• 토지주택연구
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• 제11권4호
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• pp.93-98
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• 2020

This study examined the particulate removal performance of three different types of air filters inside a heat exchanger. Of interest was the ability of each filter type in reducing the transmission of outdoor particulate matter of PM10 from entering an apartment while the heat exchanger was in operation. The study tested one commonly used medium filter (E11 grade) and two HEPA filters (H13 grade) of different thicknesses. Two different concentrations of particulate matter were used in the experiment to address different ambient air quality conditions in Korea, 32.75 ㎍/㎥ and 67.26 ㎍/㎥. Study results indicated that under the particulate matter concentration of 32.75 ㎍/㎥, all three filters were capable of removing more than 95% of the fine dust. However at a particulate matter concentration of 67.26 ㎍/㎥, the medium E11 grade filter was only able to remove about 90% of the particulates whereas the HEPA H13 grade filters were able to remove 95% or more of the particulates. The thicker HEPA filter (40T) was also more effective in removing particulates than the thinner HEPA filter (20T) by about 1.6 to 3 percentage points. Based on the findings of this study, it is recommended that HEPA filters of 20T thickness or greater be used during the high air pollution seasons of winter and spring in Korea while medium filters can be used during the other seasons to reduce outdoor air pollution transmission indoors.

• Environmental Analysis Health and Toxicology
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• 제25권1호
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• pp.27-40
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• 2010

The current study was designed to scientifically evaluate the atmospheric particulate pollution in residences relative to their proximity to a Korean major iron/metal industrial complex (IMIC). This objective was achieved by measuring the concentrations and elemental composition of particulate matter with aerodynamic diameters equal to or less than 10 ${\mu}m$(PM10) in industrial ambient air from IMIC and residential ambient air with relative proximities to IMIC. The trace metals were analyzed using an inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The industrial mean values exceeded the Korean year/70-${\mu}g/m^3$ standard for PM10, whereas the residential mean values did not. However, the maximum residential values did exceed or were close to the Korean PM10 year standard. For individual elements, the ambient concentrations ranged widely from values in the order of a few $ng/m^3$ to thousands of $ng/m^3$. The residential mean mass concentrations in the PM10 measured in the present study were higher than or similar to those reported in earlier studies. This study suggests that residents in neighborhoods near the IMIC are exposedto elevated particulate levels compared to residents living further away from such a source.

• 한국산업보건학회지
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• 제27권1호
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• pp.46-58
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• 2017

Objectives: Particulate matter (PM) at construction sites mostly originates from either construction activities or the atmospheric environment. This study was conducted to evaluate the exposure level to PM and the contribution ratio of atmosphere sources at construction sites. Methods: We reviewed literature and governmental systems related to PM exposure in occupational settings and summarized them. In the field evaluation, five construction sites and one golf course were selected: two from Gyeonggi-do Province and four from North Gyeongsang-do Province. For each site, personal samples from outdoor construction workers and area samples from the outdoor area around the construction site office were collected according to construction work types. PM concentrations reported from nearby National Ambient Air Monitoring Stations were recorded. Respirable dust concentrations, respirable silica concentrations, and several metal concentrations including Cd, Cr, Pb, and As were monitored over four months. In the end we suggested how to manage particulate matter exposure at construction sites. Results: There was little literature reporting on exposure levels of construction workers to PM. Respirable dust concentrations measured in Gyeonggi-do Province were higher than those measured in North Gyeongsang-do Province. The geometric means of respirable dust concentrations in personal samples and area samples were $37.89{\mu}g/m^3$ and $92.86{\mu}g/m^3$, respectively. The respirable dust concentrations were higher than the PM concentrations reported from nearby National Ambient Air Monitoring Station. The geometric means of respirable silica concentrations of personal samples and area samples were $1.3{\mu}g/m^3$ and $1.1{\mu}g/m^3$, respectively. All metal concentrations were lower than 10% of individual Korean occupational exposure limits. Conclusions: Assuming that personal samples consisted of ambient PM and dust originating from work activities and area samples only collected ambient PM, we concluded that the dust exposure of outdoor construction workers originated 40.8% from the atmosphere and 59.2% from construction activities. PM exposure at construction sites should be controlled by employers, as in the case of outdoor heat stress. The Korean government needs to consider setting an occupational exposure limit for respirable dust.

