OBJECTIVES: The purpose of this study is to evaluate the tire manufacturing work environments extensively and to identify workers' exposure to hazardous substances in various work processes. METHODS: Personal air sampling was conducted to measure polycyclic aromatic hydrocarbons, carbon disulfide, 1,3-butadiene, styrene, methyl isobutyl ketone, methylcyclohexane, formaldehyde, sulfur dioxide, and rubber fume in tire manufacturing plants using the National Institute for Occupational Safety Health Manual of Analytical Methods. Noise, carbon monoxide, and heat stress exposure were evaluated using direct reading instruments. Past concentrations of rubber fume were assessed using regression analysis of total particulate data from 2003 to 2007, after identifying the correlation between the concentration of total particulate and rubber fume. RESULTS: Workers were exposed to rubber fume that exceeded 0.6 mg/m3, the maximum exposure limit of the UK, in curing and production management processes. Forty-seven percent of workers were exposed to noise levels exceeding 85 dBA. Workers in the production management process were exposed to 28.1degrees C (wet bulb globe temperature value, WBGT value) even when the outdoor atmosphere was 2.7degrees C (WBGT value). Exposures to other substances were below the limit of detection or under a tenth of the threshold limit values given by the American Conference of Governmental Industrial Hygienists. CONCLUSION: To better classify exposure groups and to improve work environments, examining closely at rubber fume components and temperature as risk indicators in tire manufacturing is recommended.
Aerosols ; Atmosphere ; Butadienes ; Carbon Disulfide ; Carbon Monoxide ; Cyclohexanes ; Formaldehyde ; Hazardous Substances ; Hot Temperature ; Humans ; Limit of Detection ; Methyl n-Butyl Ketone ; Noise ; Occupational Exposure ; Occupational Health ; Polycyclic Hydrocarbons, Aromatic ; Rubber ; Styrene ; Sulfur Dioxide ; Threshold Limit Values

OBJECTIVES: The present study was designed to determine whether there is a relationship between indium compound exposure and interstitial lung damage in workers employed at indium tin oxide manufacturing and reclaiming factories in Korea. METHODS: In 2012, we conducted a study for the prevention of indium induced lung damage in Korea and identified 78 workers who had serum indium or Krebs von den Lungen-6 (KL-6) levels that were higher than the reference values set in Japan (3 microg/L and 500 U/mL, respectively). Thirty-four of the 78 workers underwent chest high-resolution computed tomography (HRCT), and their data were used for statistical analysis. RESULTS: Geometric means (geometric standard deviations) for serum indium, KL-6, and surfactant protein D (SP-D) were 10.9 (6.65) microg/L, 859.0 (1.85) U/mL, and 179.27 (1.81) ng/mL, respectively. HRCT showed intralobular interstitial thickening in 9 workers. A dose-response trend was statistically significant for blood KL-6 levels. All workers who had indium levels > or =50 microg/L had KL-6 levels that exceeded the reference values. However, dose-response trends for blood SP-D levels, KL-6 levels, SP-D levels, and interstitial changes on the HRCT scans were not significantly different. CONCLUSIONS: Our findings suggest that interstitial lung changes could be present in workers with indium exposure. Further studies are required and health risk information regarding indium exposure should be communicated to workers and employers in industries where indium compounds are used to prevent indium induced lung damage in Korea.
Indium* ; Japan ; Korea ; Lung Diseases, Interstitial ; Lung* ; Occupational Exposure ; Pulmonary Surfactant-Associated Protein D ; Reference Values ; Thorax ; Tin

