• Archives of Plastic Surgery
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• v.51 no.5
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• pp.487-494
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• 2024

Background Basal cell carcinoma (BCC) is the most common type of nonmelanoma skin cancer. Typically, resection requires a safety margin of ≥4 mm. When removing tumor cells, achieving complete excision with minimal safety margins and reconstructing the defect to preserve the original appearance are important. In this study, we used a 3-mm resection margin to confirm recurrence and re-resection rates. Methods Electronic medical records and photographic data were obtained for patients with primary BCC lesions less than 2 cm in diameter who underwent wide excision with a 3-mm surgical margin from January 2015 to November 2021. We analyzed factors determining recurrence and re-resection rates, such as tumor size, location, age, sex, underlying diseases (including immunosuppression state), ethnicity, subtypes, tumor borders, etc. Results This study included 205 patients. The mean age and follow-up period were 73.0 ± 11.5 years and 10.2 ± 8.0 months, respectively. The recurrence and re-resection rates were 1.95% and 25.85%, respectively. A statistically significant correlation was found between recurrence rate and tumor border (p = 0.013) and the re-resection rate was correlated statistically with location (p = 0.022) and immunosuppressed patients (p = 0.006). Conclusion We found that a 3-mm excision margin provided sufficient safety in small facial BCC, resulting in ease of surgery and better aesthetic outcomes. However, surgical margins must be determined case by case by integrating various patient factors. In particular, a surgical margin of ≥4 mm is required for BCC in high-risk areas, immunosuppressed patients, or poorly defined border.

• Journal of Environmental Health Sciences
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• v.44 no.5
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• pp.409-420
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• 2018

Objectives: An outbreak of humidifier disinfectant-related respiratory disease has not only been a massive disaster for end users, but it is also a concern for the workers of the manufacturers. This study presents the results of a questionnaire survey on the health effects among workers involved in the manufacture of humidifier disinfectants. Methods: Seven sites where humidifier disinfectants were manufactured were identified. A questionnaire survey was conducted to assess the physical symptoms experienced by workers related to humidifier disinfectants. Among a total of 177 workers, 42 subjects were available for the survey. Results: Twenty-one of the 42 respondents reported that they experienced respiratory or skin and mucosal irritation symptoms during work. Of the respondents who experienced symptoms, 14 believed that their symptoms were related to the work process and reported that the symptoms were experienced while working. However, no respondents reported ongoing symptoms or sequelae during the investigation period, and this result could not minimize selection bias due to low response rates. We then compared the characteristics of the group who experienced suspicious symptoms with those of the group without any symptoms. There was no statistically significant difference between two groups. Conclusions: We could not find significant health effects related to the humidifier disinfectant manufacturing process, although 21 respondents experienced stimulant symptoms and 14 respondents believed that the symptoms were related to the work process. Due to the long period of time after occupational exposure and the lack of data, there were many limitations to this study. However, this is one of the few follow-up investigations of workers related to this large-scale disaster in South Korea and the limitations of this study highlight the need to follow up with a nationwide database rather than an occasional survey.

• Journal of the Korean Society of Clothing and Textiles
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• v.44 no.6
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• pp.1037-1052
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• 2020

This study evaluates the comfort and suitability of safety clothing. We made three safety clothes 'y', 'lg', 'lgH'. Only 'y' made with fluorescence fabric has passed International Standards (ISO 20471). A wearing test investigated the physiological response and subjective sensations at 30℃ and 50% RH, six men participated. Mean skin temperature and tympanic temperature showed significant difference with experimental course (p<.05). The micro-temperature (Tm) showed significant differences between three garments on the thigh (p<.01). When wearing 'lg', Tm was the highest. Micro-humidity indicated the interaction between clothing and the experimental course on the chest with no significant difference; however, there was a low tendency when wearing 'lgH' after the second half of exercise. The sweat rate indicated a significant difference between 'lg' and 'lgH' at 20 minutes of exercise (p<.05). Three sensations showed significant differences with the time (p<.01), there was also a tendency to feel hotter and more humid when wearing 'lg'. Skin sensation showed significant differences between pre-experiment and post-experiment (p<.05), 'y' was the most preferred. The 'lg' with long-sleeved currently worn in Korea tended to feel hotter, more humid and more uncomfortable than 'y'. It indicates that there is room for improvement in Korean safety clothing.

