Risk factors for lesions of the knee menisci among workers in South Korea’s national parks

BACKGROUND: This study was designed to investigate the prevalence of the menisci lesions in national park workers and work factors affecting this prevalence. METHODS: The study subjects were 698 workers who worked in 20 Korean national parks in 2014. An orthopedist visited each national park and performed physical examinations. Knee MRI was performed if the McMurray test or Apley test was positive and there was a complaint of pain in knee area. An orthopedist and a radiologist respectively read these images of the menisci using a grading system based on the MRI signals. To calculate the cumulative intensity of trekking of the workers, the mean trail distance, the difficulty of the trail, the tenure at each national parks, and the number of treks per month for each worker from the start of work until the present were investigated. Chi-square tests was performed to see if there were differences in the menisci lesions grade according to the variables. The variables used in the Chi-square test were evaluated using simple logistic regression analysis to get crude odds ratios, and adjusted odds ratios and 95 % confidence intervals were calculated using multivariate logistic regression analysis after establishing three different models according to the adjusted variables. RESULTS: According to the MRI signal grades of menisci, 29 % were grade 0, 11.3 % were grade 1, 46.0 % were grade 2, and 13.7 % were grade 3. The differences in the MRI signal grades of menisci according to age and the intensity of trekking as calculated by the three different methods were statistically significant. Multiple logistic regression analysis was performed for three models. In model 1, there was no statistically significant factor affecting the menisci lesions. In model 2, among the factors affecting the menisci lesions, the OR of a high cumulative intensity of trekking was 4.08 (95 % CI 1.00–16.61), and in model 3, the OR of a high cumulative intensity of trekking was 5.84 (95 % CI 1.09–31.26). CONCLUSION: The factor that most affected the menisci lesions among the workers in Korean national park was a high cumulative intensity of trekking.

Reliability and validity of the workplace harassment questionnaire for Korean finance and service workers

BACKGROUND: Harassment means systemic and repeated unethical acts. Research on workplace harassment have been conducted widely and the NAQ-R has been widely used for the researches. But this tool, however the limitations in revealing differended in sub-factors depending on the culture and in reflecting that unique characteristics of the Koren society. So, The workplace harassment questionnaire for Korean finace and service workers has been developed to assess the level of personal harassment at work. This study aims to develop a tool to assess the level of personal harassment at work and to test its validity and reliability while examining specific characteristics of workplace harassment against finance and service workers in Korea. METHODS: The framework of survey was established based on literature review, focused-group interview for the Korean finance and service workers. To verify its reliability, Cronbach’s alpha coefficient was calculated; and to verify its validity, items and factors of the tool were analyzed. The correlation matrix analysis was examined to verify the tool’s convergent validity and discriminant validity. Structural validity was verified by checking statistical significance in relation to the BDI-K. RESULTS: Cronbach’s alpha coefficient of this survey was 0.93, which indicates a quite high level of reliability. To verify the appropriateness of this survey tool, its construct validity was examined through factor analysis. As a result of the factor analysis, 3 factors were extracted, explaining 56.5 % of the total variance. The loading values and communalities of the 20 items were 0.85 to 0.48 and 0.71 to 0.46. The convergent validity and discriminant validity were analyzed and rate of item discriminant validity was 100 %. Finally, for the concurrent validity, We examined the relationship between the WHI-KFSW and pschosocial stress by examining the correlation with the BDI-K. The results of chi-square test and multiple logistic analysis indicated that the correlation with the BDI-K was satatisctically significant. CONCLUSION: Workplace harassment in actual workplaces were investigated based on interviews, and the statistical analysis contributed to systematizing the types of actual workplace harassment. By statistical method, we developed the questionare, 20 items of 3 categories.

Review of carcinogenicity of asbestos and proposal of approval standards of an occupational cancer caused by asbestos in Korea

Carcinogenicity of asbestos has been well established for decades and it has similar approval standards in most advanced countries based on a number of studies and international meetings. However, Korea has been lagging behind such international standards. In this study, we proposed the approval standards of an occupational cancer due to asbestos through intensive review on the Helsinki Criteria, post-Helsinki studies, job exposure matrix (JEM) based on the analysis of domestic reports and recognized occupational lung cancer cases in Korea. The main contents of proposed approval standards are as follows; (1) In recognizing an asbestos-induced lung cancer, diagnosis of asbestosis should be based on CT. In addition, initial findings of asbestosis on CT should be considered. (2) High Exposure industries and occupations to asbestos should be also taken into account in Korea (3) An expert's determination is warranted in case of a worker who has been concurrently exposed to other carcinogens, even if the asbestos exposure duration is less than 10 years. (4) Determination of a larynx cancer due to asbestos exposure has the same approval standards with an asbestos-induced lung cancer. However, for an ovarian cancer, an expert's judgment is necessary even if asbestosis, pleural plaque or pleural thickening and high concentration asbestos exposure are confirmed. (5) Cigarette smoking status or the extent should not affect determination of an occupational cancer caused by asbestos as smoking and asbestos have a synergistic effect in causing a lung cancer and they are involved in carcinogenesis in a complicated manner.