Association of long-term indoor exposure to fine particles with pulmonary effects in Northern Taiwan

Author(s):  
Li-Te Chang ◽  
I-Jung Liu ◽  
Ta-Yuan Chang ◽  
Gui-Bing Hong ◽  
Lian-Yu Lin ◽  
...  
Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 65
Author(s):  
Maximilian Kerner ◽  
Kilian Schmidt ◽  
Stefan Schumacher ◽  
Christof Asbach ◽  
Sergiy Antonyuk

Electret filters are electrostatically charged nonwovens which are commonly used in aerosol filtration to remove fine particles from gases. It is known that the charge and thus also the filtration efficiency can degrade over time. Thus, many testing standards require to remove the charge by treatment with liquid isopropanol (IPA) or IPA-saturated air. However, the parameters influencing this discharge have not been completely clarified yet. The aim of this work was, on the one hand, to experimentally investigate the influence of the IPA treatment on different electret filters and, on the other hand, to show the optimization potential of electret filters with respect to efficiency and long-term stability by numerical simulations. The experiments revealed that the air permeability is a central influencing parameter. Small pores lead to a reduced discharge efficiency using liquid IPA, while both treatment methods are suitable for larger pores. The simulations showed that a homogeneous charge distribution within the filter depth is advantageous for the initial performance. In contrast, charge penetrating deeper in the filter medium delays the charge decay and thus increases the operating time, with the trade-off of a lower initial performance.


Author(s):  
Hsin-Fu Yeh ◽  
Hung-Hsiang Hsu

The Tatun Volcano Group (TVG) is located in northern Taiwan and consists of many springs and fumaroles. The Tayukeng (TYK) area is the most active fumarole site in the TVG. In this study, we analyzed the long-term geochemical variations of hydrothermal fluids and proposed a mechanism responsible for the variation in TYK. There are two different aquifers beneath the TYK area: a shallow SO42−-rich aquifer and a deeper aquifer rich in Cl−. TYK thermal water was mainly supplied by the shallow SO42−-rich aquifer; therefore, the thermal water showed high SO42− concentrations. After 2015, the inflow of deep thermal water increased, causing the Cl− concentrations of the TYK to increase. Notably, the inferred reservoir temperatures based on quartz geothermometry increased; however, the surface temperature of the spring decreased. We inferred that the enthalpy was lost during transportation to the surface. Therefore, the surface temperature of the spring does not increase with an increased inflow of deep hydrothermal fluid. The results can serve as a reference for understanding the complex evolution of the magma-hydrothermal system in the TVG.


2018 ◽  
Author(s):  
Xin Long ◽  
Naifang Bei ◽  
Jiarui Wu ◽  
Xia Li ◽  
Tian Feng ◽  
...  

Abstract. Although aggressive emission control strategies have been implemented recently in the Beijing–Tianjin–Hebei area (BTH), China, pervasive and persistent haze still frequently engulfs the region during wintertime. Afforestation in BTH, primarily concentrated in the Taihang and Yanshan Mountains, has constituted one of the controversial factors exacerbating the haze pollution due to its slowdown of the surface wind speed. We report here an increasing trend of forest cover in BTH during 2001–2013 based on long-term satellite measurements and the impact of the afforestation on the fine particles (PM2.5) level. Simulations using the Weather Research and Forecast model with chemistry reveal that the afforestation in BTH since 2001 generally deteriorates the haze pollution in BTH to some degree, enhancing PM2.5 concentrations by up to 6 % on average. Complete afforestation or deforestation in the Taihang and Yanshan Mountains would increase or decrease the PM2.5 level within 15 % in BTH. Our model results also suggest that implementing a large ventilation corridor system would not be effective or beneficial to mitigate the haze pollution in Beijing.


2019 ◽  
Vol 112 (5) ◽  
pp. 2055-2066 ◽  
Author(s):  
Chong-Yu Ko ◽  
Zong-Lin Chiang ◽  
Ruo-Jyun Liao ◽  
Zih-Ting Chang ◽  
Ju-Chun Chang ◽  
...  

AbstractSince 2016, Apis cerana sacbrood virus (AcSBV) has been recorded in Taiwan. It is epizootic in Apis cerana (Hymenoptera: Apidae) and causing serious loss of A. cerana. Herein, we performed a long-term survey of AcSBV prevalence in the populations of A. cerana in Northern Taiwan from January 2017 to July 2018. The surveillance of AcSBV prevalence in A. mellifera (Hymenoptera: Apidae) populations was starting and further confirmed by sequencing since April 2017; thus, these data were also included in this survey. In our survey, the average prevalence rates of AcSBV were 72 and 53% in A. cerana and A. mellifera, respectively, in 2017, which decreased to 45 and 27% in 2018. For the spatial analysis of AcSBV in two honey bee populations, Hsinchu showed the highest prevalence, followed by New Taipei, Yilan, Taipei, and Keelung, suggesting that AcSBV might have come from the southern part of Taiwan. Interestingly, the AcSBV prevalence rates from A. cerana and A. mellifera cocultured apiaries gradually synchronized. The result of phylogenetic analysis and comparison of the annual AcSBV prevalence in A. cerana-only, A. mellifera-only, and A. cerana/A. mellifera cocultured sample sites indicate cross-infection between A. cerana and A. mellifera; however, AcSBV may lose the advantage of virulence in A. mellifera. The evidence suggested that the transmission of AcSBV might occur among these two honey bee species in the field. Therefore, A. mellifera may serve as a guard species to monitor AcSBV in A. cerana, but the cross-infection still needs to be surveyed.


