Fine, ultrafine, and yellow dust: emerging health problems in Korea

Lysine-Proline-Valine peptide mitigates fine dust-induced keratinocyte apoptosis and inflammation by regulating oxidative stress and modulating the MAPK/NF-κB pathway

Airborne particulate matter (PM) poses a major environmental risk that impairs skin health by triggering oxidative stress, inflammation, and cell death. In this study, we investigated the protective effects of Lysine-Proline-Valine (KPV)-an endogenous peptide derived from α-melanocyte-stimulating hormone-against oxidative damage and inflammation induced by fine PM (PM10) in human HaCaT keratinocytes. Our results show that PM10 markedly suppresses HaCaT cell proliferation via cytotoxic effects and induces a pro-inflammatory response by increasing IL-1β secretion. Notably, treatment with 50 μg/mL of KPV restored cell viability and reduced IL-1β secretion disrupted by PM10 exposure. To counteract PM10-induced cell death, KPV inhibited reactive oxygen species (ROS) production, which is responsible for activating extracellular signal-regulated kinase and p38 mitogen-activated protein kinase. Additionally, KPV decreased the expression of apoptosis-related proteins (Bax, Bcl-2, and cleaved caspase-3) and IL-1β through suppression of the redox-sensitive transcription factor nuclear, factor-kappa B in PM10-treated HaCaT cells. Against PM10-induced inflammation, KPV effectively blocked ROS-mediated caspase-1 activation, reducing IL-1β secretion. In a three-dimensional (3D) skin model, KPV treatment effectively attenuated the inflammatory cell death induced by PM10. Collectively, these findings suggest that KPV protects keratinocytes by mitigating PM10-induced pyroptosis and holds potential as a therapeutic agent for preventing environmental pollutant-related skin damage, with promising applications in functional cosmetics and skin-protective treatments.

TXNIP regulates pulmonary inflammation induced by Asian sand dust

Asian sand dust (ASD), a seasonal dust storm originating from the deserts of China and Mongolia, affects Korea and Japan during the spring, carrying soil particles and a variety of biochemical components. Exposure to ASD has been associated with the onset and exacerbation of respiratory disorders, although the underlying mechanisms remain unclear. This study investigates ASD-induced pulmonary toxicity and its mechanistic pathways, focusing on the role of thioredoxin-interacting protein (TXNIP). Using TXNIP knock-out (KO) mice and adeno-associated virus (AAV)-mediated TXNIP overexpression transgenic mice, we explored how TXNIP modulates ASD-induced pulmonary inflammation. Mice were exposed to ASD via intranasal administration on days 1, 3, and 5 to induce inflammation. ASD exposure led to significant pulmonary inflammation, evidenced by increased inflammatory cell counts and elevated cytokine levels in bronchoalveolar lavage fluid, as well as heightened protein expression of the TXNIP/NOD-like receptor pyrin domain-containing 3 (NLRP3) inflammasome. TXNIP KO mice exhibited attenuated airway inflammation and downregulation of the NLRP3 inflammasome compared to wild-type controls, while AAV-mediated TXNIP overexpression mice showed exacerbated inflammatory responses, including elevated NLRP3 inflammasome expression, compared to AAV-GFP controls. These findings suggest that TXNIP is a key regulator of ASD-induced pulmonary inflammation.

Momordica cochinchinensis extract alleviates oxidative stress and skin damage caused by fine particulate matter

Momordica cochinchinensis (MC), commonly known as gac fruit, is a tropical fruit rich in antioxidants and bioactive compounds. This research aimed to elucidate the effect of MC on apoptosis induced by fine particulate matter with a diameter of less than 10 μm (< PM10) in epidermal keratinocyte HaCaT cells. We found that PM10 significantly diminish the viability of HaCaT cells through cytotoxic mechanisms. However, the treatment with MC at a concentration of 10 μg/mL notably restored the cellular viability decreased by PM10. MC reduced the activation of extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) by mainly preventing the generation of reactive oxygen species (ROS) in HaCaT cells subjected to PM10. Furthermore, MC exhibited a regulatory effect on the expression of genes associated with apoptosis, including B-Cell Lymphoma 2 (Bcl-2), Bcl-2 associated X protein (Bax), and cleaved caspase-3 by inhibiting the activation of the transcription factor nuclear factor-kappa B (NF-κB). These findings demonstrate that MC aids in neutralizing the apoptotic signaling pathway of free radicals produced by environmental pollutants such as PM10, which have the potential to damage skin cells and accelerate the aging process.

The composition of the bacterial communities collected from the PM10 samples inside the Seoul subway and railway station

Health implications of indoor air quality (IAQ) have drawn more attention since the COVID epidemic. There are many different kinds of studies done on how IAQ affects people's well-being. There hasn't been much research that looks at the microbiological composition of the aerosol in subway transit systems. In this work, for the first time, we examined the aerosol bacterial abundance, diversity, and composition in the microbiome of the Seoul subway and train stations using DNA isolated from the PM10 samples from each station (three subway and two KTX stations). The average PM10 mass concentration collected on the respective platform was 41.862 µg/m3, with the highest average value of 45.95 µg/m3 and the lowest of 39.25 µg/m3. The bacterial microbiomes mainly constituted bacterial species of soil and environmental origin (e.g., Acinetobacter, Brevundimonas, Lysinibacillus, Clostridiodes) with fewer from human sources (Flaviflexus, Staphylococcus). This study highlights the relationship between microbiome diversity and PM10 mass concentration contributed by outdoor air and commuters in South Korea's subway and train stations. This study gives insights into the microbiome diversity, the source, and the susceptibility of public transports in disease spreading.

