Characteristics of aerosols collected in central Taiwan during an Asian dust event in spring 2000

Determination of trace elements in the nanometer, ultrafine, fine, and coarse particulate matters in an area affected by light vehicular emissions in the city of Rio de Janeiro

The objective of this work was to determine the trace element composition in the nanometric, ultrafine, fine, and coarse particulate matters (PM) found in the surrounding area of the UERJ Chemical Technology Applications Institute, using a MSP 120 MOUDI II cascade impactor. After acid extraction, the elements were analyzed via ICP-OES, and the results obtained were treated statistically. The average concentrations of the nanometric, ultrafine, fine, and coarse particles were 11.8, 8.2, 7.7, and 7.1 μg m^-3, respectively. The total average concentration of Cd, Ni, Pb, Cr, and Fe complied with the air quality standards recommended by US EPA and WHO. When compared with other locations, the PM fractions found in this study were 1.1 to 346 times greater. Through the calculation of Pearson's correlation coefficient, a high correlation was observed between most of the trace elements studied, especially in the ultrafine, fine, and coarse fractions, which suggests that they are probably caused by the same sources of vehicular emissions. The enrichment factor was calculated to estimate the possible sources. Since Cd, Cu, Pb, and Mo are enriched by anthropic sources, they are probably influenced by vehicular emissions, in particular the wear on tires and brakes, and the burning of fossil fuel.

Effect of exposure to Asian sand dust-Particulate matter on liver Tenascin-C expression in human cancer cell and mouse hepatic tissue

Asian Sand Dust-Particulate Matter (ASD-PM) aerosol brings large amounts of wind-eroded soil particles containing high concentrations of metallic components caused by industrialization and vehicles. Proinflammatory and cytotoxic cytokines trigger local inflammatory responses and cause a systematically high incidence of cardiovascular and other diseases. Tenascin C (Tn-C) is known to be expressed in damaged tissue or in a developmental stage of tissue. In this study, we examined the expression of Tn-C and Fibronectin in human cancer-cell lines and in liver tissue of mice treated with ASD-PM to investigate the inflammatory and cell-damage effects of ASD-PM. In our in vivo study, mice were intratracheally instilled with saline suspensions of ASD-PM particles. Instillation of these particles was repeated twice a week for 12 weeks and the liver tissues were stained with hematoxylin, eosin, and Masson's trichrome, and we carried out an IF. Tn-C expression in liver tissues was detected by RT-PCR and western blot analysis. In the results, the expression of Tn-C increased in a dose-dependent manner in both RNA and Immunofluorescence assay (IF). In our in vitro study, A549 and Hep3B cell lines were incubated in culture media with Transforming Growth Factor-Beta1(TGF-β1) and ASD-PM. Immunofluorescence microscopy images showed a two times stronger expression of fluorescence in the ASD-treated group than in that treated with TGF-β1. They also showed a stronger expression of Tn-C in proportion to the concentration of ASD-PM. We confirmed that ASD-PM when inhaled formally migrated to other organs and induced Tn-C expression. ASD-PM containing metals causes expression of Tn-C in liver tissue in proportion to the concentration of ASD-PM.

Effects of co-exposure of lipopolysaccharide and β-glucan (Zymosan A) in exacerbating murine allergic asthma associated with Asian sand dust

During the 2000s, Asian sand dust (ASD) was implicated in the increasing prevalence of respiratory disorders, including asthma. We previously demonstrated that a fungus from ASD aerosol exacerbated ovalbumin (OVA)-induced airways inflammation. Exposure to heat-inactivated ASD (H-ASD) and either Zymosan A (ZymA, containing β-glucan) or lipopolysaccharide (LPS) exacerbated allergic airways inflammation in a mouse model, but the effects of co-exposure of LPS and β-glucan are unclear. We investigated the effects of co-exposure of LPS and ZymA in OVA-induced allergic airways inflammation with ASD using BALB/c mice. Exposure to OVA + LPS enhanced the recruitment of inflammatory cells to the lungs, particularly neutrophils; exposure to OVA + LPS + H-ASD potentiated this effect. Exposure to OVA + ZymA + H-ASD stimulated the recruitment of inflammatory cells to the lungs, particularly eosinophils, and serum levels of OVA-specific IgE and IgG1 antibodies, whereas exposure to OVA + ZymA did not affect most indicators of lung inflammation. Although exposure to OVA + LPS + ZymA + H-ASD affected a few allergic parameters additively or synergistically, most allergic parameters in this group indicated the same level of exposure to OVA + LPS + H-ASD or OVA + ZymA + H-ASD. These results suggest that LPS and ZymA play different roles in allergic airways inflammation with ASD; LPS mainly enhances neutrophil recruitment through H-ASD, and ZymA enhances eosinophil recruitment through H-ASD.

