC, whereas OC and EC accounted for only 1-3% and 6-26%, respectively. The XRD analysis of WEBC and WEM from household soot at varying RH levels indicated that the enhanced water uptake by these two components as well as that by bulk BC at high RH levels was due to the deliquescent salts (e.g., KCl, NHCl, KNO, and NaCl). The strong hysteresis loops observed for bulk BC and WEBC could be attributed to the organic-facilitated drastic structural and morphological rearrangement of mineral particles as evidenced by the optical microscope analysis. The diffuse reflectance infrared Fourier transform spectroscopy (DRIFTS) analysis reaffirmed the dominant role played by the inorganic component in the hygroscopic behaviors of BC.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145393DOI Listing
June 2021

Emissions of particulate PAHs from solid fuel combustion in indoor cookstoves.

Sci Total Environ 2021 Jun 26;771:145411. Epub 2021 Jan 26.

Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.

Residential solid fuel combustion is a major emission source of PAHs (polycyclic aromatic hydrocarbons) in most developing countries, including China; however, accurate estimates of PAH emissions are often challenged by limited real-world emission factors (EFs) under field conditions, which can hardly be repeated in laboratory-controlled tests. In this study, a series of field measurements was conducted to determine the emissions of 28 PAHs from different fuel-stove combinations. A total of 14 fuel-stove combinations were studied. The total EFs of 28 PAHs (EF), on the basis of fuel mass, ranged from 20.7 to 535 mg/kg, with relatively lower EFs for coal than for biomass. Biomass burning in gasifier stoves had lower PAH EFs and fewer toxic PAH species than biomass burning in traditional brick stoves. Fuel type was a significant factor affecting PAH emissions, while stove difference had a relatively smaller influence. Much higher EFs were found from these field tests than from the idealized laboratory tests, which indicated significant underestimation in inventories based on the laboratory-based EFs. Biomass and coal had different profiles, with larger intra-fuel variations in coal than those in biomass. Highly variable values of some, though not all, commonly used isomer ratios indicated substantial biases in source apportionment relying on single or simple ratios without correction, and the MCE was found to be significantly corrected with some ratios.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145411DOI Listing
June 2021

Contribution of Temperature Increase to Restrain the Transmission of COVID-19.

Innovation (N Y) 2021 Feb 16;2(1):100071. Epub 2020 Dec 16.

Institute of Reproductive and Child Health, Peking University/ Key Laboratory of Reproductive Health, National Health Commission of the People's Republic of China, Beijing 100191, P. R. China.

The COVID-19 outbreak has already become a global pandemic and containing this rapid worldwide transmission is of great challenge. The impacts of temperature and humidity on the COVID-19 transmission rate are still under discussion. Here, we elucidated these relationships by utilizing two unique scenarios, repeated measurement and natural experiment, using the COVID-19 cases reported from January 23 - February 21, 2020, in China. The modeling results revealed that higher temperature was most strongly associated with decreased COVID-19 transmission at a lag time of 8 days. Relative humidity (RH) appeared to have only a slight effect. These findings were verified by assessing SARS-CoV-2 infectivity under the relevant conditions of temperature (4°C-37°C) and RH (> 40%). We concluded that temperature increase made an important, but not determined, contribution to restrain the COVID-19 outbreak in China. It suggests that the emphasis of other effective controlling polices should be strictly implemented to restrain COVID-19 transmission in cold seasons.
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http://dx.doi.org/10.1016/j.xinn.2020.100071DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7834433PMC
February 2021

Temporal and spatial variation of PM in indoor air monitored by low-cost sensors.

Sci Total Environ 2021 May 22;770:145304. Epub 2021 Jan 22.

College of Urban and Environmental Sciences, Laboratory for Earth Surface Processes, Sino-French Institute for Earth System Science, Peking University, Beijing 100871, China. Electronic address:

Indoor air pollution has significant adverse health impacts, but its spatiotemporal variations and source contributions are not well quantified. In this study, we used low-cost sensors to measure PM concentrations in a typical apartment in Beijing. The measurements were conducted at 15 indoor sites and one outdoor site on 1-minute temporal resolution (convert to 10-minute averages for data analysis) from March 14 to 24, 2020. Based on these highly spatially-and temporally-resolved data, we characterized spatiotemporal variations and source contributions of indoor PM in this apartment. It was found that indoor particulate matter predominantly originates from outdoor infiltration and cooking emissions with the latter contributing more fine particles. Indoor PM concentrations were found to be correlated with ambient levels but were generally lower than those outdoors with an average I/O of 0.85. The predominant indoor source was cooking, leading to occasional high spikes. The variations observed in most rooms lagged behind those measured outdoors and in the studied kitchen. Differences between rooms were found to depend on pathway distances from sources. On average, outdoor sources contributed 36% of indoor PM, varying extensively over time and among rooms. From observed PM concentrations at the indoor sites, source strengths, and pathway distances, a multivariate regression model was developed to predict spatiotemporal variations of PM. The model explains 79% of the observed variation and can be used to dynamically simulate PM concentrations at any site indoors. The model's simplicity suggests the potential for regional-scale application for indoor air quality modeling.
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http://dx.doi.org/10.1016/j.scitotenv.2021.145304DOI Listing
May 2021

Inhalation exposure to size-segregated fine particles and particulate PAHs for the population burning biomass fuels in the Eastern Tibetan Plateau area.