• Journal of Preventive Medicine and Public Health
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• 제33권3호
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• pp.306-312
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• 2000

Background : Polycyclic aromatic hydrocarbons (PAH) are well known environmental pollutants. The measurement of PAH in ambient air is not commonly used, because it is quite difficult to perform and is unreliable. Using biomarkers of PAH can be an alternative approach to this problem. The PAH in ambient air is absorbed in particulate matter. Total suspended particulate(TSP) or particulate matter of less than $10{\mu}m$ in diameter (PM10) can be easily measured. Therefore, TSP or PM10 can be used as a surrogate measurements of ambient air PAH. Objectives : We investigated whether the urinary concentration of two biomarkers of PAH, 1-hydroxypyrene (1-OHP) and 2-naphthol, could reflect the total suspended particulate in the general population. Methods : In order to exclude the effects of occupational exposure and smoking, first grade middle school students were included in this study. Four middle schools within a one kilometer boundary of ambient air monitoring stations were selected. Total suspended particulate was regarded as the marker of airborne PAH. Diet and smoking data were collected by self administered questionnaires, and spot urine samples were collected. Urinary 1-OHP and 2-naphthol were analyzed by high performance liquid chromatography. Results : The correlation between urinary 1-OHP, 2-naphthol and passive smoking was not statistically significant. The correlation between urinary 1-OHP and TSP indices was not statistically significant. The correlations between urinary 2-naphthol and TSP of two lag days, one lag day, and zero lag days were statistically significant. The statistical significance of two lag days was the strongest (p=0.001), one lag day was the next (p=0.0275), and zero lag days was the weakest (p=0.0349). Conclusion : Our results imply that the urinary concentration of 2-naphthol can be applied as a PAH exposure marker for the general population with low PAH exposure.

• 한국환경독성학회:학술대회논문집
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• 한국환경독성학회 2002년도 추계국제학술대회
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• pp.155-155
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• 2002

Ambient urban particulate matters contain various transition metals. When the particulate matters are inhaled into the lung, not all but some part of metals from the particles might be mobilized to participate in a reaction that can damage various biomolecules, such as DNA and proteins. The dust particle size as well as organic acids may influence the metal mobilization. Thus, the mobilization of the metal from SRM1648 (NIST, USA) and urban particulate matters (PM2.5 and PM10) was measured in the presence of artificial or biological chelator with or without reductant. The degree of the mobilization was higher with the artificial or biological chelator than the control with saline. In some cases, a reductant increased the mobilization as much as about 5 times the control without the reductant. Especially, the mobilization of Fe was greatly influenced by the presence of reductants. In general, the degree of the mobilization of the transition metal was higher with PM2.5 than with PM10. Therefore, it is expected that, considering the previously known toxicities of the transition metals, the PM2.5 is more damaging to various biomolecules than PM10. The results also suggest that not the total amount but the mobilizable fraction of the metal in the dust particles should be considered with regard to the toxicity of the urban particulate matters.

• Annals of Occupational and Environmental Medicine
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• 제35권
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• pp.51.1-51.15
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• 2023

Background: Recently, there has been increasing worldwide concern about outdoor air pollution, especially particulate matter (PM), which has been extensively researched for its harmful effects on the respiratory system. However, sufficient research on its effects on cardiovascular diseases, such as hypertension, remains lacking. In this study, we examine the associations between PM levels and hypertension and hypothesize that higher PM concentrations are associated with elevated blood pressure. Methods: A total of 133,935 adults aged ≥ 40 years who participated in the Korean Genome and Epidemiology Study were analyzed. Multiple linear regression analyses were conducted to investigate the short- (1-14 days), medium- (1 and 3 months), and long-term (1 and 2 years) impacts of PM on blood pressure. Logistic regression analyses were conducted to evaluate the medium- and long-term effects of PM on blood pressure elevation after adjusting for sex, age, body mass index, health-related lifestyle behaviors, and geographic areas. Results: Using multiple linear regression analyses, both crude and adjusted models generated positive estimates, indicating an association with increased blood pressure, with all results being statistically significant, with the exception of PM levels over the long-term period (1 and 2 years) in non-hypertensive participants. In the logistic regression analyses on non-hypertensive participants, moderate PM₁₀ (particulate matter with diameters < 10 ㎛) and PM_2.5 (particulate matter with diameters < 2.5 ㎛) levels over the long-term period and all high PM₁₀ and PM_2.5 levels were statistically significant after adjusting for various covariates. Notably, high PM_2.5 levels of the 1 year exhibited the highest odds ratio of 1.23 (95% confidence interval: 1.19-1.28) after adjustment. Conclusions: These findings suggest that both short- and long-term exposure to PM is associated with blood pressure elevation.