Elemental and carbonaceous characterization of TSP and PM10 during Middle Eastern dust (MED) storms in Ahvaz, Southwestern Iran

Middle Eastern dust (MED) storms carry large amounts of dust particles to the Southern and Western cities of Iran. This study aimed to characterize the elemental and carbonaceous composition of total suspended particles (TSP) and PM₁₀ in Ahvaz, Iran. TSP and PM₁₀ samples were collected using two separate high-volume air samplers. The sampling program was performed according to EPA guidelines and resulted in 72 samples. Twenty-eight elements and two carbonaceous components in TSP and PM₁₀ were measured. Over the entire study period, the mean concentration (SD) of TSP and PM₁₀ was 1548.72 μg/m³ (1965.11 μg/m³) and 1152.35 μg/m³ (1510.34 μg/m³), respectively. The order of concentrations of major species were Si > Al > Ca > OC > Na > B > Zn > Mn > K > Mg and Si > Ca > Al > Na > OC > B > K > Mn > Cu > Mg for TSP and PM₁₀, respectively. Almost all elements (except for Cd, Cr, and Cu) and carbonaceous components (except for organic carbon) had dust days/non-dust days (DD/NDD) ratios higher than 1, implying that all components are somehow affected by dust storms. Crustal elements constituted the major portion of particles for both TSP and PM₁₀ in both DDs and NDDs. The enrichment factor of elements such as Ca, Fe, K, Mg, Na, and Ti was near unity. Species such as Al, Ca, Fe, K, Na, Si, and EC had high correlation coefficients in both TSP and PM₁₀ (except for EC). In conclusion, Ahvaz is exposed to high concentrations of TSP and PM₁₀ during the MED period. Immediate actions must be planned to decrease the high concentrations of particulate matter in Ahvaz's ambient air.

Interactive effects of specific fine particulate matter compositions and airborne pollen on frequency of clinic visits for pollinosis in Fukuoka, Japan

BACKGROUND

Previous studies have revealed the interactive effects of airborne pollen and particulate matter on the daily consultations for pollinosis, but it is uncertain which compositions are responsible. This study aimed to investigate the interactive effects of specific PM_2.5 compositions and airborne pollen on the daily number of clinic visits for pollinosis in Fukuoka.

METHODS

We obtained daily data on pollen concentrations, PM_2.5 compositions, PM_2.5 mass, gaseous pollutants (SO₂, NO₂, CO, and O₃), and weather variables monitored in Fukuoka between February and April, 2002-2012. In total, 73,995 clinic visits for pollinosis were made at 10 clinics in Fukuoka Prefecture during the study period. A time-stratified case-crossover design was applied to examine the interactive effects. The concentrations of PM_2.5 and its compositions were stratified into low (<15th percentile), moderate (15th-85th percentile), and high (>85th percentile) levels, and the association between airborne pollen and daily clinic visits for pollinosis was analyzed within each level.

RESULTS

We found a significant interaction between specific PM_2.5 compositions and airborne pollen. Specifically, the odds ratio of daily clinic visits for pollinosis per interquartile increase in pollen concentration (39.8 grains/cm²) at the average cumulative lag of 0 and 2 days during high levels of non-sea-salt Ca²⁺ was 1.446 (95% CI: 1.323-1.581), compared to 1.075 (95% CI: 1.067-1.083) when only moderate levels were observed. This result remained significant when other air pollutants were incorporated into the model and was fairly persistent even when different percentile cut-off points were used. A similar interaction was found when we stratified the data according to non-sea-salt SO₄^2- levels. This finding differed from estimates made according to PM_2.5 and NO₃^- levels, which predicted that the effects of pollen were strongest in the lower levels.

CONCLUSIONS

Associations between airborne pollen and daily clinic visits for pollinosis could be enhanced by high levels of specific PM_2.5 compositions, especially non-sea-salt Ca²⁺.