• Journal of Environmental Health Sciences
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• v.48 no.1
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• pp.36-43
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• 2022

Background: Preservatives are used to prevent product deterioration in modeling clay. Parabens, a representative preservative, have been found to be endocrine disruptors and cause skin irritation and allergic reactions. Isothiazolinone preservatives can be irritating to the skin, respiratory tract, and eyes. Thorough investigation and regulation of clay are necessary because clay is marketed to children, who are more sensitive to the toxic effect of chemicals. Objectives: In this study, the presence of 16 preservatives was analyzed in modeling clay and the results were compared with current standards. Methods: A total of 200 samples were collected from 28 children's clay products sold in South Korea (13 from Korea and 15 imported from overseas). Twelve preservatives, such as parabens, were analyzed using high-performance liquid chromatography (HPLC). Isothiazolinone preservatives (chloromethylisothiazolinone; CMIT, methylisothiazolinone; MIT, octylisothiazolinone; OIT, and benzisothiazolinone; BIT) were analyzed using ultra performance liquid chromatography-tandem mass spectrometery (UPLC-MS/MS). Results: Dehydroacetic acid (DHA) was detected the most in the clays at 51.50% (103 cases) detection; 38 cases (median 190.42 ㎍/g) in Korean products and 65 cases (median 169.62 ㎍/g) in Chinese products. CMIT, which is prohibited in Korea, was detected in 14 (median 16.28 ㎍/g) Chinese products. OIT, which has a chemical structure similar to CMIT was found in 28 (median 68.38 ㎍/g) samples in Korean products. Conclusions: The use of CMIT and MIT in children's products is prohibited in Korea and the European Union (EU). The detection of CMIT in Chinese clay products suggests that management is necessary for imported products. It is necessary to review the safety and regulatory status for OIT because OIT was used as a substitute for CMIT and MIT in Korean products.

• Journal of Korean Medicine Rehabilitation
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• v.24 no.3
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• pp.111-119
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• 2014

Objectives This study aims to analyze a thermal distribution in biological living tissue during warm needling therapy by using a finite element method. The analysis provides an understanding of warm needling's efficacy and safety. Methods A model which consisted of four-layered tissue and stainless steel needle was adopted to analyze the thermal distribution in living tissue with a bioheat transfer analysis. The governing equation for the analysis was a Pennes' bioheat equation. A heat source characteristic of warm needling therapy was obtained by previous experimental measurements. The first analysis of the time-dependent temperature distribution was conducted through points on a boundary between the needle and the tissue. The second analysis was conducted to visualize the horizontal temperature distribution. Results When heat source's peak temperatures was above $500^{\circ}C$ and temperature rising rates were relatively slow, the peak temperature at skin surface exceeded a threshold of pain and tissue damage ($45^{\circ}C$), whereas when the peak temperature was around $400^{\circ}C$, the peak temperature at the skin surface was within a safe limit. In addition, the conduction of combustion energy from the moxa was limited to the skin layer around the needle. Conclusions The results suggest that the skin layer around the needle can be heated effectively by warm needling therapy, but it appears to have little effect at the deeper tissue. These findings enhance our understanding of the efficacy and the safety of the warm needling therapy.

• Journal of Korean Society of Occupational and Environmental Hygiene
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• v.22 no.3
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• pp.235-243
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• 2012

Objectives: The purpose of this study is the work environment management method through risk assessment and investigation of the work place that deals with Ammonium nitrate, based on information in and outside the country. Methods: This study suggests method of work environment management through risk assessment and investigation of the work place that deals with Ammonium nitrate, and finds out cases of Ammonium nitrate causing hazard, danger and health risk, based on literature investigation. Results: Rats exposed repeatedly to $LD_{50}$ 2,217 mg/kg(rat), $LC_{50}$ 88.8 mg/L(rat, skin) which cause high level of skin irritation, reported 1 $mg/m^3$ of NOAEL, while LOAEL was less than 100 mg/kg for the rats orally administered with the $LD_{50}$ 2,217 mg/kg(rat), $LC_{50}$ 88.8 mg/L(rat, skin), for 13 weeks. Domestically 31,640 ton/y of ammonium nitrate has been used in 22 workplace and the result of workplace assessment was 0.0171-0.9983 $mg/m^3$. ADD was 8.77-59.63 ${\mu}g/kg-day$ according to the exposure scenario. In other words the result of the risk assessment goes beyond the 'standard 1'. Conclusions: Ammonium nitrate creates a high level of irritation and toxicity when coming in breathe it or contact with skin, and is classified as category3 of GHS and specific target organ toxicant (irritating respiratory system). Exposure level at work places needs to be maintained under $1mg/m^3$, to prevent workers from being damaged.

