• Safety and Health at Work
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• v.14 no.3
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• pp.279-286
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• 2023

Background: This study aimed to evaluate the association between exposure to occupational hazards and the metabolic syndrome. A secondary objective was to analyze the additive and multiplicative effects of exposure to risk factors. Methods: This retrospective cohort was based on 31,615 health examinees at the Pusan National University Yangsan Hospital in Republic of Korea from 2012-2021. Demographic and behavior-related risk factors were treated as confounding factors, whereas three physical factors, 19 organic solvents and aerosols, and 13 metals and dust were considered occupational risk factors. Time-dependent Cox regression analysis was used to calculate hazard ratios. Results: The risk of metabolic syndrome was significantly higher in night shift workers (hazard ratio = 1.45: 95% confidence interval = 1.36-1.54) and workers who were exposed to noise (1.15:1.07-1.24). Exposure to some other risk factors was also significantly associated with a higher risk of metabolic syndrome. They were dimethylformamide, acetonitrile, trichloroethylene, xylene, styrene, toluene, dichloromethane, copper, antimony, lead, copper, iron, welding fume, and manganese. Among the 28 significant pairs, 19 exhibited both positive additive and multiplicative effects. Conclusions: Exposure to single or combined occupational risk factors may increase the risk of developing metabolic syndrome. Working conditions should be monitored and improved to reduce exposure to occupational hazards and prevent the development of the metabolic syndrome.

• Safety and Health at Work
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• v.14 no.3
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• pp.287-294
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• 2023

Background: Fruit and vegetable market is an abundant source of bioaerosols. Exposure to organic and inorganic waste and long-term inhalation of bioaerosols during working hours leads to chronic respiratory symptoms. Hence, this study aimed to determine the prevalence of chronic respiratory symptoms and related factors among fruit and vegetable workers compared with the control group in Addis Ababa, Ethiopia. Methods and materials: A comparative cross-sectional study was conducted from 2020 to 2021. Data were entered in EpiData 3.1 and exported to Statistical Package for the Social Sciences (SPSS) version 25. Logistic regressions were computed to depict the data and related factors. The culture method was done to count and compare bacterial and fungal concentrations between fruit and vegetable workers and office workers. Results: In this study, the prevalence of chronic respiratory symptoms (PR = 2.87, 95% confidence interval [CI]: 1.772-4.66) was significantly higher among fruit and vegetable workers (46.7%) than controls (23.4%). Sex (adjusted odds ratio [AOR] = 2.11, 95% CI = 1.12-3.98), educational status (AOR = 1.34, 95% CI = 0.78-2.32), working hours per day (AOR = 3.91, 95% CI = 1.586-9.65), and working department (AOR = 3.20, 95% CI = 0.90-11.40) were associated with chronic respiratory symptoms. Bacterial and fungal concentrations were significantly higher in the air of the vegetable market (276 colony-forming unit) than the air in the workplace of controls (7 colony-forming unit). Conclusion: The fruit and vegetable market workers (greengrocers) had a higher prevalence of chronic respiratory symptoms relative to office workers. Respiratory protective devices should be given to deliver preventive measures.

• Journal of the Korean Institute of Landscape Architecture
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• v.48 no.5
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• pp.80-88
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• 2020

