Estimated effects of Asian dust storms on spatiotemporal distributions of clinic visits for respiratory diseases in Taipei children (Taiwan)

The population affected by dust in China in the springtime

Dust events in northern China, particularly in the springtime, affect millions of people in the source and downwind regions. We investigate the population affected by various dust levels in China in the springtime from 2003 to 2020 using satellite retrievals of dust optical depth (DOD). We select three DOD thresholds, namely DOD > 0.2, DOD > 0.3, and DOD > 0.4, to estimate the population affected and find that each year the population affected can differ by one order of magnitude. The population exposed to DOD > 0.2 ranged from 16 million (2019) to over 200 million (2006). The population exposed to DOD > 0.3 ranged from 10 million (2015) to 70 million (2006). The population exposed to DOD > 0.4 ranged from 4 million (2017) to 36 million (2006). In years when dust events are frequent, people in the source and downwind regions are both affected, whereas, in years when dust events are less frequent, people affected are mainly in the source regions. Furthermore, we use the relative index of inequality to assess whether dust hazards impose unequal pollution burdens on different socioeconomic groups. We find that low-income communities have been more likely affected by dust pollution since 2013.

Ecological study of ambient air pollution exposure and mortality of cardiovascular diseases in elderly

As an independent risk factor, ambient air pollution can assume a considerable part in mortality and worsening of cardiovascular disease. We sought to investigate the association between long-term exposure to ambient air pollution and cardiovascular disease mortality and their risk factors in Iranian's elderly population. This inquiry was conducted ecologically utilizing recorded data on cardiovascular disease mortality from 1990 to 2019 for males and females aged 50 years or more from the Global Burden of Disease dataset. Data was interned into Joinpoint software 4.9.0.0 to present Annual Percent Change (APC), Average Annual Percent Change (AAPC), and its confidence intervals. The relationship between recorded data on ambient air pollution and cardiovascular disease' mortality, the prevalence of high systolic blood pressure, high LDL cholesterol levels, high body mass index, and diabetes mellitus type2 was investigated using the Spearman correlation test in R 3.5.0 software. Our finding demonstrated that cardiovascular diseases in elderly males and females in Iran had a general decreasing trend (AAPC = -0.77% and -0.65%, respectively). The results showed a positive correlation between exposure to ambient ozone pollution (p ≤ 0.001, r = 0.94) ambient particulate and air pollution (p < 0.001, r = 0.99) and mortality of cardiovascular disease. Also, ambient air pollution was positively correlated with high systolic blood pressure (p < 0.001, r = 0.98), high LDL cholesterol levels (p < 0.001, r = 0.97), high body mass index (p < 0.001, r = 0.91), diabetes mellitus type2 (p < 0.001, r = 0.77). Evidence from this study indicated that ambient air pollution, directly and indirectly, affects cardiovascular disease mortality in two ways by increasing the prevalence of some traditional cardiovascular disease risk factors. Evidence-based clinical and public health methodologies are necessary to decrease the burden of death and disability associated with cardiovascular disease.

Changes in Ambient Bacterial Community in Northern Taiwan during Long-Range Transport: Asian Dust Storm and Frontal Pollution

Long-range transport (LRT) can carry air pollutants to downwind areas. However, studies about the impacts of LRT on bacterial communities are few. This study investigated the influence of Asian dust storms (ADS) and frontal pollution (FP) on bacterial communities in ambient air using next-generation sequencing (NGS) and Terminal Restriction Fragment Length Polymorphism (T-RFLP). Air samples were collected at Cape Fugui (CF) and National Taiwan University (NTU) in northern Taiwan before (or background days), during, and after LRTs from November 2013 to March 2015. The richness, H index, and evenness increased during FPs and then decreased after FPs. During and after ADS and FP, the prevalence of the phylum Proteobacteria decreased, but that of Firmicutes increased. The dominant class of Proteobacteria changed from Alphaproteobacteria on background days to Betaproteobacteria during LRTs. At the genus level, the high abundance of Ralstonia and Bacillus during FP and Clostridium during ADS were detected at both locations. Additionally, Ralstonia was dominant at CF during ADS. In conclusion, FP and ADS both changed the bacterial community. The indicator genus was Clostridium and Ralstonia for ADS as well as Bacillus and Ralstonia for FP. Given the potential health threats posed by the bioaerosols transported, people should avoid outdoor activities during LRTs.

North African dust intrusions and increased risk of respiratory diseases in Southern Portugal

The study of dust intrusions in Portugal is still a subject on which little investigation has been made, especially in terms of their effects. Thus, this work aims to achieve two goals: firstly, to characterize the dust intrusions in the study area; and secondly, to evaluate the possible statistical association between the dust intrusion days and hospital admissions due to respiratory diseases. Dust intrusions in Portugal are prevalent during the summer season. During this season, the dust plumes tend to cover broader areas than in the other seasons and they have origin in the North African countries. In the study area for the period between 2005 and 2015, the relative risk of urgent hospitalizations due to respiratory diseases was 12.6% higher during dust intrusion days. In order to obtain this statistical association, a Distributed Lag Nonlinear Model was developed. With this work, we expect to help the development of further studies regarding North African dust intrusions in Portugal, more precisely their effects on human health.

Lung Inflammatory Response to Environmental Dust Exposure in Mice Suggests a Link to Regional Respiratory Disease Risk

PURPOSE

The Salton Sea, California's largest lake, is designated as an agricultural drainage reservoir. In recent years, the lake has experienced shrinkage due to reduced water sources, increasing levels of aerosolized dusts in surrounding regions. Communities surrounding the Salton Sea have increased asthma prevalence versus the rest of California; however, a connection between dust inhalation and lung health impacts has not been defined.

