Concentration of atmospheric particulates during a dust storm period in central Taiwan, Taichung

The Science of the Total Environment 287 Ž2002. 141᎐145

Short communication

Concentration of atmospheric particulates during a dust storm period in central Taiwan, Taichung Guor-Cheng Fang a,U , Cheng-Nan Chang b, Yuh-Shen Wua , Shin-Chung Lua , Peter Pi-Cheng Fuc , Shyh-Chyi Chang b, Chii-Dong Cheng b, Win-Hsiao Yuend a

Air Toxic and En¨ ironmental Analysis Laboratory, Hungkuang Institute of Technology, Sha-Lu, Taichung 433, Taiwan, ROC b Department of En¨ ironmental Science, Tunghai Uni¨ ersity, Taichung 407, Taiwan, ROC c Di¨ ision of Biochemical Toxicology, National Center for Toxicological Research, Jefferson, AK 72079, USA d Department of Chemical Engineering, Hsiuping Institute of Technology, Taichung 412, Taiwan, ROC Received 3 May 2001; accepted 27 July 2001

Abstract In this study we monitored concentrations of particles in central Taiwan using PS-1 ŽGPS1 PUF Sampler. and Model 310 Universal Air Sampler TM ŽUASTM . from 02r23r2001 to 03r12r2001 at two sampling sites. During this period, an Asian dust storm moved across central Taiwan from 3r3 to 3r6. The total ambient air particle concentrations during the dust storm period were than compared with previous data from this region. In general, the average total suspended particulate ŽTSP. concentration order was during dust storm period) after dust storm period) non-dust storm period at both HKITT Žtraffic. and THUC Žrural. sampling sites. The ratio of PM 2.5rPM 10 was 60% before and after the dust storm period. However, this ratio was decreased to less than 50% during the dust storm. This demonstrates that the coarse particulate concentrations ŽPM 2.5 ᎐ 10 . increased during the dust storm period. In contrast the increase of ambient air particles concentrations after the Taiwan Chi-Chi Earthquake were mainly due to fine particles ŽPM 2.5 .. And, the increased of ambient air particles concentrations after dust storm period were mainly coarse particle ŽPM 2.5 ᎐ 10 . concentrations in central Taiwan. 䊚 2002 Elsevier Science B.V. All rights reserved. Keywords: Total suspended particulate; Fugitive dust; Dust-storm; PM 2.5 ; PM 2.5 ᎐ 10 ; Particulate matter

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Corresponding author. Tel.: q886-4-6318652; fax: q886-4-3502102. E-mail address: [email protected] ŽG.-C. Fang..

0048-9697r02r$ - see front matter 䊚 2002 Elsevier Science B.V. All rights reserved. PII: S 0 0 4 8 - 9 6 9 7 Ž 0 1 . 0 0 9 9 6 - 2

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G.-C. Fang et al. r The Science of the Total En¨ ironment 287 (2002) 141᎐145

1. Introduction Recent epidemiological studies have shown that suspended particulate matter considerably influences respiratory health. Associations between suspended particulate matter and lung function parameters, respiratory symptoms and mortality have been found ŽDockery et al., 1993.. The whole mass concentration of suspended particulates in the air is called total suspended particulates ŽTSP.. Particles less than 10 ␮m Ž0.01 mm. in aerodynamic diameter are called respiratory particulates or particulate matter10 ŽPM 10 ., whereas PM 2.5 denotes fine particles less than 2.5 ␮m in aerodynamic diameter ŽOhlstrom ¨ et al., 2000.. Nevertheless, the dust suspended in the atmosphere by dust storms is not reported as part of the routine meteorological observations. This finding was unexpected because it contrasts with the interpretation that the loess accumulations are mainly attributable to strong dust storms and dust fall events. Furthermore, this conclusion has generated some controversy in relation to the hemispheric to global-scale transport of Asian dust ŽZhang et al., 1999.. Dust particles are emitted from deserts of central Eurasia are carried east by prevailing winds of middle latitude and deposited in East Asia, even to the seas east of China. A famous example is the huge Loess created by millions of years of dust depositions. So, the dust emission inventory is of great significance and even larger than the scale of environmental problems such as acid rain and global climate change. The annual dust emission amount is some 43 million tons, and the dust emission in the spring season accounts for a half of this ŽXuan, 1999.. This study discusses changes in the concentration of particles during the dust storm period in central Taiwan. In addition, correlation coefficients between TSP, PM 2.5 , PM 2.5-10 and PM 10 were also studied during the dust storm period.

