Influence Of Particulate Matter Research Articles

Contribution of Particulates to Airborne Disease Transmission and Severity: A Review.

The emergence of coronavirus disease 2019 (COVID-19) has catalyzed great interest in the spread of airborne pathogens. Airborne infectious diseases are classified into viral, bacterial, and fungal infections. Environmental factors can elevate their transmission and lethality. Air pollution has been reported as the leading environmental cause of disease and premature death worldwide. Notably, ambient particulates of various components and sizes are harmful pollutants. There are two prominent health effects of particles in the atmosphere: (1) particulate matter (PM) penetrates the respiratory tract and adversely affects health, such as heart and respiratory diseases; and (2) bioaerosols of particles act as a medium for the spread of pathogens in the air. Particulates contribute to the occurrence of infectious diseases by increasing vulnerability to infection through inhalation and spreading disease through interactions with airborne pathogens. Here, we focus on the synergistic effects of airborne particulates on infectious disease. We outline the concepts and characteristics of bioaerosols, from their generation to transformation and circulation on Earth. Considering that microorganisms coexist with other particulates as bioaerosols, we investigate studies examining respiratory infections associated with airborne PM. Furthermore, we discuss four factors (meteorological, biological, physical, and chemical) that may impact the influence of PM on the survival of contagious pathogens in the atmosphere. Our review highlights the significant role of particulates in supporting the transmission of infectious aerosols and emphasizes the need for further research in this area.

Is there a downside to plant ecological services in the city? Influences of particulate matter on the two-spotted spider mite (Tetranychus urticae) foraging on the small-leaved lime in urban conditions

The aim of this research was to examine how particulate matter (PM) pollution affects the life history of the two-spotted spider mite (TSSM), Tetranychus urticae (Trombidiformes: Tetranychidae), in modelled urban conditions. For this purpose, experimental populations of TSSM were cultured on the foliage of small-leaved lime (Tilia cordata) contaminated with PM at intensities corresponding to differing city zones such as a park, a busy road and an industrial area. The control samples in the study were washed, unpolluted leaves. The spider mite was selected as a model organism due to its cosmopolitan distribution, broad host spectrum, resistance to a variety of pesticides and food-intake mode involving cell-content sucking, while T. cordata is widely planted in cities and has demonstrated a considerable capability for PM capture. Data on the longevity and mortality of particular instars and on female fecundity at different pollution levels were collected and statistically evaluated. Concentrations of PM typical for roads and industrial city zones significantly reduced total female fecundity (avg. 53.9 and 55.9 eggs/female, respectively, vs 79.2 in control), which entailed a slower population increase, while the survival rate of particular developmental instars (P = 0.52) and fertility curves (P = 0.19) remained unchanged. The presence of PM caused physiological effects in the mites, despite the lack of direct consumption of the pollutant by adult and juvenile instars. Considering the incomparable resilience of TSSM to unfavourable environmental factors, it is predicted that the detrimental influence of PM on other representatives of urban arthropods may be even more severe. The results suggest that there is a need for further investigations into the ecological ramifications of air purification provided by urban green spaces.

Influence of particulate matter on air quality due to “Nortes” events in the Gulf of Mexico

The Gulf of Mexico is a region of great international importance, as well as the movement of ships that occur in it, with the port of Veracruz being the most important and currently being expanded. The objective of the study was to evaluate the impact of the particulate matter resulting from this expansion, considering the “Nortes” effect that occurs annually from September to May in the Gulf of Mexico. Four periods of “Nortes” were evaluated from 2017 to 2020 were evaluated, identifying 52 events to examine their influence on air quality. Using in situ meteorological parameters and the HYSPLIT model's cluster reanalysis database, 15 “Nortes” events were linked to measurements from the air quality monitoring station located at the port. The results reveal that “Nortes” events influence poor air quality due to particulate matter within a 30 by 30 km grid, as simulated by the CALPUFF dispersion model. This was attributed to particulate matter resuspension caused by wind speeds exceeding 11 m/s within an 8 km downwind from the expansion area. A concentration range of particulate matter of 60–70 μg/m3 was associated with the effect “Nortes” at the air quality monitoring station and the CALPUFF model. However, maximum concentrations ranged from 1,030 to 2,800 μg/m3 at different receptors, as indicated by the CALPUFF model. These findings underscore the importance of accounting for the impact of meteorological phenomena on air quality during the expansion and operation of ports around the world.