Clinical effects of air pollution on the central nervous system; a review

The purpose of this review is to describe recent clinical and epidemiological studies examining the adverse effects of urban air pollution on the central nervous system (CNS). Air pollution and particulate matter (PM) are associated with neuroinflammation and reactive oxygen species (ROS). These processes affect multiple CNS pathways. The conceptual framework of this review focuses on adverse effects of air pollution with respect to neurocognition, white matter disease, stroke, and carotid artery disease. Both children and older individuals exposed to air pollution exhibit signs of cognitive dysfunction. However, evidence on middle-aged cohorts is lacking. White matter injury secondary to air pollution exposure is a putative mechanism for neurocognitive decline. Air pollution is associated with exacerbations of neurodegenerative conditions such as Alzheimer's and Parkinson's diseases. Increases in stroke incidences and mortalities are seen in the setting of air pollution exposure and CNS pathology is robust. Large populations living in highly polluted environments are at risk. This review aims to outline current knowledge of air pollution exposure effects on neurological health.

Estimation of students' exposure to metal concentrations from river-dust episodes during 1994-2012

Two elementary schools (Shiuguang and Fongrong) from Yulin County in Taiwan, near a main area of potential exposure to Aeolian river-dust, were selected to collect outdoor and indoor PM₁₀ aerosols and to measure five metals in PM₁₀ (As, Ni, Cr, Cd, and Mn). Significant relationships (p < 0.01) were found between outdoor PM₁₀ concentrations at Lunbei's air quality monitoring station and the two elementary schools. The outdoor PM₁₀ concentrations at the monitoring station and the schools' indoor PM₁₀ concentrations also showed significant correlations. This study also established a relationship between the outdoor and indoor concentrations of PM₁₀ and metals in the schools. Estimations were made regarding students' 8 h of exposure to metal concentrations from river-dust episodes during 1994-2012, based on correlation equations that were shown to be statistically significant.

Co-exposure to zymosan A and heat-inactivated Asian sand dust exacerbates ovalbumin-induced murine lung eosinophilia

Background

Epidemiological studies have implicated Asian sand dust (ASD) in the increased prevalence of respiratory disorders, including asthma. It has been observed that fungal elements such as β-glucan can be adsorbed onto ASD. In the present study, the exacerbating effect of the combined exposure to zymosan A (ZymA) containing yeast β-glucan and heat-inactivated ASD on ovalbumin (OVA)-induced murine lung eosinophilia was investigated.

Methods

BALB/c mice were repeatedly instilled intratracheally with one of eight immunogenic formulations consisting of various combinations of (1) ZymA, (2) ASD that was briefly heated to remove organic substances (H-ASD), and (3) OVA in normal saline, or each of the above alone. Pathologic changes, cytological alterations in bronchoalveolar lavage fluid (BALF), changes in inflammatory cytokines and chemokines in BALF, and OVA-specific IgE and IgG₁ antibodies in serum were investigated.

Results

Exposure to ZymA with or without OVA had no effect on most indicators of lung inflammation. Exposure to H-ASD with OVA increased the recruitment of inflammatory cells to the lungs and the serum levels of OVA-specific IgE and IgG₁. The combination OVA + ZymA + H-ASD induced a marked recruitment of eosinophils and upregulation of T helper 2 (Th2) cytokines (interleukin [IL]-4 and IL-13), IL-6, eotaxin/CCL11, and monocyte chemotactic protein (MCP)-3/CCL7 in BALF and OVA-specific IgE in serum. This treatment also induced the most severe pathological changes in the lungs of mice. ZymA was found to boost the effects of H-ASD, thereby exacerbating the OVA-induced allergic inflammation, even though ZymA alone did not have such effect.

Conclusions

The results suggest that fungal elements such as β-1,3-glucan aggravate the allergic inflammation caused by ASD. Our findings may facilitate prophylaxis of some allergic diseases in Asia.

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.