METHODS

We used an established intranasal dust exposure murine model to study the lung inflammatory response following single or repetitive (7-day) exposure to extracts of dusts collected in regions surrounding the Salton Sea (SSDE), complemented with in vitro investigations assessing SSDE impacts on the airway epithelium.

RESULTS

In these investigations, single or repetitive SSDE exposure induced significant lung inflammatory cytokine release concomitant with neutrophil influx. Repetitive SSDE exposure led to significant lung eosinophil recruitment and altered expression of genes associated with allergen-mediated immune response, including Clec4e. SSDE treatment of human bronchial epithelial cells (BEAS-2B) induced inflammatory cytokine production at 5- and 24-hours post-treatment. When BEAS-2B were exposed to protease activity-depleted SSDE (PDSSDE) or treated with SSDE in the context of protease-activated receptor-1 and -2 antagonism, inflammatory cytokine release was decreased. Furthermore, repetitive exposure to PDSSDE led to decreased neutrophil and eosinophilic influx and IL-6 release in mice compared to SSDE-challenged mice.

CONCLUSION

These investigations demonstrate potent lung inflammatory responses and tissue remodeling in response to SSDE, in part due to environmental proteases found within the dusts. These studies provide the first evidence supporting a link between environmental dust exposure, protease-mediated immune activation, and respiratory disease in the Salton Sea region.

Global Health Impacts of Dust Storms: A Systematic Review

BACKGROUND

Dust storms and their impacts on health are becoming a major public health issue. The current study examines the health impacts of dust storms around the world to provide an overview of this issue.

METHOD

In this systematic review, 140 relevant and authoritative English articles on the impacts of dust storms on health (up to September 2019) were identified and extracted from 28 968 articles using valid keywords from various databases (PubMed, WOS, EMBASE, and Scopus) and multiple screening steps. Selected papers were then qualitatively examined and evaluated. Evaluation results were summarized using an Extraction Table.

RESULTS

The results of the study are divided into two parts: short and long-term impacts of dust storms. Short-term impacts include mortality, visitation, emergency medical dispatch, hospitalization, increased symptoms, and decreased pulmonary function. Long-term impacts include pregnancy, cognitive difficulties, and birth problems. Additionally, this study shows that dust storms have devastating impacts on health, affecting cardiovascular and respiratory health in particular.

CONCLUSION

The findings of this study show that dust storms have significant public health impacts. More attention should be paid to these natural hazards to prepare for, respond to, and mitigate these hazardous events to reduce their negative health impacts.Registration: PROSPERO registration number CRD42018093325.

Estimation of PM10 pollutant and its effect on total mortality (TM), hospitalizations due to cardiovascular diseases (HACD), and respiratory disease (HARD) outcome

Dust storms not only affect the quality of life but also pose a serious health and social problem. The main source dust events include central and west Asia, the Taklimakan desert, and Middle East, carrying out high volume of particulate matter, which increased the level of PM₁₀ as representative of dust storm. The purpose of this study was to investigate the number of mortality (TM), hospitalizations due to cardiovascular diseases (HACD) and respiratory diseases (HARD) among the people of Bishkek and Ahvaz. Data validation was performed using the WHO criteria. The average time PM₁₀ in outdoor air was calculated, and its health effects were obtained by entering its annual data and population at risk, baseline incidence (BI), and relative risk index (RR) for IHD outcomes. In our study, AirQ software was used. The number of excess cases in Bishkek and Ahvaz for total mortality and cardiovascular mortality was 63 and 758 and 35 and 478 persons while for HARD and HACD was 84 and 2054 and 33 and 560 persons, respectively. The survey requires the need to enact and enforce permissible PM₁₀ levels/standards due to dust storms to reduce the health effect on humans by relevant environmental authorities both at federal and state levels.

Estimating seasonal variations of realistic exposure doses and risks to organs due to ambient particulate matter -bound metals of Delhi

This study aims to calculate deposition of PM_2.5 -bound hazardous metals in different organs after inhalation of particulate matter for the Delhi (India), and to estimate risks to organs following inhalation. Bio-accessible fractions of three PM-associated carcinogenic metals (As, Pb &Cd) were calculated using the metal values in simulated lung fluids. Depositions of metals in different organs were calculated using an integrated model consists of HRT and PBPK models. The calculation indicates that the major or significant deposition of metal Pb occurs in tissues, such as bone, muscle and blood. Most of the depositions of Cd happens in lung whereas most of the depositions of As happens in lung, muscle and skin. Most of the deposition of studied metals was found in lung (45% for arsenic and 70% for cadmium of their bio -dissolved contents). The following order of depositions of metals in different tissues were found (from highest deposition to smallest deposition): As: Lung > muscle = liver; Pb: bone > blood > muscle; Cd: lung > intestine. The combined exposures of PM_2.5 and its associated metals were found to give interaction-based hazard index greater than 1 for several months of the year, indicating a chance of health risk. Hazard quotient (HQ) <1 was seen for ingestion and dermal pathways, indicating no cause of concern. Findings indicate the need for doing periodic monitoring and estimating deposition doses and exposure risks of PM-associated metals to lungs and other organs for protecting human health.