Multi-City Analysis of the Acute Effect of Polish Smog on Cause-Specific Mortality (EP-PARTICLES Study).

Polish smog is a specific type of air pollution present in Eastern Poland, which may cause particularly adverse cardiovascular effects. It is characterized primarily by high concentrations of particulate matter (PM) and different favorable conditions of formation. Our study aimed to assess whether PM and nitrogen dioxide (NO2) have a short-term impact on mortality due to acute coronary syndrome (ACS) and ischemic stroke (IS). The study covered the years 2016-2020, a total of 6 million person-years from five main cities in Eastern Poland. To evaluate the association between air pollution and cause-specific mortality, a case-crossover study design with conditional logistic regression was used at days with LAG from 0 to 2. We recorded 87,990 all-cause deaths, including 9688 and 3776 deaths due to ACS and IS, respectively. A 10 μg/m3 increase in air pollutants was associated with an increase in mortality due to ACS (PM2.5 OR = 1.029, 95%CI 1.011-1.047, p = 0.002; PM10 OR = 1.015, 95%CI 1-1.029, p = 0.049) on LAG 0. On LAG 1 we recorded an increase in both IS (PM2.5 OR = 1.03, 95%CI 1.001-1.058, p = 0.04) and ACS (PM2.5 OR = 1.028, 95%CI 1.01-1.047, p = 0.003; PM10 OR = 1.026, 95%CI 1.011-1.041, p = 0.001; NO2 OR = 1.036, 95%CI 1.003-1.07, p = 0.04). There was a strong association between air pollution and cause-specific mortality in women (ACS: PM2.5 OR = 1.032, 95%CI 1.006-1.058, p = 0.01; PM10 OR = 1.028, 95%CI 1.008-1.05, p = 0.01) and elderly (ACS: PM2.5 OR = 1.03, 95%CI 1.01-1.05, p = 0.003; PM10 OR = 1.027, 95% CI 1.011-1.043, p < 0.001 and IS: PM2.5 OR = 1.037, 95%CI 1.007-1.069, p = 0.01; PM10 OR = 1.025, 95%CI 1.001-1.05, p = 0.04). The negative influence of PMs was observed on mortality due to ACS and IS. NO2 was associated with only ACS-related mortality. The most vulnerable subgroups were women and the elderly.

Influence of Particulate Matter on Asthma Control in Adult Asthma

No clear evidence shows the association between particulate matter (PM) with an aerodynamic diameter &lt; 10 µm (PM10) and asthma control. Therefore, the objective of this study was to determine the association between PM10 and asthma control. A retrospective observational study was conducted at the Airway Clinic, Chiang Mai University Hospital, Chiang Mai, Thailand, between January 2010 and April 2013. Various values of asthma control test (ACT) scores between high and low PM10 periods were analyzed. The association of an increased monthly average PM10 level and ACT score was analyzed using a time series analysis. There were a total of 1180 visits from 236 asthmatic patients. The monthly average ACT score was significantly lower in the high PM10 period compared with the low PM10 period. Every 10 µg/m3 increment of monthly average PM10 resulted in a significantly decreased ACT score at lag zero and one month, with an adjusted coefficient of –0.101 (95% CI; –0.165, –0.037), p-value = 0.002 and –0.079 (95% CI; –0.147, –0.012), p-value = 0.021, respectively. Monthly average PM10 significantly affected asthma control in asthmatic patients. During the air pollution period, the serial assessments of ACT should be measured for early detection of worsening asthma control.

Seasonal Variations in the Particulate Matter Accumulation and Leaf Traits of 24 Plant Species in Urban Green Space