The prenatal and postnatal effects of air pollution on asthma in children with atopic dermatitis

OBJECTIVES

Air pollution is strongly associated with asthma, but has not been determined to induce new-onset asthma development in children with atopic dermatitis (AD).

WORKING HYPOTHESIS

To assess whether prenatal/postnatal exposure to air pollutants triggers new-onset asthma development in children with AD.

STUDY DESIGN

Retrospective cohort study.

PATIENT-SUBJECT SELECTION

Data of patients <age 18 years diagnosed with eczema or AD between 2009 and 2019 were extracted from the multicenter Kaohsiung Medical University Hospital Research Database. Patients diagnosed with new-onset asthma were in the asthma group and patients without asthma history were in the non-asthma group.

METHODOLOGY

The monthly average concentration of air pollutants for 1, 3, and 5 years before the index date, and 3, 6, and 9 months prenatally were analyzed and further stratified by age, immunoglobulin (Ig) E, and the percentage of eosinophil and eosinophil cationic protein (ECP).

RESULTS

Postnatal exposure to airborne particulate matter (PM_2.5 , PM₁₀ ), sulfur dioxide (SO₂ ), ozone (O₃ ), carbon monoxide (CO), nitric oxide (NO), nitric dioxide (NO₂ ), and NO_x , and prenatal exposure to PM_2.5 , PM₁₀ , SO₂ , NO, and NO_x were significantly higher in the asthma group than in the non-asthma group. Patients having IgE above 100 IU/ml and ECP less than 24 ng/ml were significantly influenced by postnatal exposure to PM_2.5 and PM₁₀ , especially CO, to develop asthma, and those having an eosinophil count >3% were significantly influenced by prenatal exposure to PM_2.5 , especially SO₂ , NO, and NO₂ .

CONCLUSIONS

Prenatal and postnatal exposure to air pollution have an association with asthma development in AD patients.

Estimation of the concentration of nano-carbon black in tire-wear particles using emission factors of PM10, PM2.5, and black carbon

Particulate matter (PM) from automobile exhaust has drastic effects on human health. The enforcement of environmental laws has controlled vehicle emissions and reduced the total PM. However, another significant source of PM is debris from tire wear, break wear, and road wear. In particular, tire-wear particles (TWPs) are further fragmented into nanoparticles, similar to the PM_x or black carbon (BC) sources. As approximately 30 wt% of carbon black (CB) is used as filler in tires, TWPs can fragment into free-bound nano-CB. This study evaluates the emission factors of BC from the ternary plots of PM_x and BC to estimate the concentration of nano-CB in TWPs. Based on the emission factors of BC for TWP, approximately 500 monitoring data points were acquired at four different sites. Semi-closed sites in a field measurement test have 2.9-4.0 times larger BC concentration than open sites. The mass concentration of nano-CB evaluated with the BC data and emission factors at the open sites is 22.47-23.96 ng/m³, whereas that at the semi-closed sites is 66.32-90.33 ng/m³. Transmission electron microscopy analysis with scanning mobility particle sizer and selected-area electron diffraction reveals grape-like aggregated nanoparticles, which is considered as CB. To compare the effect of the washing out of airborne particulates by rain, further analysis is conducted on the interior and exterior of the tunnel on a rainy day. While the concentration of PMs was effectively reduced by rainfall, the amount of BC and CB in the interior of a tunnel was not changed. Namely, even under rainfall, nano-CB still exists in the tunnels and thus free-bound CB and nanoparticles released from TWP will be effected on the human health.

The Evolution of Vigilance and Its Atrophy Preceding the COVID-19 Global Pandemic

Introduction

Recent infectious outbreaks preceding the COVID-19 crisis resulted in the evolution of vigilance for preparedness against the next pandemic. This vigilance was maintained to varying degrees in different jurisdictions.

Objective

To evaluate the evolution of vigilance following previous epidemics and pandemics and the subsequent atrophy of vigilance prior to the COVID-19 global pandemic.

Methods

We evaluated documentation discussing US, Canada, and South Korea from March 2002 to October 2021. Our policy search strategy was rooted in academic literature, government documents and media reports.

Results

In the US, there were examples of atrophy of vigilance; however, there was clear understanding of pandemic readiness actions that were simply not executed amongst political chaos. In Canada, political mishaps were less evident at the time the pandemic unfolded. Nevertheless, atrophy was evident with erosion in preparedness programs following SARS. South Korea appeared least subjected to atrophy of vigilance. The more recent MERS outbreak prompted evolution of sustained vigilance and compliance with basic public health measures such as mask wearing.

