- Email: [email protected]
outdoor relationships for acid aerosol in meteropolitan Tainan
Abstracts
246
INDOOR
CHARACTERISTICS OF POLYCYCLIC AROMATIC HYDROCARBONS IN THE URBAN ATMOSPHERE ON TAIPEI Chih-Shan
Graduate
Institute
of Environmental
Li and Yu-Sun Ro
Health, College of Public Taipei, Taiwan, R.O.C.
Health.
National
Taiwan
University,
Fifteen polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously in the indoor and outdoor air of 14 homes in the Taipei urban area in both summer and winter seasons. The sampler was equipped with a Teflon-impregnated glass-fiber to collect particulate PAHs followed by XAD-2 resin to trap gaseous PAHs. It was observed that indoor PAH concentrations generally exceeded the corresponding outdoor PAH concentrations. Moreover, the median value of indoor/outdoor ratios of the total PAH concentrations was observed to be 1.23 which might demonstrate that there was no presence of significant indoor PAH sources in this subtropical region. Concerning seasonal variations of particulate PAHs, it was indicated that winter total PAH levels were statistically higher than the corresponding summer ones. In addition, the observed lower winter/summer ratios might be related to the absence of domestic heating in residential environments. In regard to PAH compositions, the most abundant PAH found indoors was naphthalene; fluorene and phenanthrene were the second and third highest levels indoors and outdoors. In comparison with indicators of source characteristics, it was demonstrated that petrol vehicles might be the predominant PAH source in the urban atmosphere of Taipei,
INDOOR
POLLUTION AMONG
AND SICK BUILDING SYNDROME WORKERS IN DAY-CARE CENTERS
Chih-Shan Graduate
Institute
of Environmental
Li and Ching-Wan
Health, College of Public Taipei, Taiwan. R.O.C.
SYMPTOMS
Hsu
Health,
National
Taiwan
University.
This study investigated indoor air quality and symptoms of respiratory illness of 264 nursing workers in 28 day-care centers in the Taipei area. It was indicated that geometric mean concentrations of indoor and outdoor bacteria were 735 and 384 CFUmm3, respectively. In addition. geometric mean concentrations of indoor and outdoor fungi were 1212 and 1032CFUm-3, respectively. Asperyi!lus, Cladosporium. and Penicillium were observed to be the most common microfungi indoors and outdoors. Moreover, geometric mean concentrations of house dust mite allergens, Der p 1 and Der p 5, were observed to be 58 and 14 ngg-’ dust, respectively. Additionally, the observed high prevalence of dampness or mold problems in the investigated day-care centers indicated that dampness is very common in this subtropical region, The results demonstrated significant relationship between dampness and work-related sick building syndrome of the day-care center workers. Furthermore, fungus concentrations were observed to be lower in the day-care centers with air conditioner/air cleaner than those without air conditioner/air cleaner. In addition, Asperyihs was found to be strongly associated with work-related sick building syndrome of the day-care center workers.
THE INDOOR/OUTDOOR RELATIONSHIPS FOR ACID AEROSOL IN METEROPOLITAN TAINAN Der-Min Tsai and Yee-Lin Wu Department
of Environmental
Engineering,
National
Cheng-Kung
University.
Tainan,
Taiwan.
R.0.C
Acid aerosols have been suspected to be the major causes for the deterioration of lung functions. However, most of the exposure studies were based on the results from outdoor measurements, despite that people stay more time indoor. The objectives of this study are to compare aerosol compositions and outdoor to indoor concentration ratios in meteropolitan Tainan. For comparison, the measurements were conducted at the city center and a northernwest rural site. The indoor and outdoor aerosol measurements were conducted simultaneously at elementary school and students’ home by Gilian cyclone particle sampler. The sampling periods were 8 h at school and 24 h at residential houses. The geometric average indoor/outdoor particle mass concentrations of school are 153/179 and 137/l 51 ngrn- 3 at city center and the rural site, respectively. And the geometric average of indoor/outdoor particle mass concentrations of children’s home are 75/86 and 73/81 /lgrn-” at city center and the rural site, respectively. Because of the greater concentrations of Ca2+ at school, its greater particle concentrations are likely due to the resuspension of soil. The outdoor to indoor concentration ratios of particle mass at city center and rural area were 1.16(1.79) and l.OO(1.85) (geometric average and geometric SD.), respectively. The pH values of the aerosol range from 5.2 to 7.5.