Particulate matter (PM), an extremely serious type of air pollution, leads to numerous human diseases. Mitigating PM in the urban city, where resident density has been increasing, has been a major challenge. The increase in residents leads to increasing traffic, the primary source of PM in urban areas. Plants play an important role in reducing PM and maintaining an ecological balance. For some Asian countries, such as Korea, with differing seasons and environmental conditions, PM accumulation and plant survival are greatly impacted by environmental conditions. In this study, we analyzed the amount of PM accumulation on the leaf surfaces and wax layers of 24 plant species during four seasons (spring, summer, autumn, and winter) to determine the PM accumulation in plants under different environmental conditions. The leaf traits of plant chlorophyll a (Chl a), chlorophyll b (Chl b), total chlorophyll (TChl), relative water content (RWC), leaf extract pH (pH), and leaf specific area (SLA) were analyzed to determine the influence of PM on plants and the relationship between PM and leaf traits. In this study, we found that the amount of PM accumulation differed among plants and seasons. Among the 24 plant species, plants Pinus strobus, P. parviflora, P. densiflora, Euonymus japonicus, and Acer palmatum were most adept at PM accumulation. Leaf structure, environmental conditions, such as PM concentration, and rainfall may be the main factors that impact the ability of plant leaves to accumulate PM. The plant leaf traits differed among the four seasons. PM accumulation on the leaf was negatively correlated with SLA (in all four seasons) and pH (in spring, summer, and autumn). PM was negatively correlated with Chl a, Chl b, and TChl in summer.

Fine and ultrafine airborne PM influence inflammation response of young adults and toxicological responses in vitro.

Little evidence is available regarding the impact of different sizes of inhaled particulate matter (PM) on inflammatory responses in healthy young adults in connection with toxicological responses. We conducted a five-time repeated measurement panel study on 88 healthy young college students in Guangzhou, China from December 2017 to January 2018. Blood samples were collected from each participant and tested for tumor necrosis factor alpha (TNF-α) levels every week for 5 consecutive weeks. Mass concentrations of ambient PM2.5, PM1, PM0.5 and number concentrations of ambient PM0.1 were measured. RAW 264.7 macrophages were exposed to PM (PM10-2.5, PM2.5-1, PM1-0.2, PM0.2) collected at the same time as the panel study. Cytotoxicity, oxidation and inflammatory parameters, cell cycle and genotoxicity were tested. Particles were characterized for their chemical composition. The trends of associations between PM2.5, PM1, PM0.5 and TNF-α level were consistent in lag 0 and 3 days, and the relative risk decreased as the particle size decreased. All the ambient air pollutants had the similar change trends in lag 1, 4 and 5 days. Similar results in RAW 264.7 macrophages were found; PM10-2.5 induced the greatest TNF-α and macrophage inflammatory protein 2 (MIP-2) productions and oxidative damage. PM1-0.2 and PM0.2 induced more significant dose-dependent increases of cell cycle and genotoxic response. In the component concentrations of PM samples, metal elements were PM10-2.5 > PM2.5-1 > PM0.2 ≥ PM1-0.2; ions and polycyclic aromatic hydrocarbons (PAHs) were PM0.2 > PM1-0.2 > PM2.5-1 > PM10-2.5. Our results suggested that exposure to all particle sizes was significantly associated with inflammation among healthy young adults and toxicological responses in RAW 264.7 macrophages. Different human and toxicological reactions caused by PM samples indicated the importance of investigating various particle sizes.

Predicting spatio-temporal distribution of indoor multi-phase phthalates under the influence of particulate matter

Due to the complexity of phthalates spatial and temporal distribution in indoor environment, mechanistic that govern indoor phthalates concentrations and fates need to be explored. A dynamic partition model of phthalates considering the dynamic behavior and segmented emission of size-resolved particulate matter is developed to investigate the distribution of phthalates in the gas phase, airborne particles, and settled dust and on the fixed surface. The impacts of outdoor and indoor particle source on the multi-phase concentrations of phthalates are analyzed. Outdoor haze can suddenly increase indoor particle concentration and particle-phase concentration of Di-2-ethylhexyl phthalate (DEHP). However, the haze decreases gas-phase and dust-phase concentration of DEHP. The particle emission rate Sp for cooking affects the maximum concentration of indoor particle, while cooking frequency has no effect on it. When cooking frequency increases, gas-phase concentration and particle-phase peak concentration of DEHP decreases significantly, which means the particulate matter may be a good carrier for DEHP removal. Increasing emission rate Sp of particles can significantly reduce the minimum gas-phase concentration of DEHP, nevertheless it can increase particle-phase maximum concentration of DEHP. Overall, the proposed model considering interactions of particle and phthalate can improve further understanding of phthalates’ fate and transport in residential environment, which is beneficial to the implementation of control strategy.

Impact of air pollution on outdoor cultural heritage objects and decoding the role of particulate matter: a critical review.