Long-range air pollution transport in East Asia during the first week of the COVID-19 lockdown in China

Long-range transport (LRT) of air pollutants from East Asia during the northeast monsoon season impacts several downwind locations. In 2020, the initial COVID-19 lockdowns in China overlapped with Week 3 of the Chinese New Year (CNY) holiday, and an Asian outflow event. Thus, movement of the Chinese populace from city to city was already greatly reduced by the time of the LRT episode, although the reductions in industrial output are less clear. We found NO₂ column concentrations were reduced by 24% during the CNY Week 3 this year compared to previous years. The attenuated transport event arrived to northern Taiwan with a PM_2.5 concentration <45 μg m^-3 and most often <35 μg m^-3, which is 2-3 times lower than LRT episodes of similar back-trajectory and synoptic patterns. The whole episode persisted for about 60 h, longer than most LRT episodes from China to Taiwan. CMAQ v5.2.1 modeling of the LRT event with 100% emission and reduced emission scenarios, revealed emissions in China were approximately 50% less than normal periods. Due to the length of the episode and the significant reduction in emissions, Taiwan avoided a PM_2.5 surplus of 19.2 μg m^-3 on average during the episode, equivalent to a 0.5 μg m^-3 reduction for the whole 3-month winter season. Employing the 100% emission model scenario and scaling up to the average episode hours each winter, the PM_2.5 surplus delivered via plumes on the northeast monsoon is equivalent to a 0.5 μg m^-3 surplus for the whole year.

Health Effects of Asian Dust: A Systematic Review and Meta-Analysis

BACKGROUND

Potential adverse health effects of Asian dust exposure have been reported, but systematic reviews and quantitative syntheses are lacking.

OBJECTIVE

We reviewed epidemiologic studies that assessed the risk of mortality, hospital admissions, and symptoms/dysfunction associated with exposure to Asian dust.

METHODS

We performed a systematic search of PubMed and Web of Science to identify studies that reported the association between Asian dust exposure and human health outcomes. We conducted separate meta-analyses using a random-effects model for mortality and hospital admissions for a specific health outcome and assessed pooled estimates for each lag when at least three studies were available for a specific lag.

RESULTS

We identified 89 studies that met our inclusion criteria for the systematic review, and 21 studies were included in the meta-analysis. The pooled estimates (percentage changes) of mortality from circulatory and respiratory causes for Asian dust days vs. non-Asian dust days were 2.33% [95% confidence interval (CI): 0.76, 3.93] increase at lag 0 and 3.99% (95% CI: 0.08, 8.06) increase at lag 3, respectively. The increased risk for hospital admissions for respiratory disease, asthma, and pneumonia peaked at lag 3 by 8.85% (95% CI: 0.80, 17.55), 14.55% (95% CI: 6.74, 22.94), and 8.51% (95% CI: 2.89, 14.44), respectively. Seven of 12 studies reported reduced peak expiratory flow, and 16 of 21 studies reported increased respiratory symptoms associated with Asian dust exposure. There were substantial variations between the studies in definitions of Asian dust, study designs, model specifications, and confounder controls.

DISCUSSION

We found evidence of increased mortality and hospital admissions for circulatory and respiratory events. However, the number of studies included in the meta-analysis was not large and further evidences are merited to strengthen our conclusions. Standardized protocols for epidemiological studies would facilitate interstudy comparisons. https://doi.org/10.1289/EHP5312.

Air pollutants disrupt iron homeostasis to impact oxidant generation, biological effects, and tissue injury

Air pollutants cause changes in iron homeostasis through: 1) a capacity of the pollutant, or a metabolite(s), to complex/chelate iron from pivotal sites in the cell or 2) an ability of the pollutant to displace iron from pivotal sites in the cell. Through either pathway of disruption in iron homeostasis, metal previously employed in essential cell processes is sequestered after air pollutant exposure. An absolute or functional cell iron deficiency results. If enough iron is lost or is otherwise not available within the cell, cell death ensues. However, prior to death, exposed cells will attempt to reverse the loss of requisite metal. This response of the cell includes increased expression of metal importers (e.g. divalent metal transporter 1). Oxidant generation after exposure to air pollutants includes superoxide production which functions in ferrireduction necessary for cell iron import. Activation of kinases and phosphatases and transcription factors and increased release of pro-inflammatory mediators also result from a cell iron deficiency, absolute or functional, after exposure to air pollutants. Finally, air pollutant exposure culminates in the development of inflammation and fibrosis which is a tissue response to the iron deficiency challenging cell survival. Following the response of increased expression of importers and ferrireduction, activation of kinases and phosphatases and transcription factors, release of pro-inflammatory mediators, and inflammation and fibrosis, cell iron is altered, and a new metal homeostasis is established. This new metal homeostasis includes increased total iron concentrations in cells with metal now at levels sufficient to meet requirements for continued function.

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.

[Health Effects of Asian Dust Events: A Literature Review Update of Epidemiological Evidence]

Asian dust is a phenomenon involving the long-range transport of atmospheric pollutants originating from the desert areas of China and Mongolia. In recent years, the health effects of Asian dust have raised public concerns. Numerous studies on the health effects of Asian dust have been published since the last review in 2010. Thus, a literature review was conducted to shed light on the latest epidemiologic findings. PubMed and Science Direct databases were used for the review of epidemiologic studies published between June 2009 and April 2018. We identified 53 epidemiologic studies. Mortality, ambulance transportation, hospitalization/medical examination, changes in symptomatic, functional, and examination findings, as well as birth outcomes have been reported as outcomes. When the outcomes were categorized by disease, the effects of Asian dust on respiratory, cardiovascular, and allergic diseases raised concerns. The common evidences of causation between Asian dust and these diseases were the consistency of findings and temporal sequence of association. As results of research on dose-response relationships have become available, and the possibility that the health effects of Asian dust may vary depending on its chemical composition has been pointed out, further research using the exposure level indicators of Asian dust or its chemical composition should be conducted. Furthermore, with focus on the crucial issue of reducing exposure, research related to prevention and raising awareness should be further promoted.

