The dose-response relationship of chrysotile asbestos exposure and lung cancer in cohort study / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To clarify the dose-response relationship between asbestos dust exposure and lung cancer incidence in chrysotile asbestos miners by fixed cohort study and to investigate the incidence rates of lung cancer in exposure to different concentrations of asbestos dust.</p><p><b>METHODS</b>A retrospective cohort study was conducted in 1932 asbestos miners who registered from January 1, 1981 to December 31, 1988, had worked for at least 1 year, and had no obvious cardiopulmonary diseases; the cohort study began in July 2009 and covered a time span of 29 years (1981 - 2009). The personal information, occupational history, disease history, and health data of these miners were recorded, and the monitoring data on dust concentrations in the mine over the years were collected. The dose-response relationship between asbestos dust concentration and lung cancer incidence was established by the method of life table; a regression equation was fitted to predict the excess incidence rates of lung cancer under the conditions of different working years and dust concentrations.</p><p><b>RESULTS</b>A significant dose-response relationship was observed between cumulative exposure (Ce) and cumulative probability (Px) of lung cancer incidence, and the smokers hada higher Px than nonsmokers. When Ce was less than 2000 mg/m(3)·each year, Px reached 6.58/10000; when Ce was not less than 2000 mg/m(3)·and less than 3000 mg/m(3)·each year, Px reached 91.72/10000; when Ce was more than 5000 mg/m(3)·each year, Px was as high as 141.02/10000. The three models were fitted to obtain the optimal regression equation: Px = -0.0004Ce(2) + 0.0052Ce - 0.0011 (r(2) = 0.9387). In the workshop of asbestos mine in this study, the average dust concentration was 85 times higher than the limit in 2009, so the excess incidence rate of lung cancer was 112.598/10000 if the miners worked under this condition for 40 years, according to the equation.</p><p><b>CONCLUSION</b>There is a significant dose-response relationship between cumulative asbestos exposure and lung cancer incidence in chrysotile asbestos miners. The risk for lung cancer rises as asbestos exposure increases.</p>

Study on mental workload of teachers in primary schools / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the distribution characteristics and influencing factors of mental workload of teachers in primary schools.</p><p><b>METHODS</b>National Aeronautics and Space Administration-Task Load Index (NASA-TLX) was used to assess the mental workload levels for 397 teachers of primary schools in a city.</p><p><b>RESULTS</b>The mental workload (64.34+10.56) of female teachers was significantly higher than that (61.73+ 9.77) of male teachers (P<0.05). The mental workload (65.66+10.42) of "-35" years old group was the highest. When age of teachers was younger than 35 years old, there was a positive correlation between the mental workload and age (r=0.146, P<0.05). When age of teachers was older than 35 years old, there was a negative correlation between the mental workload and age (r=-0.190, P<0.05). The teachers with higher education level felt higher mental workload (unstandardized coefficients B=1.524, standardized coefficients /=0.111, P<0.05). There was a positive correlation between the mental workload and working hours per day (unstandardized coefficients B =4.659, standardized coefficients/3 =0.223, P<0.001).</p><p><b>CONCLUSION</b>Mental workload of the teachers in primary schools is closely related to age, educational level and work hours per day. Work hours per day is an important risk factor for mental workload. Reducing work hours per day (8 hours) is an effective measure of alleviating the mental workload of teachers in primary schools.</p>

A survey report on dermatitis patients in hospital in Baoan district of shenzhen city from 1992 to 2006 / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To analyse the epidemiological distribution of dermatitis patients in hospital and provide basis for studying the basic conditions and the prevention of dermatitis especially TCE-induced dermatitis in Baoan District of Shenzhen City.</p><p><b>METHODS</b>All dermatitis patients in hospital in Baoan District from 1992 to 2006 were descriptively analysed.</p><p><b>RESULTS</b>There were 645 dermatitis patients in hospital in Baoan District. The total number of patients is tended to rise in recent years. The main age group of 16 approximately years old, followed by 26 approximately years old, the majority are workers. The clinical diagnosis are allergic dermatitis, drug-induced dermatitis, TCE-induced dermatitis. Compared with other dermatitis, women are more than men in TCE-induced dermatitis (P < 0.05). The risk of hepatic dysfunction in TCE-induced dermatitis was significantly greater than other dermatitis (P < 0.05). It is mainly distributed in electronic, metal, electroplating industry.</p><p><b>CONCLUSION</b>The TCE-induced dermatitis was one of the main occupational hazards in Baoan district. To strengthen self-protection awareness of workers, pay more attention to early work observed and occupational screening in key industries and trades workers, reduce opportunities for occupational exposure, all above can effectively reduce the occurrence of TCE-induced dermatitis.</p>

Cancer mortality and asbestosis among workers in an asbestos plant in Chongqing, China / 生物医学与环境科学（英文）