Atmospheric gases and particulate matter (PM) in contact with the material's surface lead to chemical and physical changes, which in most cases cause degradation of the cultural heritage material. Atmospheric damage and soiling are recognized as two pivotal forms of deterioration of cultural heritage materials caused by air pollution. However, the atmospheric damage effect of PM is rather complicated; its variable composition accelerates the deterioration process. Considering this, one of the important contributions of this work is to review the existing knowledge on PM influence on atmospheric damage, further recognize, and critically evaluate the main gaps in current understanding. The second phenomenon related to cultural heritage material and PM pollution is soiling. Even if soiling was recognized long ago, its definition and knowledge have not changed much for several decades. In the past, it was believed that black carbon (BC) was the primary soiling agent and that the change of the lightness could effectively measure the soiling. With the change of pollution situation, the lightness measurements do not represent the degree of soiling correctly. The additional contribution of this work is thus, the critical evaluation of soiling measurements, and accordingly, due to the change of pollution situation, redefinition of soiling is proposed. Even though numerous studies have treated soiling and atmospheric damage separately, there is an overlap between these two processes. No systematic studies exist on the synergy between soiling and atmospheric damage caused by atmospheric PM.

Numerical Simulation on Particulate Matter Emissions from a Layer House during Summer in Northeast China

Particulate matter (PM) emitted from livestock and poultry production contributes to atmospheric aerosol loading, affecting animal health and the surrounding atmospheric environment. However, developing and optimizing remediation technologies require a better understanding of air pollutant concentrations, the emission plumes, and the mechanism of emission. Previous studies have primarily focused on indoor air pollution research, while outdoor research is relatively rare. Field test research is not only costly but also consumes extensive amounts of time. The application of computational fluid dynamics (CFD) technology can save a lot of measurement time and repetitive labor, in order to better understand the diffusion fundamentals and spatial and temporal distribution differences of PM. This study monitored the PM concentrations of different particle sizes inside and outside a layer house with negative pressure ventilation in Northeast China during the summer of 2021. These data were also used to validate the three-dimensional simulation of the PM concentrations inside and outside of the layer house in various scenarios of wind directions at different times by CFD technology. Through correlation analysis, it is found that temperature was positively correlated with PM1 and PM2.5, and relative humidity and wind speed were negatively correlated with PM, which has a greater impact on PM10 and total suspended particulate (TSP). The particle size was proportional to the diffusion distance and diffusion height, time, and wind direction both have an impact on the spread of PM. Considering the environmental conditions in Northeast China, increasing the height of the fan by 1 m was suggested to reduce the diffusion of PM concentration. In addition, the diffusion patterns and transport paths in this study provide valuable information for improving control measures to minimize the influence of PM on both animal health and air quality.

Influence of Krakow Winter and Summer Dusts on the Redox Cycling of Vitamin B12a in the Presence of Ascorbic Acid

Air pollution remains a serious problem in Krakow, Poland. According to the European Environmental Agency, annual mean levels of both PM2.5 and PM10 recorded in Krakow are much higher than EU limit values. Thus, the influence of particulate matter (PM) on the function of living organisms, as well as different physiological processes, is an urgent subject to be studied. The reported research forms part of the multi-disciplinary project ‘Air Pollution versus Autoimmunity: Role of multiphase aqueous Inorganic Chemistry,’ which aims to demonstrate the PM effect on the immune system. The present studies focused on the role of dust collected in Krakow on the redox cycling of vitamin B12a in the presence of ascorbic acid. Dust samples collected during the winter 2019/2020 and summer 2020 months in the city center of Krakow were characterized using various analytical techniques. The influence of Krakow dusts on the kinetics of the reaction between nitrocobalamin and ascorbic acid was confirmed and discussed in terms of the composition of the samples. Possible reasons for the reported findings are provided.