This study explored the health hazard of those exposed to methylene chloride by assessing its atmospheric concentration when a tear gas mixture was aerially dispersed. The concentration of methylene chloride ranged from 311.1-980.3 ppm (geometric mean, 555.8 ppm), 30 seconds after the dispersion started. However, the concentration fell rapidly to below 10 ppm after dispersion was completed. The concentration during the dispersion did not surpass the National Institute for Occupational Safety and Health 'immediately dangerous to life or health' value of 2,300 ppm, but did exceed the American Conference of Governmental Industrial Hygienists excursion limit of 250 ppm. Since methylene chloride is highly volatile (vapor pressure, 349 mmHg at 20degrees C), the postdispersion atmospheric concentration can rise instantaneously. Moreover, the o-chlorobenzylidenemalononitrile formulation of tear gas (CS gas) is an acute upper respiratory tract irritant. Therefore, tear gas mixtures should be handled with delicate care.
Methylene Chloride ; National Institute for Occupational Safety and Health (U.S.) ; o-Chlorobenzylidenemalonitrile ; Respiratory System ; Tear Gases

OBJECTIVES: The purpose of this study was to measure the concentration of volatile organic compound (VOC)s originated from the chemicals used and/or derived from the original parental chemicals in the photolithography processes of semiconductor manufacturing factories. METHODS: A total of four photolithography processes in 4 Fabs at three different semiconductor manufacturing factories in Korea were selected for this study. This study investigated the types of chemicals used and generated during the photolithography process of each Fab, and the concentration levels of VOCs for each Fab. RESULTS: A variety of organic compounds such as ketone, alcohol, and acetate compounds as well as aromatic compounds were used as solvents and developing agents in the processes. Also, the generation of by-products, such as toluene and phenol, was identified through a thermal decomposition experiment performed on a photoresist. The VOC concentration levels in the processes were lower than 5% of the threshold limit value (TLV)s. However, the air contaminated with chemical substances generated during the processes was re-circulated through the ventilation system, thereby affecting the airborne VOC concentrations in the photolithography processes. CONCLUSION: Tens of organic compounds were being used in the photolithography processes, though the types of chemical used varied with the factory. Also, by-products, such as aromatic compounds, could be generated during photoresist patterning by exposure to light. Although the airborne VOC concentrations resulting from the processes were lower than 5% of the TLVs, employees still could be exposed directly or indirectly to various types of VOCs.
Humans ; Korea ; Light ; Parents ; Phenol ; Semiconductors ; Solvents ; Toluene ; Transcutaneous Electric Nerve Stimulation ; Ventilation ; Volatile Organic Compounds

BACKGROUND/AIMS: The purpose of this study was to compare the diagnostic validity of two-dimensional (2D) and three-dimensional (3D) ultrasonography (US) when predicting the extrathyroidal extension of papillary thyroid cancer. METHODS: All 2D data were interpreted in real time and 3D data were stored, rendered using tomographic ultrasound imaging (TUI), and then reviewed retrospectively. RESULTS: Extrathyroidal extension was present in 17 papillary thyroid cancers(24.3%) on pathology reports. The presence of contact was significantly associated with extrathyroidal extension on both 2D and 3D US (p = 0.007 and p = 0.003), and the sensitivity and specificity were not significantly different between 2D and 3D US (p = 1.000 and p = 0.754). The coexistence of protrusion and contact was not significantly associated with extrathyroidal extension on either 2D or 3D sonogram. CONCLUSIONS: Three-dimensional images rendered with TUI algorithms alone do not seem to be markedly superior to real-time 2D US in predicting the extrathyroidal extension of papillary thyroid cancer.
Adolescent ; Adult ; Aged ; Algorithms ; Carcinoma/*diagnostic imaging/pathology ; Female ; Humans ; *Image Interpretation, Computer-Assisted ; *Imaging, Three-Dimensional ; Male ; Middle Aged ; Neoplasm Invasiveness ; Neoplasm Staging ; Predictive Value of Tests ; Retrospective Studies ; Thyroid Neoplasms/*diagnostic imaging/pathology ; Ultrasonography/*methods ; Young Adult