Abstracts
247
Except for K+ and NH:, there is no consistent relationships between indoor and outdoor concentrations, implying the diversities of sources. Among the various chemical species, the SOi- and NO; are highly correlated, which implys that both are secondary aerosols. The high correlation between [H’] and [NH:] suggests that the acidity of particles is mainly determined by access to NH,.
DEVELOPMENT
OF A NARROW HungMin
Center
for Industrial
SIZE-DISTRIBUTION Chein
and Charles
AEROSOL
GENERATOR
C.-K. Chou
Safety and Health Technology, Industrial Hsinchu, Taiwan 310, R.O.C.
Technology
Research
Institute,
An aerosol generator capable of generating a narrow-size distribution aerosol with high mass concentrations was developed. The aerosol generator consists of a Delavan simplex nozzle and an improved virtual impactor. A polydisperse aerosol is generated through atomization/evaporation processes. Gravity is used to remove large particles and the improved virtual impactor is employed to remove small particles. The geometric standard deviation of the size distribution of the generated aerosol is less than 1.5. The performance of the aerosol generator has been tested with corn-oil, sodium chloride and uranine solution, respectively. The results indicated that the MMAD of the corn-oil droplets was 7.2 pm and the GSD was 1.48. Aerosols generated from a NaCl or uranine solution was found to have a MMAD in the range of 0.93 to 4.61 pm and GSD varying from 1.4 to 1.50. Aerosol generation rate varied from 0.04 to 15.7 mgmin- 1 depending upon the particle size produced.
DEVELOPMENT
OF A PRE-DUST-EXPLOSION
HungMin Center
for Industrial
Chein, Jang-Chang
Huang
AEROSOL and Jung-Pin
Safety and Health Technology, Industrial Hsinchu, Taiwan 310, R.O.C.
Technology
MONITOR Yu
Research
Institute,
A real-time aerosol monitor capable of monitoring and alarming high mass concentration close to dust lower explosibility limit (LEL) has been developed and evaluated. In the pre-dust-explosion aerosol monitor, particles are sampled by an aerosol diluting chamber and measured with a passive light-scattering aerosol monitor (AQ-10, EDC, Haverhill, MA, U.S.A.). The particle penetration efficiency in the aerosol sampling and diluting chamber is determined experimentally using monodisperse oleic acid droplets. The result shows that the 50% cutoff point diameter is equal to 30 pm. Size-selective flour and SAE dust are generated by pneumatic dispersion method as test aerosols to evaluate the performance of the pre-dust-explosion aerosol monitor. In this test range (SAE dust < 34.6 g m-j, flour < 12.5 gm-3), the real-time mass concentration measured with the aerosol monitor correlates with the value determined by the standard filtration method quite well. The R2 value of linearity relationship is larger than 0.95 for both test aerosols. Therefore, it is expected that the aerosol monitor is able to measure much higher concentration, even close to dust LELs.
IMPROVEMENT
AND APPLICATION
C. Y. Lai, S. H. Huang Institute
of Occupational
Medicine
and Industrial
OF A SIMPLE
and Chih-Chieh Hygiene,
National
DILUTER
Chen
Taiwan
University,
Taipei, Taiwan
The micro-orifice uniform deposit impactor (MOUDI) or the real time instruments are commonly used to measure the concentrations and size distributions of the particulate matters. The drawbacks of MOUDI are expensive, difficult to operate, and very time-consuming if the pollutant concentration is low. On that account, the real time monitors are preferred. However, they also come with the sorts of limitations. According to a preliminary study, e.g.: aerosol number concentration by the motorcycle was over lo3 particles per cubic meter, which is beyond the working range of most of the real time instruments. Consequently, a simpler, rugged, and easy-toconstruct diluter is needed to reduce the aerosol number concentration. The aerosol deposition in the diluter was measured and presented as a function of particle size. In this study, the diluter was used to determine the aerosol number concentration and size distribution exhausted by a two-stroke engine operated under idle condition. The results showed that it took over 10 min for the engine to warm up under idle condition. The count median diameter (CMD) of the discharged aerosol particles was about 236 nm, with the geometric standard deviation (GSD) was 1.57. After reaching the steady state, the CMD and GSD reduced to 198 nm and 1.55, respectively, with the number concentration around 1.6 x lo* particles per cubic meter. The aerosol charge was measured to be 0.0038 elementary charge per particle, by using an aerosol electrometer. As air/fuel ratio increased, the particle number concentration decreased, so did the CMD. The content of lubrication oil appeared to be the major contributor to increase in the size of the exhaust particles.
