Annual Changes of Lung Function in Retired Workers Exposed to Inorganic Dusts / 결핵및호흡기질환

BACKGROUND: The aim of this study was to investigate annual changes in pulmonary function in workers who were exposed to inorganic dust. METHODS: The subjects were 2,922 male patients who had been diagnosed with pneumoconiosis more than twice during 6 years from 2005 to 2010. RESULTS: Of the 2,922 cases, forced vital capacity (FVC) decreased by 54 mL in 1 year. In contrast, the annual change of forced expiratory volume in one second (FEV1) decreased by 56 mL. CONCLUSION: This is the first study that has investigated the annual change in pulmonary function in workers exposed to inorganic dust. The results will help estimate the pulmonary condition of patients who are unable to perform a pulmonary function test due to age or a disorder.

The Application of Impulse Oscillometry (IOS) in the Workers Who had been Exposed to Inorganic Dust Induced Early Airway Obstruction / 결핵및호흡기질환

BACKGROUND: We tried to examine the small airway diseases which can be found early, in workers exposed to inorganic dusts. This is measured in normal breath by using the impulse oscillometry (IOS). METHODS: The Pulmonary function test (forced vital capacit [FVC], forced expiratory volume in one second [FEV1], forced expiratory flow between 25% and 75% of vital capacity [FEF25-75]), IOS resistance (Rrs at 5, 10, 15, 20, 25, 35 Hz) and reactance (Xrs at 5, 10, 15, 20, 25, 35 Hz) were measured for 454 workers. The subjects were classified into 173 workers of normal (38.1%) and 281 patients with pneumoconiosis (61.9%). RESULTS: There were significant differences between normal and patients with FVC (3.82+/-0.61 vs. 3.53+/-0.56 L), FEV1 (2.67+/-0.63 vs. 2.35+/-0.48 L), and FEF25-75 (1.88+/-0.95 vs. 1.47+/-0.80 L/sec) between groups (p0.05), and there were significant differences between normal and patients with reactance (Xrs) 15 Hz (0.003+/-0.05 vs. -0.006+/-0.04 kPa/L/s), 20 Hz (0.043+/-0.05 vs. 0.031+/-0.04 kPa/L/s), and 35 Hz (0.141+/-0.05 vs. 0.131+/-0.05 kPa/L/s) between groups (p<0.05). CONCLUSION: We could find out that 15 Hz, 20 Hz, and 35 Hz values of reactance were significantly influenced by pneumoconiosis. When usefulness and reproducibility to carry out the IOS are considered, it is thought that in future work will be required to draw the reference values for normal Korean persons.

Changes of Pulmonary Disability Grades according to the Spirometry Reference Equations / 결핵및호흡기질환

BACKGROUND: The aim was to estimate the differences between pulmonary disability grades according to the spirometry reference equations (the Korean equation and the Morris equation). METHODS: Spirometry was performed on 16,916 male and 1,353 female special examination for pneumoconiosis, in the period of 2007~2009. Changes in predictive values for forced expiratory volume in one second (FEV1), forced vital capacity (FVC) and FEV1/FVC and in disability grade were evaluated using both equations. RESULTS: Mean FVCs for men and women were 4,218.7 mL and 2,801.5 mL in predictive values after the application of the Korean equation, and 3,763.9 mL and 2,395.6 mL after the Morris equation, respectively. Compared with the Morris equation, the Korean equation showed 10.8% and 14.5% of excesses for men and women (p<0.001). Mean FEV1s for men and women were 3,102.5 mL and 2,107.1 mL in the Korean equation, and 2,667.8 mL and 1,699.6 mL in the Morris equation, respectively. Compared with the Morris equation, the Korean equation showed 14.0% and 19.3% of excesses for men and women (p<0.001). Men and women who showed the changes of disability grades using the Korean equation in place of the Morris equation were 23.9% (4,052/16,916) and 22.9% (311/1,353) on FVC, and 23.1% (3,913/16,916) and 10.7% (145/1,353) on FEV1. CONCLUSION: Applying different reference equations for spirometry has resulted in changes for disability grades in special examination for pneumoconiosis.