2020 ◽  
Vol 12 (17) ◽  
pp. 2769
Author(s):  
Sheng-Hsiang Wang ◽  
Heng-Wai Lei ◽  
Shantanu Kumar Pani ◽  
Hsiang-Yu Huang ◽  
Neng-Huei Lin ◽  
...  

East Asia is the most complex region in the world for aerosol studies, as it encounters a lot of varieties of aerosols, and aerosol classification can be a challenge in this region. In the present study, we focused on the relationship between aerosol types and aerosol optical properties. We analyzed the long-term (2005–2012) data of vertical profiles of aerosol extinction coefficients, lidar ratio (Sp), and other aerosol optical properties obtained from a NASA Micro-Pulse Lidar Network and Aerosol Robotic Network site in northern Taiwan, which frequently receives Asian continental outflows. Based on aerosol extinction vertical profiles, the profiles were classified into two types: type 1 (single-layer structure) and type 2 (two-layer structure). Fall season (October–November) was the prevailing season for the Type 1, whereas type 2 mainly happened in spring (March–April). In type 1, air masses normally originated from three regional sectors, i.e., Asia continental (AC), Pacific Ocean (PO), and Southeast Asia (SA). The mean Sp values were 39 ± 17 sr, 30 ± 12 sr, and 38 ± 18 sr for the AC, PO, and SA sectors, respectively. The Sp results suggested that aerosols from the AC sector contained dust and anthropogenic particles, and aerosols from the PO sector were most likely sea salts. We further combined the EPA dust event database and backward trajectory analysis for type 2. Results showed that Sp was 41 ± 14 sr and 53 ± 21 sr for dust storm and biomass-burning events, respectively. The Sp for biomass-burning events in type 2 showed two peaks patterns. The first peak occurred within range of 30–50 sr corresponding to urban pollutant, and the second peak occurred within range of 60–80 sr in relation to biomass burning. Finally, our study summarized the Sp values for four major aerosol types over northern Taiwan, viz., urban (42 ± 18 sr), dust (34 ± 6 sr), biomass-burning (69 ± 12 sr), and oceanic (30 ± 12 sr). Our findings provide useful references for aerosol classification and air pollution identification over the western North Pacific.


2018 ◽  
Vol 117 (8) ◽  
pp. 720-726 ◽  
Author(s):  
Wan-Ju Yu ◽  
Shih-Yen Chen ◽  
Chi-Neu Tsai ◽  
Hsun-Ching Chao ◽  
Man-Shan Kong ◽  
...  

2008 ◽  
Vol 8 (4) ◽  
pp. 12971-12998 ◽  
Author(s):  
Y. F. Cheng ◽  
J. Heintzenberg ◽  
B. Wehner ◽  
Z. J. Wu ◽  
M. Hu ◽  
...  

Abstract. Based on the long-term in-situ observations of aerosol particle number size distributions and meteorological parameters, the traffic restriction measures during the Sino-African Summit (4–6 November 2006) in Beijing, China have been found to be remarkably efficient in reducing the number concentration of aerosol particles, in particular Aitken and accumulation mode particles, and in improving the visibility. The influence of traffic restriction in Beijing on the particle concentrations differed for different particle sizes. More significant effects on fine particles with diameters ranging from 40 to 800 nm have been found. Based on statistical analysis of long-term observation, under comparable weather conditions, the source strength of the particles in Aitken and accumulation modes seemingly was reduced by 40–60% when the traffic restrictions were in place. It may be mainly due to the reduction of secondary particle formation. Our size-dependent aerosol data also indicate that measures led to reductions in particulate air pollution in the optically most important diameter range, whereas further vehicle control measures may lead to an increase in ultrafine particle formation from the gas phase if the condensational sink further decreased. Assuming that there were no traffic restrictions and with normal levels of the vehicle emissions, the visibilities during the Summit would have been lower by about 50%. The importance of the restrictions is highest when the wind speed is lower than 3 m s−1. The fact that over 95% cases with visual range lower than 5 km during 2004 to 2007 occurred when the local wind speed was lower than 3 m s−1 may suggest that future traffic restrictions will lead to significant improvements of visibility in Beijing.


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