• Journal of Mechanical Science and Technology
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• 제20권1호
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• pp.1-12
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• 2006

This work reviews the effects of catalyst formulation and exhaust gas composition on soot oxidation in CDPF (Catalytic Diesel Particulate Filter). DOC's (Diesel Oxidation Catalysts) have been loaded with Pt catalyst (Pt/$Al_{2}O_3$) for reduction of HC and CO. Recent CDPF's are coated with the Pt catalyst as well as additives like Mo, V, Ce, Co, Fe, La, Au, or Zr for the promotion of soot oxidation. Alkali (K, Na, Cs, Li) doping of metal catalyst tends to increase the activity of the catalysts in soot combustion. Effects of coexistence components are very important in the catalytic reaction of the soot. The soot oxidation rate of a few catalysts are improved by water vapor and NOx in the ambient. There are only a few reports available on the mechanism of the PM (particulate matter) oxidation on the catalysts. The mechanism of PM oxidation in the catalytic systems that meet new emission regulations of diesel engines has yet to be investigated. Future research will focus on catalysts that can not only oxidize PM at low temperature, but also reduce NOx, continuously self-cleaning diesel particulate filters, and selective catalysts for NOx reduction.

• Environmental Engineering Research
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• 제19권4호
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• pp.331-338
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• 2014

Descriptive statistics methods were used to study the spatiotemporal variations and sources of ambient particulate matter ($PM_{10}$) in Luzhou, China. The analyzed datasets were collected from four national air quality monitoring stations: Jiushi (S1), Xiaoshi (S2), Zhongshan (S3), Lantian (S4) over the period of 2003-2012. This city was subjected serious $PM_{10}$ pollution, and the long-term annual average $PM_{10}$ concentrations varied from 76 to $136{\mu}g/m^3$. The maximum concentration was more than 3-fold of the annual average ($40{\mu}g/m^3$) issued by EPA-China for the ambient air quality. General temporal pattern was characterized by high concentrations in winter and low concentrations in summer, and general spatial gradient was in the reduction order of S2 > S4 > S3 > S1, which were both due to different particulate contributors and special meteorological conditions. The source apportionment indicated that vehicular emissions, road dusts, coal burning and chemical dusts were the major contributors of the identified $PM_{10}$ pollution, and the vehicular emissions and the road wear re-suspended particles dominated the heavy $PM_{10}$ pollution in recent years. Two other potential sources, agricultural and celebration activities could decrease the air quality in a short term. Finally, some corresponding suggestions and measures were provided to improve the air quality.

• 한국환경복원기술학회지
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• 제23권1호
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• pp.89-96
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• 2020

Adverse impact of Particulate Matters(PM10, PM2.5; PMs) significantly affects daily lives. Major countermeasures for reducing concentration of PMs were focused on emission source without considering spatial difference of PMs concentration. Thus, this study analyzed spatial·temporal distribution of PMs with observation data as well as potential contributing factors on PMs concentration. The annual average concentration of PMs have been decreased while the particulate matter warnings and alerts were significantly increased in 2018. The average concentration of PMs in spring and winter was higher than the other seasons. Also, the spatial distribution of PMs were also showed seasonality while concentration of PMs were higher in Seoul-metropolitan areas in all seasons. Climate variables, emission source, spatial structure and potential PM sinks were selected major factors which could affects on ambient concentrations of PMs. This paper suggest that countermeasures for mitigating PM concentration should consider characteristics of area. Climatic variables(temperature, pressure, wind speed etc.) affects concentrations of PMs. The effects of spatial structure of cities(terrain, ventilation corridor) and biological sinks(green infrastructure, urban forests) on concentration of PMs should be analyzed in further studies. Also, seasonality of PMs concentration should be considered for establishing effective countermeasures to reduce ambient PMs concentration.

• 한국대기환경학회:학술대회논문집
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• 한국대기환경학회 2010년도 춘계학술대회 논문집
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• pp.526-527
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• 2010