PURPOSE: It is controversial whether indoor pet exposure is either a risk or protective factor developing sensitization to pet allergens or asthma. Therefore, we investigated whether indoor pet ownership entails a risk for the development of asthma and sensitization in childhood. METHODS: The Panel Study of Korean Children (PSKC) is a general-population-based birth cohort study that recruited 2,078 mother-baby dyads in Korea between April and July of 2008. Among 1,577 children who were followed up in 2015, 559 underwent skin prick tests, spirometry and bronchial provocation tests using Provocholine. Having a cat or a dog and the prevalence of asthma were evaluated by using self-reported questionnaires and physicians’ medical records. RESULTS: During infancy, the rate of dog ownership was 4.5% (71 of 1,574) and that of cat ownership was 0.5% (8 of 1,574). Of the subjects, 7.9% (n=109) currently had at least 1 dog and 2.5% (n=34) had at least 1 cat. Pet ownership during infancy was associated with sensitization to cats or dogs (adjusted odds ratio [aOR], 4.24; 95% confidence interval [CI], 1.29–13.98), wheezing within 12 months (aOR, 5.56; 95% CI, 1.65–18.75) and current asthma (wheezing episode in the last 12 months+diagnosed asthma by physicians) (aOR, 6.36; 95% CI, 1.54–26.28). In contrast, pet ownership during the last 12 months was not associated with sensitization to cats or dogs or current asthma. CONCLUSION: Indoor pet exposure during infancy can be critical for developing sensitization to cats or dogs and asthma in childhood. Avoidance of pet exposure in early life may reduce sensitization to cats or dogs and development of asthma.
Allergens ; Animals ; Asthma ; Bronchial Provocation Tests ; Cats ; Child ; Cohort Studies ; Dogs ; Humans ; Infant ; Korea ; Medical Records ; Methacholine Chloride ; Odds Ratio ; Ownership ; Parturition ; Pets ; Prevalence ; Protective Factors ; Respiratory Sounds ; Risk Factors ; Skin ; Spirometry

BACKGROUND: A US Food and Drug Administration (FDA)-approved drug methacholine chloride (Provocholine®) was recently introduced to Korea where it is now widely used in clinical practice. We aimed to evaluate the prevalence, risk factors and cutoff value of bronchial hyperresponsiveness (BHR) to Provocholine in 7-year-old children. METHODS: Six hundred and thirty-three children from the Panel Study on Korean Children who visited 16 regional hospitals were evaluated. Skin prick tests, spirometry and bronchial provocation tests for Provocholine as well as a detailed history and physical examinations were performed. The bronchial provocation test was reliably performed on 559 of these children. RESULTS: The prevalence of ever-diagnosed asthma via medical records was 7.7%, and that of current asthma (wheezy episode in the last 12 months + diagnosed asthma by physicians) was 3.2%. The prevalence of BHR to Provocholine was 17.2% and 25.8%, respectively, for a PC20 < 8 and < 16 mg/mL. The risk factors for BHR (PC20 < 16 mg/mL) were atopic dermatitis diagnosis and current dog ownership, whereas those for current asthma were allergy rhinitis diagnosis, a history of bronchiolitis before the age of 3, recent use of analgesics/antipyretics and maternal history of asthma. The BHR prevalence trend showed an increase along with the increased immunoglobulin E (IgE) quartile. The cutoff value of PC20 for the diagnosis of current asthma in children at age 7 was 5.8 mg/mL (sensitivity: 47.1%, specificity: 87.4%). CONCLUSIONS: BHR to Provocholine (PC20 < 8 mg/mL) was observed in 17.2% of 7-year-olds children from the general population and the cutoff value of PC20 for the diagnosis of current asthma was 5.8 mg/mL in this age group. The risk factors for BHR and current asthma showed discrepancies suggesting different underlying mechanisms. Bronchial provocation testing with Provocholine will be a useful clinical tool in the future.
Animals ; Asthma ; Bronchial Hyperreactivity ; Bronchial Provocation Tests ; Bronchiolitis ; Child* ; Dermatitis, Atopic ; Diagnosis ; Dogs ; Humans ; Hypersensitivity ; Immunoglobulin E ; Immunoglobulins ; Korea ; Medical Records ; Methacholine Chloride* ; Ownership ; Physical Examination ; Prevalence* ; Rhinitis ; Risk Factors* ; ROC Curve ; Sensitivity and Specificity ; Skin ; Spirometry ; United States Food and Drug Administration

