A multilevel model analysis of correlation between population characteristics and work ability of employees / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To analyze the correlation between population characteristics and work ability of employees with a multilevel model, to investigate the important influencing factors for work ability, and to provide a basis for improvement in work ability.</p><p><b>METHODS</b>Work ability index (WAI)was applied to measure the work ability of 1686 subjects from different companies (n=6). MLwi N2.0 software was applied for two-level variance component model fitting.</p><p><b>RESULTS</b>The WAI of employees showed differences between various companies (χ2=3.378 6, P=0.0660); working years was negatively correlated with WAI (χ2=38.229 2, P=0.0001), and the WAI of the employees with 20 or more working years was 1.63 lower than that of the employees with less than 20 working years; the work ability of manual workers was lower than that of mental-manual workers (χ2=8.2726, P=0.0040), and the work ability showed no significant difference between mental workers and mental-manual workers (χ2=2.086 0, P=0.148 7).</p><p><b>CONCLUSION</b>From the perspective of probability, the multilevel model analysis reveals the differences in work ability of employees between different companies, and suggests that company, work type, and working years are the important influencing factors for work ability of employees. These factors should be improved and adjusted to protect or enhance the work ability of employees.</p>

Effects of mental workload on work ability in primary and secondary school teachers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the change pattern of primary and secondary school teachers' work ability with the changes in their mental workload.</p><p><b>METHODS</b>A total of 901 primary and secondary school teachers were selected by random cluster sampling, and then their mental workload and work ability were assessed by National Aeronautics and Space Administration-Task Load Index (NASA-TLX) and Work Ability Index (WAI) questionnaires, whose reliability and validity had been tested. The effects of their mental workload on the work ability were analyzed.</p><p><b>RESULTS</b>Primary and secondary school teachers' work ability reached the highest level at a certain level of mental workload (55.73< mental workload ≤ 64.10). When their mental workload was lower than the level, their work ability had a positive correlation with the mental workload. Their work ability increased or maintained stable with the increasing mental workload. Moreover, the percentage of teachers with good work ability increased, while that of teachers with moderate work ability decreased. But when their mental workload was higher than the level, their work ability had a negative correlation with the mental workload. Their work ability significantly decreased with the increasing mental workload (P < 0.01). Furthermore, the percentage of teachers with good work ability decreased, while that of teachers with moderate work ability increased (P < 0.001).</p><p><b>CONCLUSION</b>Too high or low mental workload will result in the decline of primary and secondary school teachers' work ability. Moderate mental workload (55.73∼64.10) will benefit the maintaining and stabilization of their work ability.</p>

Impact of work-related musculoskeletal disorders on work ability among workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To assess the impact of work-related musculoskeletal disorders (WRMDs) on work ability among workers.</p><p><b>METHODS</b>A total of 1686 workers in various occupations, such as administration and education, were enrolled as subjects using the random cluster sampling method. The WRMDs and work ability of all subjects were evaluated using standardized Nordic questionnaires for the analysis of musculoskeletal symptoms and the Work Ability Index (WAI) scale, respectively. Comparison of work ability and its classification between the disease group and the non-disease group was performed by paired t test, RxC table χ2 test, and the Wilcoxon rank-sum test. The relationship between work duration and work ability was analyzed by the Spearman correlation test and a multi-level model.</p><p><b>RESULTS</b>(1). The work ability of workers in the disease group was significantly lower than that in the non-disease group (P<0.0 1). (2) There were significant differences in work ability between workers with different work durations (<10 years, 10-20 years, and ≥20 years) (F=22.124, P< 0.01). With the increase in work duration, the work ability of workers declined in both groups, and the work ability of workers in the disease group (Spearman coefficient rs=-0. 172, P<0.01) had a more significant decline than that in the non-disease group (Spearman coefficient rs=-0.104, P<0.01). WRMDs were important risk factors for the decrease in work ability among workers. (3) There were significant differences in constituent ratios and levels of work ability classification between the disease group and the non-disease group (χ2=121.097, P<0.01; Z=-10.699, P<0.01). The proportions of workers with poor and medium work ability in the disease group were significantly higher than those in the non-disease group, while the proportion of works with excellent work ability in the disease group was significantly lower than that in the non-disease group. The similar characteristics in constituent ratios and levels of work ability classification could be found between the disease group and the non- disease group in various occupations (P<0.01).</p><p><b>CONCLUSION</b>WRMDs have a harmful effect on the work ability of workers, and the work ability of workers substantially declines with the increase in exposure time (work duration).</p>