Recommendations

Policy options need to be explored and instituted that increase protection of preparedness programs through institutional safeguards and accountability measure.

Monitoring in vivo behavior of size-dependent fluorescent particles as a model fine dust

Background

There has been growing concern regarding the impact of air pollution, especially fine dust, on human health. However, it is difficult to estimate the toxicity of fine dust on the human body because of its diverse effects depending on the composition and environmental factors.

Results

In this study, we focused on the difference in the biodistribution of fine dust according to the size distribution of particulate matter after inhalation into the body to predict its impact on human health. We synthesized Cy7-doped silica particulate matters (CSPMs) having different particle sizes and employed them as model fine dust, and studied their whole-body in vivo biodistribution in BALB/c nude mice. Image-tracking and quantitative and qualitative analyses were performed on the ex vivo organs and tissues. Additionally, flow cytometric analysis of single cells isolated from the lungs was performed. Smaller particles with a diameter of less than 100 nm (CSPM0.1) were observed to be removed relatively rapidly from the lungs upon initial inhalation. However, they were confirmed to accumulate continuously over 4 weeks of observation. In particular, smaller particles were found to spread rapidly to other organs during the early stages of inhalation.

Conclusions

The results show in vivo behavioral differences that arisen from particle size through mouse experimental model. Although these are far from the human inhalation studies, it provides information that can help predict the effect of fine dust on human health. This study might provide with insights on association between CSPM0.1 accumulation in several organs including the lungs and adverse effect to underlying diseases in the organs.

Graphical Abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-022-01419-4.

Analysis of Indoor Air Pollutants and Guidelines for Space and Physical Activities in Multi-Purpose Activity Space of Elementary Schools

Owing to the recent increase in the number of warning reports and alerts on the dangers of fine dusts, there has been an increasing concern over fine dusts among citizens. In spaces with poor ventilation, the occupants are forced to open the window to initiate natural ventilation via the direct introduction of the outside air; however, this may pose a serious challenge if the external fine-dust concentration is high. The lack of natural ventilation increases the indoor carbon dioxide (CO2) concentration, thus necessitating the installation of mechanical ventilation systems. This study analyzed the frequency of the application of mechanical ventilation systems in the Multi-purpose activity space of elementary schools, which are spaces where children require a higher indoor air quality than adults owing to the rapid increase in the CO2 concentration of the Multi-purpose activity space during activities. In addition, the architectural and equipment factors of the Multi-purpose activity spaces of nine elementary schools were characterized. The results revealed that five out of the nine elementary schools installed mechanical ventilation systems, whereas the remaining four schools installed jet air turnover systems. The indoor air quality of the Multi-purpose activity space of D elementary school, which had the minimum facility volume among the schools investigated in this study (564.2 m3), with up to 32 participants for each activity, was investigated. The results revealed that the ultrafine-dust (PM2.5) concentration of the facility was as high as 4.75 µg/m3 at a height of 1.2 m, and the CO2 concentration was as high as 3183 ppm. The results of the analysis of three elementary schools with different volumes were compared and analyzed using CONTAM simulation. This study determined the required volume per occupant and the optimum number of occupants for a given volume and presented guidelines for the optimum number of occupants, activities, and volume to reduce the high concentration of pollutants in the analyzed Multi-purpose activity space. The guideline proposed in this study is aimed at maintaining the CO2 concentration of the Multi-purpose activity space below 1000 ppm, as prescribed by the Indoor Air Quality Control in Public-Use Facilities, Etc. Act in South Korea.

Advantages of omics technology for evaluating cadmium toxicity in zebrafish

In the last decade, several advancements have been made in omics technologies and they have been applied extensively in diverse research areas. Especially in toxicological research, omics technology can efficiently and accurately generate relevant data on the molecular dynamics associated with adverse outcomes. Toxicomics is defined as the combination of toxicology and omics technologies and encompasses toxicogenomics, toxicoproteomics, and toxicometabolomics. This paper reviews the trend of applying omics technologies to evaluate cadmium (Cd) toxicity in zebrafish (D. rerio). Cd is a toxic heavy metal posing several environmental concerns; however, it is being used widely in everyday life. Zebrafish embryos and larvae are employed as standard models for many toxicity tests because they share 71.4% genetic homology with humans. This study summarizes the toxicity of Cd on the nerves, liver, heart, skeleton, etc. of zebrafish and introduces detailed omics techniques to understand the results of the toxicomic studies. Finally, the trend of toxicity evaluation in the zebrafish model of Cd based on omics technology is presented.

