The effects of microbial materials adhered to Asian sand dust on allergic lung inflammation

Desert dust is a risk factor for the incidence of acute myocardial infarction in Western Japan

BACKGROUND

Recently, there has been increasing concern about adverse health effects of exposure to desert dust events. However, the association between dust and the incidence of ischemic heart diseases is unknown. The aim of the present study was to elucidate whether Asian dust (AD), a windblown sand dust originating from mineral soil in China and Mongolia, is associated with the incidence of acute myocardial infarction (AMI).

METHODS AND RESULTS

We investigated the data regarding hospitalization because of AMI among 3068 consecutive patients from 4 AMI centers in Fukuoka, Japan, and data for AD from April 2003 to December 2010. We applied a time-stratified case-crossover design to examine the association between AD and the incidence of AMI. Using a conditional logistic regression analysis, we estimated the odds ratios of AMI associated with AD after controlling for ambient temperature and relative humidity. The occurrence of AD events 0 to 4 days before the day of admission was significantly associated with the incidence of AMI. In particular, the occurrence of AD 4 days before admission was significantly associated with the onset of AMI.

CONCLUSIONS

These data suggest that exposure to AD a few days before symptom onset is associated with the incidence of AMI.

Associations between subjective symptoms and serum immunoglobulin E levels during Asian dust events

Asian dust is a seasonal meteorological phenomenon caused by the displacement of atmospheric pollutants from the Mongolian and Chinese deserts. Although the frequency of Asian dust events and atmospheric dust levels have steadily increased in the eastern Asia region, the effects on human health remain poorly understood. In the present study, the impact of Asian dust on human health was determined in terms of allergic reactions. A total of 25 healthy volunteers were tested for a relationship between serum immunoglobulin E (IgE) levels and subjective symptoms during a 3-day Asian dust event recorded in April 2012. They filled daily questionnaires on the severity of nasal, pharyngeal, ocular, respiratory, and skin symptoms by a self-administered visual analog scale. Serum levels of non-specific IgE and 33 allergen-specific IgE molecules were analyzed. Spearman rank-correlation analysis revealed significant positive associations between nasal symptom scores and 2 microbial-specific IgE levels (Penicillium and Cladosporium). Microbes migrate vast distances during Asian dust events by attaching themselves to dust particles. Therefore, some of these symptoms may be associated with type 1 allergic reactions to certain type of microbes.

Sensitization to Asian dust and allergic rhinoconjunctivitis

OBJECTIVE

Asian dust storms frequently occur in northeast Asia and the dust occasionally even spreads as far as North America during spring. Asian dust can be harmful to human health and the environment, and thus has become one of the most serious problems for Asian countries. In the present study, we evaluated sensitization to Asian dust in Japanese patients with rhinoconjunctivitis.

METHODS

In March 2011, a prospective, non-randomized, cross-sectional study was conducted in 10 patients with allergic rhinoconjunctivitis (allergic group), 3 patients with atopic keratoconjunctivitis (atopic group), and 10 age- and sex-matched healthy control subjects (control group). Skin prick tests (SPT) were performed with untreated Asian dust, Asian dust extract, heat-sterilized Asian dust, silicon dioxide (SiO2), and phosphate-buffered saline (PBS). A panel of 14 allergen extracts was also tested, comprising extracts of pollens (cedar, orchard grass, ragweed, and mugwort), house dust (house dust mixture and Dermatophagoides pteronyssinus), animal dander (cat and dog), fungi (Alternaria tenuis, Candida, and Aspergillus), and foods (milk, egg, and wheat). Then the SPT-positive rate and the mean wheal diameter for each allergen were compared among the three groups.

RESULTS

The SPT-positive rates for untreated Asian dust, Asian dust extract, and sterilized Asian dust were significantly higher in the allergic and atopic groups than in the control group (all p<0.05). In the allergic group, there were a significant differences of the SPT-positive rates for untreated Asian dust (70%), Asian dust extract (50%), sterilized Asian dust (20%), SiO2 (20%), and PBS (0%) (p=0.0068). The SPT response to untreated Asian dust was correlated with the mean wheal diameters for four plant pollens (r=0.71, p=0.0104) and for three fungi (r=0.57, p=0.0426). Multivariate logistic regression analysis showed that significant predictors of the SPT reaction to untreated Asian dust were the mean wheal diameter for the four plant pollen (odds ratio=2.54, p=0.0138) and that for the three fungi (odds ratio=1.84, p=0.0273).