Reinforcement of Tobacco Control and Reduction in Medical Utilization for Asthma in Taiwan: A Population-Based Study

Environmental air quality can affect asthma control and the development of overt asthmatic manifestations. In this population-based study, we investigated the effect of reinforcing a smoking ban in Taiwan through the enactment of the Tobacco Hazards and Prevention Act (THPA) on healthcare utilization rate by asthmatics. Analysis was performed based on data relevant to non-hospitalized asthmatic patients with insurance claims between 2005 and 2013 from the National Health Insurance Research Database of Taiwan, reported data on Asian dust storms, and penalty rates for violations of the tobacco ban. Poisson regression showed that the risk for outpatient visits for asthma was lower after enactment of the THPA (RR = 0.98, 95% CI = 0.98-0.99), with a yearly trend of a reduced risk (RR = 0.99, 95% CI = 0.99-1.00), also lower in geographic regions with medium (RR = 0.79, 95% CI = 0.79-0.80) and high (RR = 0.91, 95% CI = 0.91-0.92) penalty rates. Subgroup analysis showed that asthma visit rates were reduced in both male and female groups after the enactment of the THPA. The risk of an asthma ER visit was increased after the enactment of the amended THPA (RR = 1.07, 95% CI = 1.05-1.09), although the yearly trend was not significant (RR = 1.00, 95% CI = 1.00-1.00). The risk of emergency room visits for asthma was significantly reduced in regions with medium (RR = 0.68, 95% CI = 0.68-0.69) and high (RR = 0.75, 95% CI = 0.74-0.76) penalty rates. Subgroup analysis showed that the visit rates were similar in both male and female groups. The effectiveness of reinforcing the smoking ban warrants further policies aimed at further reducing passive smoking.

The Contribution of Geogenic Particulate Matter to Lung Disease in Indigenous Children

Indigenous children have much higher rates of ear and lung disease than non-Indigenous children, which may be related to exposure to high levels of geogenic (earth-derived) particulate matter (PM). The aim of this study was to assess the relationship between dust levels and health in Indigenous children in Western Australia (W.A.). Data were from a population-based sample of 1077 Indigenous children living in 66 remote communities of W.A. (>2,000,000 km²), with information on health outcomes derived from carer reports and hospitalisation records. Associations between dust levels and health outcomes were assessed by multivariate logistic regression in a multi-level framework. We assessed the effect of exposure to community sampled PM on epithelial cell (NuLi-1) responses to non-typeable Haemophilus influenzae (NTHi) in vitro. High dust levels were associated with increased odds of hospitalisation for upper (OR 1.77 95% CI [1.02–3.06]) and lower (OR 1.99 95% CI [1.08–3.68]) respiratory tract infections and ear disease (OR 3.06 95% CI [1.20–7.80]). Exposure to PM enhanced NTHi adhesion and invasion of epithelial cells and impaired IL-8 production. Exposure to geogenic PM may be contributing to the poor respiratory health of disadvantaged communities in arid environments where geogenic PM levels are high.

The disappearing Salton Sea: A critical reflection on the emerging environmental threat of disappearing saline lakes and potential impacts on children's health

Changing weather patterns, droughts and competing water demands are dramatically altering the landscape and creating conditions conducive to the production of wind-blown dust and dust storms. In California, such factors are leading to the rapid shrinking of the Salton Sea, a 345 mile² land-locked "sea" situated near the southeastern rural border region known as the Imperial Valley. The region is anticipated to experience a dramatic increase in wind-blown dust and existing studies suggest a significant impact on the health and quality of life for nearby residents of this predominantly low-income, Mexican-American community. The discussion calls attention to the public health dimensions of the Salton Sea crisis. We know little about the possible long-term health effects of exposure to mobilized lakebed sediments or the numerous toxic contaminants that may become respirable on entrained particles. We draw on existing epidemiological literature of other known sources of wind-blown dust, such as desert dust storms, and related health effects to begin to understand the potential public health impact of wind-blown dust exposure. The increased production of wind-blown dust and environmental exposures to such non-combustion related sources of particulate matter are a growing health threat, due in part to drought coupled with increasing pressures on limited water resources. Recent population-based studies have linked dust storms with cardiovascular mortality, asthma hospitalization and decrease in pulmonary function in both adults and children. A growing number of studies provide evidence of the acute health effects of wind-blown dust exposures among children, which with repeated insults have the potential to influence respiratory health over time. The shrinking of the Salton Sea illustrates a public health and environmental justice crisis that requires action and attention to protect the health and well-being of local communities.

Prenatal exposure to sand and dust storms and children's cognitive function in China: a quasi-experimental study

BACKGROUND

While there is evidence that sand and dust storms can have adverse health effects, the effects of such storms on children's cognitive function has not been explored. We examined whether prenatal exposure to sand and dust storms affects children's cognitive function and, if so, whether harmful effects of sand and dust storms vary by the trimester of exposure.

METHODS

This study used nationally representative data from the China Family Panel Studies between 2010 and 2014 and data on sand and dust storms from the national Sand and Dust Weather Almanac. We selected four indicators of children's cognitive function: mathematics test scores, word-recognition test scores, the age the child began speaking in whole sentences, and the age the child began counting from one to ten. Since the annual incidence of sand and dust storms is highly variable and is largely unpredictable, we used a region-and-year fixed-effect model to compare the cognitive function of children born in the same region and year but with varying amounts of prenatal exposure to sand and dust storms. We also investigated whether the effect of sand and dust storms varied by the specific month of prenatal exposure.