Detection of Particulate Matters with a Field-Portable Microscope Using Side-Illuminated Total Internal Reflection

Field-portable observation and analysis of particulate matter (PM) is required to enhance healthy lives. Various types of the PM measurement methods are in use; however, each of these methods has significant limitations in that real time measurement is impossible, the detection system is bulky, or the measurement accuracy is insufficient. In this work, we introduce an optical method to perform a fast and accurate PM analysis with a higher-contrast microscopic image enabled by a side-illuminated total internal reflection (TIR) technique to be implemented in a compact device. The superiority of the proposed method was quantitatively demonstrated by comparing the signal-to-noise ratio of the proposed side-illuminated TIR method with a traditional halogen lamp-based transmission microscope. With the proposed device, signal-to-noise ratios (SNRs) for microbeads (5~20 µm) and ultrafine dust particles (>5 µm) increased 4.5~17 and 4~10 dB, respectively, compared to the conventional transmission microscope. As a proof of concept, the proposed method was also applied to a low-cost commercial smartphone toy microscope enabling field-portable detection of PMs. We believe that the proposed side-illuminated TIR PM detection device holds significant advantages over other commonly used systems due to its sufficient detection capability along with simple and compact configuration as well as low cost.

Tart Cherry Extract Containing Chlorogenic Acid, Quercetin, and Kaempferol Inhibits the Mitochondrial Apoptotic Cell Death Elicited by Airborne PM10 in Human Epidermal Keratinocytes

Tart cherry (Prunus cerasus L.), a medicinal food containing high concentrations of phytochemicals, has a variety of antioxidant activities and health benefits. Here, we investigate the functional effect of tart cherry during apoptotic cell death elicited by airborne particulate matter with a diameter of <10 μm (PM₁₀) in human epidermal keratinocyte HaCaT cells. The PM₁₀ particles significantly induced cytotoxicity in the HaCaT cells. The decrease in cell viability was restored upon treatment with tart cherry extract (200 μg/mL) containing chlorogenic acid, quercetin, and kaempferol. Tart cherry inhibited the intracellular reactive oxygen species (ROS) responsible for the distinctive activations of the extracellular signal-regulated kinase (ERK) and p38 mitogen-activated protein kinase (MAPK) in PM₁₀-treated HaCaT cells. Interestingly, tart cherry significantly inhibited the expression of apoptosis-related genes (B-Cell Lymphoma 2 (Bcl-2), Bcl-2 associated X protein (Bax), and caspase-3) as regulated by the activation of transcription factor nuclear factor-kappa B (NF-κB). These results demonstrate that tart cherry is a medicinal food that blocks the mitochondrial pathway of apoptosis induced by PM₁₀ in human epidermal keratinocytes.

Changes in skin wrinkles and pores due to long-term mask wear

Background

The spread of COVID‐19 has made mask wear essential. Expecting that long‐term mask wear would change the characteristics of skin, this study investigated changes in skin wrinkles and pores caused by long‐term mask wear and whether or not use of moisturizers has an effect on any changes.

Materials and methods

The study participants were 20 women who were instructed to wear a mask for at least 6 hours a day for 4 weeks. Measurements of skin wrinkles and pores were obtained before and after the 4 weeks of mask wear. The effects of application of a moisturizer were assessed by applying moisturizer within the mask‐wearing area. They completed a questionnaire about skin changes at the end of the study period.

Results

After wearing the mask for 4 weeks, there was a significant increase in the skin wrinkles and pores; both variables decreased significantly in skin areas where a moisturizer had been applied. The results of the questionnaire‐based survey indicated the study participants considered that long‐term wearing of a mask had affected their skin.

Conclusion

Wearing a mask for extended periods increases skin wrinkles and pores and using a moisturizer when wearing the mask helps to reduce this problem.

A Possible Linkage between Dust Frequency and the Siberian High in March over Northeast Asia

Spring dust frequency in northeast Asia has been investigated using various approaches to understand the mechanisms of dust emission and transport. However, little attention has been paid to the linkage between dust activity and the Siberian High (SH), particularly when the SH pressure system is highly variable. In this study, we characterize the possible physical mechanisms of dust emission and transport associated with the Siberian High Intensity (SHI) and Siberian High Position Index (SHPI) in March using 18 years of ground-based observations and reanalysis data. We found that when the SHI was strong and the SH’s center was farther east (“Strong–East period”), surface and atmospheric temperatures were cooler than when the SHI was weak and the SH’s center was farther west (“Weak-West period”), due to anomalous anticyclonic pressure and strong easterlies. As a result, a reduction in the meridional temperature gradient in the lower atmosphere suppressed dust emission and transport, due to stagnant atmospheric conditions. This anomalous anticyclonic pressure in the Strong-East case seems to reduce the development of extratropical cyclones (ETC) in northeast Asia, leading to a less effective dust transport. A case study with composite analysis also showed a similar physical mechanism: stagnant air accompanying weakened westerlies in the Strong-East period suppressed dust transport to South Korea. Our findings reveal that the intensity and position of the SH can be utilized to identify spring transboundary air pollutants in northeast Asia.

Effect of a Heating System Using a Ground Source Geothermal Heat Pump on Production Performance, Energy-Saving and Housing Environment of Pigs

Simple Summary

A geothermal heat pump (GHP) was installed in a pig house, and production performance, housing environment, energy efficiency, noxious and carbon dioxide (CO₂) gas emissions, and economics were compared between GHP and the control (conventional heating). The CO₂ gas emission, usage, and cost of electricity were reduced in the GHP-installed pig house. The GHP also maintained the inside temperature of the pig house more effectively. Furthermore, the concentration of noxious gas (NH₃) was also lower during the growing and finishing phase in the GHP-installed pig house. Therefore, the results indicate that the GHP system can be used for sustainable pig production and food security as a climate-friendly renewable energy source for livestock.

