Work-Related Risk Factors of Knee Meniscal Tears in Korean Farmers: A Cross-Sectional Study

Background@#Meniscal tears are among the major risk factors for knee osteoarthritis progression. This study aimed to investigate the relationship between meniscal tears and work-related factors in the farming occupation. @*Methods@#The participants included 486 farmers (238 men and 248 women), aged 40–69 years, who were among the 550 farmers registered in the Korea Farmer's Knee Cohort (KFKC). Data such as those on gender, age, body mass index (BMI), mechanical axis, cumulative heavy-lifting working time (CLWT), cumulative squatting working time (CSWT), and previous knee injury history were collected from the questionnaire, along with whole leg radiographic findings. Two radiologists assessed the magnetic resonance images of both knees to confirm the presence of meniscal tears. The factors related to meniscal tears were analyzed by multiple logistic regression. @*Results@#A total of 54.5% of the farmers (48.7% of men and 60.1% of women) had meniscal tears. These tears were associated with gender, age, and BMI. We also identified an association between meniscal tears and CSWT, an especially important factor in farming [10,000–19,999 working hours, odds ratio = 2.16, 95% confidence interval (CI): 1.14-4.07, ≥20,000 working hours, odds ratio = 2.35, 1.45-3.80]. However, mechanical axis, knee injury history, and CLWT were not significantly related to meniscal tears. @*Conclusion@#This study's findings show that squatting for long periods, as an occupational factor, is related to meniscal tears.

Work-Related Risk Factors of Knee Meniscal Tears in Korean Farmers: A Cross-Sectional Study

Background@#Meniscal tears are among the major risk factors for knee osteoarthritis progression. This study aimed to investigate the relationship between meniscal tears and work-related factors in the farming occupation. @*Methods@#The participants included 486 farmers (238 men and 248 women), aged 40–69 years, who were among the 550 farmers registered in the Korea Farmer's Knee Cohort (KFKC). Data such as those on gender, age, body mass index (BMI), mechanical axis, cumulative heavy-lifting working time (CLWT), cumulative squatting working time (CSWT), and previous knee injury history were collected from the questionnaire, along with whole leg radiographic findings. Two radiologists assessed the magnetic resonance images of both knees to confirm the presence of meniscal tears. The factors related to meniscal tears were analyzed by multiple logistic regression. @*Results@#A total of 54.5% of the farmers (48.7% of men and 60.1% of women) had meniscal tears. These tears were associated with gender, age, and BMI. We also identified an association between meniscal tears and CSWT, an especially important factor in farming [10,000–19,999 working hours, odds ratio = 2.16, 95% confidence interval (CI): 1.14-4.07, ≥20,000 working hours, odds ratio = 2.35, 1.45-3.80]. However, mechanical axis, knee injury history, and CLWT were not significantly related to meniscal tears. @*Conclusion@#This study's findings show that squatting for long periods, as an occupational factor, is related to meniscal tears.

Evaluation of the prevalence of musculoskeletal symptoms, presumptive diagnosis, medical care use, and sick leave among female school meal service workers

BACKGROUND: Most of the school meal service workers in Korea are middle-aged individuals. They have high workload, which increases their incidence of musculoskeletal disorders. This study aimed to evaluate the prevalence and risk factors of subjective musculoskeletal symptoms, presumptive diagnosis, medical care use, and sick leave among female school meal workers. METHODS: We analyzed the results of musculoskeletal disease screening of 1581 female school meal workers. The screening consisted of self-administered questionnaire, history taking by occupational physicians, and physical examination. The prevalence of subjective musculoskeletal symptoms, presumptive diagnosis after initial examination by occupational physicians, use of medical care for more than 7 days, and sick leave due to musculoskeletal diseases during the past year were evaluated in this study. The relative risk of four outcome indicators of musculoskeletal disorders was compared with respect to potential factors, such as age, subjective physical loading, present illness, injury experience, and type of school, using log-binomial regression. RESULTS: The prevalence of subjective musculoskeletal symptom was 79.6%; presumptive diagnosis, 47.6%; hospital visits over 7 days, 36.4%; and sick leave, 7.3%. The relative risk of musculoskeletal symptoms by age (≥50 years vs < 50 years) was 1.04 (95% confidence interval (CI): 1.00–1.09); presumptive diagnosis of musculoskeletal disease, 1.17 (95% CI: 1.06–1.30); hospital visits over 7 days, 1.26 (95% CI: 0.85–1.85); and sick leave, 1.17 (95% CI: 1.02–1.34). The relative risk of musculoskeletal symptoms due to subjective physical loading (very hard vs low) was 1.45 (95% CI: 1.33–1.58); presumptive diagnosis, 2.92 (95% CI: 2.25); hospital visits over 7 days, 1.91 (95% CI: 1.02–3.59); and sick leave, 2.11 (95% CI: 1.63–2.74). CONCLUSIONS: Subjective physical loading was a more important factor in musculoskeletal disorders than the age of female school meal workers.