With the issuance of one-week fine dust emergency reduction measures in March 2019, the public's anxiety about fine dust is increasingly growing. In order to assess the application of air purifying plant-based bio-filters to public facilities, this study presented a method for measuring pollutant reduction effects by creating an indoor environment for continuous discharge of particle pollutants and conducted basic studies to verify whether indoor air quality has improved through the system. In this study conducted in a lecture room in spring, the background concentration was created by using mosquito repellent incense as a pollutant one hour before monitoring. Then, according to the schedule, the fine dust reduction capacity was monitored by irrigating for two hours and venting air for one hour. PM₁₀, PM_2.5, and temperature & humidity sensors were installed two meters front of the bio-filters, and velocity probes were installed at the center of the three air vents to conduct time-series monitoring. The average face velocity of three air vents set up in the bio-filter was 0.38±0.16 m/s. Total air-conditioning air volume was calculated at 776.89±320.16㎥/h by applying an air vent area of 0.29m×0.65m after deducing damper area. With the system in operation, average temperature and average relative humidity were maintained at 21.5-22.3℃, and 63.79-73.6%, respectively, which indicates that it satisfies temperature and humidity range of various conditions of preceding studies. When the effects of raising relatively humidity rapidly by operating system's air-conditioning function are used efficiently, it would be possible to reduce indoor fine dust and maintain appropriate relative humidity seasonally. Concentration of fine dust increased the same in all cycles before operating the bio-filter system. After operating the system, in cycle 1 blast section (C-1, β=-3.83, β=-2.45), particulate matters (PM₁₀) were lowered by up to 28.8% or 560.3㎍/㎥ and fine particulate matters (PM_2.5) were reduced by up to 28.0% or 350.0㎍/㎥. Then, the concentration of find dust (PM₁₀, PM_2.5) was reduced by up to 32.6% or 647.0㎍/㎥ and 32.4% or 401.3㎍/㎥ respectively through reduction in cycle 2 blast section (C-2, β=-5.50, β=-3.30) and up to 30.8% or 732.7㎍/㎥ and 31.0% or 459.3㎍/㎥ respectively through reduction in cycle 3 blast section (C-3, β=5.48, β=-3.51). By referring to standards and regulations related to the installation of vegetation bio-filters in public facilities, this study provided plans on how to set up objective performance evaluation environment. By doing so, it was possible to create monitoring infrastructure more objective than a regular lecture room environment and secure relatively reliable data.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.123-128
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• 2012

An overview of the North Ecliptic Pole (NEP) deep multi-wavelength survey covering from X-ray to radio wavelengths is presented. The main science objective of this multi-wavelength project is to unveil the star-formation and AGN activities obscured by dust in the violent epoch of the Universe (z=0.5-2), when the star formation and black-hole evolution activities were much stronger than the present. The NEP deep survey with AKARI/IRC consists of two survey projects: shallow wide (8.2 sq. deg, NEP-Wide) and the deep one (0.6 sq. deg, NEP-Deep). The NEP-Deep provides us with a $15{\mu}m$ or $18{\mu}m$ selected sample of several thousands of galaxies, the largest sample ever made at these wavelengths. A continuous filter coverage at mid-IR wavelengths (7, 9, 11, 15, 18, and $24{\mu}m$) is unique and vital to diagnose the contribution from starbursts and AGNs in the galaxies at the violent epoch. The recent updates of the ancillary data are also provided: optical/near-IR magnitudes (Subaru, CFHT), X-ray (Chandra), FUV/NUV (GALEX), radio (WSRT, GMRT), optical spectra (Keck/DEIMOS etc.), Subaru/FMOS, Herschel/SPIRE, and JCMT/SCUBA-2.

• Journal of Environmental Health Sciences
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• v.34 no.4
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• pp.300-310
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• 2008