Abstract

This study examined the effects of a heating system using a ground source geothermal heat pump (GHP). A GHP was installed in a pig house, and a comparative analysis was performed between the GHP and the control (conventional heating system) in terms of the production performance, housing environment, noxious gas emissions, electricity consumption, and economics. The geothermal system performance index, such as the coefficient of performance (COP), inlet, and outlet temperature, were also evaluated. The outflow temperature during each period (weaning, growing, and finishing) was significantly higher than the inflow temperature in all three components of the GHP system. Similarly, the average internal temperature of the GHP-connected pig house was increased (p < 0.05) during each period. The carbon dioxide (CO₂) concentration, electricity usage, and cost of electricity during the 16-week experimental period were reduced significantly in the GHP system relative to the control. The concentrations of ammonia (NH₃) during the growing and finishing period and the concentrations of formaldehyde during the weaning phase were also lower in the GHP-installed pig house (p < 0.05). These results indicate that the GHP system can be used as an environmentally friendly renewable energy source in pig houses for sustainable pig production without harming the growth performance.

Temporal-spatial variation and environmental risk assessment of pharmaceuticals in tributaries of the Han River watershed, South Korea

Eight compounds from three categories of pharmaceuticals [5 antibiotics, 2 non-steroidal anti-inflammatory drugs, and 1 anti-epileptics] were monitored at 24 sites in the tributaries of the Han River watershed in South Korea, 2016. The seasonal occurrence, temporal-spatial variation, potential compound source(s), and a risk assessment of this watershed, which is the largest drinking water source in the country, were investigated. Clarithromycin was detected most frequently (72.2%) with the greatest median concentration (0.151 ± 0.072 μg L^-1), followed by carbamazepine and sulfamethoxazole. The seasonality of the pharmaceuticals was observed, with higher concentrations and detection frequencies in spring than in summer and autumn; this was possibly caused by lower levels of microbial activities associated with lower water temperatures than other seasons. In terms of geographical variation, urban areas had higher pharmaceutical concentrations than rural areas, which was attributed to the former's high population density and largest wastewater treatment plants (WWTPs) regardless of season. The total concentration and detection frequency of WWTPs were 12.4 and 2.5 times higher in downstream sites than upstream sites, thereby conveying that WWTPs were the main source for the presence of pharmaceuticals in tributaries. According to the results produced from calculations of the risk quotient (RQ) of aquatic organisms, clarithromycin and sulfamethazine were identified as posing relatively high ecological risk (RQ > 1) during the spring that was identified for this study. This study can provide policymakers with scientific support for prioritizing pollutant management and collections of global data on emerging pollutants.

Segmenting the South Korean Public According to Their Preferred Direction for Electricity Mix Reform

The current South Korean government headed by President Moon Jae-in has put a great deal of effort into electricity mix reform by pushing forward the phasing out of coal and nuclear power and the expansion of natural gas and new renewable energy in the country’s electricity generation processes. Noting the importance of understanding public responses to energy policy, the present study segmented the South Korean public according to their preferred direction for electricity mix reform using a nationwide sample. Through a series of latent class analyses, we extracted four distinct segments: Gradual Reformists, Drastic Reformists, Selective Gradual Reformists, and Status-quo Seekers. Overall, apart from the Status-quo Seekers segment (8.75%), support for the transition from coal and nuclear power to natural gas and new renewable energy seems to be the prevailing opinion of the Korean public. However, the degree of such preferences varies across the segments. In addition, regardless of the segment, the South Korean public generally seems to categorize the energy sources in a manner consistent with the underlying framework of the government’s electricity mix reform: they tend to treat coal and nuclear power similarly and natural gas and new renewable energy similarly.

The association between traffic-related air pollution and obstructive sleep apnea: A systematic review

Recent evidence suggests that air pollution exposure may be a contributing risk factor for obstructive sleep apnea (OSA), however, current evidence is conflicting. This systematic review aims to determine the association between air pollution and OSA in the general population, and examine for potential effect modification by seasonality, temperature and humidity. Five full-text articles were included in the review out of 905 articles found by systematically searching PubMed, Embase and Scopus databases. The included studies were limited to OSA in adults that were conducted in middle to high-income countries. The results highlight heterogeneity in the diagnostic criteria for OSA and method used to assess air pollution exposure. There is some evidence to support a relationship between air pollution exposure and OSA. However, the duration of exposure to different air pollutants including particulate matter (PM_2.5 and PM₁₀) and nitric oxides (NO₂) in relation to OSA varied across different seasons, temperatures, and countries. This variability of the pollutants across studies warrants a more robust study design using time-series analysis with multiple follow-ups to strengthen the evidence for this relationship before considering its implications.