CONCLUSIONS

Asian dust may act as an adjuvant to promote allergic disease induced by inhaled allergens such as pollen and fungi.

Effect of Asian sand dust on Japanese cedar pollinosis

OBJECTIVE

Asian sand dust (ASD), originating in the deserts of Mongolia and China, spreads over large areas and is associated with adverse effects on human health in East Asia, including asthma, heart disease, and some allergic diseases. However, the effect of ASD on patients with seasonal allergic rhinitis caused by Japanese cedar pollen (SAR-JCP), the most common form of allergic rhinitis, remains unclear. The aim of this study was to investigate the effect of ASD on SAR-JCP patients.

METHODS

A total of 41 patients with SAR-JCP recorded nasal and ocular allergic symptom scores in a diary. We assessed the influence of ASD events on patients with SAR-JCP during the JCP season and before and after the JCP season.

RESULTS

ASD events did not influence nasal and ocular allergy symptoms during the JCP season. Scores for sneezing and runny nose were significantly increased by ASD events in the pre-JCP season. Ocular symptom scores were significantly increased by ASD events in the post-JCP season.

CONCLUSION

Our results suggest that ASD may exacerbate allergy symptoms even before mass scattering of JCP, which usually does not cause allergic symptoms in patients with SAR-JCP. ASD also induced conjunctivitis symptoms after the JCP season. However, we did not observe any adverse effects of ASD on allergic symptoms during the JCP season.

Enhancement of OVA-induced murine lung eosinophilia by co-exposure to contamination levels of LPS in Asian sand dust and heated dust

Background

A previous study has shown that the aggravation of Asian sand dust (ASD) on ovalbumin (OVA)-induced lung eosinphilia was more severe in lipopolysaccharide (LPS)-rich ASD than in SiO₂-rich ASD. Therefore, the effects of different LPS contamination levels in ASD on the aggravation of OVA-induced lung eosinophilia were investigated in the present study.

Methods

Before beginning the in vivo experiment, we investigated whether the ultra-pure LPS would act only on TLR4 or not using bone marrow-derived macrophages (BMDMs) of wild–type, TLR2-/-, TLR4-/- and MyD88-/- BALB/c mice. ASD collected from the desert was heated to remove toxic organic substances (H-ASD). BALB/c mice were instilled intratracheally with 12 different testing samples prepared with LPS (1 ng and 10 ng), H-ASD, and OVA in a normal saline solution. The lung pathology, cytological profiles in the bronchoalveolar lavage fluid (BALF), the levels of inflammatory cytokines/chemokines in BALF and OVA-specific immunoglobulin in serum were investigated.

Results

The LPS exhibited no response to the production of TNF-α and IL-6 in BMDMs from TLR4-/-, but did from TLR2-/-. H-ASD aggravated the LPS-induced neutrophilic lung inflammation. In the presence of OVA, LPS increased the level of eosinophils slightly and induced trace levels of Th2 cytokines IL-5 and IL-13 at the levels of 1 ng and 10 ng. In the presence of OVA and H-ASD, LPS induced severe eosinophil infiltration and proliferation of goblet cells in the airways as well as remarkable increases in Th2 cytokines IL-5 and IL-13 in BALF. The mixture containing LPS (1 ng) showed adjuvant activity on OVA-specific IgE and IgG1 production.

Conclusions

The results suggest that H-ASD with naturally-occurring levels of LPS enhances OVA-induced lung eosinophilia via increases in Th2-mediated cytokines and antigen-specific immunoglobulin. These results indicate that LPS is a strong candidate for being a major aggravating substance in ASD.

Asian dust particles induce macrophage inflammatory responses via mitogen-activated protein kinase activation and reactive oxygen species production

Asian dust is a springtime meteorological phenomenon that originates in the deserts of China and Mongolia. The dust is carried by prevailing winds across East Asia where it causes serious health problems. Most of the information available on the impact of Asian dust on human health is based on epidemiological investigations, so from a biological standpoint little is known of its effects. To clarify the effects of Asian dust on human health, it is essential to assess inflammatory responses to the dust and to evaluate the involvement of these responses in the pathogenesis or aggravation of disease. Here, we investigated the induction of inflammatory responses by Asian dust particles in macrophages. Treatment with Asian dust particles induced greater production of inflammatory cytokines interleukin-6 and tumor necrosis factor-α (TNF-α) compared with treatment with soil dust. Furthermore, a soil dust sample containing only particles ≤10 μm in diameter provoked a greater inflammatory response than soil dust samples containing particles >10 μm. In addition, Asian dust particles-induced TNF-α production was dependent on endocytosis, the production of reactive oxygen species, and the activation of nuclear factor-κB and mitogen-activated protein kinases. Together, these results suggest that Asian dust particles induce inflammatory disease through the activation of macrophages.