Size-segregated urban particulate matter: mass closure, chemical composition, and primary and secondary matter content

Forty-nine components of ambient particulate matter (PM) in size-fractionated PM were investigated at an urban background site in Katowice (Silesian Agglomeration in Southern Poland) in the non-heating season of 2012. PM was analyzed for two groups of carbon compounds (organic (OC) and elemental (EC) carbon, Lab OC-EC Aerosol Analyzer), five major water-soluble ions (NH₄⁺, Cl^-, SO₄^2-, NO₃^-, and Na⁺ contents in PM water extracts, ion chromatography), 26 elements (X-ray fluorescence spectrometry), and 16 polycyclic aromatic hydrocarbons (PAHs, gas chromatography). The distributions of the masses of these components among 13 basic PM fractions were determined, and chemical mass closure was checked for each of these fractions separately. The particles having their aerodynamic diameters in the interval 0.03-0.26 μm, the fraction PM_0.03-0.26, contributed about 13 % to the total PM mass. This PM fraction consisted of primary particles predominantly composed of various inorganic compounds, primary organic compounds, and, in lesser amounts, of elemental carbon, secondary ions, and secondary organic compounds. The second particle fraction, PM_0.26-1.6, consisted mainly of secondary matter, and its mass contribution to the total PM mass was about 59 %. The third fraction, PM_1.6-40, was a fraction of coarse particles composed of mineral/soil and organic matter and elemental carbon. It contributed to the PM mass about 28 %. For each of PM_0.03-0.26, PM_0.26-1.6, and PM_1.6-40, the health hazard from its 16 PAH contents was determined by computing toxicity factors. PM_0.26-1.6 posed the greatest health hazard from the mixture of the 16 PAHs that it contained, PM_1.6-40 was the next, and the hazard from the PM_0.03-0.26-bound 16 PAHs was the smallest. The molecular diagnostic ratios computed for these three fractions were specific for coal and wood combustion; some indicated the road traffic effects.

Influence of regional biomass burning on the highly elevated organic carbon concentrations observed at Gosan, South Korea during a strong Asian dust period

PM2.5 carbonaceous particles were measured at Gosan, South Korea during 29 March-11 April 2002 which includes a pollution period (30 March-01 April) when the highest concentrations of major anthropogenic species (nss-SO4 (2-), NO3 (-), and NH4 (+)) were observed and a strong Asian dust (AD) period (08-10 April) when the highest concentrations of mainly dust-originated trace elements (Al, Ca, Mg, and Fe) were seen. The concentrations of elemental carbon (EC) measured in the pollution period were higher than those measured in the strong AD period, whereas an inverse variation in the concentrations of organic carbon (OC) was observed. Based on the OC/EC ratios, the possible source that mainly contributed to the highly elevated OC concentrations measured in the strong AD period was biomass burning. The influence of the long-range transport of smoke plumes emitted from regional biomass burning sources was evaluated by using MODIS (Moderate Resolution Imaging Spectroradiometer) satellite data for fire locations and the potential source contribution function analysis. The most potential source regions of biomass burning were the Primorsky and Amur regions in Far Eastern Russia and southeastern and southwestern Siberia, Russia. Further discussion on the source characteristics suggested that the high OC concentrations measured in the strong AD period were significantly affected by the smoldering phase of biomass burning. In addition to biomass burning, secondary OC (SOC) formed during atmospheric long-range transport should be also considered as an important source of OC concentration measured at Gosan. Although this study dealt with the episodic case of the concurrent increase of dust and biomass burning particles, understanding the characteristics of heterogeneous mixing aerosol is essential in assessing the radiative forcing of aerosol.

Aerosol characteristics of different types of episode

Daily and hourly average data from nine air-quality monitoring stations distributed across central Taiwan, which include ten items (i.e., PM₁₀, PM₂.₅, wind direction, wind speed, temperature, relative humidity, SO₂, NO₂, NO, and CO), were collected from 2005 to 2009. Four episode types: long-range transport with dust storms (DS), long-range transport with frontal pollution (FP), river dust (RD), and stagnant weather (SW), and one mixed type of episode were identified. Of these four episode types, the SW was the dominant type, averaging about 70%. The mean ratio of PM₂.₅/PM₁₀ was the lowest during the RD episodes (0.42), while the mean ratio of PM₂.₅/PM₁₀ was the highest during the SW episodes (0.64). Fine aerosol (PM₂.₅) and coarse aerosol (PM₁₀-₂.₅) samples were collected by high-volume samplers for chemical composition analysis, from only three stations (Douliou, Lunbei, and Siansi) during the days of SW, RD, DS, and FP. The concentrations of PM₂.₅ and three ionic species (NH₄⁺, NO₃⁻, and SO₄²⁻) all showed significant differences among the four episode types. The highest levels of NO₃⁻ (12.1 μg/m(3)) and SO₄²⁻ (20.5 μg/m(3)) were found during the SW and FP episodes, respectively. A comparison on the spatial similarity of aerosol compositions among the episodes and/or non-episodes (control) was characterized by the coefficient of divergence (CD). The results showed higher CD values in PM₁₀-₂.₅ than in PM₂.₅, and the CD values between RD episodes and the other three episodes were higher than those between two types of episode for the other three episodes. The ratios of SOR (sulfur oxidation ratio), SO₄²⁻/EC (elemental carbon), NOR (nitrogen oxidation ratio), and NO₃⁻/EC showed that sulfate formation was most rapid during the FP, while nitrate formation was most rapid during the SW.

