• Proceedings of the Korea Air Pollution Research Association Conference
• /
• 1999.04a
• /
• pp.289-290
• /
• 1999

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.26 no.3
• /
• pp.324-333
• /
• 2016

Objectives: We aimed to compare the sampling performance of different flow-based impactor samplers for collecting fungal spores and bacteria and to explore the association of the level of bioaerosols with activity patterns of occupants in daycare center settings. Methods: For comparison of sampling performance, two different flow-based samplers (greater than 100 L/min or not) were selected; a low flow-based sampler (one-stage Andersen sampler) and two high flow-based samplers (DUO SAS SUPER 360 sampler, BUCK bio-culture sampler). We collected airborne mold and bacteria in 30 daycare centers with various levels of contaminated air. Three repeat samplings per each sampler were performed. Mold and bacteria were grown for 96 hours at $25{\pm}1^{\circ}C$ and 48 hours at $35{\pm}1^{\circ}C$, respectively. The Andersen and SAS samplers were used for investigating the association between the level of bioaerosols and the activity patterns of occupants in daycares. Particular matters 10($PM_{10}$), temperature, and relative humidity were monitored as well. Samplings were carried out with one-hour interval from 9 to 5 O'clock. For statistical comparisons, Kruskal-Wallis test, Wilcoxon's signed rank test, and multiple regression analysis were carried out. Results: The airborne level of molds by the low flow-based sampler were significantly higher than that of high flow-based samplers (indoor, P=0.037; outdoor, P=0.041). However, no statistical difference was observed in the airborne level of bacteria by each sampler. Also the level of bioaerosols varied by the time, particularly with different activity patterns in daycare centers. The higher level of mold and bacteria were observed in play time in indoor. Similarly, the concentrations of $PM_{10}$ were significantly associated with the level of bioaerosols (P<0.05). Conclusions: Our findings indicate that the flow rate of sampler, rather than total air volume, could be able to affect the results of sampling. Also, the level of airborne mold and bacteria vary behavior patterns of occupants in indoor of daycare settings. Therefore, different samplers with other flow rate may be selected for mold or bacteria sampling, and activity patterns should be considered for bioaerosol sampling as well.

• Journal of Korean Society for Atmospheric Environment
• /
• v.18 no.E2
• /
• pp.69-77
• /
• 2002

The nationwide NO$_2$monitoring program has been carried out using the passive sampler in Korea since 1993. During the sixteenth periods of measurement, total 26,474 sites of data were collected through eight years. In this paper, the roadside NO$_2$concentration of six major cities were analyzed. As results, the most frequent NO$_2$concentration of Seoul, Incheon, and Daegu ranged from 40 to 60 ppb, and that of Pusan, Kwanju, and Daejeon was from 20 to 40 ppd. Despite that the automobile number of Incheon was less than that of Daegu and Pusan, the exceedence rate of Korean national ambient air quality standard and ninetieth percentile concentration of Incheon were almost the same level as Seoul. In addition, the mean and standard deviation of roadside NO$_2$concentration of Seoul and Incheon was also appeared to be higher than that of other cities. These results indicates that NO$_2$concentration on roadside was affected by the traffic volumes and the traffic flow conditions.

• Journal of Korean Society for Atmospheric Environment
• /
• v.18 no.5
• /
• pp.383-391
• /
• 2002

Six types of ozone passive samplers were fabricated with three different filter substrates and two colorants, and tested for their feasibility on atmospheric monitoring. These passive samplers are based on a colorant which fades (indigo carmine and ChromAir (K&M environmental Inc.)) or produces color (mixture of 3-methyl-2-benzothiazolinone acetone azine and 2-phenylphenol colorant) upon reaction with ozone, whose concentration can be determined by reflectance measurement of the color change. Three filters, namely Whatman No.1 paper, SG81 chromatography paper and Silica Gel coated on polyester (TLC Plates), were prepared and coated with two colorants. The response of these passive samplers in ozone chamber were tested and compared with ChromAir (K&M environmental Inc.) passive sampler. The response of Silica Gel filter impregnated with indigo carmine was the best at the constant concentration exposure.

• Journal of Korean Society for Atmospheric Environment
• /
• v.22 no.1
• /
• pp.117-126
• /
• 2006

The purpose of this study is to develop a badge-type passive sampler for the measurement of short-term nitrogen dioxide and to evaluate its performance. The principle of the method is a colorimetric reaction of nitrogen dioxide with sulfanilic acid, N-1-naphthylethylendiamine, and phosphoric acid. First, it has been shown that the filter paper should be rinsed with ultrapure water and ultrasound, and then dried in a vacuumed desiccator. The concentration and volume of absorption reagent (triethanolamine) were $20\%$ and 100 ${\mu}L$, respectively. The extraction time was determined as 60 min. Second, duplicate measurements (n= 116) were carried out for evaluating the precision of the passive sampler. The relative error and the correlation coefficient between duplicates are $3.4\pm 3.0\%$ and 0.994, respectively. In addition, the $95\%$ confidence interval of intraclass correlation coefficient and the estimated value are 0.992$\sim$0.996 and 0.994, respectively. Third, a paired t-test was carried out for evaluating the accuracy of the passive sampler (n=40). In the result of the test, the $95\%$ confidence interval of the difference was -1.710 ppb <$\gamma$< 0.788 ppb. Finally, the average concentration of blanks, measurement detection limit, limit of detection, and limit of quantification are $2.4\pm 0.4$ ppb, 104 ppb, 3.8 ppb, and 7.0 ppb, respectively.