Evaluation of pollutants characteristics and effect of dissolved and particulate contaminants in tributaries of an urban watershed

The importance of tributary management is increasing owing to the increase and diversity of pollutant sources in watersheds. In this study, the characteristics of dissolved and particulate contaminants in tributaries of the Anyang watershed, South Korea, were investigated using various analytical indicators (e.g., organic matter, nutrients, and spectroscopic analysis), heat maps, and multivariate analysis techniques, including cluster analysis and principal component analysis (PCA), to evaluate water quality characteristics of the tributaries and major pollutant sources. The influence of particulate matter from each tributary was also evaluated by investigating changes in sediment composition and re-suspended sediment oxygen demand (RSOD) at the mainstream of Anyang. The heat map patterns of the evaluated tributaries reflect sufficiently the characteristics of the pollutant sources, which enables the differentiation of the pollutant source according to the tributary locations and seasons. PCA results showed that water quality and spectral indicators reflected the different characteristics of the tributary; thus, it enabled a more diverse evaluation of tributary depending on pollutant source and season. The tributary watershed showed a high suspended solids (SS) discharge load depending on the watershed area (r = 0.94, p < 0.05), and the sediment near the tributary with higher SS discharge load revealed a higher content of fine sand (0.002–0.2 mm, r = 0.84, p < 0.05). The finer the particles derived from tributaries are, the higher the increase in RSOD is due to resuspension, most of which are caused by microbial activity (> 80%). Our results demonstrate that comprehensive and visual evaluation—including spectral indicators and heat maps analysis—of the tributary characteristics of pollutant sources is an efficient approach of broadening the knowledge of the distribution and effects of particulate matter from tributaries.

Can particulate matter be identified as the primary cause of the rapid spread of CoViD-19 in some areas of Northern Italy?

Northern Italy was the most affected by CoViD-19 compared to other Italian areas and comprises zones where air pollutants concentration was higher than in the rest of Italy. The aim of the research is to determine if particulate matter (PM) has been the primary cause of the high CoViD-19 spread rapidity in some areas of Northern Italy. Data of PM for all the 41 studied cities were collected from the local environmental protection agencies. To compare air quality data with epidemiological data, a statistical analysis was conducted identifying the correlation matrices of Pearson and Spearman, considering also the possible incubation period of the disease. Moreover, a model for the evaluation of the epidemic risk, already proposed in literature, was used to evaluate a possible influence of PM on CoViD-19 spread rapidity. The results exclude that PM alone was the primary cause of the high CoVid-19 spread rapidity in some areas of Northern Italy. Further developments are necessary for a better comprehension of the influence of atmospheric pollution parameters on the rapidity of spread of the virus SARS-CoV-2, since a synergistic action with other factors (such as meteorological, socio-economic and cultural factors) could not be excluded by the present study.Graphical abstract

Aircraft vertical profiles during summertime regional and Saharan dust scenarios over the north-western Mediterranean basin: aerosol optical and physical properties

Abstract. Accurate measurements of the horizontal and vertical distribution of atmospheric aerosol particle optical properties are key for a better understanding of their impact on the climate. Here we present the results of a measurement campaign based on instrumented flights over north-eastern Spain. We measured vertical profiles of size-segregated atmospheric particulate matter (PM) mass concentrations and multi-wavelength scattering and absorption coefficients in the western Mediterranean basin (WMB). The campaign took place during typical summer conditions, characterized by the development of a vertical multi-layer structure, under both summer regional pollution episodes (REGs) and Saharan dust events (SDEs). REG patterns in the region form under high insolation and scarce precipitation in summer, favouring layering of highly aged fine-PM strata in the lower few kma.s.l. The REG scenario prevailed during the entire measurement campaign. Additionally, African dust outbreaks and plumes from northern African wildfires influenced the study area. The vertical profiles of climate-relevant intensive optical parameters such as single-scattering albedo (SSA); the asymmetry parameter (g); scattering, absorption and SSA Ångström exponents (SAE, AAE and SSAAE); and PM mass scattering and absorption cross sections (MSC and MAC) were derived from the measurements. Moreover, we compared the aircraft measurements with those performed at two GAW–ACTRIS (Global Atmosphere Watch–Aerosol, Clouds and Trace Gases) surface measurement stations located in north-eastern Spain, namely Montseny (MSY; regional background) and Montsec d'Ares (MSA; remote site). Airborne in situ measurements and ceilometer ground-based remote measurements identified aerosol air masses at altitudes up to more than 3.5 kma.s.l. The vertical profiles of the optical properties markedly changed according to the prevailing atmospheric scenarios. During SDE the SAE was low along the profiles, reaching values &lt; 1.0 in the dust layers. Correspondingly, SSAAE was negative, and AAE reached values up to 2.0–2.5, as a consequence of the UV absorption increased by the presence of the coarse dust particles. During REG, the SAE increased to &gt; 2.0, and the asymmetry parameter g was rather low (0.5–0.6) due to the prevalence of fine PM, which was characterized by an AAE close to 1.0, suggesting a fossil fuel combustion origin. During REG, some of the layers featured larger AAE (&gt; 1.5), relatively low SSA at 525 nm (&lt; 0.85) and high MSC (&gt; 9 m2 g−1) and were associated with the influence of PM from wildfires. Overall, the SSA and MSC near the ground ranged around 0.85 and 3 m2 g−1, respectively, and increased at higher altitudes, reaching values above 0.95 and up to 9 m2 g−1. The PM, MSC and MAC were on average larger during REG compared to SDE due to the larger scattering and absorption efficiency of fine PM compared with dust. The SSA and MSC had quite similar vertical profiles and often both increased with height indicating the progressive shift toward PM with a larger scattering efficiency with altitude. This study contributes to our understanding of regional-aerosol vertical distribution and optical properties in the WMB, and the results will be useful for improving future climate projections and remote sensing or satellite retrieval algorithms.