FINDINGS

We included 1236 observations for the analysis of mathematics and word-recognition test scores, 2693 observations in the analysis of the age the child began speaking in whole sentences, and 1951 observations for the analysis of the age the child began counting from one to ten. Every 10 additional days of prenatal exposure to sand and dust storms was associated with a 0·20 SD (95% CI 0·06 to 0·35, p=0·009) reduction in word test scores, 0·04 (-0·00 to 0·09, p=0·089) additional months to begin speaking in sentences, and 0·14 (0·03 to 0·25, p=0·021) additional months to begin counting, but was not significantly associated with mathematics test scores (reduction of 0·02 SD, -0·19 to 0·15). 10 additional days of prenatal exposure to sand and dust storms in the seventh gestational month was associated with a 0·18 SD (0·10 to 0·25) reduction in mathematics test scores, a 0·34 SD (0·18 to 0·50) reduction in word test scores, an additional 0·33 months (0·07 to 0·59) to begin speaking in sentences, and an additional 0·20 months (0·04 to 0·35) to begin counting.

INTERPRETATION

Our results suggest that protecting pregnant women from the effects of sand and dust storms in the critical periods of fetal brain development could generate benefits for the cognitive function of the next generation.

FUNDING

None.

Desert Dust and Health: A Central Asian Review and Steppe Case Study

In Asian deserts environmental and anthropomorphic dust is a significant health risk to rural populations. Natural sources in dry landscapes are exacerbated by human activities that increase the vulnerability to dust and dust-borne disease vectors. Today in Central and Inner Asian drylands, agriculture, mining, and rapid development contribute to dust generation and community exposure. Thorough review of limited dust investigation in the region implies but does not quantify health risks. Anthropogenic sources, such as the drying of the Aral Sea, highlight the shifting dust dynamics across the Central EurAsian steppe. In the Gobi Desert, our case study in Khanbogd, Mongolia addressed large-scale mining’s potential dust risk to the health of the local population. Dust traps showed variable exposure to particulates among herder households and town residents; dust density distribution indicated that sources beyond the mine need to be considered when identifying particulate sources. Research suggests that atmospheric dust from multiple causes may enhance human particulate exposure. Greater awareness of dust in greater Central Asia reflects community concern about related health implications. Future human well-being in the region will require more thorough information on dust emissions in the changing environment.

Spatio-temporal variability of particulate matter in the key part of Gansu Province, Western China

To investigate the spatial and temporal behaviors of particulate matter in Lanzhou, Jinchang and Jiayuguan during 2014, the hourly concentrations of PM2.5 and PM10 were collected from the Ministry of Environmental Protection (MEP) in this study. The analysis indicated that the mean annual PM10 (PM2.5) concentrations during 2014 were 115 ± 52 μg/m³ (57 ± 28 μg/m³), 104 ± 75 μg/m³ (38 ± 22 μg/m³) and 114 ± 72 μg/m³ (32 ± 17 μg/m³) in Lanzhou, Jinchang and Jiayuguan, respectively, all of which exceeded the Chinese national ambient air quality II standards for PM. Higher values for both PM fractions were generally observed in spring and winter, and lower concentrations were found in summer and autumn. Besides, the trend of seasonal variation of particulate matter (PM) in each city monitoring site is consistent with the average of the corresponding cities. Anthropogenic activities along with the boundary layer height and wind scale contributed to diurnal variations in PM that varied bimodally (Lanzhou and Jinchang) or unimodally (Jiayuguan). With the arrival of dust events, the PM10 concentrations changed dramatically, and the PM10 concentrations during dust storm events were, respectively, 19, 43 and 17 times higher than the levels before dust events in Lanzhou, Jinchang and Jiayuguan. The ratios (PM2.5/PM10) were lowest, while the correlations were highest, indicating that dust events contributed more coarse than fine particles, and the sources of PM are similar during dust storms. The relationships between local meteorological parameters and PM concentrations suggest a clear association between the highest PM concentrations, with T ≤ 7 °C, and strong winds (3-4 scale). However, the effect of relative humidity is complicated, with more PM10 and PM2.5 exceedances being registered with a relative humidity of less than 40% and 40-60% in Lanzhou, while higher exceedances in Jinchang appeared at a relative humidity of 80-100%.

Association between Ambient Air Pollution and Emergency Room Visits for Respiratory Diseases in Spring Dust Storm Season in Lanzhou, China

Background: Air pollution has become a major global public health problem. A number of studies have confirmed the association between air pollutants and emergency room (ER) visits for respiratory diseases in developed countries and some Asian countries, but little evidence has been seen in Western China. This study aims to concentrate on this region. Methods: A time-series analysis was used to examine the specific effects of major air pollutants (PM₁₀, SO₂ and NO₂) on ER visits for respiratory diseases from 2007 to 2011 in the severely polluted city of Lanzhou. We examined the effects of air pollutants for stratified groups by age and gender, accounting for the modifying effect of dust storms in spring to test the possible interaction. Results: Significant associations were found between outdoor air pollution concentrations and respiratory diseases, as expressed by daily ER visits in Lanzhou in the spring dust season. The association between air pollution and ER visits appeared to be more evident on dust days than non-dust days. Relative risks (RRs) and 95% CIs per 10 µg/m³ increase in 3-day PM₁₀ (L3), 5-day SO₂ (L5), and the average of current and previous 2-day NO₂ (L01) were 1.140 (1.071–1.214), 1.080 (0.967–1.205), and 1.298 (1.158–1.454), respectively, on dust days. More significant associations between PM₁₀, SO₂ and NO₂ and ER visits were found on dust days for elderly females, elderly males and adult males, respectively. Conclusions: This study strengthens the evidence of dust-exacerbated ER visits for respiratory diseases in Lanzhou.