The effect of Asian sand dust-activated respiratory epithelial cells on activation and migration of eosinophils

CONTEST: Asian sand dust (ASD) contains various chemical and microbiological materials. ASD aggravate the inflammatory response of respiratory epithelial cells and symptoms of asthma.

OBJECTIVE

To evaluate the inflammatory effects of ASD on the activation of bronchial epithelial cells and the effect on the activation and migration of eosinophils.

MATERIALS AND METHODS

BEAS-2B cells were exposed to three forms of ASD: particles less than 10 μm in diameter (PM), dried sand dust (SD) and sand dust collected from the Gobi Desert (GB). Activation of the epithelial cells was determined using interleukin-6 (IL-6), IL-8, granulocyte macrophage colony-stimulating factor (GM-CSF), regulated on activation normal T expressed and secreted (RANTES), and eotaxin. Eosinophil migration was induced with bronchial epithelial cell conditioned medium. Eosinophils were stimulated with the ASDs and production of superoxide and eosinophil cationic protein was measured.

RESULTS

PM and SD enhanced the production of IL-6, IL-8 and RANTES. However, only IL-6 production was significantly increased with GB. Conditioned medium stimulated PM and SD enhanced the migration of eosinophils. PM and SD strongly activated eosinophils.

DISCUSSION AND CONCLUSIONS

ASD, which contains smaller particles and air pollutants, might exacerbate the inflammatory process of bronchial tissue and asthmatic symptoms with the production of inflammatory mediators and tissue eosinophilia.

Changes in fluorescence spectra of bioaerosols exposed to ozone in a laboratory reaction chamber to simulate atmospheric aging

A laboratory system for exposing aerosol particles to ozone and rapidly measuring the subsequent changes in their single-particle fluorescence is reported. The system consists of a rotating drum chamber and a single-particle fluorescence spectrometer (SPFS) utilizing excitation at 263 nm. Measurements made with this system show preliminary results on the ultra-violet laser-induced-fluorescence (UV-LIF) spectra of single aerosolized particles of Yersinia rohdei, and of MS2 (bacteriophage) exposed to ozone. When bioparticles are exposed in the chamber the fluorescence emission peak around 330 nm: i) decreases in intensity relative to that of the 400-550 nm band; and ii) shifts slightly toward shorter-wavelengths (consistent with further drying of the particles). In these experiments, changes were observed at exposures below the US Environmental Protection Agency (EPA) limits for ozone.

Effects of fetal exposure to urban particulate matter on the immune system of male mouse offspring

Urban particulate matter (UPM) has been shown to have an aggravating effect on Th2-associated immune systems in adult mice. However, the effects of fetal exposure to UPM on immune response in offspring have not been elucidated. In the present study, we administered UPM (200 µg/animal) by intratracheal injection to pregnant dams on days 7 and 14 of gestation. Subsequently, 9- and 24-week-old male offspring were intratracheally injected with ovalbumin (OVA) (four times at 2-week intervals) to create a mouse model of bronchial asthma. We then evaluated the progression of allergic manifestations in the offspring through histological findings, the number of inflammatory cells in bronchoalveolar lavage fluid (BALF), and protein concentration of cytokines and chemokines in BALF 5, 10, 15, and 30 weeks after birth. Histological examination showed that fetal exposure to UPM alone caused slight eosinophil and lymphocyte infiltration in the submucosa of the airway and bronchial epithelium and significant increases in the number of macrophages. Moreover, postnatal intratracheal administration of OVA to offspring exposed to UPM in utero caused significant increases in the numbers of macrophages, eosinophils, and lymphocytes and in the concentrations of their relevant cytokines and chemokines, showing that fetal exposure to UPM aggravated the chemically sensitized immune system of male offspring.

