• Journal of the Korea Organic Resources Recycling Association
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• v.29 no.4
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• pp.5-13
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• 2021

Ammonia, primarily originating from urinary urea of the livestock manure, is known to play as a major precursor of fine particulate matter (PM2.5) generation which leads to a decrease in air quality and to harmful effects on public health. The objective of this study was to evaluate the effect of acetohydroxamic acid (AHA) addition on inhibition of ammonia conversion from urea. The experiment was performed at different urea concentration (500-4,000 mg Urea-N/L), AHA concentration (0-4,000 mg AHA/L), pHs (pH 6-10), and temperature (10-35℃). The result showed that the urease inhibition efficiency increased at higher concentration of AHA. However, the specific urease inhibition activity decreased at higher pH, showing 867.1±6.7 Unit/g AHA at pH 6 and 1,167.9±17.4 Unit/g AHA at pH 10, respectively. Decreased urease inhibition efficiency at both AHA and control was observed at higher temperature. This finding indicates that AHA can be used as the urease inhibitor for reducing ammonia emission in the management of livestock manure.

• Journal of the Korean Institute of Landscape Architecture
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• v.50 no.6
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• pp.30-41
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• 2022

This study investigates the heat mitigation effects and thermal comfort improvement due to urban parks during summer. Self-developed monitoring devices to measure long-term microclimate data were installed in three spots, including the park plaza, waterside, and roadside in Seoul Forest Park, and measurements were taken from July 9 to July 30. The results of the measurement are as follows. The daily temperature of the park plaza and waterside were found to be 2.7℃ and 2.9℃ lower than the roadside and 5.5℃ and 7.4℃ lower than the roadside from 10:00 to 16:00. In addition, the Universal Thermal Climate Index (UTCI) measurement was applied to measure the thermal comfort at each point. In the average daily analysis, a significant difference was found between the park plaza, the waterside, and the roadside, and a greater difference was found between 10:00 to 16:00. Also, although there was no significant difference due to the weather condition, a statistically significant difference was also found in the average PM₁₀ and CO₂ concentrations. It is found to be higher in the order from the roadside, park plaza, and waterside for PM₁₀ concentration and park plaza, roadside, and waterside for CO₂. In sum, although the difference in measured microclimate data and thermal comfort index results were different depending on the time and weather conditions at the three points, the park plaza and waterside, which are located inside the park, showed improved thermal comfort conditions and lower temperatures than the roadside outside the park.

• Journal of the Korean earth science society
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• v.32 no.3
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• pp.276-293
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• 2011

In this study a modeling system consisting of Weather Research and Forecasting (WRF), Sparse Matrix Operator Kernel Emissions (SMOKE), the Community Multiscale Air Quality (CMAQ) model, and the CMAQ-Model of Aerosol Dynamics, Reaction, Ionization, and Dissolution (MADRID) model has been applied to estimate enhancements of $PM_{10}$ during Asian dust events in Korea. In particular, 5 experimental formulas were applied to the WRF-SMOKE-CMAQ (MADRID) model to estimate Asian dust emissions from source locations for major Asian dust events in China and Mongolia: the US Environmental Protection Agency (EPA) model, the Goddard Global Ozone Chemistry Aerosol Radiation and Transport (GOCART) model, and the Dust Entrainment and Deposition (DEAD) model, as well as formulas by Park and In (2003), and Wang et al. (2000). According to the weather map, backward trajectory and satellite image analyses, Asian dust is generated by a strong downwind associated with the upper trough from a stagnation wave due to development of the upper jet stream, and transport of Asian dust to Korea shows up behind a surface front related to the cut-off low (known as comma type cloud) in satellite images. In the WRF-SMOKE-CMAQ modeling to estimate the PM10 concentration, Wang et al.'s experimental formula was depicted well in the temporal and spatial distribution of Asian dusts, and the GOCART model was low in mean bias errors and root mean square errors. Also, in the vertical profile analysis of Asian dusts using Wang et al's experimental formula, strong Asian dust with a concentration of more than $800\;{\mu}g/m^3$ for the period of March 31 to April 1, 2007 was transported under the boundary layer (about 1 km high), and weak Asian dust with a concentration of less than $400\;{\mu}g/m^3$ for the period of 16-17 March 2009 was transported above the boundary layer (about 1-3 km high). Furthermore, the difference between the CMAQ model and the CMAQ-MADRID model for the period of March 31 to April 1, 2007, in terms of PM10 concentration, was seen to be large in the East Asia area: the CMAQ-MADRID model showed the concentration to be about $25\;{\mu}g/m^3$ higher than the CMAQ model. In addition, the $PM_{10}$ concentration removed by the cloud liquid phase mechanism within the CMAQ-MADRID model was shown in the maximum $15\;{\mu}g/m^3$ in the Eastern Asia area.