Effects of work-related factors on self-reported smoking among female workers in call centers: a cross-sectional study

OBJECTIVES: This study conducted to investigate work-related factors in relation to smoking among women working in call centers in Gwangju, South Korea. METHODS: From 56 call centers (7320 employees), we selected 10 and conducted a survey using a structured questionnaire by randomly selecting 10% of workers from each center. A total of 387 subjects participated in this survey We analyzed for 375 respondents, after excluding men and those with missing responses. We analyzed the relationships of work-related factors such as emotional labor, workplace violence, employment type, annual salary, working hours, employment period with smoking, using multiple logistic regression analysis. Emotional labor and workplace violence were measured using the Korean Emotional Labor Scale (K-ELS) and Korean Workplace Violence Scale (K-WVS). RESULTS: The prevalence of current smoking among call center female workers was 13.6%. Univariate analysis showed that “Emotional disharmony and hurt”, “Experience of psychological and sexual violence from supervisors and co-workers” among items of K-ELS and K-WVS, working hours, annual salary correlated with smoking. After adjusting for emotional labor, workplace violence, employment type, annual salary, working hours, employment period, and age, only working hours show a significant association with smoking. Women who worked 40–49 h had 3.50 times (95% CI = 1.04–11.80) and worked more than 50 h had 8.68 times (95% CI = 1.89–39.78) greater odds of smoking as compared with women who worked less than 40 h. CONCLUSIONS: Smoking was associated with working hours among female workers in call center. However, emotional labor and workplace violence did not show significant relationships with smoking.

Systemic sclerosis due to crystalline silica exposure among jewelry workers in Korea: two case reports

BACKGROUND: Occupational exposure to crystalline silica is a potential risk factor for various systemic autoimmune diseases including systemic sclerosis. The etiology of systemic sclerosis is not conclusively known, but there are epidemiological studies that show the relationship between exposure to crystalline silica and risk of systemic sclerosis. Here we report, for the first time, two cases of crystalline silica-related systemic sclerosis in patients who worked in crystal processing in the jewelry-manufacturing field. CASE PRESENTATION: Case 1 is a 57-year-old man who had worked mainly in crystal processing for multiple jewelry-processing companies for 17 years, since the age of 15 years. He contracted tuberculosis at the age of 25 years and showed Raynaud's phenomenon of both the hands and feet at age 32 years. Digital cyanosis and sclerosis developed at approximately age 41 years. The patient was diagnosed with systemic sclerosis at age 48 years. Case 2 is a 52-year-old man who worked in crystal processing for various jewelry-processing companies for 7 years, since the age of 23 years. He first showed signs of cyanosis in the third and fourth digits of both hands at age 32 years, was diagnosed with Raynaud's syndrome at age 37 years, and was diagnosed with systemic sclerosis at age 38 years. Crystal processing is a detailed process that involves slabbing and trimming the selected amethyst and quartz crystals, which requires close proximity of the worker's face with the target area. In the 1980s and 1990s, the working hours were 12 h per day, and the working environment involved 15 workers crowded into a small, 70-m2 space with poor ventilation. CONCLUSION: Two workers who processed crystals with a maximum crystalline silica content of 56.66% developed systemic sclerosis. Considering the epidemiological and experimental evidence, exposure to crystalline silica dust was an important risk factor for systemic sclerosis. An active intervention is necessary to reduce exposure in similar exposure groups in the field of jewelry processing.