Relationship between asian dust and ischemic stroke: a time-stratified case-crossover study

BACKGROUND AND PURPOSE

Particulate matter is increasingly recognized as a cause of human diseases, including cardiovascular diseases. However, the association between Asian dust (AD), a windblown sand dust originating from mineral soil in the deserts of China and Mongolia, and the incidence of cardiovascular diseases is unclear. The aim of the present study was to elucidate whether AD is associated with the incidence of ischemic stroke.

METHODS

This study investigated the onset time of 7429 consecutive patients with ischemic stroke who were admitted to seven stroke centers in Fukuoka, Japan, between June 1999 and March 2010. Meteorologic variables and air pollutants, including AD and suspended particulate matters, were investigated during the identical period. A time-stratified case-crossover study was conducted to assess the association between AD and stroke incidence using a conditional logistic regression analysis.

RESULTS

Although AD was not significantly associated with the overall incidence of ischemic stroke, there was a relationship specific to the stroke subtypes. AD was significantly associated with the incidence of atherothrombotic brain infarction after adjusting for expected confounders, including meteorologic variables and other air pollutants. No association was detected in other types of ischemic stroke.

CONCLUSION

These data suggest that AD does not increase the overall incidence of ischemic stroke, but it is specifically associated with the risk of atherothrombotic brain infarction.

Dust storms and the risk of asthma admissions to hospitals in Kuwait

OBJECTIVE

Arid areas in the Arabian Peninsula are one of the largest sources of global dust, yet there is no data on the impact of this on human health. This study aimed to investigate the impact of dust storms on hospital admissions due to asthma and all respiratory diseases over a period of 5 years in Kuwait.

METHODS

A population-based retrospective time series study of daily emergency asthma admissions and admissions due to respiratory causes in public hospitals in Kuwait was analyzed in relation to dust storm events. Dust storm days were defined as the mean daily PM(10)>200 μg/m(3) based on measurements obtained from all six monitoring sites in the country.

FINDINGS

During the five-year study period, 569 (33.6%) days had dust storm events and they were significantly associated with an increased risk of same-day asthma and respiratory admission, adjusted relative risk of 1.07 (95% CI: 1.02-1.12) and 1.06 (95% CI: 1.04-1.08), respectively. This was particularly evident among children.

CONCLUSION

Dust storms have a significant impact on respiratory and asthma admissions. Evidence is more convincing and robust compared to that from other geographical settings which highlights the importance of public health measures to protect people's health during dust storms and reduce the burden on health services due to dust events.

[Possibility of exacerbation of allergy by lunar regolith]

Japan, U.S.A. and other foreign space agencies have plans for the construction of a lunar base and long-term stay of astronauts on the moon. The surface of the moon is covered by a thick layer of soil that includes fine particles called "lunar regolith", which is formed by meteorite impact and space weathering. Risk assessment of particulate matter on the moon is important for astronauts working in microgravity on the moon. However, there are few investigations about the biological influences of lunar regolith. Especially, there is no investigation about allergic activity to lunar regolith. The main chemical components of lunar regolith are SiO2, Al2O3, CaO, FeO, etc. Of particular interest, approximately 50% of lunar regolith consists of SiO2. There is a report that the astronauts felt hay fever-like symptoms from the inhalation of the lunar regolith. Yellow sand, whose chemical components are similar to lunar regolith, enhances allergenic reactions, suggesting the possibility that lunar regolith has an adjuvant-like activity. Although intraperitoneal administration of lunar regolith with ovalbumin to mouse did not show enhancement of allergenic reactions, further evaluation of lunar regolith's potential to exacerbate the effects of allergies is essential for development of the moon.

Asian dust storm elevates children's respiratory health risks: a spatiotemporal analysis of children's clinic visits across Taipei (Taiwan)

Concerns have been raised about the adverse impact of Asian dust storms (ADS) on human health; however, few studies have examined the effect of these events on children’s health. Using databases from the Taiwan National Health Insurance and Taiwan Environmental Protection Agency, this study investigates the documented daily visits of children to respiratory clinics during and after ADS that occurred from 1997 to 2007 among 12 districts across Taipei City by applying a Bayesian structural additive regressive model controlled for spatial and temporal patterns. This study finds that the significantly impact of elevated children’s respiratory clinic visits happened after ADS. Five of the seven lagged days had increasing percentages of relative rate, which was consecutively elevated from a 2-day to a 5-day lag by 0.63%∼2.19% for preschool children (i.e., 0∼6 years of age) and 0.72%∼3.17% for school children (i.e., 7∼14 years of age). The spatial pattern of clinic visits indicated that geographical heterogeneity was possibly associated with the clinic’s location and accessibility. Moreover, day-of-week effects were elevated on Monday, Friday, and Saturday. We concluded that ADS may significantly increase the risks of respiratory diseases consecutively in the week after exposure, especially in school children.