near a major road in front of the Hungkuang Institute of Technology ŽHKITT. and on the Tunghai University Campus ŽTHUC., which are described as traffic and rural sampling sites, respectively. Additionally, three EPA air pollutant monitoring stations ŽHis-Tun, Chung-Min and Sha-Lu. were also included and compared with the data measured in this study ŽFig. 1.. TSP Ž24 h., PM 2.5 Ž24 h. and PM 2.5 ᎐ 10 Ž24 h. were also measured at the THUC Žrural. sampling rural site. The sampling period was from 02r23r2001 to 03r12r2001 at these sampling sites. Meanwhile, an Asian dust storm moved across central Taiwan from 3r3 to 3r6.. Total ambient air particles concentrations during the dust storm period were compared with previous data for this region for this study. 2.2. PS-1 sampler The PS-1 ŽGPS1 PUF Sampler, General Metal Work. consists of a dual chamber, sampling module, flow vent, magnehelic gas, voltage variator, elapsed time indicator, pump, 7-day skip timer, exhaust hose and aluminum shelter. Glass filter paper and quartz filter was used in this study. The flow rate of PS-1 was adjusted try using a GMW-25 Calibration Kit and was adjusted to 200 l miny1 in this study. The operation procedure is the same as a previous study ŽFang et al., 1999..

2. Experimental method 2.1. Sampling program Ambient particle concentration was sampled

Fig. 1. Map of central Taiwan, Taichung area. The air pollutant monitoring stations are indicated by M1 ŽSha-Lu., M2 ŽHsi-Tun. and M3 ŽChung-Min. the sampling sites by S1 ŽHKITT, traffic. and S2 ŽTHUC, rural..

G.-C. Fang et al. r The Science of the Total En¨ ironment 287 (2002) 141᎐145

2.3. Uni¨ ersal sampler The Model 310 Universal Air Sampler TM ŽUASTM . is for atmosphere aerosols and used to determine mass concentration, and organic or inorganic analysis. The sampler has an inlet sampling flow rate of 300 l miny1 . This sampler allows operation as a high volume dichotomous sampler for size fractionation of airborne particle in the 0᎐2.5 ␮m and 2.5᎐10 ␮m aerodynamic size ranges. Particles - 10 ␮m flow to the PM 2.5 classifier located downstream. Particles in the 2.5᎐10-␮m range are collected on a 62-mm= 165 mm filter and those smaller than 2.5 ␮m are collected on a 200-mm= 250 mm final filter. The filtered air streams are then directed through the PUF sampler to collect the volatile organic compounds in the filtered air stream ŽUniversal Air Sampler, 1996..

3. Results and discussion The sampling number, sampling period, and average particle concentrations are listed in Table 1. At the HKITT Žtraffic. sampling site, the highest TSP concentrations Ž229.0 ␮g my3 . occurred during the dust storm period. The period after dust storm was ranked second Žaverage 139.5 ␮g my3 ., followed by the non-dust storm period Žaverage 126.9 ␮g my3 .. The concentration in the THUC Žrural. area ranged from 85.4 ␮g my3 Žnon-dust storm period. to 164.8 ␮g my3 Ždust

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storm period.. Statistical analysis of the TSP concentrations for the dust storm period and non-dust storm period at the HKITT Žtraffic. sampling sites yielded a t-statistic of y0.02, which is greater than yta,3 s y3.18, suggesting that the sample concentration means are different. These results implied that the particle concentrations were higher than usual during the dust storm period. In general, the average total suspended particulate ŽTSP. concentration order was during the dust storm period) after dust storm period) non-dust storm period at both HKITT Žtraffic. and THUC Žrural. sampling sites. This was consistent with the data obtained from air pollutant monitoring stations ŽHis-Tun, Chung-Min and Sha-Lu. in Taiwan. Table 2 shows atmospheric particulate concentrations measured at the THUC Žrural. sampling sites. The concentrations for TSP, PM 2.5 , PM 2.5 ᎐ 10 and PM 10 increased during the dust storm period. The average PM 10 concentrations were all higher than 100 ␮g my3 during the dust storm period at the THUC Žrural. sampling sites. The PM 2.5r PM 2.5 ᎐ 10 ratios ranged between 1.11 and 4.64 and between 0.86 and 0.99 in the non-dust storm period and dust storm period, respectively. After the dust storm the range was 1.47 ; 2.06. The ratios of PM 2.5rPM 10 and PM 2.5rTSP remained almost constant during the dust storm period. They ranged from approximately 0.46 to 0.50 and 0.33 to 0.35 for PM 2.5rPM 10 and PM 2.5rTSP, respectively, at the THUC Žrural. sampling sites during the dust storm period. In general, the percentages of

