Asian Dust Storm Research Articles

Evolution of trace elements in the planetary boundary layer in southern China: Effects of dust storms and aerosol‐cloud interactions

AbstractAerosols and cloud water were analyzed at a mountaintop in the planetary boundary layer in southern China during March–May 2009, when two Asian dust storms occurred, to investigate the effects of aerosol‐cloud interactions (ACIs) on chemical evolution of atmospheric trace elements. Fe, Al, and Zn predominated in both coarse and fine aerosols, followed by high concentrations of toxic Pb, As, and Cd. Most of these aerosol trace elements, which were affected by dust storms, exhibited various increases in concentrations but consistent decreases in solubility. Zn, Fe, Al, and Pb were the most abundant trace elements in cloud water. The trace element concentrations exhibited logarithmic inverse relationships with the cloud liquid water content and were found highly pH dependent with minimum concentrations at the threshold of pH ~5.0. The calculation of Visual MINTEQ model showed that 80.7–96.3% of Fe(II), Zn(II), Pb(II), and Cu(II) existed in divalent free ions, while 71.7% of Fe(III) and 71.5% of Al(III) were complexed by oxalate and fluoride, respectively. ACIs could markedly change the speciation distributions of trace elements in cloud water by pH modification. The in‐cloud scavenging of aerosol trace elements likely reached a peak after the first 2–3 h of cloud processing, with scavenging ratios between 0.12 for Cr and 0.57 for Pb. The increases of the trace element solubility (4–33%) were determined in both in‐cloud aerosols and postcloud aerosols. These results indicated the significant importance of aerosol‐cloud interactions to the evolution of trace elements during the first several cloud condensation/evaporation cycles.

Do rainfalls wash out anthropogenic airborne magnetic particulates?

We separated dust particles from the mesh-filtered sets of rainwaters collected on rainy days with daily precipitations exceeding 10 mm per day. A total of 136 rainwaters (or snow during the winter season) samples collected from February 2009 to February 2013 were analyzed. In particular, 33 out of 136 rainwaters were collected during or just after the Asian dust storm (ADS) events. Values of pH were relatively higher during warmer seasons. During ADS events, precipitations were alkaline, possibly due to abundant supply of alkaline minerals from the deserts source area to the precipitation. Compositional analysis on particulate matter (PM) indicated that Fe (and Al, K, and Mg) enriched the dusts collected during ADS, with respect to events than those without ADS. We found that ADS rainfall events are effective in selectively eliminating dust particles. However, high rainfall does not necessarily indicate more dilution of dusts. On microscopic examination, we observed natural soils, natural dust of pedogenesis or weathering origin, anthropogenic C–Fe-rich particles, and anthropogenic C-rich particles. Because of its small size, the stoichiometry of ADS-related, Fe-rich dust particles was inferred from the magnetic analysis. Presence of Verwey transition near 100–120 K and experimental determination of Curie points near 580 °C indicate that magnetic mineral responsible for the magnetic properties of ADS-related dusts was magnetite.

A twentieth century major soluble ion record of dust and anthropogenic pollutants from Inilchek Glacier, Tien Shan

AbstractUsing a high‐resolution (~18 samples/year) major soluble ion record (Na+, K+, Mg2+, Ca2+, Cl−, NO3−, and SO42−) covering the period 1908–1995 A.D. from the Inilchek Glacier, Tien Shan, Kyrgyzstan, we provide a detailed climate and environmental proxy record for the region. Chemical concentrations, empirical orthogonal function analyses, and noncrustal excess calculations are used to identify natural and potential anthropogenic depositional trends. Dominant dust proxy species (i.e., Ca2+) reveal highest concentrations during the 1950s–1970s, with declining decadal trends through the end of the record. These trends likely reflect decreases in central Asian dust storm activity post‐1950, which has been associated with coupled atmospheric circulation variability and anthropogenic activities. Comparison between Ca2+ and ERA‐Interim (1979–1995) climate reanalysis data indicates a strong relationship to spring (March–May) geopotential height patterns in northwest China and southern Siberia associated with the Siberian High. Noncrustal contribution (excess) estimates of NO3−, K+, SO42−, and Cl− concentrations suggest discernable anthropogenic inputs began between the 1950s and 1970s, increased into the middle/late 1980s, and declined in the 1990s. Excess trends coincide with Former Soviet Union consumption, production, and emission of fossil fuels and fertilizers, reflecting the rapid growth of agriculture and industry, as well as economic declines in the middle to late 1980s/early 1990s. Excess‐Cl− trends reflect timings that coincide with the construction of the Pavlodar Chemical Plant and the military production of Cl2 in Kazakhstan. NOAA Hybrid Single‐Particle Lagrangian Integrated Trajectory back trajectory frequency analysis suggests eastern Uzbekistan (e.g., Fergana Valley), Kyrgyzstan, and southern Kazakhstan as the primary pollutant sources to the study region.