246
INDOOR
CHARACTERISTICS OF POLYCYCLIC AROMATIC HYDROCARBONS IN THE URBAN ATMOSPHERE ON TAIPEI Chih-Shan
Graduate
Institute
of Environmental
Li and Yu-Sun Ro
Health, College of Public Taipei, Taiwan, R.O.C.
Health.
National
Taiwan
University,
Fifteen polycyclic aromatic hydrocarbons (PAHs) were measured simultaneously in the indoor and outdoor air of 14 homes in the Taipei urban area in both summer and winter seasons. The sampler was equipped with a Teflon-impregnated glass-fiber to collect particulate PAHs followed by XAD-2 resin to trap gaseous PAHs. It was observed that indoor PAH concentrations generally exceeded the corresponding outdoor PAH concentrations. Moreover, the median value of indoor/outdoor ratios of the total PAH concentrations was observed to be 1.23 which might demonstrate that there was no presence of significant indoor PAH sources in this subtropical region. Concerning seasonal variations of particulate PAHs, it was indicated that winter total PAH levels were statistically higher than the corresponding summer ones. In addition, the observed lower winter/summer ratios might be related to the absence of domestic heating in residential environments. In regard to PAH compositions, the most abundant PAH found indoors was naphthalene; fluorene and phenanthrene were the second and third highest levels indoors and outdoors. In comparison with indicators of source characteristics, it was demonstrated that petrol vehicles might be the predominant PAH source in the urban atmosphere of Taipei,
INDOOR
POLLUTION AMONG
AND SICK BUILDING SYNDROME WORKERS IN DAY-CARE CENTERS
Chih-Shan Graduate
Institute
of Environmental
Li and Ching-Wan
Health, College of Public Taipei, Taiwan. R.O.C.
SYMPTOMS
Hsu
Health,
National
Taiwan
University.
This study investigated indoor air quality and symptoms of respiratory illness of 264 nursing workers in 28 day-care centers in the Taipei area. It was indicated that geometric mean concentrations of indoor and outdoor bacteria were 735 and 384 CFUmm3, respectively. In addition. geometric mean concentrations of indoor and outdoor fungi were 1212 and 1032CFUm-3, respectively. Asperyi!lus, Cladosporium. and Penicillium were observed to be the most common microfungi indoors and outdoors. Moreover, geometric mean concentrations of house dust mite allergens, Der p 1 and Der p 5, were observed to be 58 and 14 ngg-’ dust, respectively. Additionally, the observed high prevalence of dampness or mold problems in the investigated day-care centers indicated that dampness is very common in this subtropical region, The results demonstrated significant relationship between dampness and work-related sick building syndrome of the day-care center workers. Furthermore, fungus concentrations were observed to be lower in the day-care centers with air conditioner/air cleaner than those without air conditioner/air cleaner. In addition, Asperyihs was found to be strongly associated with work-related sick building syndrome of the day-care center workers.
THE INDOOR/OUTDOOR RELATIONSHIPS FOR ACID AEROSOL IN METEROPOLITAN TAINAN Der-Min Tsai and Yee-Lin Wu Department
of Environmental
Engineering,
National
Cheng-Kung
University.
Tainan,
Taiwan.
R.0.C
Acid aerosols have been suspected to be the major causes for the deterioration of lung functions. However, most of the exposure studies were based on the results from outdoor measurements, despite that people stay more time indoor. The objectives of this study are to compare aerosol compositions and outdoor to indoor concentration ratios in meteropolitan Tainan. For comparison, the measurements were conducted at the city center and a northernwest rural site. The indoor and outdoor aerosol measurements were conducted simultaneously at elementary school and students’ home by Gilian cyclone particle sampler. The sampling periods were 8 h at school and 24 h at residential houses. The geometric average indoor/outdoor particle mass concentrations of school are 153/179 and 137/l 51 ngrn- 3 at city center and the rural site, respectively. And the geometric average of indoor/outdoor particle mass concentrations of children’s home are 75/86 and 73/81 /lgrn-” at city center and the rural site, respectively. Because of the greater concentrations of Ca2+ at school, its greater particle concentrations are likely due to the resuspension of soil. The outdoor to indoor concentration ratios of particle mass at city center and rural area were 1.16(1.79) and l.OO(1.85) (geometric average and geometric SD.), respectively. The pH values of the aerosol range from 5.2 to 7.5.