Pathological Study of Chronic Pulmonary Toxicity Induced by Intratracheally Instilled Asian Sand Dust (Kosa)

Asian sand dust (ASD) events are associated with an increase in pulmonary morbidity and mortality. The number of ASD events has increased rapidly in the east Asian region since 2000. To study the chronic lung toxicity of ASD, saline suspensions of low doses (200 and 400 µg) and high doses (800 and 3,000 µg) of ASD were intratracheally instilled into ICR mice. Animals were sacrificed at 24 hr, 1 week, or 1, 2, or 3 months after instillation. Histopathological examination revealed that ASD induced acute inflammation at 24 hr after instillation. The acute inflammation was transient and subsided at 1 week and 1 month after instillation. At 2 and 3 months after instillation, focal infiltration of lymphocytes with accumulation of epithelioid macrophages, which is a suggestive finding of transformation to granuloma, and granuloma formation were occasionally observed. Aggregation of macrophages containing particles was observed in the pulmonary lymph nodes at 3 months after instillation in high-dose groups. Prolonged inflammatory foci (granuloma) and presence of ASD particles in pulmonary lymph nodes would have a chance to induce immunological modulation leading to adverse health effects in the exposed animals.

Effects of Asian sand dust on mucin gene expression and activation of nasal polyp epithelial cells

BACKGROUND

Asian sand dust (ASD) contains a variety of chemical and microbiological materials such as lipopolysaccharide (LPS) and beta-glucan that can cause inflammation. The increase in the atmospheric concentration of ASD has been associated with asthma severity and adverse effects on respiratory function. The aim of this study was to evaluate the effect of ASD on the inflammatory process and mucin gene expression in nasal epithelial cells.

METHODS

Primary nasal polyp epithelial cells were exposed to ASD for 72 hours, and then the supernatants were collected. To determine the activation of the epithelial cells, IL-6, IL-8, and granulocyte-macrophage colony-stimulating factor were measured. In addition, the potential cytotoxic effects of ASD on the epithelial cells were evaluated. Quantitative reverse-transcription polymerase chain reaction for MUC4, MUC5AC, MUC5B, and MUC8 mRNA expression, in the nasal epithelial cells, was performed.

RESULTS

ASD stimulated the production of chemical mediators in a time-dependent manner. The cytokine production was highest at 100 micrograms/mL of ASD. MUC4 and MUC5B mRNA expression was significantly increased at 10 and 50 micrograms/mL of ASD.

CONCLUSION

Atomospheric exposure to various chemical species and microbiological materials carrying ASD may affect upper airway inflammation through the production of inflammatory cytokines and mucin.

Asian sand dust enhances allergen-induced th2 allergic inflammatory changes and mucin production in BALB/c mouse lungs

Purpose

Recent studies have reported that Asian sand dust (ASD) has a potential risk of aggravating airway inflammation. The purpose of this study was to investigate the effect of ASD on inflammation and mucin production in the airways of allergic mice.

Methods

Forty BALB/c female mice were divided into four groups: saline (group 1); ASD (group 2); ovalbumin (OVA) alone (group 3); and OVA+ASD (group 4). OVA-specific immunoglobulin E (IgE) in serum and interleukin (IL)-4, IL-5, IL-13, and interferon-gamma (IFN-γ) in bronchoalveolar lavage fluid (BALF) were measured by enzyme-linked immunosorbent assay (ELISA). Hematoxylin & eosin (H&E) and Periodic acid-Schiff (PAS) staining was performed on lung tissues. In addition, immunohistochemical staining for IL-4, IL-5, MUC5AC, and transforming growth factor alpha (TGF-α) was conducted.

Results

Serum IgE levels were significantly higher in group 4 than in group 3 (P<0.05). IL-4 and IL-5 in BALF were significantly higher in group 4 than in group 3 (P<0.05, respectively). Based on H&E staining, inflammatory cell numbers were significantly greater in group 4 than in the other groups (P<0.05). The number of PAS-positive cells was also significantly greater in groups 3 and 4 than in groups 1 and 2 (P<0.05). The numbers of IL-4 and IL-5-positive cells were higher in group 4 than in group 3 (P<0.05). The number of MUC5AC and TGF-α-positive cells were also higher in group 4 than in group 3 (P<0.05).

