Association between Asian dust exposure and respiratory function in children with bronchial asthma in Nagasaki Prefecture, Japan

BACKGROUND@#Studies on the adverse effects of Asian dust (AD) on respiratory function in children are scarce. The objective of this study was to examine the association between AD and respiratory function by measuring peak expiratory flow rates (PEFRs) in asthmatic children.@*METHODS@#The study was carried out from March to May from 2014 through 2016. One hundred ten children with bronchial asthma were recruited from four hospitals in the Goto Islands and south Nagasaki area in Nagasaki prefecture. The parents were asked to record their children's PEFRs every morning/evening and clinical symptoms in an asthma diary. AD was assessed from light detection and ranging data, and a linear mixed-effects model was used to estimate the effects of AD on daily PEFR. Time-stratified case-crossover analyses were performed to examine the association between AD and asthma attacks defined by reduction levels in PEFR.@*RESULTS@#AD was detected on 11 days in the Goto Islands, and on 23 days in the south Nagasaki area. After adjusting for age, sex, temperature, and daily oxidants, we found a consistent association between AD and a 1.1% to 1.7% decrease in PEFR in the mornings and a 0.7% to 1.3% decrease in the evenings at a lag of 0 to 5 days. AD was not associated with the number of asthma attacks, respiratory symptoms, or other symptoms at any lag days examined.@*CONCLUSIONS@#Exposure to AD was associated with reduced PEFR, although the effects were not large enough to induce clinically apparent symptoms, in clinically well-controlled asthmatic children.

Toxicity and health effects of Asian dust: a literature review

Asian dust, called Hwangsa in Korean, is windblown dust originating from the desert areas of China and Mongolia. Public concern on the possible adverse health effects of Asian dust has increased recently. Some experimental studies have reported that Asian dust aggravates the allergic response and induces cytotoxicity by promoting the release of reactive oxygen species. Asian dust may potentiate common cold symptoms associated with rhinovirus infection by enhancing inflammatory cytokines and increasing viral replication. In many epidemiologic studies conducted not only in Korea but also in Taiwan and Japan, Asian dust exposure has been reported to be associated with an increase in mortality and hospital visits and admission due to cardiovascular and respiratory disease as well as increased respiratory symptoms and decreased pulmonary function. The frequency and scale of Asian dust events are expected to increase due to environmental change such as desertification in northern China and climate change. We need an Asian dust preparedness strategy including monitoring of dust-related health outcomes as well as an enhanced Asian dust forecasting system to protect people from the effects of Asian dust events.

Acute Effects of Asian Dust Events on Respiratory Symptoms and Peak Expiratory Flow in Children with Mild Asthma

The aim of this study was to investigate the possible adverse effects of Asian dust events on respiratory health in asthmatic children. Fifty-two children with mild asthma were studied for eight consecutive weeks in the spring of 2004 (March 8 to May 2). During the study period, five Asian dust days were identified; we included a lag period of two days following each of the events. Subjects recorded their respiratory symptom diaries and peak expiratory flow (PEF) twice daily during the study period; and they underwent methacholine bronchial challenge tests. The subjects reported a significantly higher frequency of respiratory symptoms during the Asian dust days than during the control days. They showed significantly more reduced morning and evening PEF values, and more increased PEF variability (10.1%+/-3.5% vs. 5.5%+/-2.2%) during the Asian dust days than during the control days. Methacholine PC20 was not significantly different between before and after the study period (geometric mean: 2.82 mg/mL vs. 3.16 mg/mL). These results suggest that the short-term Asian dust events might be associated with increased acute respiratory symptoms and changes in PEF outcomes. However, there might be little long-term influence on airway hyperresponsiveness in children with mild asthma.

Particulate Matter 10 from Asian Dust Storms Induces the Expression of Reactive Oxygen Species, NF-kappaB, TGF-beta and Fibronectin in WI-26 VA4 Epithelial Cells / 결핵및호흡기질환

BACKGROUND: Particulate matter may be toxic to human tissue. Ambient air particulate matter < or =10micrometer in aerodynamic size (PM10), which changes under different environmental conditions, is a complex mixture of organic and inorganic compounds. The Asian dust event caused by meteorological phenomena can also spread unique particulate matter in affected areas. We evaluated production of ROS, TGF-beta, fibronectin, and NF kappa B by exposing normal epithelial cells to Asian dust particulate matter. METHODS: Bronchial epithelial cells were exposed to 0, 50, 100microgramg/ml of a suspension of PM10 for 24 h. ROS were detected by measurement of DCF release from DCF-DA by FACScan. TGF-beta, fibronectin, and NF kappa B were detected by western blotting. RESULTS: PM10 exposure increased the expression of TGF-beta, fibronectin, and NF kappa B. ROS production and TGF-betalevels were significantly higher with 50 or 100microgram/ml PM10. Fibronectin and NF kappa B production were significantly higher after 100microgram/ml of PM10. CONCLUSION: PM10 from Asian dust particles might have fibrotic potential in bronchial epithelial cells via ROS induction after PM10 exposure.