Cases of acute mercury poisoning by mercury vapor exposure during the demolition of a fluorescent lamp factory

BACKGROUND: In 2015, workers dismantling a fluorescent lamp factory in Korea were affected by mercury poisoning from exposure to mercury vapor. CASE PRESENTATION: Eighteen out of the 21 workers who participated in the demolition project presented with symptoms of poisoning and, of these, 10 had persistent symptoms even at 18 months after the initial exposure to mercury vapor. Early symptoms of 18 workers included a general skin rash, pruritus, myalgia, sleep disturbance, and cough and sputum production. Following alleviation of these initial symptoms, late symptoms, such as easy fatigue, insomnia, bad dreams, and anxiety disorder, began to manifest in 10 out of 18 patients. Seven workers underwent psychiatric care owing to sleep disturbance, anxiety disorder, and depression, and three workers underwent dermatologic treatment for hyperpigmentation, erythematous skin eruption, and chloracne-like skin lesions. Furthermore, three workers developed a coarse jerky movement, two had swan neck deformity of the fingers, and two received care at an anesthesiology clinic for paresthesia, such as burning sensation, cold sensation, and pain. Two workers underwent urologic treatment for dysfunction of the urologic system and impotence. However, symptomatic treatment did not result in satisfactory relief of these symptoms. CONCLUSION: Awareness of the perils of mercury and prevention of mercury exposure are critical for preventing health hazards caused by mercury vapor. Chelation therapy should be performed promptly following mercury poisoning to minimize damage.

Comparison of facet joint degeneration in firefighters and hospital office workers

BACKGROUND: There are few published studies on the relationship between occupational lumbar load and facet joint degeneration (FJD). This cross-sectional study was conducted to evaluate the effect of physical lumbar load on FJD by comparing magnetic resonance imaging (MRI) findings of firefighters (FFs) and hospital office workers (HOWs). METHODS: We randomly sampled 341 male FFs and 80 male HOWs by age stratification. A questionnaire and clinical examination, including MRI of the lumbar spine (T12-S1), were conducted. FJD was diagnosed and graded by using the classification of Pathria et al., and reclassified into two groups as follows: no FJD (grade 0) and FJD (grades 1, 2, and 3). The prevalence of FJD was analyzed according to occupational group. RESULTS: The prevalence of FJD ranged from 31% (L1–L2) to 75% (L4–L5) in the FFs, and from 18% (L1–L2) to 69% (L4–L5) in the HOWs. After adjustment for age, body mass index, and frequency of physical exercise, the adjusted odds ratios (OR) for FJD in the FFs were significantly higher than those in the HOWs at all lumbar spinal levels, except for L3–L4 (L1–L2: OR, 2.644; 95% confidence interval [CI], 1.317–5.310; L2–L3: OR, 2.285; 95% CI, 1.304–4.006; L4–L5: OR, 1.918; 95% CI, 1.037–3.544; L5–S1: OR, 1.811; 95% CI, 1.031–3.181). CONCLUSION: This study shows that FFs exhibit a greater likelihood of having FJD than HOWs after controlling for other risk factors of FJD. This suggests that the physical occupational demands of FFs affect their risk of developing FJD.