Performance Evaluation of Hybrid Air Purification System with Vegetation Soil and Electrostatic Precipitator Filters

This paper describes designing, manufacturing, and evaluating an eco-friendly modular-type air purification system to enhance the removal efficiency of fine particulate matter (PM) in urban public spaces, especially in hotspots. This system consists of artificial soil based-vegetation and electrostatic precipitator (ESP) filters. Unlike the so-called passive removal method, which adsorbs fine PM only by the leaves of plants, the vegetation soil filter based on multi-layered different artificial soils adopts an active removal method in which air purification is performed in the soil itself, bypassing external air by using the air circulation fan in the soil. The ESP filter is designed and evaluated to have a high fine PM removal efficiency, even at high suction velocity, to remove large amounts of outdoor fine PM. Throughout the experimental measurements on the hybrid air purification system with vegetation soil and ESP filters, it is observed that the vegetation soil filter has a 78.5% reduction efficiency for PM2.5 and a 47% for PM10 at the inlet air velocity of 0.15 m/s. The ESP filter also has a 73.1% reduction efficiency for PM2.5 and 87.3% for PM10 at an inlet air velocity of 3 m/s. Based on the performance evaluations of the vegetation soil filter and the ESP filter, it is noted that each individual module will be applied to an air purification tower with vertical expansion and installed in a high concentration area of fine PM in a downtown area to contribute to the fine PM reduction in the community.

Hepatoprotective Effects of Streptococcus thermophilus LM1012 in Mice Exposed to Air Pollutants

In this study, we explored whether the use of Streptococcus thermophilus LM1012 (TL-LM1012) as a safe probiotic exerts hepatoprotective effects by suppressing oxidative stress and inflammation in vitro and alleviating aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) production in vivo. In a series of safety tests, TL-LM1012 was found to have a negative response to hemolysis and biogenic amines, as well as susceptibility to antibiotics. TL-LM1012 protected cell viability and suppressed cytotoxicity by inhibiting oxidative stress and induced heme oxygenase-1 and superoxide dismutase activity in a dose-dependent manner in diesel exhaust particulate matter (DEPM)-treated HepG2 cells. Moreover, proinflammatory cytokines, including tumor necrosis factor-α, interleukin (IL)-6, and IL-1β, were suppressed in DEPM-treated splenocytes. In DEPM-treated mice, oral administration of TL-LM1012 regulated AST, ALT, and LDH production in the serum after 14 days of treatment. These findings indicate that TL-LM1012, a safe probiotic, provides a potent preventive or therapeutic effect against liver disease caused by air pollution.

(-)-Loliolide Isolated from Sargassum horneri Protects against Fine Dust-Induced Oxidative Stress in Human Keratinocytes

The emergence of fine dust (FD) among air pollutants has taken a toll during the past few decades, and it has provided both controversy and a platform for open conversation amongst world powers for finding sustainable solutions and effective treatments for health issues. The present study emphasizes the protective effects of (-)-loliolide (HTT) isolated from Sargassum horneri against FD-induced oxidative stress in human HaCaT keratinocytes. The purification of (-)-loliolide was carried out by centrifugal partition chromatography. HTT did not show any cytotoxicity, and it further illustrated the potential to increase cell viability by reducing the reactive oxygen species (ROS) production in FD-stimulated keratinocytes. Furthermore, HTT suppressed FD-stimulated DNA damage and the formation of apoptotic bodies, and it reduced the population of cells in the sub-G₁ apoptosis phase. FD-induced apoptosis was advancing through the mitochondria-mediated apoptosis pathway. The cytoprotective effects of the HTT against FD-stimulated oxidative damage is mediated through squaring the nuclear factor E2-related factor 2 (Nrf2)-mediated heme oxygenase-1 (HO-1) pathway, dose-dependently increasing HO-1 and NAD(P)H dehydrogenase (quinone) 1 (NQO1) levels in the cytosol while concomitantly improving the nuclear translocation of Nrf2. Future studies could implement the protective functionality of HTT in producing pharmaceuticals that utilize natural products and benefit the diseased.

Banhahubak-Tang Tablet, a Standardized Medicine Attenuates Allergic Asthma via Inhibition of Janus Kinase 1 (JAK1)/ Signal Transducer and Activator of Transcription 6 (STAT6) Signal Pathway

Exposure to particulate matter (PM) has been known to be one of the risk factors to cause allergic asthma, leading to development of respiratory disease. Banhahubak-tang tablet (BHT), a standardized Korean Medicine, is prescribed for neurasthenia, laryngopharyngitis and asthma. In this study, we investigated therapeutic effects of BHT on airway inflammation in ovalbumin (OVA) and PM smaller than 10 μm (PM10)-induced allergic asthma mice. To establish allergic asthma with airway hyper-responsiveness by PM10, BALB/c mice were sensitized and challenged with OVA and PM10, and orally administered BHT. Histological staining was performed to assess airway remodeling. Serum and bronchoalveolar lavage fluid (BALF) was collected for measuring immunoglobulin levels and counting inflammatory cells, respectively. Expression levels of Janus kinase 1 (JAK1)/signal transducer and activator of transcription 6 (STAT6), pro-inflammatory cytokines and type 2 T-helper (Th2)-related cytokines were analyzed in vivo and in vitro models. Histopathological analysis demonstrated that BHT suppressed inflammatory cell infiltration, mucus hypersecretion and collagen deposition in the airway. BHT administration effectively decreased number of inflammatory cells in BALF. BHT reduced total serum Immunoglobulin E (IgE) and Immunoglobulin G (IgG) levels. In addition, BHT significantly inhibited the phosphorylation of JAK1 and STAT6 expressions. Release of pro-inflammatory cytokines and Th2-related cytokines were down-regulated by BHT. In conclusion, BHT mitigated airway inflammation by down-regulating pro-inflammatory and Th2-related cytokines via JAK1/STAT6 signaling. BHT might be a promising herbal medicine for preventing airway inflammation. Moreover, an intervention study among humans is needed to further evaluate the possible beneficial effects of BHT in allergic asthma.