In order to further determine the mass concentration and ion composition of size-segregated particulate matter (PM) during the non-Asian dust storm of spring, $PM_{2.5}$ (fine particle), $PM_{10-2.5}$ (coarse particle), and $PM_{over-10}$ (PM with an aerodynamic diameter larger than $10{\mu}m$) were collected using a MCI (multi-nozzle cascade impactor) sampler of a three-stage filter pack in the spring season of 2007 in the Iksan area. During the sampling period from 5 April to 21 April, a total of 34 samples for size-segregated PM were collected, and then measured for PM mass concentrations by gravimetric measurements and for water-soluble inorganic ion species by using ion chromatography. Average mass concentrations of $PM_{2.5}$, $PM_{10-2.5}$, $PM_{over-10}$ were $35.4{\pm}11.5{\mu}g/m^3$, $13.3{\pm}5.5{\mu}g/m^3$ and $9.5{\pm}4.7{\mu}g/m^3$, respectively. On average, $PM_{2.5}$ accounted for 74% of $PM_{10}$. Compared with the literature from other areas in Korea, the measured concentration of $PM_{2.5}$ were relatively high. Water-soluble inorganic ion fractions in $PM_{2.5}$, $PM_{10-2.5}$, and $PM_{over-10}$ were found to be 47.8%, 28.5%, and 14.7%, respectively. Among the water-soluble inorganic ion species, $SO_4^{2-}$, $NO_3^-$ and $NH_4^+$ were the main components in $PM_{2.5}$, while $NO_3^-$ dominantly existed in both $PM_{10-2.5}$ and $PM_{over-10}$. Non-seasalt $SO_4^{2-}$ (nss-$SO_4^{2-}$ and $NO_3^-$ were found to mainly exist as the neutralized chemical components of $(NH_4)_2SO_4$ and $NH_4NO_3$ in fine particles.

• Publications of The Korean Astronomical Society
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• v.32 no.1
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• pp.213-217
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• 2017

The recent updates of the North Ecliptic Pole deep ($0.5deg^2$, NEP-Deep) multi-wavelength survey covering from X-ray to radio-wave is presented. The NEP-Deep provides us with several thousands of $15{\mu}m$ or $18{\mu}m$ selected galaxies, which is the largest sample ever made at these wavelengths. A continuous filter coverage in the mid-infrared wavelength (7, 9, 11, 15, 18, and 24 µm) is unique and vital to diagnose the contributions from starbursts and AGNs in the galaxies out to z=2. The new goal of the project is to resolve the nature of the cosmic star formation history at the violent epoch (e.g. z=1-2), and to find a clue to understand its decline from z=1 to present universe by utilizing the unique power of the multiwavelength survey. The progress in this context is briefly mentioned.

• Journal of Environmental Health Sciences
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• v.40 no.1
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• pp.10-16
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• 2014

Objectives: This pilot study assessed secondhand smoke (SHS) exposure in smoking and non-smoking nightclubs in Seoul, Korea by measuring the concentration of particulate matter smaller than $2.5{\mu}m$ ($PM_{2.5}$). Methods: This comparative study was conducted in three nightclubs in Seoul. While one non-smoking nightclub was measured on weekdays and weekends, different smoking nightclubs were measured on weekdays and weekends. The concentration of $PM_{2.5}$ was observed using a real-time monitor over an average of three hours. The number of people in the clubs was also estimated. Settled dust was collected in a smoking and a non-smoking nightclub and analyzed for NNK concentration. Results: The $PM_{2.5}$ concentration in the smoking nightclubs was higher than those found in the non-smoking nightclub by 26 times on weekdays and three times on weekends. Indoor $PM_{2.5}$ concentration was correlated with the number of people in the smoking nightclubs. Relatively high $PM_{2.5}$ concentration was observed in the non-smoking nightclub on weekends. NNK concentration in the smoking nightclub was 7 times higer than in the non-smoking nightclub. Conclusion: Smoking in nightclubs caused high $PM_{2.5}$ concentration. Although the non-smoking nightclub had a lower $PM_{2.5}$ concentration, $PM_{2.5}$ concentration on weekends was higher due to the smoking room. Complete prohibition of smoking in nightclubs can protect patrons from secondhand smoke exposure.