PURPOSE: Data are lacking on the association between the allergic rhinitis (AR) phenotype and sensitization to specific allergens or bronchial hyperresponsiveness (BHR) in children. We here investigated risk factors and comorbidities, including sensitization to specific allergens and BHR, for the AR phenotype by AR and its Impact on Asthma (ARIA) classification in a general population-based birth cohort study. METHODS: We enrolled 606 children aged 7 years from the Panel Study of Korean Children. The AR phenotype was assigned in accordance with the ARIA classification in children. Skin prick tests and Provocholine provocation test were performed. Risk factors and comorbidities for AR phenotypes were then analyzed. RESULTS: The prevalence of mild and moderate to severe AR in our study cohort was 37.2% and 8.8%, respectively. Recent use of analgesics or antipyretics and current cat ownership were associated with the risk of mild persistent AR. Sensitizations to Dermatophagoides Pteronyssinus (Der p), Japanese hop and cat were associated with moderate to severe persistent AR. Children with moderate to severe AR had a higher risk of current asthma and BHR compared to mild AR cases (adjusted odds ratio [aOR], 5.26; 95% confidence interval [CI], 1.77–15.62). Moderate to severe AR with allergic sensitization was associated with the highest risk of BHR (aOR, 11.77; 95% CI, 3.40–40.74). CONCLUSIONS: Moderate to severe-persistent AR is more closely related to respiratory comorbidities and sensitizations than mild AR. Stratifying the AR phenotype by ARIA classification may assist in disease management.
Allergens ; Analgesics ; Animals ; Antipyretics ; Asian Continental Ancestry Group ; Asthma ; Bronchial Hyperreactivity ; Cats ; Child ; Classification ; Cohort Studies ; Comorbidity ; Dermatophagoides pteronyssinus ; Disease Management ; Humans ; Methacholine Chloride ; Odds Ratio ; Ownership ; Parturition ; Phenotype ; Prevalence ; Rhinitis, Allergic ; Risk Factors ; Skin

BACKGROUND: Since the bioavailability of itraconazole capsule is influenced by patients gastric acidity, it results in treatment failure due to its low dissolution and subsequent low absorption when administered in fasting. Itraconazole Melt-Extrusion tablet has been lately developed in order to improve its dissolution profile. It is the first clinical study to evaluate the efficacy and safety of itraconazole Melt-Extrusion tablet in Korea. OBJECTIVE: This study was conducted to evaluate the efficacy and safety of itraconazole melt-extrusion tablet 400mg daily for 1 week(pulse therapy) for hyperkeratotic type of tinea pedis and manus. METHODS: A clinical and mycological investigation was made of 812 outpatients with hyperkeratotic type of tinea pedis and/or tinea manus who had visited at 52 general hospitals under the lead of the Korean Dermatological Association from June to December, 1998. Patients confirmed by clinically and microscopically as hyperkeratotic type of tinea pedis and/or tinea manus were administered 2 tablets twice a day for one week and followed up for 8 weeks from the start of the medication. RESULTS: The results were summarized as follows; 1. Clinical symptoms of hyperkeratotic type of tinea pedis and/or tinea mauns were significantly improved at the end of study, week 8(p<0.001). 2. Clinical response rate, defined as more than 50% decrease of the sum of the clinical symptom scores, was 79.3%(512/646). 3. Mycological cure rate, dafined as both culture and KOH negative at week 8, was 78.2%(244 /312). 4. 40(5.5%) patients, of the 727 patients evaluable for drug safety evaluation, were reported to have adverse event. CONCLUSION: Itraconazole Melt-Extrusion tablet 400mg/day for 1 week (pulse therapy) is effective and safe in the treatment of hyperkeratotic type of tinea pedis and/or tinea manus.
Absorption ; Biological Availability ; Fasting ; Gastric Acid ; Hospitals, General ; Humans ; Itraconazole* ; Korea ; Outpatients ; Tablets ; Tinea Pedis* ; Tinea* ; Treatment Failure