<p><b>OBJECTIVE</b>To investigate whether asbestosis is a risk factor for mortality of lung cancer.</p><p><b>METHODS</b>A fixed cohort study was established in an asbestos plant in Chongqing, China, and followed up for 30 years from the beginning of 1972. Basic personal information on life state, cause of death, and diagnosis of asbestosis was collected. Multiple logistic regressions were applied to analyze risk factors.</p><p><b>RESULTS</b>During the 30-year follow-up, 584 male workers constituting a total of 14,664 person-years were monitored and data were analyzed. Among them, 203 (34.8%) died and the mortality rate was 13.8 per 1000 person-years, cancer accounting for 37.4%. Excess risks were observed for lung cancer (OR = 3.72) and nonmalignant respiratory diseases (OR = 2.73) among workers with asbestosis. High-exposure level was another risk factor for lung cancer (OR = 3.20). Workers with category II of asbestosis demonstrated a higher OR of both lung cancer and nonmalignant respiratory diseases than those with category I of asbestosis.</p><p><b>CONCLUSION</b>High asbestos exposure level and asbestosis were the risk factors for death of lung cancer and nonmalignant respiratory diseases. Asbestosis is an independent risk factor for lung cancer among Chinese workers exposed to chrysotile, the risk increases with the increasing profusion of opacities of lung.</p>

Development and evaluation of Comprehensive Work Ability Index scales / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To compile the instrument of comprehensive work ability evaluation-Comprehensive Work Ability Index (CWAI) scales.</p><p><b>METHODS</b>One hundred and ninety-eight employees were selected with the random cluster sampling method from a factory. On the basis of the work ability theory, CWAI scales, a self-rating scales on work ability, was developed according to the standardized processes of scales compilation. Item differentiation analysis, principal component analysis and factor analysis as well as intra-item reliability were used for selecting the item of CWAI scales.</p><p><b>RESULTS</b>Work ability was assessed with a comprehensive work ability index, which was a comprehensive indicator constructed on the basis of the responses to the scales. It was derived as the sum of the five items including self-rating work ability domain, physiological domain (disease, sick leave etc.), psychological domain (work satisfaction, mental state etc.), social functions dominant (social support, social flexibility etc.) and work ability prediction domain.</p><p><b>CONCLUSION</b>CWAI scales correspond with the theoretical structure. However, the reliability and validity of CWAI scales must be assessed before the formal application.</p>

Reliability and validity of Comprehensive Work Ability Index scales / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To test the reliability and the validity of Comprehensive Work Ability Index (CWAI) scales.</p><p><b>METHODS</b>For evaluating the reliability and validity of CWAI scales, 1959 subjects employed in various kinds of occupations were selected with the random cluster sampling method. 245 subjects of them were retested at intervals of 2 to 4 weeks in order to assess the test-retest reliability. The sample for criterion validity consisted of 86 subjects. The inter-item consistency (Cronbach's alpha coefficient, Spearman-Brown coefficient, theta coefficient and Omega coefficient), test-retest reliability (intra-class correlation coefficient) and Pearson correlation were calculated to assess the reliability of CWAI scales. Pearson correlation analysis, and factor analysis were used to assess the validity of CWAI scales.</p><p><b>RESULTS</b>The reliability analysis showed that CWAI was significantly correlated with the item scores (P < 0.01), and most of the correlation coefficients were higher than 0.30. Generally speaking, Cronbach's alpha coefficients (ranging from 0.701 to 0.808), theta coefficient (ranging from 0.703 to 0.845) and Omega coefficient (ranging from 0.802 to 0.942) and Spearman-Brown coefficient (0.860) conformed to the requirements of psychometric study. The intra-class correlation coefficient (ranging from 0.597 to 0.897) suggested that the test-retest consistency was good at intervals of 2 to 4 weeks. In point of the theoretic concept and development method, the content validity of CWAI scales was satisfactory. The intra-class correlation coefficient for the concurrent validity was 0.650 (P < 0.01) when WAI scales were taken as the criterion. Factor analysis revealed that when eight common factors were drawn from the 17 items of CWAI scales, the cumulative variance of eigenvalues amounted to 71.894%. Each item had communality over 0.60 and its factor loading (0.538 approximately 0.948) attached to the relevant common factor was over 0.40. The common factors with higher factor loading were basically consistent with the theoretic concept of CWAI scales.</p><p><b>CONCLUSION</b>CWAI scales are reliable and valid.</p>

Nested case-control study of chrysotile and lung cancer / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To investigate the relationship between simple exposure to chrysotile and lung cancer.</p><p><b>METHODS</b>The nested case-control study method was used. All of lung cancer cases collected from a male fixed prospective cohort with follow-up of 30 years served as cases and a 1:4 matched proportion was used to select non-cancer case as controls. Controls matched for sex age (+/-5 years old), work time (+/-5 years) and smoking were collected in the same cohort.</p><p><b>RESULTS</b>Forty cases died of lung cancer in the study cohort, and the incidence was higher than the average incidence (SMR =1.77). The top four work types of death density were raw material (741.5), combing and spinning (424.3), weaving (365.0), and repairing (285.5), which was consistent with exposed level. According to the exposed level of chrysotile, the research objects were divided into the high level group and the low level group. The result demonstrated that lung cancer incidence of the high exposed level group of chrysotile was higher (OR = 3.7 95% CI 2.30 approximately 8.16), compared with the low exposed level group.</p><p><b>CONCLUSION</b>Simple exposure to chrysotile can increase the risk of lung cancer for workers who are exposed to chrysotile.</p>

