Mitochondria can be used as important biomarkers of pollutants on human health, and fine particulate matter (PM2.5) has been documented to cause respiratory damage. However, current studies about the ...relationship between PM2.5 and mitochondria in respiratory tract are limited and warrant further detailed investigations. Hence, the study was aimed to evaluate effects of PM2.5 on mitochondrial structure, investigate the link between PM2.5-induced mitochondrial disorder and respiratory damage, and delineate the possible mechanisms using both in vitro and in vivo models. PM2.5 exposure resulted in damage of mitochondrial structure, including mitochondrial dynamic, DNA biogenesis and morphological alteration 16HBE cells. Furthermore, PM2.5 elevated ROS formation. However, DPI and NAC (inhibitor of ROS) in supplement restored PM2.5-induced mitochondrial disorder. PM2.5 also contributed to the 16HBE cells apoptosis via mitochondrial pathway. Additionally, the results coincided with the in vivo data which were obtained from bronchial tissues of SD rats exposed to PM2.5 for 30 days. Collectively, this study uncovers that PM2.5 leads to the disorder of mitochondrial structure via ROS generation, and then results in respiratory damage. It provides further understanding about the detrimental effect of PM2.5 on respiratory damage, and reveals a mechanistic basis for preventing outcomes in polluted environments.
•The temporal trends of aerosol pH and its key driver's in a coastal city were investigated.•Sensitivity tests revealed that SO42−, NHx, t and RH drove the variations of aerosol pH.•Meteorological ...factors (52.9%) and chemical compositions (41.3%) commonly contributed the aerosol ΔpH.•The elevated PM2.5 led to an increase in pH and ALWC while the opposite was for the increasing O3 levels.
Aerosol acidity (pH) plays an important role in the multiphase chemical processes of atmospheric particles. In this study, we demonstrated the seasonal trends of aerosol pH calculated with the ISORROPIA-II model in a coastal city of southeast China. We performed quantitative analysis on the various influencing factors on aerosol pH, and explored the responses of aerosol pH to different PM2.5 and O3 pollution levels. The results showed that the average aerosol pH was 2.92 ± 0.61, following the order of winter > spring > summer > autumn. Sensitivity tests revealed that SO42−, NHx, T and RH triggered the variations of aerosol pH. Quantitative analysis results showed that T (37.9%-51.2%) was the main factors affecting pH variations in four seasons, followed by SO42− (6.1%-23.7%), NHx (7.2%-22.2%) and RH (0–14.2%). Totally, annual mean meteorological factors (52.9%) and chemical compositions (41.3%) commonly contributed the aerosol ΔpH in the coastal city. The concentrations of PM2.5 was positively correlated with aerosol liquid water content (R2 = 0.53) and aerosol pH (R2 = 0.26), indicating that the increase in pH was related with the elevated NH4NO3 and decreased SO42−, and also the changes of T and RH. The Ox (O3 + NO2) was moderately correlated with aerosol pH (R2 = -0.48), attributable to the fact that the proportion of SO42− increased under high T and low RH conditions. The study strengthened our understanding of the contributions of influencing factors to aerosol pH, and also provided scientific evidences for chemical processes of atmospheric particles in coastal areas.
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In this paper, a new technique to obtain a fundamental solution is developed. The well-known Cayley-Hamilton theorem in linear algebra is adopted to obtain the inverse of the differential operator ...(in its symbolic form) of the governing equation and hence the corresponding fundamental and particular solutions are obtained. Several examples are presented to demonstrate the use of the presented technique.
Several meshless methods that are used to solve the partial differential equations are particular solutions based numerical methods. These numerical methods can only be applied to solve the partial ...differential equations if researchers have derived a particular solution of some equations beforehand. The main contribution of this article is the derivation of the family of particular solutions of the Poisson’s equation in 3D with the oscillatory radial basis functions in the forcing term. Numerical results obtained by solving three elliptic partial differential equations presented here validates the derived particular solutions in the method of particular solutions.