Integrated Analysis of Dust Transport and Budget in a Severe Asian Dust Event

Asian dust storms markedly affect the ecosystem, environment, ocean biogeochemical cycle, and regional climate. Numerous measurements and model simulations have been performed to investigate the sources and transport of Asian dust. However, until now, few studies have performed a comprehensive quantification of the dust budget, resulting in significant uncertainty about the characterization of dust transport, emission, and deposition. In this study, a severe dust event in East Asia that occurred from April 28 till May 3, 2011, was analyzed in terms of dust transport characteristics based on multi-satellite observations and the Hybrid Single-Particle Lagrangian Integrated Trajectory (HYSPLIT) model. In particular, the dust budget of the event was quantitatively estimated using a new atmospheric reanalysis dataset, namely the second Modern-Era Retrospective Analysis for Research and Applications (MERRA-2). The multi-satellite observations and models indicated that dust events such as this are uncommon. A two-layered dust structure was found in southeast China, the lower (< 1.5 km) and elevated (> 3 km) layers of which mainly originated from the Gobi and Taklimakan Deserts, respectively. The dust budget in East Asia, as estimated from MERRA-2, revealed a high dust mass loading (5.7–6.6 Tg) between 70°E and 140°E from April 29 till May 1, with the highest daily dust loading (approximately 6.6 Tg) reported on April 30. The total dust emission was 6.3 Tg over a 6-day period (April 28–May 3), and the maximum amount (nearly 5.9 Tg) of dust was deposited on the ground in the region. The dust flux amounts horizontally transported across the longitudinal boundary of 70°E and 140°E were 1.7 and 2.8 Tg, respectively.

Instantaneous influence of dust storms on the optical scattering property of the ocean: a case study in the Yellow Sea, China.

Asian dust storms originating from arid or semi-arid regions of China or her adjacent regions have important impact on the atmosphere and water composition, and ecological environment of the Eastern China Seas. This research used data collected in the middle of the South Yellow Sea, China, during a dust storm event from 23 April to 24 April 2006 to analyze the instantaneous influence of dust storms on optical scattering properties, which are closely related to particle characteristics. The analysis results showed that the dust storm had a remarkable influence on the optical scattering property in the upper mixed layer of water, and dust particles drily deposited from the dust storm with an aerosol optical depth of nearly 2.5 into the water could induce a 0.14 m-1 change in the water optical scattering coefficient at 532 nm at the depth of 4 m. The duration of the instantaneous influence of the dust storm on the water optical scattering properties was short, and this influence disappeared rapidly within approximately 3 hours after the end of the dust storm.

Abstract 11434: Air Pollution is Associated With Ischemic Stroke via Cardiogenic Embolism

Introduction: Both individual and environmental factors influence stroke risk and the effect might differ across stroke subtypes. The prevalence of cardioembolic stroke is increasing in Asian and other developing countries, which may be associated with the ambient air pollution as well as an aging population. However, the association between air pollution and stroke subtype remains unclear. Hypothesis: This study investigated the impact of short-term exposure to air pollution on ischemic stroke subtype, while focusing on stroke caused via cardioembolism. Methods: From a nationwide multicenter prospective stroke registry database, 13,535 acute ischemic stroke patients hospitalized to 12 participating centers were enrolled in this study. Data on the hourly concentrations of particulate matter &lt;10μm (PM 10 ), nitrogen dioxide (NO 2 ), sulfur dioxide (SO 2 ), ozone (O 3 ), and carbon monoxide (CO) were collected from 181 nationwide air pollution surveillance stations. The average values of these air pollutants over the 7 days prior to stroke onset from nearest air quality monitoring station in each patient were used to determine association with stroke subtype. Results: PM 10 and SO 2 concentrations were independently associated with an increased risk of cardioembolic stroke, as compared to large artery atherosclerosis and non-cardioembolic stroke. In sensitivity analyses, the proportion of cases of cardioembolic stroke was positively correlated with the PM 10 , NO 2 , and SO 2 quintiles. Moreover, seasonal (including Asian dust storms in spring and winter) and geographic (including polluted mid-sized cities) factors were related to an increased proportion of cardioembolic stroke, which may be attributed to the high levels of air pollution. Conclusions: Our findings suggest that the short-term exposure to air pollutants is associated with cardioembolic stroke subtype, and greater care should be taken for those susceptible to cerebral embolism during peak pollution periods. Public and environmental health policies to reduce air pollution could help slow down global increasing trends of cardioembolic stroke.