Potential health benefits of controlling dust emissions in Beijing

Although the adverse impact of fine particulate matter (i.e., PM2.5) on human health has been well acknowledged, little is known of the health effects of its specific constituents. Over the past decade, the annual average dust concentrations in Beijing were approximately ∼14 μg m(-3), a value that poses a great threat to the city's 20 million residents. In this study, we quantify the potential long-term health damages in Beijing resulting from the dust exposure that occurred from 2000 to 2011. Each year in Beijing, nearly 4000 (95% CI: 1000-7000) premature deaths may be associated with long-term dust exposure, and ∼20% of these deaths are attributed to lung cancer. A decomposition analysis of the inter-annual variability of premature deaths in Beijing indicates that dust concentrations determine the year-to-year tendency, whereas population growth and lung cancer mortality rates drive the increasing tendency of premature death. We suggest that if Beijing takes effective measures towards reducing dust concentrations (e.g., controlling the resuspension of road dust and the fugitive dust from construction sites) to a level comparable to that of New York City's, the associated premature deaths will be significantly reduced. This recommendation offers "low-hanging fruit" suggestions for pollution control that would greatly benefit the public health in Beijing.

Asian Dust and Pediatric Emergency Department Visits Due to Bronchial Asthma and Respiratory Diseases in Nagasaki, Japan

Background

The adverse health effects of Asian dust (AD) on the respiratory system of children are unclear. We hypothesized that AD events may lead to increased visits by children to emergency medical centers due to bronchial asthma and respiratory diseases, including bronchial asthma.

Methods

We used anonymized data on children receiving primary emergency treatment at Nagasaki Municipal Primary Emergency Medical Center, Japan between March 2010 and September 2013. We used Light Detection and Ranging (LIDAR) data to assess AD exposure and performed time-stratified case-crossover analyses to examine the association between AD exposure and emergency department visits. The main analysis was done with data collected from March through May each year.

Results

The total number of emergency department visits during the study period was 756 for bronchial asthma and 5421 for respiratory diseases, and the number of “AD days” was 47. In school children, AD events at lag day 3 and lag day 4 were associated with increased emergency department visits due to bronchial asthma, with odds ratios of 1.837 (95% confidence interval [CI], 1.212–2.786) and 1.829 (95% CI, 1.179–2.806), respectively. AD events were significantly associated with respiratory diseases among preschool children at lag day 0, lag day 1, and lag day 2, with odds ratios of 1.244 (95% CI, 1.128–1.373), 1.314 (95% CI, 1.189–1.452), and 1.273 (95% CI, 1.152–1.408), respectively. These associations were also significant when the results were adjusted for meteorological variables and other air pollutants.

Conclusions

The study findings suggested that AD exposure increases emergency department visits by children.

Short-term population-based non-linear concentration-response associations between fine particulate matter and respiratory diseases in Taipei (Taiwan): a spatiotemporal analysis

Fine particulate matter <2.5 μm (PM2.5) has been associated with human health issues; however, findings regarding the influence of PM2.5 on respiratory disease remain inconsistent. The short-term, population-based association between the respiratory clinic visits of children and PM2.5 exposure levels were investigated by considering both the spatiotemporal distributions of ambient pollution and clinic visit data. We applied a spatiotemporal structured additive regression model to examine the concentration-response (C-R) association between children's respiratory clinic visits and PM2.5 concentrations. This analysis was separately performed on three respiratory disease categories that were selected from the Taiwanese National Health Insurance database, which includes 41 districts in the Taipei area of Taiwan from 2005 to 2007. The findings reveal a non-linear C-R pattern of PM2.5, particularly in acute respiratory infections. However, a PM2.5 increase at relatively lower levels can elevate the same-day respiratory health risks of both preschool children (<6 years old) and schoolchildren (6-14 years old). In preschool children, same-day health risks rise when concentrations increase from 0.76 to 7.44 μg/m(3), and in schoolchildren, same-day health risks rise when concentrations increase from 0.76 to 7.52 μg/m(3). Changes in PM2.5 levels generally exhibited no significant association with same-day respiratory risks, except in instances where PM2.5 levels are extremely high, and these occurrences do exhibit a significant positive influence on respiratory health that is especially notable in schoolchildren. A significant high relative rate of respiratory clinic visits are concentrated in highly populated areas. We highlight the non-linearity of the respiratory health effects of PM2.5 on children to investigate this population-based association. The C-R relationship in this study can provide a highly valuable alternative for assessing the effects of ambient air pollution on human health.

Emergency room visits associated with particulate concentration and Asian dust storms in metropolitan Taipei

This study evaluated risks of emergency room visits (ERV) for all causes, circulatory diseases, and respiratory diseases associated with concentrations of particulate matter (PM10 and PM2.5) and Asian dust storms (ADS) from 2000 to 2008 in metropolitan Taipei. Cumulative 4-day (lag 0-3) relative risks (RR) and confidence intervals (CI) of cause-specific ERV associated with daily concentrations of PM10 or PM2.5 and ADS based on study period (ADS frequently inflicted period: 2000-2004 and less-inflicted period: 2005-2008) were estimated using a distributed lag non-linear model with Poisson distribution. Risks associated with ADS-inflicted season (winter and spring), strength (ratio of stations with Pollutant Standard Index above 100 is < 0.5 or ≥ 0.5), and duration (ADS lasting for 1-3 days or ≥ 4 days) were especially evaluated. In non-linear models, an increase in PM10 from 10 μg/m(3) to 50 μg/m(3) was associated with increased risk of ERV for all causes and respiratory disease with cumulative 4- day RR of 1.18 (95% CI: 1.13, 1.24) and 1.37 (95% CI: 1.23, 1.54), respectively. From 2005 to 2008, the cumulative 4-day RR for an ERV related to an increase in PM2.5 from 5 μg/m(3) to 30 μg/m(3) is 1.21 (95% CI: 1.03, 1.41) for respiratory diseases, and 1.15 (95% CI: 1.08, 1.22) for all causes. In comparison with normal days, elevated ERV of all causes and respiratory diseases was also associated with winter ADS (with corresponding RRs of 1.10 (95% CI: 1.07, 1.13) and 1.14 (95% CI: 1.08, 1.21)) and shorter and less area-affected ADS (with corresponding RRs of 1.07 (95% CI: 1.01, 1.10) and 1.09 (95% CI: 1.03, 1.14)) from 2000 to 2004. Results of this study demonstrate that population health risk varies not only with PM concentration, but also with the ADS characteristics.