Conclusions

Our data suggest that ASD increases cytokine expression and mucin production in an allergic murine model. The increased inflammatory reactions were related to cytokine production.

Impact of air pollution on allergic diseases

The incidence of allergic diseases in most industrialized countries has increased. Although the exact mechanisms behind this rapid increase in prevalence remain uncertain, a variety of air pollutants have been attracting attention as one causative factor. Epidemiological and toxicological research suggests a causative relationship between air pollution and the increased incidence of asthma, allergic rhinitis, and other allergic disorders. These include ozone, nitrogen dioxide and, especially particulate matter, produced by traffic-related and industrial activities. Strong epidemiological evidence supports a relationship between air pollution and the exacerbation of asthma and other respiratory diseases. Recent studies have suggested that air pollutants play a role in the development of asthma and allergies. Researchers have elucidated the mechanisms whereby these pollutants induce adverse effects; they appear to affect the balance between antioxidant pathways and airway inflammation. Gene polymorphisms involved in antioxidant pathways can modify responses to air pollution exposure. While the characterization and monitoring of pollutant components currently dictates pollution control policies, it will be necessary to identify susceptible subpopulations to target therapy/prevention of pollution-induced respiratory diseases.

The acute and long-term effects of Middle East sand particles on the rat airway following a single intratracheal instillation

Military personnel deployed in the Middle East have emphasized concerns regarding high levels of dust generated from blowing desert sand and the movement of troops and equipment. Airborne particulate matter levels (PM(10); PM < 10 μm) in the region may exceed 1500 μg/m(3), significantly higher than the military exposure guideline (MEG) of 50 μg/m(3). Increases in PM(10) have been linked to a rise in incidences of asthma, obstructive pulmonary disease, lung cancer, and cardiovascular diseases. Male Sprague-Dawley rats received a single intratracheal (IT) instillation of 1, 5, or 10 mg of Middle East PM(10) collected at a military occupied site in Kuwait, silica (positive control), or titanium dioxide (TiO(2); negative control) suspended in 400 μl sterile saline, or saline alone (vehicle control). Twenty-four hours, 3 d, 7 d and 6 mo postexposure (n = 15/group), organs including lung were evaluated for histopathological changes and for particle contaminants. Bronchoalveolar fluid (BALF) was also analyzed for cellular and biochemical parameters, including cytokines and chemokines. Instillation of silica resulted in early, pronounced, sustained inflammation indicated by significant increases in levels of total protein and neutrophils, and activities of lactate dehydrogenase activity and β-glucuronidase activity. Lower magnitude and transient changes using the same markers were observed in animals exposed to TiO(2) and Middle East PM(10). The results suggest that for acute exposures, this Middle East PM(10) is a nuisance-type dust with relatively low toxicity. However, since average deployment of military personnel to the Middle East is 180 d with potential for multiple follow-on tours, chronic exposure studies are needed to fully understand the pulmonary effects associated with Middle East PM exposure.

Asian dust storm particles induce a broad toxicological transcriptional program in human epidermal keratinocytes

Exposure to airborne dust particles originated from seasonal Asian dust storms in Chinese and Mongolian deserts results in increased incidence of a range of diseases including asthma, contact dermatitis and conjunctivitis. The areas affected by Asian dust particles extend from East China to the west coast of North America. In order to study toxicological mechanisms in human skin, we evaluated the effects of dust particles collected during Asian dust storms (Asian dust particles) on gene expression in human epidermal keratinocytes (HEK). In HEK, exposure to Asian dust particles significantly increased gene expressions of cytochrome P450 1A1 (CYP1A1), CYP1A2, and CYP1B1, which is an indication of aryl hydrocarbon receptor (AHR) activation. In addition, Asian dust particles increased gene transcription of the cytokines IL-6, IL-8, and GM-CSF, which have broad pro-inflammatory and immunomodulatory properties. Asian dust particles significantly up-regulated expression of caspase 14 in HEK, suggesting that Asian dust particles directly affect keratinocyte differentiation. We also demonstrated that protein extract of pollen, a material frequently adsorbed onto Asian dust particles, potentially contributes to the increased transcription of IL-6, CYP1A1, CYP1A2, and CYP1B1. Taken together, these studies suggest that Asian dust particles can exert toxicological effects on human skin through the activation of the cellular detoxification system, the production of pro-inflammatory and immunomodulatory cytokines, and changes in the expression of proteins essential in normal epidermal differentiation.