• Toxicological Research
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• v.35 no.2
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• pp.103-117
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• 2019

The mixture of 5-chloro-2-methylisothiazol-3(2H)-one (CMIT) and 2-methylisothiazol-3(2H)-one (MIT), CMIT/MIT, is a preservative in cosmetics. CMIT/MIT is a highly effective preservative; however, it is also a commonly known skin sensitizer. Therefore, in the present study, a risk assessment for safety management of CMIT/MIT was conducted on products containing 0.0015% of CMIT/MIT, which is the maximum MIT level allowed in current products. The no observed adverse effect level (NOAEL) for CMIT/MIT was 2.8 mg/kg bw/day obtained from a two-generation reproductive toxicity test, and the skin sensitization toxicity standard value for CMIT/MIT, or the no expected sensitization induction level (NESIL), was $1.25{\mu}g/cm^2/day$ in humans. According to a calculation of body exposure to cosmetics use, the systemic exposure dosage (SED) was calculated as 0.00423 mg/kg bw/day when leave-on and rinse-off products were considered. Additionally, the consumer exposure level (CEL) amounted to $0.77512{\mu}g/cm^2/day$ for all representative cosmetics and $0.00584{\mu}g/cm^2/day$ for rinse-off products only. As a result, the non-cancer margin of safety (MOS) was calculated as 633, and CMIT/MIT was determined to be safe when all representative cosmetics were evaluated. In addition, the skin sensitization acceptable exposure level (AEL)/CEL was calculated as 0.00538 for all representative cosmetics and 2.14225 for rinse-off products; thus, CMIT/MIT was considered a skin sensitizer when all representative cosmetics were evaluated. Current regulations indicate that CMIT/MIT can only be used at concentrations 0.0015% or less and is prohibited from use in other cosmetics products. According to the results of this risk assessment, the CMIT/MIT regulatory values currently used in cosmetics are evaluated as appropriate.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.39 no.3
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• pp.251-257
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• 2013

In this study, ultraviolet protection factor (Sun Protection Factor, SPF) was investigated to provide basic data for subject safety and research of ultraviolet (UV) irradiation test in the future. Trial subjects (395 people) of skin type I, II, and III were evaluated according to skin type standard table. After measuring the skin color using a colorimeter, ITA (Individual Typology Angle) value was calculated. Subjects with 28 and above ITA value were positioned comfortably to be UV irradiated for 60 s and erythema was evaluated 24 hours after application. MED (Minimal Erythema Dose) was investigated where the minimal amount of erythema existed among UVB irradiated area. Statistical analysis was investigated using Statistical Package the Social Sciences program. As a result, the darker skin color results in the higher MED value since the higher skin type number results increased MED value and female has higher MED value than male since female has darker skin type than male. There was no relation between MED difference by ages in all different ages. However, it is hard to draw a conclusion as above since the number of subjects were not sufficient to support statistical significance for MED values by different ages. However, MED values by skin types obtained through this study can be used as a standard when MED value is expected to evaluate efficacy of sunscreen product and as basic data for further safety of clinical researches.

• Journal of Food Hygiene and Safety
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• v.36 no.1
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• pp.77-85
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• 2021

Glucosylceramides (GluCer) are known to play an important role in both water retention and epidermal permeability barrier function in the mammalian stratum corneum. In this study, we investigated the effects of pineapple fruit extract containing glucosylceramides (PFEG) on the maintenance and recovery of skin barrier function using atopic dermatitis-induced animal models. Five-week-old male Hos:HR-1 mice were divided into four groups fed on standard diet, unsaturated fatty acids-deficient (HR-AD) diet, and HR-AD diet supplemented with 0.01% or 0.1% pineapple-GluCer. Skin barrier function was evaluated by transepidermal water loss (TEWL), dermal moisture content, moisture content of the stratum corneum and wrinkle formation. The control group (HR-AD administration group) showed increased transepidermal water loss (TEWL), while the epidermal moisture content and the moisture content of the stratum corneum slowly decreased. However, in the PFEG groups (with 0.1% or 0.01% glucosylceramide), the TEWL levels were significantly reduced at 2 weeks. The PFEG also helped maintain skin moisturizing function by significantly suppressing the decrease of the epidermal moisture content and the moisture content of the stratum corneum. These results show that the PFEG is effective for maintaining and improving the function of the skin barrier. Therefore, this study suggests that PFEG is a potential candidate material for skin functional foods.

• Journal of the Society of Naval Architects of Korea
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• v.28 no.1
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• pp.150-168
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• 1991

A practical procedure for the ultimate compressive strength-based safety and reliability assessment of the double skin upper deck structure is described. The external compressive stress acting on the upper deck structure which is due to the still water and wave-induced sagging moment is approximately estimated by using the existing rule of classification society. The ultimate compressive stress of double skin structure under the action of sagging moment is analyzed by using idealized structural unit method. Here an idealized plate element subjected to uniaxial load is formulated by idealizing the nonlinear behaviour of the actual element taking account of the initial imperfections in the form of initial deflection and welding residual stress. The interaction effect between the local and global failure in the structure is also taken into consideration. The accuracy of the present method is verified comparing with the present solution and the existing numerical and experimental results for unit member and welded box columns. The safety of the structure is evaluated using the concept of conventional central safety factor and the reliability assessment is made by using Cornel's MVFOSM method. The present procedure is then applied to upper deck structure of double skin product oil carrier. The influence of the initial imperfections and the yield stress of the material on the safety and reliability of the structure is investigated.