Transport of East Asian dust storms to the marginal seas of China and the southern North Pacific in spring 2010

The transport of a super-severe dust storm that occurred in East Asia from 19 to 22 March 2010 has been well documented by both model simulations and surface observations. We investigated the transport of this severe dust storm and several other spring 2010 dust storms using model simulations, backward trajectories, and measurements from the Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation (CALIPSO) satellite. The model simulations indicated that the emission of dust in spring 2010 was about 35% higher than that in spring 2006 and was twice that of the 44-year average from 1960 to 2003. The dust emissions over two major source regions (western China and the Gobi Desert) in spring 2010 accounted for 86% of the total amount of dust. The simulated depositional flux over the two major source regions was c.2.7–9.0 times that over two marginal seas (the Yellow Sea and the East China Sea) and more than two magnitudes higher than that over the North Pacific Subtropical Gyre. The mean extinction coefficient observed by the CALIPSO satellite over the two source regions was c.1.3–3.7 times that over the two marginal seas and one magnitude higher than that over the North Pacific. This was consistent with the result from our model, suggesting that this model is able to capture the major features of dust storms. The vertical profiles recorded by the CALIPSO satellite indicated that the dust aerosol mainly floated from the ground to 13 km above ground level over the source regions and above the seas. A multiple dust layer appeared over the seas and the backward trajectories suggested that the dust aerosol in different layers may have been sourced from different regions.

Differences in allergic inflammatory responses between urban PM2.5 and fine particle derived from desert-dust in murine lungs

The biological and chemical natures of materials adsorbed onto fine particulate matter (PM2.5) vary by origin and passage routes. The exacerbating effects of the two samples—urban PM2.5 (U-PM2.5) collected during the hazy weather in a Chinese city and fine particles (ASD-PM2.5) collected during Asian sand dust (ASD) storm event days in Japan—on murine lung eosinophilia were compared to clarify the role of toxic materials in PM2.5. The amounts of β-glucan and mineral components were higher in ASD-PM2.5 than in U-PM2.5. On the other hand, organic chemicals, including polycyclic aromatic hydrocarbons (PAHs), were higher in U-PM2.5 than in ASD-PM2.5. When BALB/c mice were intratracheally instilled with U-PM2.5 and ASD-PM2.5 (total 0.4mg/mouse) with or without ovalbumin (OVA), various biological effects were observed, including enhancement of eosinophil recruitment induced by OVA in the submucosa of the airway, goblet cell proliferation in the bronchial epithelium, synergic increase of OVA-induced eosinophil-relevant cytokines and a chemokine in bronchoalveolar lavage fluid, and increase of serum OVA-specific IgG1 and IgE. Data demonstrate that U-PM2.5 and ASD-PM2.5 induced allergic inflammatory changes and caused lung pathology. U-PM2.5 and ASD-PM2.5 increased F4/80+ CD11b+ cells, indicating that an influx of inflammatory and exudative macrophages in lung tissue had occurred. The ratio of CD206 positive F4/80+ CD11b+ cells (M2 macrophages) in lung tissue was higher in the OVA+ASD-PM2.5 treated mice than in the OVA+U-PM2.5 treated mice. These results suggest that the lung eosinophilia exacerbated by both PM2.5 is due to activation of a Th2-associated immune response along with induced M2 macrophages and the exacerbating effect is greater in microbial element (β-glucan)-rich ASD-PM2.5 than in organic chemical-rich U-PM2.5.