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.

Characterization of ionic composition of TSP and PM10 during the Middle Eastern Dust (MED) storms in Ahvaz, Iran

Because of the recent frequent observations of major dust storms in southwestern cities in Iran such as Ahvaz, and the importance of the ionic composition of particulate matters regarding their health effects, source apportionment, etc., the present work was conducted aiming at characterizing the ionic composition of total suspended particles (TSP) and particles on the order of ∼10 μm or less (PM(10)) during dust storms in Ahvaz in April-September 2010. TSP and PM(10) samples were collected and their ionic compositions were determined using an ion chromatography. Mean concentrations of TSP and PM(10) were 1,481.5 and 1,072.9 μg/m(3), respectively. Particle concentrations during the Middle Eastern Dust (MED) days were up to four times higher than those in normal days. Ionic components contributed to only 9.5% and 11.3% of the total mass of TSP and PM(10), respectively. Crustal ions were most abundant during dust days, while secondary ions were dominant during non-dust days. Ca(2+)/Na(+) and Cl(-)/Na(+) ratios can be considered as the indicators for identification of the MED occurrence. It was found that possible chemical forms of NaCl, (NH(4))(2)SO(4), KCl, K(2)SO(4), CaCl(2), Ca(NO(3))(2), and CaSO(4) may exist in TSP. Correlation between the anionic and cationic components suggests slight anion and cation deficiencies in TSP and PM(10) samples, though the deficiencies were negligible.

Assessing human exposure risk to cadmium through inhalation and seafood consumption

The role of cadmium (Cd) bioaccessibility in risk assessment is less well studied. The aim of this study was to assess human health risk to Cd through inhalation and seafood consumption by incorporating bioaccessibility. The relationships between trophically available Cd and bioaccessibility were constructed based on available experimental data. We estimated Cd concentrations in human urine and blood via daily intake from seafood consumption and inhalation based on a physiologically-based pharmacokinetic (PBPK) model. A Hill-based dose-response model was used to assess human renal dysfunction and peripheral arterial disease risks for long-term Cd exposure. Here we showed that fish had higher bioaccessibility (~83.7%) than that of shellfish (~73.2%) for human ingestion. Our results indicated that glomerular and tubular damage among different genders and smokers ranged from 18.03 to 18.18%. Our analysis showed that nonsmokers had 50% probability of peripheral arterial disease level exceeding from 3.28 to 8.80%. Smoking populations had 2-3 folds higher morbidity risk of peripheral arterial disease than those of nonsmokers. Our study concluded that the adverse effects of Cd exposure are exacerbated when high seafood consumption coincides with cigarette smoking. Our work provides a framework that could more accurately address risk dose dependency of Cd hazard.

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

BACKGROUND

Increases in certain cause-specific hospital admissions have been reported during Asian dust storms (ADS), which primarily originate from north and northwest China during winter and spring. However, few studies have investigated the relationship between the ADS and clinic visits for respiratory diseases in children.

OBJECTIVE

We investigated the general impact to children's health across space and time by analyzing daily clinic visits for respiratory diseases among preschool and schoolchildren registered in 12 districts of Taipei City during 1997-2007 from the National Health Insurance dataset.

METHODS

We applied a structural additive regression model to estimate the association between ADS episodes and children's clinic visits for respiratory diseases, controlling for space and time variations.