Anti-asthmatic effects of lepidii seu Descurainiae Semen plant species in ovalbumin-induced asthmatic mice

ETHNOPHARMACOLOGICAL EVIDENCE

Lepidii seu Descurainiae Semen (LDS) is used as a traditional herbal medicine in northeast Asia, mainly in Korea, Japan, and China to treat lung disorders including coughs and phlegm caused by acute and chronic airway inflammation.

AIM OF THE STUDY

Recently, interest regarding health problems incurred by air pollution has rapidly grown. Herbal medicines are being considered as alternative agents to treat various diseases. In the present study, we evaluated and compared the anti-inflammatory effects of LDS, which is derived from Lepidium apetalum Willd. extracts (LAE) and Descurainia sophia (L.) Webb ex Prantl extracts (DSE), on allergic airway inflammation.

MATERIALS AND METHODS

We established an ovalbumin-induced asthmatic mouse model to evaluate the efficacy of LDS extracts. We performed histological examination and measured relevant inflammatory mediators and cells in bronchoalveolar lavage fluid and lung. Furthermore, we conducted an in vitro T helper 2 (Th2) polarization assay, flow cytometry, and western blot analysis.

RESULTS

Asthmatic phenotypes were attenuated by LDS extract treatments. LDS extract administration significantly reduced mucus production, inflammatory cell infiltration into airways, and eosinophil activation. Furthermore, LDS extracts reduced the expression of type 2 cytokines and inhibited differentiation and activation of Th2 cells.

CONCLUSION

LDS alleviated eosinophilic inflammation by inhibiting Th2 cell differentiation, and DSE was more effective in attenuating allergic lung inflammation than LAE.

The Effects of Short-Term and Very Short-Term Particulate Matter Exposure on Asthma-Related Hospital Visits: National Health Insurance Data

PURPOSE

The purpose of this study was to investigate the effects of short-term and very short-term exposure to particulate matter (PM) exceeding the daily average environmental standards for Korea (≤100 μg/m³ for PM10 and ≤50 μg/m³ for PM2.5) on on asthma-related hospital visits.

MATERIALS AND METHODS

This was a population-based, case-crossover study using National Health Insurance and air pollution data between January 1, 2014 and December 31, 2016. The event day was defined as a day when PM exceeded the daily average environmental standard (short-term exposure) or daily average environmental standard for 2 hours (very short-term exposure). The control day was defined as the same day of the week at 1 week prior to the event day.

RESULTS

Compared with control days, asthma-related hospital visits on the 24-hr event days and 2-hr event days increased by 4.10% and 3.45% for PM₁₀ and 5.66% and 3.74% for PM_2.5, respectively. Asthma-related hospital visits increased from the 24-hr event day for PM₁₀ to 4 days after the event day, peaking on the third day after the event day (1.26, 95% confidence interval, 1.22-1.30). Hospitalizations also increased on the third day after the event. While there was a difference in magnitude, PM_2.5 exposure showed similar trends to PM₁₀ exposure.

CONCLUSION

We found a significant association between short-term and very short-term PM exposure exceeding the current daily average environmental standards of Korea and asthma-related hospital visits. These results are expected to aid in establishing appropriate environmental standards and relevant policies for PM.

Monitoring the impact of desert dust outbreaks for air quality for health studies

We review the major features of desert dust outbreaks that are relevant to the assessment of dust impacts upon human health. Our ultimate goal is to provide scientific guidance for the acquisition of relevant population exposure information for epidemiological studies tackling the short and long term health effects of desert dust. We first describe the source regions and the typical levels of dust particles in regions close and far away from the source areas, along with their size, composition, and bio-aerosol load. We then describe the processes by which dust may become mixed with anthropogenic particulate matter (PM) and/or alter its load in receptor areas. Short term health effects are found during desert dust episodes in different regions of the world, but in a number of cases the results differ when it comes to associate the effects to the bulk PM, the desert dust-PM, or non-desert dust-PM. These differences are likely due to the different monitoring strategies applied in the epidemiological studies, and to the differences on atmospheric and emission (natural and anthropogenic) patterns of desert dust around the world. We finally propose methods to allow the discrimination of health effects by PM fraction during dust outbreaks, and a strategy to implement desert dust alert and monitoring systems for health studies and air quality management.