Particulate Matter from Asian Dust Storms Induces the Expression of Proinflammatory Cytokine in A549 Epithelial Cells / 결핵및호흡기질환

BACKGROUND: PM10(Particulate matter with a diameter < 10micrometer), which is characterized by different environmental conditions, is a complex mixture of organic and inorganic compounds. The Asian dust event caused by meteorological phenomena can also produce unique particulate matter in affected areas. This study investigated the cytokine produced by A549 epithelial cells exposed to particles collected during both the Asian dust pfenomenon and ambient air particles in a non-dusty period. METHOD: Air samples were collected using a high volume air sampler(Sibata Model HV500F) with an air flow at 500l/min for at least 6 hours. The cytokine messenger RNA(mRNA) was measured using a reverse transcriptase polymerase chain reaction(RT-PCR). The A549 cells were exposed to 10 to 500microgram/microliter of a suspension containing PM10 for 24 hours. Each was compared with those in the non-exposed control cells. RESULT: The mRNA levels of interleukin(IL)-1alpha, IL-Ibeta , IL-8, and the granulocyte macrophage colony stimulating factor(GM-CSF) increased after veing exposed to PM10 in the ambient air particles, compared with those in the non-exposed control cells. The increase in IL-1alpha and IL-8 were dose dependent at a PM10 concentration between 100microgram/microliter and 500microgram/microliter. The mRNA level of IL-8 in the A549 epithelial cells was higher during the in the Asian dust period(500microgram/microliter) than during the non dust period. CONCLUSION: A549 cells exposed to the PM10 collected during the Asian dust period produce more proinflammatory cytokine than during non-dusty period. This cytokine enhances the local inflammatory response in the airways and can also contribute to the systemic component of this inflammatory process.

Detection of Pathogenic Viruses in the Atmosphere during Asian Dust Events in Incheon City / 결핵및호흡기질환

BACKGROUND: Ambient particles during Asian dust events are usually less than 10micrometer in size, and known to be associated with the adverse effects on the general population. There is little evidence linking Asian dust to adverse effects on the airways. In 2002, the authors found that particulate matter during Asian dust events had an effect on the symptoms and pulmonary function of patients with bronchial asthma. An aggravating factor might be that of a viral infection, but this remains unclear. Conversely, it has been speculated that African dust may carry the virus responsible for foot and mouth disease. Asian dust events are also likely to be responsible for transporting viruses, some of which are pathogenic, and common in many environments. Therefore, in this study, air samples were screened for the presence of viruses. METHODS: Air samples were collected 20 times each during Asian dust events and under non-dust conditions, for at least 6 hours per sample, using a high volume air sampler (Sibata Model HV500F), with an airflow rate of 500L/min, between April and August 2003, and between April and August 2004. The samples were then screened for the presence of targeted viruses (Influenza A, B, Hog cholera virus, and Aphthovirus) using a polymerase chain reaction method. RESULTS: One Asian dust event occurred between April and August 2003, and 3 between April and August 2004, with a 24 hour average PM10 level of 148.0microgram/m(3). The 24 hour average PM10 level was 57microgram/m(3). There was a significant difference in?the PM10 concentration between dusty and clear days. No viruses (Influenza virus, Aphthovirus, and Hog cholera virus) were identified in the air samples obtained during the dusty days. CONCLUSIONS: Although no virus was detected in this study, further studies will be needed to identify suspected viruses carried during Asian dust events, employing more appropriate virus detection conditions.