• Journal of the Korean Society of Urban Environment
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• v.18 no.4
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• pp.531-546
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• 2018

Air quality forecasting system with Asian dust emissions was developed in East Asia, and $PM_{10}$ forecasting performance of chemical transport model with Asian dust emissions was validated and evaluated. The chemical transport model (CTM) with Asian dust emission was found to supplement $PM_{10}$ concentrations that had been under-estimated in China regions and improved statistics for performance of CTM, although the model were overestimated during some periods in China. In Korea, the prediction model adequately simulated inflow of Asian dust events on February 22~24 and March 16~17, but the model is found to be overestimated during no Asian dust event periods on April. However, the model supplemented $PM_{10}$ concentrations, which was underestimated in most regions in Korea and the statistics for performance of the models were improved. The $PM_{10}$ forecasting performance of air quality forecasting model with Asian dust emissions tends to improve POD (Probability of Detection) compared to basic model without Asian dust emissions, but A (Accuracy) has shown similar or decreased, and FAR (False Alarms) have increased during 2017.Therefore, the developed air quality forecasting model with Asian dust emission was not proposed as a representative $PM_{10}$ forecast model in South Korea.

• Journal of the Korean earth science society
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• v.43 no.2
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• pp.283-302
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• 2022

Despite the nationwide COVID-19 lockdown in China since January 23, 2020, haze days with high PM₁₀ levels of 88-98 ㎍ m^-3 occurred on February 1 and 2, 2020. During these haze days, the East Asian region was affected by a warm and stagnant air mass with positive air temperature anomalies and negative zonal wind anomalies at 850 hPa. The Weather Research and Forecasting model coupled with Chemistry (WRF-Chem) was used to analyze the variation of regional PM₁₀ aerosol transport in Korea due to decreased anthropogenic emissions in East Asia. The base experiment (BASE), which applies the basic anthropogenic emissions in the WRF-Chem model, and the control experiment (CTL) applied by reducing the anthropogenic emission to 50%, were used to assess uncertainty with ground-based PM₁₀ measurements in Korea. The index of agreement (IOA) for the CTL simulation was 0.71, which was higher than that of BASE (0.67). A statistical analysis of the results suggests that anthropogenic emissions were reduced during the COVID-19 lockdown period in China. Furthermore, BASE and CTL applied to zero-out anthropogenic emissions outside Korea (BASE_ZEOK and CTL_ZEOK) were used to analyze the variations of regional PM₁₀ aerosol transport in Korea. Regional PM₁₀ transport in CTL was reduced by only 10-20% compared to BASE. Synthetic weather variables may be another reason for the non-linear response to changes in the contribution of regional transport to PM₁₀ in Korea with the reduction of anthropogenic emissions in East Asia. Although the regional transport contribution of other inorganic aerosols was high in CTL (80-90%), sulfate-nitrate-ammonium (SNA) aerosols showed lower contributions of 0-20%, 30-60%, and 30-60%, respectively. The SNA secondary aerosols, particularly nitrates, presumably declined as the Chinese lockdown induced traffic.

• Journal of Korean Society of Environmental Engineers
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• v.30 no.10
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• pp.1006-1012
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• 2008

The effect of small and medium scale shipyard operations on environmental pollutions related with civil appeal of nearby residential areas was estimated. PM-10(particles with an aerodynamic diameter less than or equal to 10 $\mu$m) concentrations were higher, as the sampling sites were nearer from shipyards. PM-10 concentrations of sampling sites closer to shipbuilding companies were higher during the normal operation periods than on vacation at which only small works were done. The larger amount of dry deposition was observed as the sampling sites were closer to shipyards. The odor intensity was highly influenced by ambient temperature. Almost all odor intensities measured by air dilution sensory test went over the emission standard in summer. Odor properties measured by instrumental analysis were observed to exceed the emission standard enforced to the shipyards. Odor compounds such as ammonia, sulfur compounds and trimethylamine went over the standard. Concentrations of styrene and aldehydes were lower than the olfactory threshold. All equivalent sound levels measured at daytime except the value of SP-3 pont were in excess of the environmental standard. Almost all sound levels at nighttime in all measuring sites were higher than the environmental standard. The results of this study shows counterplans need to be established for reducing the civil appeal related pollutions in the research areas.

• Journal of the Korean Data and Information Science Society
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• v.26 no.6
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• pp.1409-1416
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• 2015

The change of temperature influences on the various aspect, especially human health, plant and animal's growth, economics, industry, and culture of the country. In this article, the autoregressive error (ARE) model has been considered for analyzing the monthly temperature data at the Suwon monitoring site in Korea. In the ARE model, five meteorological variables, four greenhouse gas variables and five pollution variables are used as the explanatory variables for the temperature data set. The five meteorological variables are wind speed, rainfall, radiation, amount of cloud, and relative humidity. The four greenhouse gas variables are carbon dioxide ($CO_2$), methane ($CH_4$), nitrous oxide ($N_2O$), and chlorofluorocarbon ($CFC_{11}$). And the five air pollution explanatory variables are particulate matter ($PM_{10}$), sulfur dioxide ($SO_2$), nitrogen dioxide ($NO_2$), ozone ($O_3$), and carbon monoxide (CO). Among five meteorological variables, radiation, amount of cloud, and wind speed are more influence on the temperature. The radiation influences during spring, summer and fall, whereas wind speed influences for the winter time. Also, among four greenhouse gas variables and five pollution variables, chlorofluorocarbon, methane, and ozone are more influence on the temperature. The monthly ARE model explained about 43-69% for describing the temperature.