Table 1 The total suspended particulates ŽTSP. concentrations at the sampling sites and air pollutant monitoring stations ŽUnit s ␮g my3 . Sampling period

N

Sampling sites HKITT Žtraffic.

Non-dust storm period Ž2001.2.23; 2001.3.2. Dust storm period Ž2001.3.3; 2001.3.6. After dust storm period Ž2001.3.7; 2001.3.12. Total sampling period Ž2001.2.23; 2001.3.12.

Air pollutant monitoring stations THUC Žrural.

His-Tun

Chung-Min

Sha-Lu

8

126.9" 53.0

85.4" 35.0

75.7" 35.8

70.7" 36.6

54.7" 23.8

4

229.0" 56.9

164.8" 12.7

123.7" 13.7

117.5" 12.7

111.5" 18.4

6

139.5" 42.1

85.9" 20.4

85.9" 48.8

74.3" 40.0

68.1" 23.4

18

153.8" 63.2

103.2" 42.4

89.8" 40.4

82.3" 37.8

71.8" 31.1

G.-C. Fang et al. r The Science of the Total En¨ ironment 287 (2002) 141᎐145

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Table 2 Atmospheric particulates at the THUC Žrural. sampling site Sampling date

THUC Žrural. sampling site Ž␮g my3 . TSP

PM2.5

PM2.5 ᎐ 10

PM10

PM2.5 rPM2.5 ᎐ 10

PM2.5 rPM10

PM2.5 rTSP

2001.2.23 2001.2.24 2001.2.25 2001.2.26 2001.2.27 2001.2.28 2001.3.1 2001.3.2 2001.3.3 2001.3.4 2001.3.5 2001.3.6 2001.3.7 2001.3.8 2001.3.9 2001.3.10 2001.3.11 2001.3.12 Average S.D.

78.4 87.5 55.4 74.6 51.3 64.5 115.9 155.8 153.9 174.5 177.1 153.8 79.2 78.4 72.3 126.9 82.3 76.2 103.2 42.4

34.5 33.9 26.4 35.8 29.7 49.6 38.2 41.0 53.5 56.9 62.2 53.9 41.4 38.7 35.6 55.1 29.5 27.4 41.3 11.2

22.1 25.7 16.2 15.7 17.6 10.7 23.2 36.8 54.2 66.5 72.6 56.0 28.2 20.1 22.2 30.2 18.3 13.3 30.5 18.9

56.6 59.6 42.6 51.5 47.3 60.3 61.4 77.8 107.7 123.4 134.8 109.9 69.6 58.8 57.8 85.3 47.8 40.7 71.8 28.7

1.56 1.32 1.63 2.28 1.69 4.64 1.65 1.11 0.99 0.86 0.86 0.96 1.47 1.93 1.60 1.82 1.61 2.06 1.67 0.85

0.61 0.57 0.62 0.70 0.63 0.82 0.62 0.53 0.50 0.46 0.46 0.49 0.59 0.66 0.62 0.65 0.62 0.67 0.60 0.09

0.44 0.39 0.48 0.48 0.58 0.77 0.33 0.26 0.35 0.33 0.35 0.35 0.52 0.49 0.49 0.43 0.36 0.36 0.43 0.12

Weather situation Clear Clouds Clouds Clouds Clouds Clouds Clear Clear Clear Clear Clear Clear Clouds Clouds Clouds Clear Clear Clouds

Fig. 2. Particle concentrations variation of total suspended particulates ŽTSP. after the earthquake and dust storm period in central Taiwan. Data source: Aug-99 to Dec-99 and Jul-00 to Aug-00 were from Fang et al. Ž2000. and Fang et al. Ž2001., respectively.