Dust-induced radiative feedbacks in north China: A dust storm episode modeling study using WRF-Chem

Abstract Radiative forcing of dust aerosol and the radiative feedbacks on the planetary boundary layer (PBL) in North China during a typical Asian dust storm in the early April of 2011 was investigated by an online coupled meteorology-chemistry-aerosol model WRF-Chem. Dust-induced daily mean radiative forcing (RF) at the ground surface and in the atmosphere were estimated to be −21.1 W m−2 and 12.7 W m−2, respectively, over Gobi desert, and −13.1 W m−2 and 4.8 W m−2, respectively, in downwind region over the North China Plain (NCP). Comparatively, radiative perturbation on short-wave radiation was approximately twice that on long-wave radiation in magnitude. In the daytime, when solar radiation dominated, the surface cooling and atmospheric heating due to dust increased PBL stability, leading to reductions of PBL height (PBLH) about 90 m and decreases in wind speed up to 0.4 m s−1. On the contrary, the radiative forcing in terrestrial radiation caused an opposite response at night, especially in the downwind region. Although dust emission was repressed by weakened wind speed during daytime, the elevated PBLH along with larger deflation at night lifted more dust particles to higher altitude (by up to 75 m in average), which prolonged dust residence time in the atmosphere and further intensified dust loading in downwind areas. Taking dust radiative feedbacks into consideration notably narrowed gaps between model-predicted air temperature vertical profiles with corresponding observations, suggesting a significant importance of dust-radiation interaction in PBL meteorology during dust storms.

Forecasting of Asian dust storm that occurred on May 10–13, 2011, using an ensemble-based data assimilation system

An ensemble-based assimilation system that used the MASINGAR mk-2 (Model of Aerosol Species IN the Global AtmospheRe Mark 2) dust forecasting model and satellite-derived aerosol optical thickness (AOT) data, processed in the JAXA (Japan Aerospace Exploration Agency) Satellite Monitoring for Environmental Studies (JASMES) system with MODIS (Moderate Resolution Imaging Spectroradiometer) observations, was used to quantify the impact of assimilation on forecasts of a severe Asian dust storm during May 10–13, 2011. The modeled bidirectional reflectance function and observed vegetation index employed in JASMES enable AOT retrievals in areas of high surface reflectance, making JASMES effective for dust forecasting and early warning by enabling assimilations in dust storm source regions. Forecasts both with and without assimilation were validated using PM10 observations from China, Korea, and Japan in the TEMM WG1 dataset. Only the forecast with assimilation successfully captured the contrast between the core and tail of the dust storm by increasing the AOT around the core by 70–150% and decreasing it around the tail by 20–30% in the 18-h forecast. The forecast with assimilation improved the agreement with observed PM10 concentrations, but the effect was limited at downwind sites in Korea and Japan because of the lack of observational constraints for a mis-forecasted dust storm due to cloud.

Proteomic Analysis of Microbial Community Inhabiting Asian Dust Source Region

The Asian desert dust storm originating from desert regions of northern China negatively influences plant and human health causing various diseases. The soil samples collected from the dust storm site were characterized by a meta‐proteomic approach using an automated two‐dimensional liquid phase fractionation system and matrix‐assisted laser desorption ionization time‐of‐flight mass spectrometry. Thirty‐eight proteins were detected and identified using Expasy database as a frame of reference. The samples consisted of various bacterial species including plant pathogens and soil bacteria which cause diseases. Soil proteomics provides a deeper analysis and better understanding of the microbial community.

Abstract 16822: Dust Storms in the United States are Associated With Increased Cardiovascular Mortality

Introduction: Extreme weather events such as dust storms are predicted to become more frequent as the global climate warms through the 21st century. Studies of Asian, Saharan, Arabian, and Australian dust storms have found associations with cardiovascular and total non-accidental mortality and hospitalizations for stroke. However, the only population-level epidemiological work on dust storms in the United States was focused on a single small metropolitan area (Spokane, WA), and it is uncertain whether its null results are representative of the country as a whole. Hypothesis: Dust storms in the United States are associated with daily cardiovascular mortality. Methods: Dust storm incidence data (N=141), including date and approximate location, as well as meteorological station observations, were taken from the U.S. National Weather Service. County-level mortality data for the years 1993-2005 were acquired from the National Center for Health Statistics. Ambient particulate matter monitor concentrations were obtained from the U.S. Environmental Protection Agency. Inference was performed used conditional logistic regression models under a case-crossover design while accounting for the nonlinear effect of temperature. Results: We found a 9.5% increase in cardiovascular mortality at a two-day lag (95% CI: [0.31%,19.5%], p = 0.042). The results were robust to adjusting for heat waves and ambient particulate matter concentrations. Analysis of storms occurring only on days with &lt;0.1 inches of precipitation strengthened these results and in addition yielded a mean daily increase of 4.0% across lags 0-5 (95% CI: [0.07%,20.8%], p = 0.046). In Arizona, the U.S. state with the largest number of storms, we observed a 13.0% increase at a three-day lag (CI: [0.40%,27.1%], p = 0.043). Conclusions: Dust storms in the U.S. are associated with increases in lagged cardiovascular mortality. This has implications for the development of public health advisories and suggests that further public health interventions may be needed. Disclaimer: This work does not represent official U.S. Environmental Protection Agency policy.