Air pollution and urinary n-acetyl-B-glucosaminidase levels in residents living near a cement plant

BACKGROUND: To identify adverse renal effects due to air pollution derived from a cement plant in Korea. Urinary n-acetyl-B-glucosaminidase (U-NAG) levels in residents living near a cement plant were compared to those in a group who lived farther away from the plant. METHODS: From June to August 2013 and from August to November 2014, laboratory tests for U-NAG and heavy metal were conducted on 547 study participants. Based on the level of air pollution exposure, subjects were divided into the “less exposed group,” (LEG) which consisted of 66 persons who lived more than 5 km away from the cement plant, the “more exposed group from the rural area” (MEG-R), which consisted of 272 persons, and the “more exposed group from downtown area” (MEG-D), which consisted of 209 persons who lived within a 1 km radius of the cement plant. U-NAG levels >5.67 U/L were defined as “higher U-NAG” levels. We compared the prevalence of higher U-NAG levels and estimated the adjusted odds ratio (OR) by air pollution exposure using a chi-square test and multiple logistic regression analysis. Further, we estimated the interaction between air pollution exposure and heavy metal exposure in renal toxicity. RESULTS: The OR of higher U-NAG levels by MEG-D and MEG-R compared to LEG was 2.13 (95 % CI 0.86–4.96) and 4.79 (95 CI 1.65–10.01), respectively. Urinary cadmium (U-Cd), urinary mercury (U-Hg), age, occupation, hypertension, and diabetes had a significant association with higher U-NAG levels. However, blood lead (B-Pb), sex, and smoking were not associated with higher U-NAG. Especially, concurrent exposure to heavy metals (U-Hg or/and U-Cd) and air pollution had an additive adverse effect. In the group with both 4th quartile heavy metal exposure (U-Cd or/and U-Hg) and air pollution exposure, the OR in MEG-R and MEG-D was 6.49 (95 % 1.42–29.65) and 8.12 (95 % CI 1.74–37.92), respectively, after adjustment for age, occupation, hypertension, diabetes. CONCLUSIONS: U-NAG levels seem to be affected by air pollution exposure as well as age, hypertension, diabetes, and even low levels of cadmium and low levels of mercury. Moreover, concurrent exposure to heavy metals and air pollution can have additive cytotoxic renal effects.

Emphysema prevalence related air pollution caused by a cement plant

BACKGROUND: To identify adverse pulmonary health effects due to air pollution derived from a cement plant in Korea. The emphysema prevalence in residents around a cement plant was compared to that in the group who live far away from the plant by chest films (PA and lateral view) and high-resolution computed tomography (HRCT) lung images. METHODS: From June to August in 2013 and from August to November in 2014, chest films and HRCT scan were conducted on residents over the age of 40 who lived around a cement plant. The residents were divided into two groups; a “more exposed group (MEG)” which consisted of 1,046 people who lived within a 1 km radius and a “less exposed group (LEG)” which consisted of 317 people who lived more than 5 km away from the same plant. We compared the emphysema prevalence and estimated the OR of this between the MEG and the LEG by using a chi-square and logistic regression on chest films and HRCT. RESULTS: The emphysema prevalence was 9.1 % in the LEG, 14.3 % in the MEG on chest films and 11.4 %, 17.8 % on the HRCT, respectively. The OR of the emphysema prevalence in MEG was 2.92 (95 % CI 1.77-4.83) on the chest films, 2.56 (95 % CI 1.64–3.99) on the HRCT after sex, age, body mass index (BMI), smoking history, residency period and firewood used history were adjusted. The OR in the less than 29 pack-years smoking history was 1.66 (95 % CI 0.92–3.06) and in the more than 30 pack-years was 3.05 (95 % CI 1.68–5.52) on the chest films, and was 1.68 (95 % CI 0.98–2.90), 2.93 (95 % CI 1.72–4.98) on the HRCT, respectively. CONCLUSION: The emphysema prevalence seems to be affected by the level of exposure to air pollution derived from the cement plant as well as sex, age, BMI, and smoking history in this study. Moreover, the OR of the case of the more exposed to the air pollution was similar to that of the case in smoking.