Asian sand dust aggregate causes atopic dermatitis-like symptoms in Nc/Nga mice

Background

Asian sand dust (ASD) originates from the arid and semiarid areas of China, and epidemiologic studies have shown that ASD exposure is associated with various allergic and respiratory symptoms. However, few studies have been performed to assess the relationship between skin inflammation and ASD exposure.

Methods

Twelve-week-old NC/Nga mice were divided into 6 groups (n = 8 for each group): hydrophilic petrolatum only (control); hydrophilic petrolatum plus ASD (ASD); hydrophilic petrolatum and heat inactivated-ASD (H-ASD); Dermatophagoides farinae extract (Df); Df and ASD (Df + ASD), and; Df and H-ASD (Df + H-ASD). The NC/Nga mice in each group were subjected to treatment twice a week for 4 weeks. We evaluated skin lesions by symptoms, pathologic changes, and serum IgE levels.

Results

ASD alone did not induce atopic dermatitis (AD)-like skin symptoms. However, Df alone, Df + H-ASD and Df + ASD all induced AD-like symptoms, and dermatitis scores in the group of Df + ASD group were significantly greater than that of the Df group (P = 0.0011 at day 21; and P = 0.017 at day 28). Mean serum IgE was markedly increased in the Df and Df + ASD groups, compared to the ASD and control groups (P < 0.0001), and serum IgE levels in the Df + ASD group were significantly higher compared to the Df group (P = 0.003).

Conclusions

ASD alone did not cause AD-like symptoms in NC/Nga mice. However, AD-like symptoms induced by Df, a major allergen, were enhanced by adding ASD. Although no epidemiological studies have been conducted for the association between ASD and symptoms of dermatitis, our data suggest that it is likely that ASD may contribute to the exacerbation of not only respiratory symptoms, but also skin diseases, in susceptible individuals.

The effect of sand storms on acute asthma in Riyadh, Saudi Arabia

OBJECTIVE

Major sand storms are frequent in the Middle East. This study aims to investigate the role of air particulate matter (PM) level in acute asthma in children in Riyadh, Saudi Arabia.

METHODS

An aerosol spectrometer was used to evaluate PM < 10μm in diameter (PM10) and PM < 2.5 μm in diameter (PM2.5) concentrations in the air every 30 minutes throughout February and March 2012 in Riyadh. Data on children 2-12 years of age presenting to the emergency department of a major children's hospital with acute asthma during the same period were collected including their acute asthma severity score.

RESULTS

The median with interquartile range (IQR) levels of PM10 and PM2.5 were 454 μg/m(3) (309,864) and 108 μg/m(3) (72,192) respectively. There was no correlation between the average daily PM10 levels and the average number of children presenting with acute asthma per day (r = -0.14, P = 0.45), their daily asthma score (r = 0.014, P = 0.94), or admission rate ( r= -0.08, P = 0.65). This was also true for average daily PM2.5 levels. In addition, there was no difference in these variables between days with PM10 >1000 μg/m(3), representing major sand storms, plus the following 5 days and other days with PM10< 1000 μg/m(3).

CONCLUSION

Sand storms, even major ones, had no significant impact on acute asthma exacerbations in children in Riyadh, Saudi Arabia. The very high levels of PM, however, deserve further studying especially of their long-term effects.

Investigation on the lung function of general population in Ilam, west of Iran, as a city exposed to dust storm

BACKGROUND

Dust storm is one of the most important natural sources of air pollution in the Middle East that has caused a major concern in recent years. The aim of this study was to evaluate the respiratory tract function of people living in Ilam city (Iran) during dust storm.

METHODS

A sample size of 250 people was selected and the cluster sampling was randomly used from 13 health centers in Ilam city. Pulmonary function test (PFT) was determined via a standard spirometry apparatus. Vital capacity (VC), Forced Vital capacity (FVC), FVC in first second (FEV1), FEV1/VC, FEV1/FVC, peek expiratory flow (PEF), forced expiratory flow (FEF25-75%), forced expiratory flow (FEF25-75%), forced expiratory flow (FEF75-85%), forced mid flow time (FMFT) and maximum voluntary ventilation (MVV) were measured.

RESULTS

Mean values of respiratory capacities measured in all participants excluding FEV1/VC and FMFT were less than predicted mean values by ECCS reference. 21.6% of the population suffered from obstructive lesions. This value among males (24.1%) was more than females (19.6%). This could be related to more exposure (outdoor jobs) of males with dust storms.

CONCLUSION

The results also showed a negative significant relationship between duration of inhabitance in Ilam city and all respiratory capacities. Further studies are needed for confident confirmation of whether reduction of respiratory capacities among Ilamian people is only related to dust storms.