Ecotoxicol Environ Saf 2021 Mar 25;211:111959. Epub 2021 Jan 25.

Laboratory of Earth Surface Processes, College of Urban and Environmental Sciences, Peking University, Beijing 100871, China.

Indoor biomass burning produces large amounts of small particles and hazardous contaminants leading to severe air pollution and potentially high health risks associated with inhalation exposure. Personal samplers provide more accurate estimates of inhalation exposure. In this study, inhalation exposure to size-segregated particles and particulate polycyclic aromatic hydrocarbons (PAHs) for the biomass user was studied by deploying personal samplers. The study found that daily PM inhalation exposure level was as high as 121 ± 96 μg/m, and over 84% was finer PM. For PAHs, the exposure level was 113 ± 188 ng/m, with over 77% in PM. High molecular weight PAHs with larger toxic potentials enriched in smaller particles resulting in much high risks associated with PAHs inhalation exposure. Indoor exposure contributed to ~80% of the total inhalation exposure as a result of high indoor air pollution and longer residence spent indoor. The highest exposure risk was found for the male smoker who conducted cooking activities at home.
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http://dx.doi.org/10.1016/j.ecoenv.2021.111959DOI Listing
March 2021

Increased air pollution exposure among the Chinese population during the national quarantine in 2020.

Nat Hum Behav 2021 02 4;5(2):239-246. Epub 2021 Jan 4.

Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA, USA.

The COVID-19 quarantine in China is thought to have reduced ambient air pollution. The overall exposure of the population also depends, however, on indoor air quality and human mobility and activities. Here, by integrating real-time mobility data and a questionnaire survey on time-activity patterns during the pandemic, we show that despite a decrease in ambient PM during the quarantine, the total population-weighted exposure to PM considering both indoor and outdoor environments increased by 5.7 μg m (95% confidence interval, 1.2-11.0 μg m). The increase in population-weighted exposure was mainly driven by a nationwide urban-to-rural population migration before the Spring Festival coupled with the freezing of the migration backward due to the quarantine, which increased household energy consumption and the fraction of people exposed to rural household air pollution indoors. Our analysis reveals an increased inequality of air pollution exposure during the quarantine and highlights the importance of household air pollution for population health in China.
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http://dx.doi.org/10.1038/s41562-020-01018-zDOI Listing
February 2021

Upregulation of endothelial cell-derived exosomal microRNA-125b-5p protects from sepsis-induced acute lung injury by inhibiting topoisomerase II alpha.

Inflamm Res 2021 Feb 2;70(2):205-216. Epub 2021 Jan 2.

Department of Critical Care Medicine, Minhang Hospital, Fudan University, No. 39, Xinling Road, Minhang District, Shanghai, 201199, China.

Objective: Emerging evidence has revealed that exosomal microRNAs (miRNAs) are implicated in human diseases. However, role of exosomal miR-125b-5p in sepsis-induced acute lung injury (ALI) remains further explored. We focused on the effect of exosomal miR-125b-5p on ALI progression via targeting topoisomerase II alpha (TOP2A).

Methods: The ALI mouse models were established by cecal ligation and perforation, which were then treated with miR-125b-5p agomir or overexpressed TOP2A. Next, the pathological structure of ALI mouse lung tissues were observed, miR-125b-5p, TOP2A and vascular endothelial growth factor (VEGF) expression was determined, and the lung water content, inflammatory response, protein content in bronchoalveolar lavage fluid (BALF) and cell apoptosis in ALI mouse lung tissues were assessed. Exosomes were extracted from endothelial cells (ECs) and identified, which were then injected into the modeled mice to observe their roles in ALI. The targeting relationship between miR-125b-5p and TOP2A was confirmed.

Results: MiR-125b-5p was downregulated while TOP2A was upregulated in ALI mice. MiR-125b-5p elevation or ECs-derived exosomes promoted VEGF expression, improved pathological changes and restrained lung water content, inflammatory response, protein content in BALF and cell apoptosis in lung tissues ALI mice. TOP2A overexpression reversed the repressive role of miR-125b-5p upregulation in ALI, while downregulated miR-125b-5p abrogated the effect of ECs-derived exosomes on ALI. TOP2A was confirmed as a direct target gene of miR-125b-5p.

Conclusion: Our study indicates that ECs-derived exosomes overexpressed miR-125b-5p to protect from sepsis-induced ALI by inhibiting TOP2A, which may contribute to ALI therapeutic strategies.
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http://dx.doi.org/10.1007/s00011-020-01415-0DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7776283PMC
February 2021
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