• Biomedical Science Letters
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• v.28 no.4
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• pp.317-321
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• 2022

Due to COVID-19 pandemic, wearing face masks is obligatory to prevent respiratory virus transmissions in the community. However, there are few studies of the desirable number of wearing a face mask, and how to store them for reuse. Therefore, in this study, a survey was conducted among 208 healthy adults, and 27 kf-94 masks worn for 1, 2, and 3 days were collected. To estimate the risk of bacterial contamination, we analyzed the extent of bacterial contamination of the BHI medium and 16S rRNA gene sequencing. With an increase in the number of days of using the mask, the degree of bacterial contamination of the used mask gradually increased. As a result of 16S rRNA PCR performed for strain identification, Staphylococcus, known as a pathogenic bacterium, was identified the most. In conclusion, we found that wearing a cotton KF mask provides an optimal environment for microbes, which are related to the skin and respiratory system, to thrive. Therefore, it is also important to reduce the risk of bacterial infection of the face mask with appropriate sterilization methods.

• Applied Chemistry for Engineering
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• v.34 no.6
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• pp.596-602
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• 2023

Chromium-based metal-organic frameworks (MIL-101(Cr)) were synthesized, and their potential use as a filling material for gas masks or protective clothing was assessed through adsorption experiments using diisopropyl methyl phosphate (DIMP) as a simulant for chemical warfare agents. MIL-101(Cr) was prepared using acetic acid (MIL-101(Cr)-A) and sodium hydroxide (MIL-101(Cr)-N) as modulators. The use of acetic acid as a modulator resulted in a larger specific surface area and a higher DIMP adsorption capacity. MIL-101(Cr)-A absorbed approximately 160% of its own weight of moisture when exposed to an environment with a relative humidity of 90% for 10 days, surpassing other adsorbents such as activated carbon. The DIMP adsorption capacity of MIL-101(Cr)-A decreased to about 40% of its initial adsorption capacity after 24 hours of exposure to an environment with a relative humidity of 90%. However, this capacity is still higher compared to that of activated carbon used in commercial gas masks, suggesting a high potential for future use as a filling material for gas masks or protective clothing.

• Korean Journal of Psychosomatic Medicine
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• v.32 no.1
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• pp.10-23
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• 2024

This study examines the changes in attractiveness and social perception of mask wearers during the COVID-19 pandemic. Before COVID-19, masks were seen as a sign of infection, decreasing the wearer's attractiveness. However, with the widespread normalization of mask-wearing during the pandemic, the perception mechanisms have become more complex. The attractiveness and social perception of mask wearers now vary based on factors such as the wearer's baseline attractiveness, race, and attitudes toward masks. Consequently, research findings on perception changes due to mask-wearing have been inconsistent. This inconsistency is due to the lack of standardized experimental methods and the failure to account for individual differences among participants, as well as insufficient theoretical background in the studies. From a psychiatric perspective, it is essential to formulate and test new hypotheses centered around the psychological mechanisms related to the human behavioral immune system when studying attractiveness perception during a pandemic. Notably, attention should be given to how differences in the activation of individuals' behavioral immune systems influence perceptions of mask wearers. Understanding these dynamics can provide crucial insights into how social perceptions and aversions impact mental health, thereby shedding light on various psychiatric issues that arise during infectious disease outbreaks.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.26 no.3
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• pp.350-366
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• 2016

Objectives: No 3D anthropometric analyses have been conducted for Korean children's faces for the purpose of designing respiratory protective devices. The aim of this study was to develop masks against yellow dust and fine particulates, particularly for children in Korea. Methods: This study utilized a 3D scanning method to obtain 16 facial anthropometric data from children, ages of 5 to 13 years old. A total of 144 boys and girls were recruited from the kindergarten, elementary schools and middle schools in Seoul. With facial dimensions obtained, cluster analysis was performed to categorize them into similar facial groups. For each cluster, an optimal mask was designed and manufactured using a 3D printer. In addition, lung function data were obtained from 62 subjects and compared with those of normal adults. The pulmonary physiological results were subsequently used to suggest a test method for mask certification. Results: Facial shapes were classified into tree clusters: small, medium, and large. The face width and length for the first group were small with high nosal protrusion. The face width and length for the second group were the largest among the three clusters. The third group had the largest angle of nose root - gnathion(n-prn-gn). Age was the most significant variable in the facial dimensions. Children's pulmonary physiological capacity was about 60% of adults' capacity. The results of fit test using the prototype masks developed showed very good fits for children. Conclusions: For Korean children, three mask sizes will be sufficient and practical for providing protection against yellow dust and fine particulates. Anthropometric data obtained using digitalized 3D face analysis can be very effective for designing respiratory devices. 3D images can be accurate and easily measured for multiple dimensions, particularly for curved areas of the face. It is imperative to adopt different test methods for certifying respiratory protective devices for children, since their pulmonary physiological capacity is inferior compared with that of adults.

• Environmental and Resource Economics Review
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• v.28 no.3
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• pp.355-383
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• 2019

This study is to investigate whether averting costs for wearing $anti-PM_{10}$ masks and using air purifiers at home to reduce exposure from $PM_{10}$ are influenced by subjective risk perceptions and/or objective $PM_{10}$ concentration levels, whose estimates will be used to measure the willingness to pay for $PM_{10}$ risk reduction. An empirical analysis was conducted on a sample of 1,224 respondents who participated in the web-based survey in the late October of 2017. As we reflect the potential endogeniety bias in the estimation of averting cost functions of using air purifiers, the coefficients of risk perception were differed by 6~7 times. Respondents. subjective risk perceptions were influenced by individuals' knowledge, attitudes and demographic variables, as well as the levels of $PM_{10}$ concentrations in their residential region. The marginal willingness to pay for risk reductions at the mean levels of their risk perceptions were measured at 1,000 won per month from wearing $anti-PM_{10}$ masks and 6,000 won for using air purifiers respectively.