From Historical Dust ail to Early Warning of Asian Dust Events in Korea

Asian dust is the windblown dust, frequently originating from the Sand desert, Gobi desert, and Loess plateau in Northern China and Mongolia during the spring season. This dust phenomenon is called as "Hwangsa" in Korea meaning yellow sand. Dust can be lifted into the middle troposphere by strong winds in the source regions. In this article, we will overview the historical records of Hwangsa and Early warning of Hwangsa in Korea. The symbolic word "Woo-Tou" was used to describe dust phenomenon, which was defined as a descending substance in the atmosphere other than water droplets. During that period we believed dust as an impetuous order toward king from God. Why dust falls from the sky? Did I do something wrong? The time when we reflected ourselves with modest mind. That was our image 100 years ago. Now Hwangsa is treated as a part of natural phenomena. Hwangsa flew from dried area such as China and Mongolia to Korean peninsular and appears as in yellow color. Particularly, human being's inappropriate management on earth soil makes origin area of Hwangsa to be expanded. Hwangsa, which occurs by overlapping of natural phenomena and artificial factors, causes various problems. To deal successfully with Hwangsa, we should cooperate with each other and expect peace in northeast Asia.

The Health Effects of Asian Dust Event

The Korean peninsula has a long history of spring time dust clouds blown by winds from the arid deserts of Mongolia and China, these are called Yellow sand or Asian dust event. Public concern about the possible adverse effects of these dust events has increased, because the dust arrives in Korea after having passed over heavily industrialized eastern China. Most studies on the Asian dust have been focused on the physiochemical properties of the dust. Just several studies have been published on the matter of the health effects of the Asian dust both domestically and internationally. Even though the dust of crustal origin like the Asian dust is not considered as harmful as the dust from the exhaust gas, many people have experienced the eye symptoms and the respiratory symptoms such as cough, sputum, and chest tightness during the yellow sand period. However it is not clear that the increased risk of experiencing respiratory symptoms during the dust period leads to increased risk of hospitalization or mortality. Limited epidemiologic studies suggest that the aged people and the patients with cardiopulmonary disease are more susceptible to possible harmful effects of the Asian dust.

Perceptions of the Asian Dust: Analysis of the Newspaper Articles about the Asian Dust / 예방의학회지

OBJECTIVES: There is an increasing concern for the social, economic, environmental and health effects of the Asian dust (Hwang-sa in Korean language) in Korea. In this study, we intended to indirectly determine ordinary people's perception about the Asian dust by analyzing the contents of newspaper articles dealing with it. METHODS: By using article searching services in the internet websites of three newspaper companies, we collected newspaper articles dealing with the Asian dust during the period from January 1st of 1998 to December 31st of 2002. We classified the articles into four categories: those forecasting the occurrence of the Asian dust, those about measures to cope with it, those about its occurrence in the neighboring foreign countries, and those about its effects. In particular, we analyzed articles about the health effects of the Asian dust more distinctly. RESULTS: A total of 1, 225 articles dealing with the Asian dust were found during the 5 year period. The number of articles increased from 102 in 1998 to 518 in 2002, approximately a five-fold increase. The numbers of articles about health effects, environmental effects and economical effects were 191 (44%), 171 (41%) and 147 (34%), respectively. It was reported that various diseases such as respiratory diseases (87%), eye problems (69%), and skin diseases (12%) were associated with the Asian dust. CONCLUSION: The increasing concern for the negative effects of the Asian dust necessitates more studies about this field. As the effects of the Asian dust are various, the information on the major concern of ordinary people could help establish the research agendas and measures for the Asian dust.

Effects of Ambient Particulate Matter(PM10) on Peak Expiratory Flow and Respiratory Symptoms in Subjects with Bronchial Asthma During Yellow Sand Period / 결핵

BACKGROUND: Ambient particles during Asian dust events are usually sized less than 10 micrometer, known to be associated with the adverse effects on the general populations. But, there has been no considerable evidence linking these particles to the adverse effects on airways. The objectives of this study was to investigate the possible adverse effects of Asian dust events on respiratory function and symptoms in subjects with bronchial asthma. PATIENTS AND METHODS: From march to June 2002, Asthmatic patients who were diagnosed with bronchial challenge test or bronchodilator response were enrolled. We divided them into three groups; mild, moderate, and severe, according to the severity. Subjects with other organ insufficiency such as heart, kidney, liver, and malignancy were excluded. All patients completed twice daily diaries and recorded peak flow rate, respiratory symptom, and daily activity. Daily and hourly mean pollutant levels of particulate matter 20% (p<0.05), night time symptom(p<0.05), and a decrease in mean PEF (p<0.05), which were calculated by the longitudinal data analysis. Otherwise, there was no association between PM10 level and bronchodialtor inhaler, and daytime respiratory symptoms. CONCLUSIONS: This study shows evidence that ambient air pollution, especially PM10, during Asian dust events, could be one of the many aggravating factors at least in patients with airway diseases. This data can be used as a primary source to set up a new policy on air environmental control and to evaluate the safety of air pollution index. We also expect that this research will help identify precise components of dust, which are more linked to the adverse effects.