RESULTS

Compared with weeks before ADS events, the rate of clinic visits during weeks after ADS events increased 2.54% (95% credible interval = 2.43, 2.66) for preschool children (≤ 6 years of age) and 5.03% (95% credible interval = 4.87, 5.20) for schoolchildren (7-14 years of age). Spatial heterogeneity in relative rates of clinic visits was also identified. Compared with the mean level of Taipei City, higher relative rates appeared in districts with or near large hospitals and medical centers.

CONCLUSION

To our knowledge, this is the first population-based study to assess the impact of ADS on children's respiratory health. Our analysis suggests that children's respiratory health was affected by ADS events across all of Taipei, especially among schoolchildren.

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.

Natural versus anthropogenic inhalable aerosol chemistry of transboundary East Asian atmospheric outflows into western Japan

The eastward transport of aerosols exported from mainland Asia strongly influences air quality in the Japanese archipelago. The bulk of the inhalable particulate matter (PM(10)) in these intrusions comprises either natural, desert-derived minerals (mostly supermicron silicates) or anthropogenic pollutants (mostly submicron sulphates), in various states of mixing. We analyse PM(10) collected in Kumamoto, SW Japan, during three contrasting types of aerosol intrusions, the first being dominated by desert PM which became increasingly mixed with anthropogenic components as time progressed, the second being a relatively minor event mixing fine, distal desert PM with anthropogenic materials, and the third being dominated by anthropogenic pollutants. Whereas the chemistry of the natural mineral component is characterised by "crustal" elements (Si, Al, Fe, Mg, K, Li, P, Sc, V, Rb, Sr, Zr, Th, lanthanoids), the anthropogenic component is rich in secondary inorganic compounds and more toxic metallic elements (NH(4)(+), SO(4)(2-), As, Pb, Cd, Cu, Zn, Sn, Bi, Sb, and Ge). Some desert-dust (Kosa) intrusions are more calcareous than others, implicating geologically different source areas, and contain enhanced levels of NO(3)(-), probably as supermicron Ca(NO(3))(2) particles produced by chemical reaction between NOx pollutants (mostly from industry and traffic) and carbonate during atmospheric transport. The overall trace element chemistry of aerosol intrusions into Kumamoto shows low V/Rb, low NO(3)(-)/SO(4)(2-), enhanced As levels, and unfractionated La/Ce values, which are all consistent with anthropogenic sources including coal emissions rather than those derived from the refining and combustion of oil fractionates. Geographically dispersed, residual sulphatic plumes of this nature mix with local traffic (revealed by OC and EC concentrations) and industrial emissions and dissipate only slowly, due to the dominance of submicron accumulation mode PM which is atmospherically persistent, and raise questions over the chronic health effects of breathing finely respirable sulphatic aerosol containing enhanced amounts of toxic metals.

The effects of transported Asian dust on the composition and concentration of ambient fungi in Taiwan

This study was conducted to evaluate the effects of transported Asian dust and other environmental parameters on the levels and compositions of ambient fungi in the atmosphere of northern Taiwan. We monitored Asian dust events in Taipei County, Taiwan from January 2003 to June 2004. We used duplicate Burkard portable air samplers to collect ambient fungi before, during, and after dust events. Six transported Asian dust events were monitored during the study period. Elevated concentrations of Aspergillus (A. niger, specifically), Coelomycetes, Rhinocladiella, Sporothrix and Verticillium were noted (p < 0.05) during Asian dust periods. Botryosporium and Trichothecium were only recovered during dust event days. Multiple regression analysis showed that fungal levels were positively associated with temperature, wind speed, rainfall, non-methane hydrocarbons and particulates with aerodynamic diameters ≤10 μm (PM(10)), and negatively correlated with relative humidity and ozone. Our results demonstrated that Asian dust events affected ambient fungal concentrations and compositions in northern Taiwan. Ambient fungi also had complex dynamics with air pollutants and meteorological factors. Future studies should explore the health impacts of ambient fungi during Asian dust events, adjusting for the synergistic/antagonistic effects of weather and air pollutants.