• Journal of Environmental Health Sciences
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• v.46 no.6
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• pp.750-756
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• 2020

Objectives: After coronavirus disease 2019 (COVID-19) was declared a pandemic, the South Korean government announced guidelines on wearing masks to prevent its spread. The guidelines have changed depending on the severity of the spread of COVID-19. This study aimed to identify mask-wearing behaviours to counter the spread of COVID-19 in indoor and outdoor environments. Methods: The type of mask worn and proper wearing were observed in cafés, supermarkets, underground shopping malls, and streets in Seoul. Behavioral assessment was repeated in August at social distancing levels 1 and 2, in October at social distancing level 1, and in November after the mask mandates. Results: In August, 22.1% of subjects in cafés, 90.8% in supermarkets, 91.8% in underground shopping malls, and 83.6% on outdoor streets wore masks properly. In October, the proportion of correct wearers increased in all locations. After masks became mandatory in November, about 97% of users of supermarkets, underground shopping malls, and streets wore masks properly. In cafés, the proportion of proper wearers was 61.5% with both social distancing level 2 in August and the mandate in November. The number of KF-certified mask wearers continued to increase from August to November. Conclusion: This study investigated mask-wearing behaviors to counter COVID-19 through observations in indoor and outdoor places in Seoul. Mask-wearing behavior was different depending on the place and the government guidelines in place. The results could be used for evaluation of the current guidelines for COVID-19.

• Journal of the Korean Applied Science and Technology
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• v.38 no.2
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• pp.465-475
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• 2021

This study conducted an online and offline survey of 210 people from March 11 to 27, 2021 for the purpose of investigating and analyzing the current status of skin stress recognition and beauty care behavior due to wearing masks. The collected data were analyzed using SPSS 25.0 with Cronbach's α, Frequency Analysis, Chi-square test, and One way Anova. The average daily mask wearing time of more than 7 hours during the Covid-19 period was 43.8%, and skin stress recognition by wearing masks was highest among those in their 30s (M=4.27) and service workers (M=4.64), and those with acne and skin troubles (M=4.47) perceived high stress. The most important factor for home care treatment was cleansing(67.6%) and for beauty care was skin care(36.7%). Considerations factors on beauty care were 54.3% for service and customer care capabilities, and on body shape management method 45.7% for exercise. According to this study, respondents are recognizing skin stress due to the long-term use of masks, and home care treatment has been increasing as the esthetic salon has become unstable to visit due to the Covid-19 epidemic.

• The Korean Society of Law and Medicine
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• v.24 no.1
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• pp.67-98
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• 2023

In the early stages of the COVID-19 pandemic, Korea took the lead in implementing "social distancing" policies more strongly than other countries. In addition to making it mandatory to wear a mask according to the policy, all patients using medical institutions are tested for COVID-19 to prevent Healthcare-Associated Infections, and only those patients who test negative have been regulated to receive face-to-face medical treatment. In this process, situations such as the disabled, who have difficulty wearing masks, were not taken into account, and emergency patients did not receive timely treatment or surgery from medical personnel. In response, the National Human Rights Commission of Korea has decided that forcing everyone to wear a mask and restricting access to medical institutions constitutes discrimination against the disabled. Therefore, the purposes this study has that, the first is to review cases of human rights discrimination against persons with disabilities due to measures to prevent the transmission of infectious diseases that did not consider the characteristics of persons with disabilities in the COVID-19 situation and issues regarding the decisions of the National Human Rights Commission of Korea, the second is to find a reasonable plan and the need for measures to prevent refusal of treatment by medical institutions for the disabled who have difficulty wearing masks.

• (The) Research of the performance art and culture
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• no.22
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• pp.5-43
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• 2011

Before the Korean War, Korean mask dramas had been performed as parts of seasonal customs and had been passed down in connection with various seasonal events, such as village rites, tug of war, torch fighting, Jisinbabgi(stepping on evil spirits), Gilnori, and Sattonoreum. However, after the Korean War, the dramas were played independently regardless of those seasonal events; thus, they have lost their original functions and meanings. After the Korean War, the lion dance in the Bukcheong lion mask play included two lions (as opposed to one lion prior to the Korean War) and the Aeonesung and Sadang dances were added. The scene in which a lion eats a child changed to a lion eating a rabbit doll. Furthermore, whereas mask types used to be diverse, they are now standardized to one type of lion mask. In the Yangju Byulsandae-nori, eight monks and Waejangnye, Aesadang appeared in 'Aesadang Bubgonori', but now the Malddugi mask character is added. Current performances omit sexually suggestive scenes. In the pre-Korean War version of the old man and old woman act, the old man sang a song to the soul of the dead woman, but now a shaman appears and performs an exorcism. In the dialogues, vulgar and sexual statements have been shortened as many audience members are women and children. Regarding the appearance of the masks, the lotus leaf, the monk with Scabies, and sannim masks have been significantly changed. Bongsantalchum has also changed, especially in the old monk act. Previously, two Somu used to appear whereas now only one appears. The scene of the shoe seller's and the monkey's departure is also different. Furthermore, while the former masks once had big eye holes on each side of the nose, now the masks have smaller holes on the eyes.

• The Journal of the Korean dental association
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• v.21 no.2 s.165
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• pp.141-150
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• 1983