• Journal of Korean Society for Atmospheric Environment
• /
• v.1 no.1
• /
• pp.93-98
• /
• 1985

Mass size distribution of atmospheric particulates were measured using an Andersen using an Andersen sampler in urban air. The atmospheric particulates were fractionated in eight stages of an Andersen sampler operating at 28.4$\ell/min$ and collected on polyester sheets. A quartz filter was placed behind the last stage collect permeated partculates. The size distribution of atmospheric particulates were divided around 1-2 $\mu$m into two groups, coarse and fine particulates regardless of sampling times. The variation of course particulates concentration was higher than fine particulates among sampling times. Different meterorological conditions and natural phenomena brought high variation of course particulates' concentration. The rain caused removal of coarse particulates seriously and the yellow and may take part in a increase of the course particulates in spring. The average concentration of atmospheric particulates to be collected by Andersen sampler was 170.8 $\mug/m^3$ during 3 times of sampling. Among them the average concentration of atmospheric particulates which could penetrated under a bronchi and alveoli were 70.4$\mug/m^3$ and 36.6$\mug/m^3$ respectively.

• Journal of the Korean Society of Safety
• /
• v.10 no.2
• /
• pp.105-112
• /
• 1995

The concentrations of $NO_2$ were measured to estimate a new developed long term exposure $NO_2$ sampler at Pusan City considering the meteorological factors from May to July, in 1994. The monthly mean concentration of $NO_2$ was 15.9 PPb and 36.2 ${\mu}\ell$/day $NO_2$ and their high values were shown in the downtown of Pusan City which show potential pollution due to the increase of traffic activities and micrometeorological factors In and around the City. As a result of statistical correlation between $NO_2$ concentration by new sampling method and $NO_2$ concentration by the handy air sampler and chemiluminescent nitrogen oxides analyzer, 1994, correlation coefficients were high(r=0.93) and showed more than 0.88 value in the high concentration data set, which was arbitrarily divided into 30${\mu}\ell$ $NO_2$ concentration in an attempt to further investigate these relationships. Therefore, use of new developed long term exposure $NO_2$ sampler is good for $NO_2$ measurement and valuable for estimation of air quality in the urban and Industrial area.

• Environmental engineer
• /
• s.158
• /
• pp.12-15
• /
• 1999

• Journal of Environmental Science International
• /
• v.1 no.1
• /
• pp.41-46
• /
• 1992

To perform a long-term ambient sampling study at a residential site, an air sampler was constructed to collect 24-hour integrated air samples suitable for the volatile organic compounds (VOCs) analysis. It includes an esthetically acceptance due to proximity to homes, as fell as providing the required sampling specifications. The VOCs sampler accomodates four 5/8 "stainless steel(SS) traps packed with adsorbent(Tenax) and is capable of four flow rates in the range of 5 to 50 cc/min. Sintered metal filters(10 micrometer) were directly connected to the inlet of the trap adapters. Additional specifications include: 1) constructed of organically inert materials, 2) weatherproof, 3) battery operated, 4) collecting of VOCs at a breathing zone level, and 5) quiet operation with micro diaphragm pumps wrapped by the sponge. The pump/battery system was separated from the sampling shelter. Sound levels measured for this system were below permissible sound levels (NJDEP) at a residential site. The sampler has been successfully operated at both ground level in a residential area and on the roof of a one story elementary school.hool.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.15 no.3
• /
• pp.261-269
• /
• 2005

To investigate the field applicability of a diffusive sampler (3M OVM #3500, passive sampling method) authors conducted a simultaneous measurement of personal organic solvents exposure in the air of the workplaces by charcoal tube with low volume sampler (active sampling method) and diffusive sampler. Samples were collected and analyzed by NIOSH method ($NMAM^{(R)}$) from thirty-eight workers in 12 factories who work in 6 different processes. Geometric mean (GM) and geometric standard deviation (GSD) were used to describe the result. To compare the results of the two methods, paired t-test was used. According to the manual of the exposure assessment of the mixed organic solvents (Ministry of Labor, Korea), Em was calculated. Simple linear regression was used to evaluate the relationship between the two methods. Results were as follows; 1. Eight different solvents (ethyl acetate, n-hexane, toluene, xylene, acetone, isopropyl alcohol, methyl ethyl ketone (MEK), and methyl isobutyl ketone) were detected simultaneously in the two methods and the concentrations of the personal exposure were lower than 0.5 TLV level. The concentration of the charcoal tube method was higher than that of a diffusive sampler in n-hexane and MEK (p<0.05). 2. Em of the charcoal tube method was higher than that of diffusive sampler method but not significantly different and was lower than the OEL (Occupational Exposure Limit) in all 6 processes. 3. There was a significant correlation between the two methods in low concentrations of the 8 organic solvents (p<0.05). In conclusion, there was no difference in charcoal tube method and diffusive sampler method in low concentrations of some organic solvents, diffusive sampler can be applied to assess the personal monitoring in low level exposure.