Serum Levels of Interleukin-8 and Tumor Necrosis Factor-alpha in Coal Workers' Pneumoconiosis: One-year Follow-up Study

OBJECTIVES: Various cytokines induced by inhalation of coal dust may mediate inflammation and lead to tissue damage or fibrosis, such as coal workers' pneumoconiosis (CWP). METHODS: To investigate the relevance of serum cytokines in CWP, the levels of serum interleukin-8 (IL-8) and tumor necrosis factor-alpha (TNF-alpha) as CWP biomarkers in 110 retired coal miners (22 controls and 88 CWP subjects) were related to cross sectional findings and 1-year progressive changes of the pneumoconiosis. Progressive changes of CWP were evaluated by paired comparison of chest radiographs. Analysis by a receiver operating characteristic curve assessed the biomarker potential of each cytokine. RESULTS: The mean serum IL-8 level was significantly higher in CWP compared to controls and IL-8 levels correlated with the degree of CWP. The median serum TNF-alpha level was significantly higher in subjects with progressive CWP compared to subjects without CWP progression. The area under the ROC curve for IL-8 (0.70) and TNF-alpha (0.72) for CWP identification and progression, respectively, indicated the biomarker potential of the two cytokines. Serum cutoff values of IL-8 and TNF-alpha were 11.63 pg/mL (sensitivity, 69%; specificity, 64%) and 4.52 pg/mL (sensitivity, 67%; specificity, 79%), respectively. CONCLUSION: The results suggest that high levels of serum IL-8 are associated with the presence of CWP and those of serum TNF-alpha are associated with the progression of CWP.

Current Status of Pneumoconiosis Patients in Korea

This study identifies the number of pneumoconiosis patients after eliminating deceased patients between 2003 and 2008 as of January 1st and estimates it for the next five years. From 2003 to 2008, the pneumoconiosis patients were 16,929, 17,224, 17,366, 17,566, 17,542, and 17,546, respectively. The number of pneumoconiosis patients will have increased by 1,014 from 2008 to 18,560 in 2013 after applying the average change rates taken from 2003 to 2007. It takes 15-20 yr to develop coal workers' pneumoconiosis (the main cause in Korea) and patients will continue to be diagnosed with pneumoconiosis for some years to come since it has only been 20 yr since the decline of the coal mining industry in Korea. In addition, pneumoconiosis patients are increasing in industries in which the risk of pneumoconiosis was relatively low shows the necessity to improve dust-exposed workplace environments.

A Case of Reactive Airways Dysfunction Syndrome in a Synthetic Resin Manufacture Factory / 대한산업의학회지

BACKGROUND: Reactive airways dysfunction syndrome (RADS), which represents between 5% and 18% of new-onset, work-related asthma, remains underreported in spite of increasing reports of occupational asthma cases through occupational asthma surveillance in Korea. We report a 61-year-old male who developed RADS after exposure to a high level of toxic gases from a workplace accident. CASE: The patient who had worked for 21 years at a PVC manufacture factory and had retained good health until Aug 22, 2007, when he was exposed to PVC (polyvinyl chloride), DEHP (Di (2-Ethylhexyl) Phthalate), dibutyl tin maleate and epoxidized soybean oil gases from a heated mixer. Within several minutes of exposure, he developed coughing, rhinorrhea, dyspnea and wheezing. Pulmonary function tests (PFTs) showed an FVC of 3.81 L(82% of predicted), FEV1 of 1.63 L/s (50% of predicted), FEV1/FVC% of 43 %, and FEV1 of 1.80 L/s that increased by 170 ml and 10.4% in response to bronchodilator. After 7 months of treatment with inhaled steroids and bronchodilators, repeat PFTs showed an FVC of 6.56 L(143.5% of predicted), FEV1 of 3.21 L(99.3% of predicted), and FEV1/FVC% of 48.9%. A methacholine challenge test was negative at a concentration of 25 mg/ml. CONCLUSION: RADS occurred due to exposure to raw material vapors or their thermal decomposition products.

The prevalence and risk factors of childhood obesity in elementary students in Seoul

BACKGROUND: The purpose of this study was to provide useful information for prevention and management of childhood obesity in a school-based setting. METHODS: One thousand and 981 elementary children from 2 different elementary schools in Seoul were studied. The survey concerning the risks of childhood obesity was carried out by having parents answer a questionnaire. RESULTS: The prevalence of childhood obesity was 18.1% showing significantly higher rate in boys than in girls (P<0.05). It was found that obese children had a higher intake of fish and meat (P<0.05) and a lower intake of vegetables compared to the non-obese group (P<0.05). Obesity was more prevalent among children who frequently skipped breakfast (P<0.05) and also more prevalent among an only child (P<0.05). The obese children significantly spent more time watching TV (P<0.05). There was a higher family history of obesity, hypercholesterolemia and DM in the obese group (P<0.05). The factors which significantly attributed to childhood obesity were birth weight, parenteral BMI, and father's age (P<0.05). CONCLUSION: The prevalence of childhood obesity was 18.1%. There was a statistically significant correlation between childhood obesity and gender, eating habit, time spent on watching TV, number of siblings, birth weight, parenteral BMI, father's age and family history such as obesity, hypercholesterolemia and DM.