Ventilation impairment of residents around a cement plant

OBJECTIVES: To identify adverse health effects due to air pollution derived from a cement plant in Korea. The ventilation impairment in residents around a cement plant was compared to another group through a pulmonary function test (PFT). METHODS: From June to August of 2013, both a pre and post-bronchodilator PFT was conducted on a "more exposed group (MEG)" which consisted of 318 people who lived within a 1 km radius of a cement plant and a "less exposed group (LEG)" which consisted of 129 people who lived more than 5 km away from the same plant. The largest forced expiratory volume in a one second (FEV1) reading and a functional residual capacity (FVC) reading were recorded after examining the data from all of the usable curves that were agreed upon as valid by PFT experts of committee of National Institute of Environmental Research. The global initiative for chronic obstructive lung disease (GOLD) criteria for COPD, defined the FEV1/FVC ratio == 0.7 and FVC% predicted < 80% were as the restrictive type. The FVC% predicted value was estimated using Korean equation. We compared the proportion of lung function impairments between the MEG and the LEG by using a chi-square, and estimated the OR of obstructive and restrictive ventilation impairments by logistic regression. RESULTS: The obstructive type impairment proportion was 9.7% in the MEG, whereas it was 8.5% in the LEG. The restrictive type was 21.6% in the MEG which was more than the 12.4% of the LEG. The odds ratio (OR) of total ventilation impairment in the MEG was 2.63 (95% CI 1.50 ~ 4.61) compared to the LEG. The OR of obstructive type in the MEG was 1.60 (95% CI 0.70 ~ 3.65), the smoking history was 3.10 (CI 1.10 ~ 8.66) whereas OR of restrictive type in the MEG was 2.55 (95% CI 1.37 ~ 4.76), the smoking history was 0.75 (95% CI 0.35 ~ 1.60) after adjusting for sex and age. Level of exposure to particulate played a role in both types. However, it appeared to be a significant variable in restrictive type, while smoking history was also an important variable in obstructive type. CONCLUSION: Although this study is a limited cross-section study with a small number of subjects, ventilation impairment rate is higher in the MEG. There might be a possibility that it is due to long-term exposure to particulate dust generated by the cement plant.

Compensation for Occupational Skin Diseases

The Korean list of occupational skin diseases was amended in July 2013. The past list was constructed according to the causative agent and the target organ, and the items of that list had not been reviewed for a long period. The revised list was reconstructed to include diseases classified by the International Classification of Diseases (10th version). Therefore, the items of compensable occupational skin diseases in the amended list in Korea comprise contact dermatitis; chemical burns; Stevens-Johnson syndrome; tar-related skin diseases; infectious skin diseases; skin injury-induced cellulitis; and skin conditions resulting from physical factors such as heat, cold, sun exposure, and ionized radiation. This list will be more practical and convenient for physicians and workers because it follows a disease-based approach. The revised list is in accordance with the International Labor Organization list and is refined according to Korean worker's compensation and the actual occurrence of occupational skin diseases. However, this revised list does not perfectly reflect the actual status of skin diseases because of the few cases of occupational skin diseases, incomplete statistics of skin diseases, and insufficient scientific evidence. Thus, the list of occupational diseases should be modified periodically on the basis of recent evidence and statistics.

Cardiovascular Disease Risk of Bus Drivers in a City of Korea

OBJECTIVE: To prevent the occurrence of CV events such as MI and stroke among professional drivers in Korea, bus drivers were compared to other occupations through the Framingham risk scoring system (FRS) or metabolic syndrome (MS) of cardiovascular disease (CVD) risk assessment methods. METHODS: In October 2012, a health examination survey was conducted for 443 male bus drivers in a big city. Their CVD risk factors were compared to those of a 'total employed' (A group) and 'crafts and machine operators' (B group) extracted from Fifth Korea National Health and Nutrition Examination Survey (KNHANES, 2010) data by using FRS and MS. We calculated proportions of the CVD risk factors distribution between bus drivers and the A, B groups by the bootstrapping method. The Odds ratio (OR) between CV event risk combining MS with CHD equivalent risk of FRS and occupational factors like shift patterns and professional driving duration/age ratios (PDAR) of bus drivers was calculated through multinominal logistic regression. RESULTS: The proportion of BMI > or = 25 kg/m2 was 53.9% and waist circumference > or = 90cm was 40.9% among bus drivers. Hypertension and MS prevalence of bus drivers was 53.3%, 49.9% which is higher than 17.6%, 22.6% in the A group and 19.7%, 23.8% in the B group respectively. OR of high CV event risk in alternate shift was 2.58 (95% CI 1.33~5.00) in comparison with double shift pattern and OR in PDAR > or = 0.5 was 2.18 (95% CI 1.15~4.14). CONCLUSION: Middle aged male drivers in a big city of Korea stand a higher chance of developing CV event than other professions of the same age.