After nearly twenty years of rapid modernization and urbanization in China, huge achievements have transformed the daily lives of the Chinese people. However, unprecedented environmental consequences ...in both indoor and outdoor environments have accompanied this progress and have triggered public awareness and demands for improved living standards, especially in residential environments. Indoor pollution data measured for >7000 dwellings (approximately 1/3 were newly decorated and were tested for volatile organic compound (VOC) measurements, while the rest were tested for particles, phthalates and other semi-volatile organic compounds (SVOCs), moisture/mold, inorganic gases and radon) in China within the last ten years were reviewed, summarized and compared with indoor concentration recommendations based on sensory or health end-points. Ubiquitous pollutants that exceed the concentration recommendations, including particulate matter, formaldehyde, benzene and other VOCs, moisture/mold, inorganic gases and radon, were found, indicating a common indoor air quality (IAQ) issue in Chinese dwellings. With very little prevention, oral, inhalation and dermal exposure to those pollutants at unhealthy concentration levels is almost inevitable. CO2, VOCs, humidity and radon can serve as ventilation determinants, each with different ventilation demands and strategies, at typical occupant densities in China; and particle reduction should be a prerequisite for determining ventilation requirements. Two directional ventilation modes would have profound impacts on improving IAQ for Chinese residences are: 1) natural (or window) ventilation with an air cleaner and 2) mechanical ventilation with an air filtration unit, these two modes were reviewed and compared for their applicability and advantages and disadvantages for reducing human exposure to indoor air pollutants. In general, mode 2 can more reliably ensure good IAQ for occupants; while mode 1 is more applicable due to its low cost and low energy consumption. However, besides a roadmap, substantial efforts are still needed to develop affordable, applicable and general ventilation solutions to improve the IAQ of residential buildings in China.
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•Indoor air pollution data measured in >7000 residences in China were summarized.•Particulate matters, VOCs, SVOCs, moisture/mold, inorganic gases and radon were ubiquitous.•Ventilation prerequisites, determinants and requirements were discussed.•Natural (window) ventilation+air cleaner and mechanical ventilation+air filtration was compared.
Maternal exposure to fine particular matter (PM2.5) during pregnancy, including ambient and household PM2.5, has been linked with increased risk of preterm birth (PTB). However, the global ...spatio-temporal distribution of PTB-related deaths and disability-adjusted life years (DALYs) attributable to PM2.5 is not well documented. We estimated the global, regional, and national patterns and trends of PTB burden attributable to both ambient and household PM2.5 from 1990 to 2019.
Based on the Global Burden of Disease Study (GBD) 2019 database, we obtained the numbers of deaths and DALYs as well as age-standardized mortality rate (ASMR) and age-standardized DALY rate (ASDR) of PTB attributable to total, ambient, and household PM2.5 by socio-demographic index (SDI) and sex during 1990–2019. The average annual percentage changes (AAPCs) were calculated to assess the temporal trends of attributable burdens.
In 2019, 126,752 deaths and 11.3 million DALYs related to PTB worldwide (two-thirds in Western Sub-Saharan Africa and South Asia) could be caused by excess PM2.5 above the theoretical minimum-risk exposure level (TMREL), of which 39 % and 61 % were attributable to ambient PM2.5 and household PM2.5, respectively. From 1990 to 2019, the global ASMR due to ambient PM2.5 increased slightly by 7.08 % whereas that due to household PM2.5 decreased substantially by 58.81 %, although the latter still dominated the attributable PTB burden, especially in low and low-middle SDI regions. Similar results were also observed for ASDRs. In addition, PTB burden due to PM2.5 was higher in male infants and in lower SDI regions.
Globally in 2019, PM2.5 remains a great concern on the PTB burden, especially in Western Sub-Saharan Africa and South Asia. Between 1990 and 2019, age-standardized burden of PTB due to ambient PM2.5 increased globally, while that due to household PM2.5 decreased markedly but still dominated in low and low-middle SDI regions.