G.-C. Fang et al. r The Science of the Total En¨ ironment 287 (2002) 141᎐145

PM 2.5rPM 10 were approximately 60% before and after the dust storm period, but, this ratio decreased to less than 50% during the dust storm, because the coarse particulates concentrations ŽPM 2.5 ᎐ 10 . increased during the dust storm period. The total suspended particulates ŽTSP. after the earthquake and during the dust storm period in central Taiwan are compared in Fig. 2. The results indicated that the particles were higher during the dust storm than in the period following the Chi-Chi earthquake at the traffic sampling site ŽHKITT.. TSP particle concentration distributions trends were consistent at traffic ŽHKITT. and rural ŽTHUC. sampling sites. Generally speaking, the increase in ambient air particles concentrations after the Taiwan Chi-Chi Earthquake were mainly in the fine particle ŽPM 2.5 . concentrations. However, the increase of ambient air particles concentrations after the dust storm was mainly due to coarse particles ŽPM 2.5 ᎐ 10 . in central Taiwan. 4. Conclusion The major conclusions of this study are as follows: 1. The HKITT Žtraffic. sampling site had the highest TSP concentrations Ž229.0 ␮g my3 . during the dust storm period. The concentrations were approximately 1.8 times the normal as non dust storm particle concentrations Ž126.9 ␮g my3 . at the HKITT Žtraffic. sampling site. Statistical results also proved that particle concentrations were different during the dust storm period. 2. The ratio of PM 2.5rPM 10 was approximately 60% before and after the dust storm period. However, this ratio decreased to less than 50% during the dust storm, showing that coarse particulate concentrations ŽPM 2.5 ᎐ 10 . increased during dust the storm. 3. The total suspended particulate ŽTSP. concentrations during the dust storm period was higher than after the Taiwan Chi-Chi

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earthquake at the traffic sampling site ŽHKITT.. The increased of ambient air particles concentrations after the Taiwan Chi-Chi Earthquake were mainly caused by higher fine particle ŽPM 2.5 . concentrations. However, the increased in ambient air particle concentrations after the dust storm were mainly in coarse particle ŽPM 2.5 ᎐ 10 . concentrations in central Taiwan.

Acknowledgements The authors gratefully acknowledge the National of Science Council of the ROC ŽTaiwan. for the financial support under project No. NSC 892211-E-241-007. References Dockery DW, Pope CA, Xu X, Spengler JD, Ware JH, Fay ME, Ferris BG, Speizer FE. An association between air pollution and mortality in six US cities. New Engl J Med 1993;329:1753᎐1759. Fang GC, Chang CN, Wu YS, Fu PCP, Chang KF, Yang DG. The characterization study of TSP, PM 2.5 ᎐ 10 and PM 2.5 in the rural site of central Taiwan. Sci Total Environ 1999;232:177᎐184. Fang GC, Chang CN, Wang NP, Wu YS, Wang V, Fu PPC, Cheng CD, Chen SC, Lin DY. The study of TSP, PM 2.5 ᎐ 10 and PM 2.5 during Taiwan Chi-Chi Earthquake in the traffic site of central Taiwan, Taichung. Chemosphere 2000; 41:1727᎐1731. Fang GC, Chang CN, Wu YS, Fu PPC, Chang SC, Cheng CD, Yuen WH. Characteristic study of ambient air particulate and metallic elements concentration, composition and meteorological condition around central Taiwan. Environ Technol 2001; submitted. Ohlstrom ¨ MO, Lehtinen KEJ, Moisio M, Jokiniemi JK. Fineparticle emissions of energy production in Finland. Atmos Environ 2000;34:3701᎐3711. Universal Air Sampler. Model 310 Universal Air Sampler TM Instruction Manual ŽUSATM.. Minneapolis, MN: MSP Corporation, 1996. Xuan J. Dust emission factors for environment of Northern China. Atmos Environ 1999;33:1767᎐1776. Zhang XY, Arimoto R, An ZS. Glacial and interglacial patterns for Asian dust transport. Q Sci Rev 1999;18:811᎐819.