Abstracts
247
Except for K+ and NH:, there is no consistent relationships between indoor and outdoor concentrations, implying the diversities of sources. Among the various chemical species, the SOi- and NO; are highly correlated, which implys that both are secondary aerosols. The high correlation between [H’] and [NH:] suggests that the acidity of particles is mainly determined by access to NH,.
DEVELOPMENT
OF A NARROW HungMin
Center
for Industrial
SIZE-DISTRIBUTION Chein
and Charles
AEROSOL
GENERATOR
C.-K. Chou
Safety and Health Technology, Industrial Hsinchu, Taiwan 310, R.O.C.
Technology
Research
Institute,
An aerosol generator capable of generating a narrow-size distribution aerosol with high mass concentrations was developed. The aerosol generator consists of a Delavan simplex nozzle and an improved virtual impactor. A polydisperse aerosol is generated through atomization/evaporation processes. Gravity is used to remove large particles and the improved virtual impactor is employed to remove small particles. The geometric standard deviation of the size distribution of the generated aerosol is less than 1.5. The performance of the aerosol generator has been tested with corn-oil, sodium chloride and uranine solution, respectively. The results indicated that the MMAD of the corn-oil droplets was 7.2 pm and the GSD was 1.48. Aerosols generated from a NaCl or uranine solution was found to have a MMAD in the range of 0.93 to 4.61 pm and GSD varying from 1.4 to 1.50. Aerosol generation rate varied from 0.04 to 15.7 mgmin- 1 depending upon the particle size produced.
DEVELOPMENT
OF A PRE-DUST-EXPLOSION
HungMin Center
for Industrial
Chein, Jang-Chang
Huang
AEROSOL and Jung-Pin
Safety and Health Technology, Industrial Hsinchu, Taiwan 310, R.O.C.
Technology
MONITOR Yu
Research
Institute,
A real-time aerosol monitor capable of monitoring and alarming high mass concentration close to dust lower explosibility limit (LEL) has been developed and evaluated. In the pre-dust-explosion aerosol monitor, particles are sampled by an aerosol diluting chamber and measured with a passive light-scattering aerosol monitor (AQ-10, EDC, Haverhill, MA, U.S.A.). The particle penetration efficiency in the aerosol sampling and diluting chamber is determined experimentally using monodisperse oleic acid droplets. The result shows that the 50% cutoff point diameter is equal to 30 pm. Size-selective flour and SAE dust are generated by pneumatic dispersion method as test aerosols to evaluate the performance of the pre-dust-explosion aerosol monitor. In this test range (SAE dust < 34.6 g m-j, flour < 12.5 gm-3), the real-time mass concentration measured with the aerosol monitor correlates with the value determined by the standard filtration method quite well. The R2 value of linearity relationship is larger than 0.95 for both test aerosols. Therefore, it is expected that the aerosol monitor is able to measure much higher concentration, even close to dust LELs.
IMPROVEMENT
AND APPLICATION
C. Y. Lai, S. H. Huang Institute
of Occupational
Medicine
and Industrial
OF A SIMPLE
and Chih-Chieh Hygiene,
National
DILUTER
Chen
Taiwan
University,
Taipei, Taiwan
The micro-orifice uniform deposit impactor (MOUDI) or the real time instruments are commonly used to measure the concentrations and size distributions of the particulate matters. The drawbacks of MOUDI are expensive, difficult to operate, and very time-consuming if the pollutant concentration is low. On that account, the real time monitors are preferred. However, they also come with the sorts of limitations. According to a preliminary study, e.g.: aerosol number concentration by the motorcycle was over lo3 particles per cubic meter, which is beyond the working range of most of the real time instruments. Consequently, a simpler, rugged, and easy-toconstruct diluter is needed to reduce the aerosol number concentration. The aerosol deposition in the diluter was measured and presented as a function of particle size. In this study, the diluter was used to determine the aerosol number concentration and size distribution exhausted by a two-stroke engine operated under idle condition. The results showed that it took over 10 min for the engine to warm up under idle condition. The count median diameter (CMD) of the discharged aerosol particles was about 236 nm, with the geometric standard deviation (GSD) was 1.57. After reaching the steady state, the CMD and GSD reduced to 198 nm and 1.55, respectively, with the number concentration around 1.6 x lo* particles per cubic meter. The aerosol charge was measured to be 0.0038 elementary charge per particle, by using an aerosol electrometer. As air/fuel ratio increased, the particle number concentration decreased, so did the CMD. The content of lubrication oil appeared to be the major contributor to increase in the size of the exhaust particles.