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•We presented a detailed profile for the global burden of PTB attributable to PM2.5.•Western Sub-Saharan Africa and South Asia experienced great burdens.•PTB burden due to ambient PM2.5 increased slightly from 1990 to 2019.•PTB burden due to household PM2.5 decreased but still dominated in lower SDI regions.
In this paper, two localized meshless methods based on polynomial basis functions are utilized to solve axisymmetric problems. In the first approach, we applied the localized method of particular ...solutions (LMPS) and the closed-form particular solution to simplify the two-stage approach using Chebyshev polynomial as the basis functions for solving axisymmetric problems. We also propose the modified local Pascal polynomial method (MLPM) to compare the results with LMPS. Since only the low order polynomial basis functions are used, no preconditioning treatment is required and the solution is quite stable. Four numerical examples are given to demonstrate the effectiveness of the proposed methods.
Particular solutions play a critical role in solving inhomogeneous problems using boundary methods such as boundary element methods or boundary meshless methods. In this short article, we derive the ...closed-form particular solutions for the Laplace and biharmonic operators using the Gaussian radial basis function. The derived particular solutions are implemented numerically to solve boundary value problems using the method of particular solutions and the localized method of approximate particular solutions. Two examples in 2D and 3D are given to show the effectiveness of the derived particular solutions.
•Estimates of PM2.5 concentrations in 2030 declined compared with 2015.•If the age structure maintains, PM2.5-related premature death in 2030 related to 2015 decreased.•With the population aging, ...PM2.5-related premature death would sharply increase in 2030.
Fine particulate matter (PM2.5) pollution is one of the most critical environmental and public health problems in China and has caused an enormous disease burden, especially long-term PM2.5 exposure. Global climate change represents another environmental challenge in the coming decades and is also an essential factor affecting PM2.5 pollution. Moreover, China has an aging population with a changing population size and falling age-standardized mortality rates. However, little evidence exists evaluating the potential impacts from climate change and population aging on the long-term PM2.5 exposure-related disease burden. This study quantifies the impacts of climate and population changes on changes in the disease burden attributed to long-term PM2.5 exposure from 2015 to 2030 in mainland China, which could add evidence for the revision of relevant environmental standards and health policies.
This modeling study investigated long-term PM2.5 exposure-related mortality across China based on PM2.5 projections under Intergovernmental Panel on Climate Change Representative Concentration Pathways (RCPs) and population scenarios from shared socioeconomic pathways (SSPs). PM2.5 concentrations were simulated by the Weather Research and Forecasting (WRF) and Community Multiscale Air Quality (CMAQ) modeling systems. In addition, three types of population projections in 2030 relative to 2015 were set up as follows: (i) the population remained the same as that in 2015; (ii) the population size changed under SSPs, but the age structure remained the same; (iii) both the population size and age structure changed under SSPs. The global exposure mortality model (GEMM) was adopted to estimate PM2.5-related premature deaths.
Ambient PM2.5 concentrations decreased from 2015 to 2030 under the two climate and emission scenarios. Estimates of related premature mortality in 2030 declined compared with that in 2015 due to lower PM2.5 concentrations (RCP4.5: −16.8%; RCP8.5: −16.4%). If the age structure of the population remained unchanged and the population size changed under SSPs, the nonaccidental premature mortality also showed a decrease ranging from −18.6% to −14.9%. When both population size and age structure changed under SSPs, the population in China would become older. Nonaccidental premature mortality would sharply increase by 35.7–52.3% (with a net increase of 666–977 thousand) in 2030.
The PM2.5 pollution in 2030 under both RCP4.5 and RCP8.5 would slightly improve. The population sizes in 2030 projected by SSPs are relatively stable compared with that in 2015. However, the modest decrease due to air pollution improvement and stable population size would be offset by population aging.
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