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.

Detection of Asian dust storms from geostationary satellite observations of the INSAT-3D imager

Asian dust storm outbreaks significantly influence air quality, weather, and climate. Therefore, it is desirable to have qualitative and quantitative information on the time, location, and coverage of these outbreaks at high spatial and temporal resolution. The imager on board the Indian metrological geostationary satellite INSAT-3D observes Asia at a temporal resolution of 30 min and a spatial resolution of 1, 4, 8, and 4 km in the visible, middle infrared (MIR), water vapour (WV), and thermal infrared (TIR) bands, respectively. In this article, an algorithm is described for detecting desert dust storms from INSAT-3D imager data. The algorithm described here is a combination of various pre-existing methods such as infrared split-window, MIR and TIR brightness temperature difference, and visible to MIR reflectance ratio, which are based on the fact that dust exhibits features of spectral dependence and contrast over the visible, MIR, and TIR spectrum that are different from clouds, surface, and clear-sky atmosphere. Using the Atmospheric Infrared Sounder (Aqua/AIRS) dust score as proxy, INSAT-3D dust storm products were tested under different scenarios such as dust storms and dust transport in Asia. TIR observations from the geostationary platform of INSAT-3D allows computation of the infrared difference dust index (IDDI), which gives a quantitative measure of dust loading relative to clear atmosphere. Moreover, due to the high temporal resolution (30 min) of INSAT-3D observations, INSAT-3D-derived dust products allow more precise monitoring of dust transportation as compared with dust products derived from polar satellite observations.

Toxicoproteomic approaches for analysis of microbial community inhabiting Asian dust particles

In this review, we provide an overview of the bio-analytical approaches for proteomic analysis of Asian dust storms. Asian dust has been known to travel with high-speed eastward winds and affects air quality over Japan and even the western coast of the U.S. during severe occurrences. Several reports have shown that Asian dust particles have a negative effect on a wide range of industries and human health activities. Here we give a short overview of Asian dust feature and its proteomic analysis approaches including 2-DE PAGE, metaproteomic analysis of large environmental samples, and automatic techniques for dust microbial analysis. Following this, we discuss the detection system of Asian dust particles that can be integrated with biosensor platform.

Evaluation of the toxicity of a Kosa (Asian duststorm) event from view of food poisoning: observation of Kosa cloud behavior and real-time PCR analyses of Kosa bioaerosols during May 2011 in Kanazawa, Japan

Kosa (Asian duststorm) is a well-known phenomenon where particles are transported from Mongolia and northwestern China via Eastern Asia to the American continent. Kosa bioaerosols (airborne microorganisms within Kosa) were frequently found during Kosa event, and there is concern that they may affect human health. For biological observation and evaluation of Kosa events, we made sampling of aerosols in Kosa events on May 2 (KOSA1) and May 13 (KOSA2), 2011, at Kanazawa, Japan. From the data of lidar from Toyama, SPRINTARS simulation model and the backward trajectories of air masses, both events were originated in desert area of Mongolia. KOSA episode 1 was stronger than KOSA episode 2 above the surface boundary layer, and KOSA episode 2 contained the particles from the local source such as soil, sea salt, and various particles formed in the polluted atmosphere. The DNA to total suspended particle matter (SPM) ratios in KOSA1 and KOSA2 were 0.012 and 0.00978, respectively. Bacterial species compositions were identified qualitatively. Many Gammaproteobacteria were cloned and identified from both KOSA. Quantitative toxicity observations to assess the risk of food poisoning were performed by real-time PCR of food poisoning bacteria, Bacillus and Staphylococcus spp. The ratios of the concentrations of Bacillus and Staphylococcus spp. relative to SPM in KOSA1 and KOSA2 were 33.1 and 43.1 copies μg-SPM−1, respectively. The results of toxicity evaluations by the mathematical simulations suggested that compared with KOSA1, KOSA2 had a 1.35 times higher risk of causing food poisoning.