Exposures to Ambient Particulate Matter Affect Semen Quality: A Case Study of Wenzhou, China

Background: Previous studies have shown that particulate matter (PM) may have a negative effect on semen quality. However, the results of most studies on the association between PM and semen quality are inconsistent. Objectives: To assess the potential influence of PM on semen parameters during different exposure periods. Methods: Using data form the First Affiliated Hospital of Wenzhou Medical University in Wenzhou, China, we analyzed 8822 semen samples between March 3, 2014 and March 15, 2019. Multiple linear regression models were used to assess the association of semen parameters (progressive motility, total motility, total sperm number, sperm concentration, semen volume and sperm morphology) with personal exposure to PM2.5 and PM10 during the period of sperm development (0-90 days before each semen examination) and key periods (0-9 days, 10-14 days and 70-90 days before each semen examination). Results: Overall, during the 0-90 lag days, PM2.5 and PM10 were associated with reduced progressive motility (β: -1.1114; 95% CI: -1.2178, -1.0050; β: -0.7116; 95% CI: -0.7856, -0.6375), reduced total motility (-2.7613; -3.1109, -2.4118; -1.7766; -2.0196, -1.5337), and increased sperm concentration (0.0168; 0.0102, 0.0234; 0.0091; 0.0045, 0.0137). In addition, during all key periods, we observed that PM2.5 and PM10 showed negative correlations with progressive motility and total motility (all P<0.05). Also, similar results were observed in the normal semen group and the abnormal semen group. Conclusions: Our findings suggest that PM exposure may have a negative effect on sperm progressive motility and total motility, but it may have a positive effect on sperm concentration.

Protective Effect of Aerobic Physical Training on Oxidative Stress Caused by Particulate Matter in Rats

Introduction: Particulate matter (PM) is an atmospheric pollutant associated with many deleterious health effects. Oxidative stress is among these effects, that can result from a local inflammatory response to systemic damage to the organism. Studies indicate that when an individual is submitted to aerobic physical training, it generates an antioxidant protective effect that overcomes the damages caused by PM. Objective: Therefore, the aim of this study was to evaluate the influence of the particulate matter PM2.5 and PM10 on the oxidative stress parameters. Methods: The evaluation of the influence of PM on oxidative stress parameters was performed by the dosages of superoxide dismutase, catalase, glutathione peroxidase, and total antioxidant power in male Wistar rats not exposed to the particulate matter, with and without aerobic physical training, and exposed to PM2.5 and PM10, with and without aerobic physical training. This protocol lasted five weeks. Results: The antioxidant enzymes analyzed that presented significant differences were catalase, and glutathione peroxidase. Conclusions: From this research, it was possible to perceive that PM influences negatively on the oxidative stress and in the weight of the rats and that the aerobic exercise generates a protective effect against these damages.