• The Journal of Internal Korean Medicine
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• v.38 no.6
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• pp.891-901
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• 2017

Objectives: The aim of the study was to evaluate the anti-asthmatic effect of alismatis rhizoma and alisol acetate B combination therapy in a murine asthma model. Methods: C57BL/6 mice were sensitized to and challenged with a mixture of ragweed, dust mite, and aspergillus to induce an asthma animal model. Alismatis rhizoma extract and alisol acetate B combination therapy was co-administered only in the experimental group. To evaluate the anti-asthmatic effect of the combination therapy, inflammatory cell counts in bronchoalveolar lavage (BAL) fluid were determined, and tissue was examined histologically with hematoxylin and eosin (H & E) and periodic acid-Schiff (PAS) stains, by enzyme-linked immunosorbent assay (ELISA) of IgE, IL-4, and IL-5, and with reverse transcription polymerase chain reaction (RT-PCR) of IL-5, IL-33, MUC5AC. Results: Alismatis rhizoma and alisol acetate B combination therapy reduced the number of inflammatory cells, alleviated histologic features, and down-regulated all the investigated asthma mediators, IgE, IL-4, IL-5, IL-33, and MUC5AC. Conclusions: According to the above results, alismatis rhizoma and alisol acetate B combination therapy may have therapeutic potential for asthma.

• Parasites, Hosts and Diseases
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• v.54 no.4
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• pp.447-453
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• 2016

Acanthamoeba, a free-living amoeba, is widely distributed in the environment, water sources, soil, dust, and air. It can cause keratitis in contact lens wearers with poor hygiene and also fatal granulomatous amebic encephalitis (GAE) in immunocompromised hosts. The aim of this study was to gain some insights into the distribution and genotypes of the potentially pathogenic species of Acanthamoeba present in water sources in north of Iran. Total 43 Acanthamoeba species were isolated from 77 water samples taken from different water sources within the Mazandaran province in Northern Iran (Sari city and suburbs). Isolates were identified based on cyst and trophozoite morphological characteristics as well genetics. PCR fragments corresponding to the small-subunit 18S rRNA gene were sequenced for 20 of 43 positive isolates. The results revealed that 83.3% of sequenced isolates belonged to the T4 genotype and the rest belonged to the T2 genotype. Our results indicated that Acanthamoeba is widely distributed in Sari city. As the incidence in Iran of amoebic keratitis has increased in recent years, the exact estimation of the prevalence of this amoeba and its predominant genotype may play a crucial role in prevention of the disease. Sari city has several rivers, seashores, and natural recreational amenities, which attract visitors during the year. This is the first report of Acanthamoeba genotypes from water sources in Sari city, Mazandaran province of Iran, and the results suggest that more attention is needed to protect the visiting population and immunocompromised individuals.

• Hwankyungkyoyuk
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• v.20 no.3
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• pp.63-75
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• 2007

This paper focused on examining the middle school students' perceptions of characteristics(personal knowledge, human responsibility, impact on personal life, and predicted trend, behavior will) of 10 global and 8 local environmental issues. Subjects(N=516) demonstrated by completing a survey that they perceived the characteristics of issues differently on global and local scales, and to a degree those characteristics are related. First, middle school students' perceptions of global and local environmental issues were above mid-point mainly, and perceptions of local environmental issues were higher than those of global environmental issues. At perceptions of characteristics, They perceived that the personal knowledge of global environmental issues were higher than those of local issues, that the human responsibility effects on global environmental issues more than local environmental issues, that global environmental issues in the future, will be more serious. For each environmental issues, the perception of global warming among the global issues was highest, the perception of yellow dust and air pollution among the local issues was highest. For perceptions of characteristics, behavior will to solve the environmental issues was lower than that of 4 characteristics(personal knowledge, human responsibility, impact on personal life, and predicted trend). Second, there was significant difference of the perceptions of two scale environmental issues for area and sex. It showed that Seoul students' perceptions were higher than Kong-ju students' perceptions according to area, and that girl students' perceptions were higher than boy students' perceptions according to sex. Third, correlations among issues were significant. Especially, it was positive relationship between knowledge and human responsibility, human responsibility and impact on personal human responsibility and predicted trend. Educators and communicators should take into account the perceived characteristics of environmental issues and choose effective information sources and teaching methods to improve students' understanding of human-induced environmental changes.