Effect Of Fine Particulate Matter And Its Constituents On Mortality During Asian Dust Storm Events In Seoul, Korea

Although the difference in fine particulate matter (PM2.5) constituents during Asian dust storms (ADS) and non-ADS days has been reported in previous studies, the difference in health effects of PM...

Markers of East Asian dust storms in March 2010

The variations in particulate matter (PM) and in eighteen metallic elements in four different particle sizes in the air of southern Taiwan were investigated from February to March 2010. The variation in mean mass concentrations of PM2.5, PM2.5–10, PM10, and TSP between Asian dust storm (ADS) and non-dust storm (NDS) periods suggested that the dominant fractions were PM2.5–10 and PM2.5, respectively. The obvious differences in metallic element concentrations between ADS and NDS periods suggested that crustal elements (Fe, Mg, Sr, Co, Ba and Mn) can be used as dust storm indicators, in addition to Ca and Al. Both mass fractions and metallic concentration ratios indicated that the PM2.5–10 fraction can distinguish between ADS and NDS periods. An enrichment factor (EFc) demonstrated that most anthropogenic elements were significantly lower in ADS periods than in NDS periods. The EFc values for anthropogenic elements in coarse particles may be used as indicators of dust storm invasion as well. An association was found between the extent of dust storm effects on receptors and the residence time (duration) of the event, in addition to the transport pathway.

Mortality associated with particulate concentration and Asian dust storms in Metropolitan Taipei

This study evaluates mortality risks from all causes, circulatory diseases, and respiratory diseases associated with particulate matter (PM10 and PM2.5) concentrations and Asian dust storms (ADS) from 2000 to 2008 in Metropolitan Taipei. This study uses a distributed lag non-linear model with Poisson distribution to estimate the cumulative 5-day (lags 0–4) relative risks (RRs) and confidence intervals (CIs) of cause-specific mortality associated with daily PM10 and PM2.5 concentrations, as well as ADS, for total (all ages) and elderly (≥65 years) populations based on study periods (ADS frequently inflicted period: 2000–2004; and less inflicted period: 2005–2008). Risks associated with ADS characteristics, including inflicted season (winter and spring), strength (the ratio of stations with Pollutant Standard Index >100 is <0.5 or ≥0.5), and duration (ADS persisted for 1–3 or ≥4 days), were also evaluated. Nonlinear models showed that an increase in PM10 from 10 μg/m3 to 50 μg/m3 was associated with increased all-cause mortality risk with cumulative 5-day RR of 1.10 (95% CI: 1.04, 1.17) for the total population and 1.10 (95% CI: 1.02, 1.18) for elders. Mortality from circulatory diseases for the elderly was related to increased PM2.5 from 5 μg/m3 to 30 μg/m3, with cumulative 5-day RR of 1.21 (95% CI: 1.02, 1.44) from 2005 to 2008. Compared with normal days, the mortality from all causes and circulatory diseases for the elderly population was associated with winter ADS with RRs of 1.05 (95% CI: 1.01, 1.08) and 1.08 (95% CI: 1.01, 1.15), respectively. Moreover, all-cause mortality was associated with shorter and less area-affected ADS with an RR of 1.04 for total and elderly populations from 2000 to 2004. Population health risk differed not only with PM concentration but also with ADS characteristics.

Difference in Pro-Inflammatory Cytokine Responses Induced in THP1 Cells by Particulate Matter Collected on Days with and without ASIAN Dust Storms.

The associations between particulate matter from Asian dust storms (ADS) and health disorders differ among studies, and the underlying mechanisms remain unclear. In this study, ADS and non-ADS particles were tested for their potential to induce pro-inflammatory cytokines associated with adverse respiratory effects. Particulate matter was collected in Japan during four periods in 2013 (2 × ADS periods; 2 × non-ADS). THP1 cells were exposed to this particulate matter, and the levels of various interleukins (ILs), and tumor necrosis factor (TNF)-α were measured. Levels of IL-2 increased significantly following exposure to all particulate matter samples (compared to levels in a solvent control). Increased levels of IL-10 and TNF-α were also observed following exposure to particles collected during three (one ADS and two non-ADS) and two (one ADS and one non-ADS) collection periods, respectively. Thus, the effects of particulate matter on cytokine responses differed according to collection period, and the effects of ADS particles differed for each ADS event. Additionally, the levels of pro-inflammatory cytokines induced by ADS particles were not always higher than those induced by non-ADS particles.