Modification of atmospheric sand-associated bacterial communities during Asian sandstorms in China and South Korea

The transport of desert soil into the atmosphere during desert sandstorms can affect the Earth's climate and environmental health. Asian desert sandstorms occur almost every year during the Spring, as the atmosphere in the Northern hemisphere warms. It is conceivable that these Asian desert sandstorms may transport microbes from deserts, such as the Gobi and Taklamaken deserts, over long distances in China, east Asia and the Pacific. In this study, we examined local atmospheric sand particle-associated bacterial populations collected in the absence (sterile sand exposed for 24 h to the air in the absence of a sandstorm) and presence of sandstorms in five Asian cities. We used pyrosequencing of PCR-amplified 16S rDNA genes from sand-extracted total DNA to overcome cultivation limitations of bacterial enumeration. We found that >90% of the control and sandstorm sequences could be classified as representing bacteria belonging to four phyla: Proteobacteria, Bacteriodetes, Actinobacteria and Firmicutes. The sand-associated bacterial populations in sandstorm samples were distinct from sand-associated bacteria in the absence of a sandstorm. Members of the phylum Proteobacteria were found to significantly increase in sandstorm samples (P=0.01). Principal component analyses showed that the sand-associated bacterial populations were best clustered by sampling year, rather than location. DNA sequences representing bacteria belonging to several genera (including putative human pathogens) were observed to increase in sand-associated samples from sandstorms, whereas others were found to decrease, when comparing sand-associated bacterial populations versus those in control samples, suggesting human/environmental implications of sandstorm events.

Acute increase of children's conjunctivitis clinic visits by Asian dust storms exposure - a spatiotemporal study in Taipei, Taiwan

Adverse health impacts of Asian dust storms (ADS) have been widely investigated and discussed in respiratory disease, but no study has examined the association between ADS events and their impact on eye diseases, especially in children. The impact of ADS events on the incidence of children's conjunctivitis is examined by analyzing the data from children's clinic visits registered in the 41 districts of Taipei area in Taiwan during the period 2002-2007. The structural additive regression modeling approach was used to assess the association between ADS events and clinic visits for conjunctivitis in children with consideration of day-of-the-week effects, temperature, and air quality levels. This study identifies an acute increase in the relative rate for children's conjunctivitis clinic visits during ADS periods with 1.48% (95% CI = 0.79, 2.17) for preschool children (aged <6 years old) and 9.48% (95% CI = 9.03, 9.93) for schoolchildren (aged ≥6 years old), respectively. The relative rates during post-ADS periods were still statistically significant, but much lower than those during ADS periods. The spatial analysis presents geographic heterogeneity of children's conjunctivitis clinic visits where higher relative rates were more likely observed in the most populated districts Compared to previous ADS studies related to respiratory diseases, our results reveals significantly acute impacts on children's conjunctivitis during ADS periods, and much influence on schoolchildren. Vulnerable areas were also identified in high density population.

Desert dust and human health disorders

Dust storms may originate in many of the world's drylands and have an effect not only on human health in the drylands themselves but also in downwind environments, including some major urban centres, such as Phoenix, Kano, Athens, Madrid, Dubai, Jedda, Tehran, Jaipur, Beijing, Shanghai, Seoul, Taipei, Tokyo, Sydney, Brisbane and Melbourne. In some parts of the world dust storms occur frequently throughout the year. They can transport particulate material, pollutants, and potential allergens over thousands of km from source. The main sources include the Sahara, central and eastern Asia, the Middle East, and parts of the western USA. In some parts of the world, though not all, the frequency of dust storms is changing in response to land use and climatic changes, and in such locations the health implications may become more severe. Data on the PM10 and P2.5 loadings of dust events are discussed, as are various pollutants (heavy metals, pesticides, etc.) and biological components (spores, fungi, bacteria, etc.). Particulate loadings can far exceed healthy levels. Among the human health effects of dust storms are respiratory disorders (including asthma, tracheitis, pneumonia, allergic rhinitis and silicosis) cardiovascular disorders (including stroke), conjunctivitis, skin irritations, meningococcal meningitis, valley fever, diseases associated with toxic algal blooms and mortality and injuries related to transport accidents.

Spatial vulnerability under extreme events: a case of Asian dust storm's effects on children's respiratory health

Asian dust storm (ADS) events have raised concerns regarding their adverse impact on human health. Whether ADS events can result in the heterogeneity of health impacts on children across space and time has not been studied. The goal of this study is to examine the spatial vulnerability impact of ADS events on children's respiratory health geographically and to analyze any patterns related to ADS episodes. From 1998 to 2007, data from both preschool children's and schoolchildren's daily respiratory clinic visits, gathered from patients located in 41 districts of Taipei City and New Taipei City, are analyzed in a Bayesian spatiotemporal model in order to investigate the interaction between spatial effects and ADS episodes. When adjusting for the temporal effect, air pollutants, and temperature, the spatial pattern explicitly varies during defined study periods: non-ADS periods, ADS periods, and post-ADS periods. Compared to non-ADS periods, the relative rate of children's respiratory clinic visits significantly reduced 0.74 to 0.99 times in most districts during ADS periods, while the relative rate rose from 1.01 to 1.11 times in more than half of districts during post-ADS periods, especially in schoolchildren. This spatial vulnerability denotes that the significantly increased relative rate of respiratory clinic visits during post-ADS periods is primarily located in highly urbanized areas for both children's populations. Hence, the results of this study suggest that schoolchildren are particularly more vulnerable to the health impacts of ADS exposure in terms of higher excessive risks over a larger spatial extent than preschool children, especially during post-ADS periods.

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.