Urban particulate matter in Beijing, China, enhances allergen-induced murine lung eosinophilia

It has been reported that ambient particulate matter (PM) in some large cities, such as Beijing, China, causes adverse respiratory health effects. However, there is currently no experimental report on the relationship between bronchial asthma and urban PM (UPM) in northeast Asia. In this study, the microbial and chemical substances adsorbed onto UPM collected in Beijing were excluded by heat-treatment at 360 degrees C for 30 min. The effects of UPM or heated UPM (H-UPM) toward allergic lung inflammation were compared in murine lungs to investigate the role of organic substances. ICR mice were administrated intratracheally with the two kinds of UPM and/or ovalbumin (OVA) 4 times at 2-week intervals. UPM and H-UPM enhanced eosinophil recruitment induced by OVA in the alveoli and in the submucosa of the airway, which has a goblet cell proliferation in the bronchial epithelium. UPM and H-UPM synergistically increased Th-2 cytokines--interleukin (IL)-4 and IL-13, eosinophil-relevant cytokines and chemokines, such as IL-5 and monocyte chemotactic protein-3 (MCP-3), induced by OVA in bronchoalveolar lavage fluid (BALF). The enhancing effects were much greater in UPM than in H-UPM. UPM induced adjuvant effects on specific immunoglobulin E (IgE) and IgG1 production by OVA. In an in vitro study using RAW264.7 cells, UPM increased the expression of Toll-like receptor 2 (TLR2) mRNA, but not TLR4 mRNA. H-UPM caused no expression of both TLR mRNAs. These results suggest that the aggravated lung eosinophilia in UPM was due to activation of a Th2-associated immune response via the activation of TLR2 by microbial materials. Chemical materials of air pollutant origin contained in UPM, and inorganic components (elemental carbon, mineral elements) in H-UPM, could also cause the aggravation.

Pathological Study of Acute Pulmonary Toxicity Induced by Intratracheally Instilled Asian Sand Dust (Kosa)

The objective of this study was to investigate acute lung toxicity caused by Asian sand dust. Simulated Asian sand dust collected from the Tennger desert in China (CJ-2 particles) and Asian sand dust collected from the atmosphere in Japan (Tottori particles) were used. Saline suspensions of 50, 200, 800, and 3,000 µg Asian sand dust were intratracheally instilled to ICR mice. Localized accumulation of the dust particles was observed in the bronchioles and the alveoli of the lung tissues; acute inflammatory changes characterized by infiltration of macrophages and neutrophils were observed around the particles. Degenerated alveolar walls and bronchial epithelial cells, as well as a weakened positive immunolabeling for laminin, were observed to be associated with particle attachment. Positive immunolabelings for interleukin-6, tumor necrosis factor–α inducible nitric oxide synthase, and dimeric copper- and zinc-containing superoxide dismutase were observed mainly in the inflammatory cells in the lesions; these findings were not observed in the controls or in areas lacking lesions. These results suggest that Asian sand dust particles caused damage to the lung tissue through a direct physical effect. In addition, secondary released cytokines and oxidative stress generated in the lesion may be involved in the development of the acute lung toxicity.

Desert dust exposure is associated with increased risk of asthma hospitalization in children

RATIONALE

Desert dust particles, including quartz, which causes inflammatory responses in the airway in animal studies, are transported to widespread regions around the globe. Epidemiologically, areas impacted by desert dust storms, such as communities in the Middle East and the Caribbean, seem to have higher incidences of asthma than might be expected.

OBJECTIVES

We investigated the magnitude of association between airborne mineral dust concentration and hospitalization of children for asthma exacerbation by using Light Detection And Ranging (LIDAR) with a polarization analyzer for an exposure measurement, which can distinguish mineral dust particles from other particles.

METHODS

A case-crossover design was used. The exposure measurement was LIDAR's nonspherical extinction coefficient. The outcome measurement was hospitalization of children aged 1 to 15 years for asthma exacerbation in eight principal hospitals in Toyama, a local area in Japan bordering the Japan Sea, during February to April, 2005 to 2009.