Effect of Particulate Matter on the Tear Film in Contact Lens Wearers

Purpose : To investigate the influence of particulate matter (PM) on tear film in contact lens (CL) wearers, the tear volume and stability were evaluated according to the level of PM. Methods : Thirty-one myopes in their 20s wearing glasses and CL were participated, and they were required to wear soft CL (L brand, 55% water content) for 8 hours a day. The subjects were divided into the normal and dry eye groups according to the OSDI score. The levels of PM were divided good (0~30 ㎍/m³) and bad (51~100 ㎍/m³) according to the criteria provided by the Korea Environment Corporation. The tear tests were conducted both on the good and bad PM days. Tear volume was evaluated by OCCUTUBE and the stability was evaluated by TBUT and NIBUT. The results were analyzed using SPSS according to the level of PM. Results : On the day of bad PM level, the tear volume and stability were significantly decreased both wearing glasses and CL (p＜0.050) on to the level of dry eye. With the CL wearing tear volume was decreased even on the day of good PM level and TBUT was decreased on the day of bad PM level compared with glasses wearing. In dry eye group, TBUT was decreased significantly with CL wearing compared with normal group on the day of bad PM level. Conclusion : PM reduces both the amount and stability of tear that it could be the one of causes of dry eye, and wearing CL at the bad PM level deteriorated the tear film stability that the symptoms of dry eye patients may be worsened, so it is thought that wearing glasses should be recommended for contact lens wearers on the day of bad PM to prevent the dry eye.

Role of air pollution by particulate matter in the pathogenesis of cardiovascular diseases. Prevention measures

The review highlights contemporary concepts about the role of atmospheric air pollution by particulate matter (PM) in pathogenesis of cardiovascular diseases (CVD). We used publications from the PubMed and Russian Science Citation Index databases. The influence of PM on the development and progression of CVD is considered depending on size, origin, chemical composition, concentration in air. PM with an aerodynamic diameter of ≤2,5 μm (PM2,5) are recognized as the most dangerous. Epidemiological studies have established a dose-dependent effect PM. Oxidative stress, damage of genome of cell and epigenetic changes associated with PM effect are the important component of CVD pathogenesis. Systematization of scientific data through a formalized description helps to understand the pathogenesis of CVD and facilitates its practical use for assessing the risk of occurrence, early diagnosing, prognostication, increasing the effectiveness of treatment, and developing preventive measures.

Inhibitory effect of particulate matter on toll-like receptor 9 stimulated dendritic cells by downregulating mitogen-activated protein kinase and NF-κB pathway

ABSTRACT Ambient particulate matter (PM) is associated with adverse health consequences. However, the influence of PM on the innate immune system is poorly understood. The aim of the present study was to examine the effect of diesel particulate matter 2.5 μm (PM2.5, SRM1650b) on dendritic cells. PM2.5 significantly reduced cytokine levels of interleukin (IL)-12 p40, IL-6 and TNF-α levels in CpG-DNA (TLR9 ligand)-stimulated dendritic cells. To determine the mechanisms underlying this observed inhibition induced by PM2.5, western blot analysis was conducted. PM2.5 was found to downregulate ERK1/2, JNK1/2, p38 MAPKs, and NF-κB pathways. PM2.5 exposure decreased TLR9-dependent NF-κB and activator protein (AP-1) reporter luciferase activities. Our findings demonstrate that PM2.5 reduced the production of cytokines which may be associated with inhibition of MAPK and NF-κB signaling pathway. Further, data suggest the immunosuppressive effect of PM2.5 on the innate immune cells may lead to serious damage to the host immune system.

The Impact of Particulate Matter on Outdoor Activity and Mental Health: A Matching Approach.

Exposure to air pollution affects human activity and health. Particularly, in Asian countries, the influence of particulate matter on humans has received wide attention. However, there is still a lack of research about the effects of particulate matter on human outdoor activities and mental health. Therefore, we aimed to explore the association between exposure to particulate matter with a diameter of less than 10 µm (PM10) and outdoor activity along with mental health in South Korea where issues caused by particulate matter increasingly have social and economic impacts. We examined this relationship by combining the physical and habitual factors of approximately 100,000 people in 2015 from the Korean National Health Survey. To measure each individual’s exposure to particulate matter, we computed the total hours exposed to a high PM10 concentration (>80 μg/m3) in a given district one month before the survey was conducted. After dividing all districts into six groups according to the exposed level of the high PM10, we applied the propensity score-weighting method to control for observable background characteristics. We then estimated the impact of the high PM10 on outdoor activity and mental health between the weighted individuals in each group. Our main findings suggest that the impact of PM10 on outdoor activity and stress shows an inverted-U shaped function, which is counterintuitive. Specifically, both outdoor activity and stress levels tend to be worsened when the exposure time to a high PM10 (>80 μg/m3) was more than 20 h. Related policy implications are discussed.