• Journal of Environmental Health Sciences
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• v.46 no.6
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• pp.667-675
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• 2020

Objectives: Exposure to fine dust (PM10) could contribute to the occurrence of cardiovascular disease or respiratory abnormalities. Since garlic is known to possess an anti-oxidative stress effect, the present study was performed to evaluate the effect of garlic intake on fine dust-mediated pulmonary toxicity. Methods: Rats were intratracheally instilled with fine dust at 15 mg/kg body weight (BW)/day for five days following five-day intragastric intubation of garlic at 0.7 or 1.4 g/kgBW/day, or 13.1 mg/kgBW/day S-allyl-cysteine (SAC) as a reference component in garlic. Blood and bronchoalveolar lavage fluid (BALF) were collected. Results: Deposit of fine dust was visually and histopathologically observed in the lungs. Body weight gain during the instillation period was significantly lowered in all the groups instilled with fine dust. Neutrophil numbers in blood were significantly elevated in the fine dust alone group, but this alteration was diminished in the groups administered with garlic. Levels of serum glutathione were lower in the rats instilled with fine dust alone, and this decrease in the glutathione level seems dose-dependently compensated among the groups administered with garlic. Similar findings were observed in the BALF with statistical significance. Typical pulmonary histopathological observation related with inflammation was demonstrated in the lungs of the rats exposed to fine dust alone, whereas such histopathologic findings were not improved in the groups administered with garlic. Conclusion: The present study suggests that garlic intake could alleviate fine dust-mediated pulmonary or systemic toxicities. Further investigation is necessary to delineate the mechanism of garlic-mediated effects on pulmonary function.

• Journal of Environmental Health Sciences
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• v.49 no.6
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• pp.344-352
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• 2023

Background: With its developed port and related industries, the concentration of fine dust is high in Busan compared to other cities in South Korea. Many studies have reported the health effects of fine dust, but there has been a lack of information regarding concentrations of volatile organic compounds among those who exposed to high levels of fine dust. Objectives: This study aimed to define an area with high concentrations of particulate matter and perform biomonitoring surveys among the residents of the area. Methods: Air quality data was collected and the mean level of each district in Busan was derived. We then defined the area with the highest concentrations of PM₁₀ as a target site. Urine samples were collected from the 400 participants and analyzed for VOCs metabolites - trans,trans-Muconic Acid (t,t-MA) and N-AcetylS-(benzyl)-L-cysteine (BMA). Interviews were conducted by trained investigators to examine demographic information. The levels of t,t-MA and BMA were compared with representative South Korean population data (Korean National Environmental Health Survey). The association of the VOC metabolites and fine dust were analyzed by general linear regression analysis. Results: The mean of PM₁₀ in the target site was 42.50 ㎍/m³ from 2018 to 2020. Among the 400 participants in the target site, 74.8% were female and the average age of the participants was 66 years. The geometric mean of t,t-MA was 71.15 ㎍/g creatinine and the BMA was 7.00 ㎍/g creatinine among the residents. The levels were higher than the geometric mean from the 4th KoNEHS. The levels of t,t-MA showed significance in BMI, smoking status, and household income. BMA showed significance in gender and age. Conclusions: Compared to the general population of South Korea, the target site's residents had higher biomonitoring levels. Based on this study, continuous screening for high risk areas, including the target site, and biomonitoring of the residents are required.

• Journal of Korean Ophthalmic Optics Society
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• v.17 no.2
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• pp.215-222
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• 2012

Purpose: This study was performed to investigate the influence of indoor air qualities of an office environment on dry eye syndrome for wearing contact lens and non-wearing contact lens. Methods: To study the effects of indoor air qualities on dry eye syndrome for seventy-one subjects, $CO_2$, temperature, humidity, TSP, PM10, HCHO were measured. Each subject was tested by a McMonnie's dry eye syndrome questionnaire, a Schirmer Tear Test-I (S.T.T-I), a Schirmer Tear Test-II with anesthetics (S.T.T-II), and Tear film break-up time (T.B.U.T) in the their offices. Results: There was significant relation between the indoor air quality and dry eye syndrome for wearing contact lens and non-wearing when TSP was over $200{\mu}g/m^3$, PM10 was higher than $86.7{\mu}g/m^3$ and Formaldehyde was over $0.4{\sim}1.0{\mu}g/m^3$. However, there was no significant effect on dry eye syndrome with $CO_2$ (p=.0146), temperature (p=0.074) and humidity (p=0.053). Conclusions: It was indicated that $CO_2$, temperature and humidity were no effect on dry eye syndrome in the office environment. However TSP, PM10, formaldehyde, and wearing contact lens were effect on dry eye syndrome. Therefore, the entire management of wearing contact lens and the individual evaluation of the indoor air quality are required.