The Differences the Relationship According to Body Part between Occupational Stress and Self-reported Musculoskeletal Disorder Symptoms as Seen in Surveys of Public Office Workers Using VDT / 대한산업의학회지

OBJECTIVES: The investigation of the degree of the relationship according to body part between occupational stress and musculoskeletal symptoms in the neck, shoulder, elbow, and hands of workers performing computer tasks. METHODS: In August and September 2009, we conducted a survey of 529 public office workers employed by the National Health Insurance Corporation using structured questionnaires in order to find demographic factors, work related factors, job stress, physical computer task load and musculoskeletal symptoms. Nordic musculoskeletal questionnaire, Quick DASH (Disabilities of the Arm, Shoulder and Hand Score), and the Northwick Park neck pain questionnaire were all used to evaluate their musculoskeletal symptoms. The presence of symptoms segregated by body part determined the dependent variables. The degree of job stress and other confounder variables determined the independent variables. We calculated the odds ratio employing multiple logistic regressions. RESULTS: A score of > or =5 in the VAS (Visual Analogue Scale) 10-point scale and the presence of symptoms lasting at least 1 week determined the musculoskeletal symptom group in regards to the Nordic musculoskeletal questionnaire. The neck pain odds ratio was adjusted by sex, age, work hours, employment duration, physical computer task load and depression. It was determined to be 2.92 (95% CI 1.76~4.84) in the higher to lower occupational stress group. The shoulder pain odds ratio was 1.96 (95% CI 1.18~3.24), elbow pain 0.55 (95% CI 0.21~1.43), and hand pain 1.71 (95% CI 0.99~2.95). A score of > or =10 in the 100-unit scale determined the musculoskeletal symptom group in regards to the Northwick Park neck pain questionnaire and the Quick DASH. The neck symptom odds ratio was 2.73 (95% CI 1.66~4.49) and the upper extremity symptom figure was 2.18 (95% CI 1.29~3.68). CONCLUSIONS: This study suggests that the relevance between neck and shoulder symptoms and occupational stress was obvious, however the relevance between elbow and hand pain and job stress was not as clear or ambiguous.

Occupational Stress and MMPI-2 Profile of Workers in Some Plants Undergoing Labor Dispute / 대한산업의학회지

OBJECTIVES: To identify changes in relationships with superiors or colleagues at work and family members and social networks at home, based on occupational stress and psychological characteristics in during the process of restructuring some plants undergoing a long-term labor dispute. METHODS: This study invested 213 workers involved in a long-term labor dispute using the KOSS (Korean Occupational Stress Scale) and the MMPI-2 (Minnesota Multiphasic Personality Inventory) and questionnaires. The KOSS and MMPI-2 scores in accordance with aggressiveness of trade union activity and changes in human relationships were compared. In addition, the odds ratio of whether there were differences in health behavior (perception of health status, smoking, alcohol abuse, medical treatment) and the absenteeism rate was calculated by logistic regression analysis. RESULTS: For members of the aggressiveness of trade union activity group, the rate at which the relationship between superiors or colleagues deteriorated was high, as was the total KOSS score, occupational system and lack of reward score of KOSS subclass. The depression subclass score of MMPI-2 was generally high, while the score of hypochondriasis, hysteria, psychopathic deviate, hypomania was high, and social introversion was low in the active group. In cases in which there were high score of psychopathic deviate, hypomania and paranoia, there were also signs of negative health behavior. CONCLUSIONS: Occupational stress caused by a long-term labor dispute, accompanied with depression can result in an aggressive, hostile and vulnerable personalities and have a negative impact on health behavior.