Study on current status of work-related musculoskeletal disorders evaluation / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To characterize the distribution of work-related musculoskeletal disorders (WRMD) among the occupational population.</p><p><b>METHODS</b>A total of 1686 people of various occupations were recruited with random cluster sampling. Standardized Nordic questionnaires for the analysis of musculoskeletal systems were used to evaluate WRMD at the neck, shoulder, or lower back in the past one year. The annual prevalence of WRMD was determined. Difference analysis was performed with t-test, ANOVA, or chi-square test. The relationship between personal characteristics and WRMD was analyzed by unconditional logistic regression.</p><p><b>RESULTS</b>(1) WRMD were most frequently observed at the neck, followed by the lower back, and was least observed at the shoulder (P < 0.05). The prevalence of WRMD among mental workers was significantly higher than those among physical workers and mental-physical workers (P < 0.01). The prevalence of WRMD among female workers was significantly higher than that among male workers (P < 0.05). (2) In general, the prevalence of WRMD significantly rose with the increases in age (<30, 30∼, 40∼, and ≥ 50 years) or working years (<10, 10∼, and ≥ 20 years) (P < 0.05). (3) In the face of sickness or injury, physical workers and mental workers showed a relatively high absence rate but a relatively low medical visiting rate (13.05%). (4) Unconditional logistic regression analysis showed that mental work, gender, and working year were the main influential factors for WRMD among workers.</p><p><b>CONCLUSION</b>Workers of different types of occupation, genders, ages, and working years have different risks of WRMD at the neck, shoulder, and lower back.</p>

Analysis of mortality in chrysotile asbestos miners in China / 华中科技大学学报（医学）（英德文版）

In order to investigate the mortality of a cohort of chrysotile asbestos miners in China and evaluate its association with exposure to chrysotile, a fixed cohort of 1932 workers in chrysotile asbestos mine was established in 1981 and followed till June 1, 2010. Information on vital status, cause of death and smoking habits was collected. The workers were divided into two groups according to their exposure status. The exposed group was composed of frontline workers who worked directly on mining or processing asbestos products. The control group consisted of those who were not directly exposed to asbestos in their work. Standardized mortality ratio (SMR) was calculated according to Chinese national death rates. Cox proportional hazards model was applied to estimate the adjusted relative risks of deaths from major causes in exposed and control groups. The results of this study showed that main causes of mortality were malignant neoplasm, cardiovascular disease, cerebrovascular disease and respiratory disease for chrysotile miners. The mortality rate was 939.20 per 100 000 person-years for workers. The SMR for all causes of death was 1.46 in the cohort. Statistically significant mortality excesses were found for lung cancer (SMR=1.51), pulmonary heart disease (SMR=2.70), respiratory disease (SMR=1.93), asbestosis (SMR=9.62), and accident (SMR=1.59). The mortalities from malignant neoplasm, lung cancer, cerebrovascular disease and digestive disease in the exposed group were significantly higher than those in the control group. The findings indicate that chrysotile exposure is a risk factor for lung cancer, respiratory disease, cerebrovascular disease and digestive disease.

Study on the relationship between occupational stress and psychological health state among oil workers / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To study the relationship between occupational stress and psychological health state among oil workers.</p><p><b>METHODS</b>1,230 oil workers in 122 work types of oil industry were selected and written occupational stress questionary(OSQ) and symptom check list (SCL-90).</p><p><b>RESULTS</b>Petroleum workers' psychological health states were poor with increasing occupational stress degree. The scores in physical symptoms(1.87 +/- 0.80, 1.72 +/- 0.70), depression(1.74 +/- 0.76, 1.62 +/- 0.67), horror(1.48 +/- 0.65, 1.39 +/- 0.55) in the high and medium stress group were obviously higher than those in low stress group(1.55 +/- 0.61, 1.43 +/- 0.54, 1.28 +/- 0.46, respectively, P < 0.05). The score of mood state in the high and medium stress group was obviously higher than that in low stress group(P < 0.05). Psychological health states and mood state in the petroleum workers with short service length are significantly poorer than that with long service length(P < 0.01).</p><p><b>CONCLUSION</b>Occupational stress should affect psychological health state of petroleum workers.</p>

Changes of Menstrual Function of Female Workers in Plastic Plants / 环境与健康杂志

Objective To study the effects of occupational exposure to endocrine disrupters (ECDs) in plastic plants. Methods 719 female workers including observation group exposed to plastic manufacture production environment and control group not exposed to plastic manufacture production environment were selected by the cluster sampling method and were investigated using the unified questionnaire on female reproductive function. Results The observation group showed significantly higher prevalence rates of abnormal menstruation, and irregular menstrual period, menstrual cycle and menstrual quantity compared with those of control group (P

STUDY ON ENERGY METABOLISM OF ADULTS WITH ABNORMAL BODY WEIGHT / 营养学报

Objective: To study the energy metabolism on adults with abnormal body weight. Method: Twenty four men aged 20-30 years old were chosen as the subjects whose BMI were more than 25 in obesity group, less than 18.5 in lean group and from 18.5 to 23 in normal group. K4b2 expiry monitor was used to study the energy metabolism of the subjects. Results: The total food intakes, the total energy intakes and the basal metabolism expenditure of the obese subjects were significantly higher than those in the normal and the lean group (P