MEASUREMENTS AND MAIN RESULTS

During the study period, there were 620 admissions for asthma exacerbation, and 6 days with a heavy dust event (daily mineral dust concentration > 0.1 mg/m(3)). Conditional logistic regression showed a statistically significant association between asthma hospitalization and a heavy dust event. The crude odds ratio (OR) of the heavy dust event for hospitalization on the day was 1.88 (95% confidence interval [CI], 1.04-3.41; P = 0.037), and the OR of heavy dust event during the previous week was 1.83 (95% CI, 1.31-2.56; P = 0.00043). The OR adjusted by other air pollutant levels, pollen, and meteorological factors was 1.71 (95% CI, 1.18-2.48; P = 0.0050).

CONCLUSIONS

Heavy dust events are associated with an increased risk of hospitalizations for asthma.

[Health effects of Asian dust events: a review of the literature]

Asian dust, called 'kosa' in Japan, is the long-range transport of atmospheric pollutants originating from the desert areas of China and Mongolia. Although Asian dust has a long history of appearing in Japan, it is only quite recently that there is increasing concern for its possible adverse health effects. We reviewed the epidemiologic evidence of potential health effects of Asian dust events. PubMed was used to search for the following keywords: Asian dust, yellow sand, desert dust, dust storm, sandstorm, mortality, death, morbidity, hospitalization, hospital admission, health, pulmonary and respiratory. The search was limited to the epidemiologic studies published between January 1980 and May 2009. JMEDPlus was used to search for Japanese literature. Seventeen studies were retrieved from PubMed and one study from JMEDPlus. In addition, one study was identified for reviewing from the references of another study. In total, we identified 19 epidemiologic studies (3 for mortality, 13 for hospital visits or admissions and 3 for respiratory functions or symptoms) mainly from Taiwan and Korea. There were many combinations of outcomes and lagged exposures examined, and some suggested possible associations of dust exposure with an increase in mortality and hospital visits and admissions due to cardiovascular and respiratory diseases, whereas the rest of the studies did not show statistically significant associations. The evidence from these studies was limited because exposure assessments were inadequately described and potential confounders were insufficiently controlled. Well-designed epidemiological studies are required to clarify any potential health effects of Asian dust events in Japan.

Depositional behaviors of plutonium and thorium isotopes at Tsukuba and Mt. Haruna in Japan indicate the sources of atmospheric dust

Monthly plutonium and thorium depositions at Tsukuba (28m asl) and Mt. Haruna (1370m asl) were measured during 2006 and 2007 (Jan 2006-Dec 2007 at Tsukuba, Nov 2006-Dec 2007 at Mt. Haruna). The monthly (239,240)Pu depositions ranged from 0.044 to 2.67mBq m(-2) at Tsukuba and from 0.05 to 0.9mBq m(-2) at Mt. Haruna during the measurement periods. Monthly (239,240)Pu deposition did not differ markedly between the two sites except in April 2007. Seasonal pattern of monthly (239,240)Pu depositions at both sites showed high in spring and low in summer, and typical of seasonal variations in northeastern Asia. Thorium deposition at Tsukuba was higher than that at Mt. Haruna except in May and June 2007. (230)Th/(232)Th activity ratios were used to partition deposition samples into locally and remotely derived fractions. The results revealed that a major proportion of total (239,240)Pu and Th deposits are derived from remote sources, especially in spring.

Aggravating effect of natural sand dust on male reproductive function in mice

Purpose

Although adverse health effects of environment (such as cadmium, pesticides, diesel exhaust, etc.) on the male reproductive system have been suggested, there is little experimental evidence of such an effect of atmospheric sand dust. In the present study, the effects of sand dust (mineral particles) were investigated on the male reproductive system of mice.

Methods

Two types of sand dusts (Asian sand dust and Arizona sand dust) were intratracheally administered (0.1 mg/mouse 4 times every other week) to ICR male mice and then male reproductive organ weight, daily sperm production (DSP), histological analysis and serum testosterone level were measured.

Results

Histological examination showed that interstitial edema was produced by both sand dust types, and partial vacuolation of the seminiferous tubules was detected in the exposed mice. Moreover, exposure to these natural sand dusts significantly decreased DSP. On the other hand, there was no significant differences in serum testosterone concentration.

Conclusions

These results suggest that natural sand dust-exposure produced adverse effects on mouse male reproductive function.