Cellular Phone Use and Risk of Tumors: Systematic Review and Meta-Analysis.

We investigated whether cellular phone use was associated with increased risk of tumors using a meta-analysis of case-control studies. PubMed and EMBASE were searched from inception to July 2018. The primary outcome was the risk of tumors by cellular phone use, which was measured by pooling each odds ratio (OR) and its 95% confidence interval (CI). In a meta-analysis of 46 case-control studies, compared with never or rarely having used a cellular phone, regular use was not associated with tumor risk in the random-effects meta-analysis. However, in the subgroup meta-analysis by research group, there was a statistically significant positive association (harmful effect) in the Hardell et al. studies (OR, 1.15-95% CI, 1.00 to 1.33- n = 10), a statistically significant negative association (beneficial effect) in the INTERPHONE-related studies (case-control studies from 13 countries coordinated by the International Agency for Research on Cancer (IARC); (OR, 0.81-95% CI, 0.75 to 0.89-n = 9), and no statistically significant association in other research groups' studies. Further, cellular phone use with cumulative call time more than 1000 h statistically significantly increased the risk of tumors. This comprehensive meta-analysis of case-control studies found evidence that linked cellular phone use to increased tumor risk.

Occupational post-traumatic stress disorder: an updated systematic review.

BACKGROUND: Although numerous studies on occupational post-traumatic stress disorder (PTSD) have been conducted prior to the 1950-2010 seminal systematic review by Skogstad et al., the prevalence, risk factors, and impact of this disorder following traumatic events in occupational settings remain unclear. This study aims to address this knowledge gap by reviewing the literature published after 2010. METHODS: We reviewed literature from databases such as PubMed and Google Scholar using PRISMA guidelines to identify studies that address occupational PTSD and examined the status (prevalence or incidence), the risk factors, and the health effects of PTSD among workers. RESULTS: In total, 123 articles were identified, and finally, 31 (25.2%) articles were selected after excluding duplicates. Various occupational traumatic physical events were reported such as natural or manmade disaster, explosion, accident, handling refugee corpses, or bullying at work. Risk of PTSD was closely associated with working conditions, severity of injury, history of mental disorder, occurrence of psychiatric symptoms at the time of the event, personality, interpersonal relationships, etc. Workers with PTSD were likely to experience a deterioration of physical and psychological health and impairment of social and occupational functioning. CONCLUSIONS: Our review suggests that many workers remain highly vulnerable to occupational PTSD and its consequences.

Trends in Obesity Prevalence by Occupation Based on Korean National Health and Nutrition Examination Survey From 1998 to 2015.

BACKGROUND: It is well known that the prevalence of obesity in Korea is increasing over time, however it is not known how the trends among occupational groups and sex differ in such increasing trends. This study was designed to provide recent trends of obesity among workers in Korea and to identify whether there were differences among occupational groups. METHODS: We used data from the Korean National Health and Nutrition Examination Survey, Phases I to VI (1998-2015), to analyze trends in the prevalence of obesity in adult Korean workers. Obesity was defined as a body mass index of 25 kg/m2 or higher. Occupations were classified into 3 groups: (a) nonmanual workers, (b) service/sales workers, and (c) manual workers. RESULTS: During the period of the Korean National Health and Nutrition Examination Survey Phases I to VI, the prevalence of obesity in male workers increased in all occupations (31.1% to 39.5% in manual workers, 32.3% to 38.2% in service/sales workers, and 25.3% to 39.7% in manual workers). However, female workers did not show any particular tendency toward obesity, except for a significant decrease in the prevalence rate in service/sales workers (30.8% to 23.9%, p for trend = 0.0048). CONCLUSION: The trends of obesity prevalence by sex and occupation were different. For male manual workers, the prevalence rate increased steadily during the data period, while it decreased steadily in female sales/service workers.

Effect of teacher's working conditions on voice disorder in Korea: a nationwide survey.

BACKGROUND: Korean teacher's working conditions are deteriorating. There is concern about the deterioration of teachers' health and voice disorder is one of the most common problems. Teacher's vocal health is important for them and their students. The aim of the present study was to investigate working conditions that may affect voice disorders. METHODS: In all, 79 primary and secondary schools were randomly selected for a nationwide school system survey (N = 3345). In 64 schools, 1617 (48.3%) teachers participated via a postal self-report questionnaire from June 2016 to August 2016. After applying inclusion and exclusion criteria, data from 1301 teachers' were used for analysis. Multiple logistic regression was used to investigate the associations between general, work-related factors, and frequent voice disorders (fVDs) to estimate the adjusted odds ratio(aOR). RESULTS: Teachers who reported voice symptoms more than once a week (fVD) made up 11.6%. In a multiple logistic regression, fVD was significantly associated with female, difficulty in applying for sick leave as needed, music teachers (primary school), and less than 6 h of sleep per day (primary school). The aOR for fVD was 2.72 (0.83-8.10) in the longest working hours group (> 52 h/wk) among the primary school teachers, and 1.90 (0.80-4.73) in the longest class hour group (≥ 20 h/wk), 1.52 (0.90-2.62) in homeroom teachers among the secondary school teachers, but not statistically significant. CONCLUSIONS: Korean teachers' working conditions are associated with fVDs. The school health system must take steps to prevent and treat voice disorders of teachers.