Relationship between Occupational Stress-Emotional Labor and Musculoskeletal Symptoms and Experience of Absence or Early Leave in Some Civil Affairs Officials / 대한산업의학회지

OBJECTIVES: The objectives of this study are to identify the relationship between the Korean occupational stress scale (KOSS) and emotional labor, and to study the association between emotional labor and musculoskeletal symptoms, absence or early leave due to physical problems among civil affairs officials. METHODS: 391 public workers who provide social insurance service were analyzed. A structured self-reported questionnaire was used to assess sociodemographics, job stress, emotional labor, musculoskeletal symptoms and the experience of absence or early leave due to physical problems. For a comprehensive understanding of the relationship among these factors, multiple logistic regression analysis was used. RESULTS: The Pearson coefficient was 0.409 between the job demand of KOSS and the emotional labor score. The odds ratio of musculoskeletal symptoms is 2.32(95% CI: 1.17~4.61), 2.48(95% CI: 1.15~5.33) in the groups of moderate and, high emotional labor score, respectively, compared to the low score group. On the other hand, the odds ratio of the experience of absence or early leave due to physical problems is 2.43(95% CI: 1.24~4.76) and, 3.08(95% CI: 1.44~6.57) in the same groups. CONCLUSIONS: Emotional labor acts as a factor of job demand of KOSS, and has an effect on musculoskeletal symptoms and absence or early leave among civil affairs officials.

Radiological Flattening of Lumbar Lordosis and Related Factors in Some Korean Farmers / 대한산업의학회지

OBJECTIVES: To determine if agricultural work is related to radiological flattening of lumbar lordosis, and to identify the relationship between of back pain and flat back in selected Korean farmers. METHODS: Between June 2006 and July 2008, 414 farmers, 155 (37.4%) males and 259 (62.6%) females participated in this study. We collected data on hazardous agricultural work postures and other factors from interviews, surveys, and x-ray views of lateral lumbar. The operational definition of a flat back was below -1 SD of lordotic angle, with a normal distribution between L1 and S1 level. Logistic regression analysis was conducted to evaluate the relationship between flat back and hazardous working posture ratio, sex, the severity of back pain. RESULTS: Mean lordotic angle was 42.9+/-15.7degrees. Flat back had a higher prevalence in the females (24.7%) than the males (5.8%). The odds ratio of flat back risk is 3.30 (95% CI: 1.46~7.46) in the females compared to the males, 1.31 (95% CI: 0.61~2.79), 4.11 (95% CI: 1.77~9.55) in the group of hazardous working posture ratio compared to the low risk group, 2.78 (95% CI: 1.27~6.07), 5.74 (95% CI: 2.27~14.49) in the group of L4-L5 disc space narrowing compared to normal group, 3.06 (95% CI: 1.27~7.31), 5.45 (95% CI: 1.70~17.46) in the group of lumbar spine compression fracture compared to no fracture. Odds ratio of severe back pain is 2.29 (95% CI: 1.12~4.72) in the group of flat back compared to normal group. CONCLUSIONS: Hazardous agricultural working postures, such as 'low- lifting, pulling, pushing work and high- squatting posture work' are associated with flat back. Low back pain is significantly associated with flat back group in female farmers.

Work-Relatedness of Occupational Contact Dermatitis in a Tire Factory / 대한산업의학회지

OBJECTIVES: This study investigated occupational contact dermatitis in a tire factory, prompted by a long history of complaints of skin ailments by the factory workers. METHODS: Participants (n=160) completed a questionnaire concerning job characteristics and skin symptoms, and received a medical examination. Fifty-four workers with suspected work-related contact dermatitis were chosen for a patch test of contact-related dermatitis. RESULTS: The most frequent positive reactions of patch test were produced by diphenylguanidine, formaldehyde and cobalt. Twenty-one of the 54 individuals (38.9%) were judged to have work-related skin disease. CONCLUSIONS: Exposure to natural and synthetic rubbers and additive materials pose a risk of contact dermatitis in a tire manufacturing environment. Improved sanitary work practices and public health awareness measures are suggested.