Asian dust and titanium dioxide particles-induced inflammation and oxidative DNA damage in C57BL/6 mice

Inhaled particulate matter (PM) might influence many adverse health effects in human body, including increased exacerbations of pulmonary and cardiovascular diseases. In this study, we examined the associations between PM and pulmonary adverse effects. Two types of particles, Asian dust (AD) and titanium dioxide (TiO(2)), were administered intratracheally to C57BL/6 mice. The mice were exposed to saline and saline suspensions of 20 mg/kg of AD, TiO(2) particles twice a week for 12 weeks. Following exposure with these particles, the lungs were analyzed histopathologically by hematoxylin and eosin (H&E) and Masson's trichrome (MT) staining. Oxidative injuries were determined by immunohistochemistry (IHC) for 8-oxoguanine in the lungs and Comet assays in peripheral blood mononuclear cells (PBMCs) of C57BL/6 mice. Mice exposed to AD and TiO(2) showed significant inflammatory changes and oxidative damages in the lungs as compared with the control group. DNA damage in PBMCs was also increased significantly in AD and TiO(2)-exposed mice. However, lung fibrosis was minimal and there was no significant difference between PM exposed and control mice. Exposure to AD and TiO(2) particles-induced similar inflammatory damages in the lungs and elicited oxidative DNA damage in the PBMCs.

Spatial variations of the aerosols in river-dust episodes in central Taiwan

Daily and hourly average data of PM(10) from 17 air-quality monitoring stations distributed throughout four counties and along four rivers (the Ta-an River, the Tachia River, the Wu River and the Choshui River) in central Taiwan were collected from November 15 to 21, 2008. During this period, the wind speed and daily PM(10) concentrations increased drastically from the 17th to the 19th, and reached a maximum level on the 19th. Six air-quality monitoring stations (Dajia, Wurih, Siansi, Dungnan, Lunbei and Taisi) in the central Taiwan were selected for sampling fine (PM(2.5)) and coarse (PM(10-2.5)) aerosols samples during and after the river-dust episode. Most of the ratios of [crustal elements (Fe or Al)/reference elements (Cd or Mo)] for the samples obtained during episode are higher than those obtained after episode. The values of Fe(10-2.5)/Cd(10-2.5) and Fe(10-2.5)/Mo(10-2.5) were very high in Lubei, Taisi, and Dungnan stations where heavy aeolian river dust occurred. These data suggest that the ratios of Fe(10-2.5)/Cd(10-2.5) and Fe(10-2.5)/Mo(10-2.5) can be successfully used as indexes to evaluate the comparative degree of effect of aeolian river dust on the atmosphere of multiple stations.

[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.

Factors affecting the concentrations of PM10 in central Taiwan

In this study, the synoptic weather types that have high probability and low probability of producing PM10 episode are referred to as HPE and LPE, respectively. Multiple linear regressions analysis showed that NO2 was the most important contributor (35.61%) to the concentrations of PM10 for HPE weather. For LPE weather, the season factor had the greatest contribution (48.11%) to the concentrations of PM10. Using the correlation coefficients between the concentrations of PM10 and SO2 or NO2 on HPE and LPE to calculate the increase of PM10 from LPE to HPE, we found that the increase of PM10 owing to the increase of SO2 and NO2 from LPE to HPE was 12.93microg/m3 which was about 51% of the total amount of PM10 increased from LPE to HPE. Results of factor analysis showed that the first component could be attributed to the result of local pollution especially for the weather patterns of types P3 and P6, while the secondary component for the weather patterns of types P1 and P4 can be attributed to the long-range transport of SO2 pollutants from China.

Concentration and emission sources of airborne metals in particulate matter in the industrial district of Médio Paraíba, state of Rio de Janeiro, Brazil

Total suspended particles and 12 airborne metals were determined in 4 sampling sites in the industrial region of Médio Paraíba, Brazil. The geometrical means for the four sampling locals were (in units of microg/m3): 65.9 in Barra Mansa, 57.3 in Jardim Paraíba (Volta Redonda), 41.7 in Resende, and 48.9 in Volta Grande (Volta Redonda). These values are lower than levels previously determined in urban and industrial locals of the Metropolitan Area of Rio de Janeiro. For metals, the higher concentrations were obtained for Ca, Zn, Al, Fe, and Mg. Ca, Zn, and Al levels are higher than those determined in other industrial areas. These three metals are used in steel manufacturing, the main economical activity of the region. Enrichment factors for Zn, Cu, Cd, and Pb are higher than 10, suggesting an industrial input. Statistical analysis show a high correlation among Ca, Mg, Zn, Cr, Al, Mn, and Fe, all of them used as raw materials in steel manufacturing and/or accumulated as industrial blast furnace slag and steelworks slag.