Screen-Based Sports Simulation Using Acoustic Source Localization

In this paper, we introduce a novel acoustic source localization in a three-dimensional (3D) space, based on a direction estimation technique. Assuming an acoustic source at a distance from adjacent microphones, its waves spread in a planar form called a planar wavefront. In our system, the directions and steering angles between the acoustic source and the microphone array are estimated based on a planar wavefront model using a delay and sum beamforming (DSBF) system and an array of two-dimensional (2D) microelectromechanical system (MEMS) microphones. The proposed system is designed with parallel processing hardware for real-time performance and implemented using a cost-effective field programmable gate array (FPGA) and a micro control unit (MCU). As shown in the experimental results, the localization errors of the proposed system were less than 3 cm when an impulsive acoustic source was generated over 1 m away from the microphone array, which is comparable to a position-based system with reduced computational complexity. On the basis of the high accuracy and real-time performance of localizing an impulsive acoustic source, such as striking a ball, the proposed system can be applied to screen-based sports simulation.

Study of the Relationship between Urban Expansion and PM10 Concentration Using Multi-Temporal Spatial Datasets and the Machine Learning Technique: Case Study for Daegu, South Korea

To protect the population from respiratory diseases and to prevent the damages due to air pollution, the main cause of air pollution should be identified. This research assessed the relationship between the airborne particulate concentrations (PM10) and the urban expansion in Daegu City in South Korea from 2007 to 2017 using multi-temporal spatial datasets (Landsat images, measured PM10 data) and the machine learning technique in the following steps. First, the expanded urban areas were detected from the multiple Landsat images using support vector machine (SVM), a widely used machine learning technique. Next, the annual PM10 concentrations were calculated using the long-term measured PM10 data. Finally, the degrees of increase of the expanded urban areas and of the PM10 concentrations in Daegu from 2007 to 2017 were calculated by counting the pixels representing the expanded urban areas and computing variation of the annual PM10 concentrations, respectively. The experiment results showed that there is a minimal or even no relationship at all between the urban expansion and the PM10 concentrations because the urban areas expanded by 55.27 km2 but the annual PM10 concentrations decreased by 17.37 μg/m³ in Daegu from 2007 to 2017.

Maternal Exposure to Particulate Matter during Pregnancy and Adverse Birth Outcomes in the Republic of Korea

Air pollution has become a global concern due to its association with numerous health effects. We aimed to assess associations between birth outcomes in Korea, such as preterm births and birth weight in term infants, and particulate matter < 10 µm (PM₁₀). Records from 1,742,183 single births in 2010⁻2013 were evaluated. Mean PM₁₀ concentrations during pregnancy were calculated and matched to birth data by registered regions. We analyzed the frequency of birth outcomes between groups using WHO criteria for PM₁₀ concentrations with effect sizes estimated using multivariate logistic regression. Women exposed to PM₁₀ > 70 µg/m³ during pregnancy had a higher rate of preterm births than women exposed to PM₁₀ ≤ 70 µg/m³ (7.4% vs. 4.7%, P < 0.001; adjusted odds ratio (aOR) 1.570; 95% confidence interval (CI): 1.487⁻1.656). The rate of low birth weight in term infants increased when women were exposed to PM₁₀ > 70 µg/m³ (1.9% vs. 1.7%, P = 0.278), but this difference was not statistically significant (aOR 1.060, 95% CI: 0.953⁻1.178). In conclusion, PM₁₀ exposure > 70 µg/m³ was associated with preterm births. Further studies are needed to explore the pathophysiologic mechanisms and guide policy development to prevent future adverse effects on birth outcomes.

Susceptibility to ambient particulate matter on emergency care utilization for ischemic heart disease in Seoul, Korea

Many epidemiological studies have reported associations between ambient particulate matter (PM) and cardiovascular diseases. However, the effects associated with PM that promote cardiovascular events among susceptible populations who may respond differently than the general population to the same ambient air pollutants remain unclear. We conducted a time-series study with generalized additive models to assess the association between ambient PM10 and emergency department (ED) visits for ischemic heart disease (IHD) in Seoul, Republic of Korea from 2005 to 2009. The ED data and previous medical records within the 5 years of each IHD event to examine the effect of PM10 in a susceptible population were obtained from Health Insurance Review and Assessment Service. Overall, the adjusted relative risks (RRs) of ED visits for IHD were not statistically significant for PM10, but significant positive RRs were found for groups with hypertension (1.018; 95 % confidence interval [CI] 1.002-1.035) and those who are ≥80 years of age (1.019; 1.002-1.037) for same-day exposure and with diabetes (1.019; 1.002-1.037) for single-lag models. Subgroup analyses revealed gender differences in ED visits for IHD in hypertensive patients and those who are ≥80 years of age; positive correlations were found only in males with the lag models. Our study suggests that ambient PM10 is significantly associated with ED visits for IHD, especially in males with hypertension, diabetes mellitus, or who are aged ≥80 years. Identification of populations susceptible to air pollution is of paramount importance to establishing recommendations or guidelines for high-risk individuals.