The appraisal of reliability and validity of subjective workload assessment technique and NASA-task load index / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To test the reliability and validity of two mental workload assessment scales, i.e. subjective workload assessment technique (SWAT) and NASA task load index (NASA-TLX).</p><p><b>METHODS</b>One thousand two hundred and sixty-eight mental workers were sampled from various kinds of occupations, such as scientific research, education, administration and medicine, etc, with randomized cluster sampling. The re-test reliability, split-half reliability, Cronbach's alpha coefficient and correlation coefficients between item score and total score were adopted to test the reliability. The test of validity included structure validity.</p><p><b>RESULTS</b>The re-test reliability coefficients of these two scales and their items were ranged from 0.516 to 0.753 (P < 0.01), indicating the two scales had good re-test reliability; the split-half reliability of SWAT was 0.645, and its Cronbach's alpha coefficient was more than 0.80, all the correlation coefficients between its items score and total score were more than 0.70; as for NASA-TLX, both the split-half reliability and Cronbach's alpha coefficient were more than 0.80, the correlation coefficients between its items score and total score were all more than 0.60 (P < 0.01) except the item of performance. Both scales had good inner consistency. The Pearson correlation coefficient between the two scales was 0.492 (P < 0.01), implying the results of the two scales had good consistency. Factor analysis showed that the two scales had good structure validity.</p><p><b>CONCLUSION</b>Both SWAT and NASA-TLX have good reliability and validity and may be used as a valid tool to assess mental workload in China after being revised properly.</p>

Analysis on the incidence and relevant risk factors of campus violence among college students / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the incidence and risk factors of campus violence and to provide evidence for preventing campus violence among college students.</p><p><b>METHODS</b>5300 college students in two universities in a province of China were selected to participate in the study and were interviewed with questionnaires. Logistic regression was used for data analysis.</p><p><b>RESULTS</b>(1) In total, 3910 useable questionnaires were gathered to show a response rate of 73.77%. 17.98% of the college students reported they had ever experienced campus violence in the last one year. 29.60% of the male students experienced campus violence so as 7.27% of the female students. The incidence of violence among male students was significantly higher than those of female students (chi2 = 329.89, P = 0.000). (2) Among male students who were victims of campus violence, the incidence rates of threat or blackmail, emotional abuse, physical assault, verbal sexual harassment, sexual assault were 18.03%, 13.97%, 10.77%, 0.85%, 0.48% respectively. Among female students who were victims of campus violence, the incidence rates were 3.64%, 5.84%, 1.38%, 1.33%, 1.13% respectively. The main source of the violence was from their schoolmates. (3) 10.40% of the male students reported they were perpetrators of campus violence in the last year, while 1.47% of the female students reported so. Schoolmates were the main subjects of their aggressive behaviors. (4) Among the college students who were victims of campus violence, logistic regression analysis revealed that smoking, drinking alcohol, frequently getting computer online were important risk factors. The OR values were 1.48, 2.96, 1.66 respectively. Among college students who were perpetrators of campus violence, the OR values were 2.92, 1.88, 2.09 respectively.</p><p><b>CONCLUSION</b>Campus violence among college students was serious, suggesting that intervention measures should be taken.</p>

The effect of cadmium pollution on reproductive health in females / 中华流行病学杂志

<p><b>OBJECTIVE</b>To study the relationship between cadmium pollution and its adverse effects on female reproductive health status in people living in cadmium polluted area in Zhenghe, Fujian provinces.</p><p><b>METHODS</b>Data through laboratory studies on reproductive health of female residents in Cd-pollution area were studied and compared with those in control areas in Zhenghe.</p><p><b>RESULTS</b>Both prevalence rates of abnormal menstrual cycle and dysmenorrhea in unmarried women in Cd-pollution area (19.1% vs. 42.6%) were significantly higher than those in control area (5.7% vs. 18.9%) and the rates of sterility in married women in Cd-pollution area (6.3%) were significantly higher than those in control area (1.1%). During the first two pregnancies, rates of queasiness, disgorgement, spontaneous abortion and stillbirth in married women in polluted area were 44.7%, 31.7%, 10.27% and 4.23%, significantly higher than those 26.5%, 17.8%, 2.85% and 1.05% in control area, with significant differences (P < 0.05). Results from cumulative odds model analysis showed that: living in Cd-pollution area was a possible risk factor related to female reproductive health (OR = 2.072), after the other risk factors being under control.</p><p><b>CONCLUSION</b>The female reproductive health status of people residing in the cadmium polluted area had already been deteriorated.</p>

Norm study of occupational stress on the professionals in Chengdu and Chongqing area / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To establish the norm of occupational stress on the professionals in Chengdu and Chongqing area.</p><p><b>METHODS</b>According to the "Occupation Sorting Canon in the People's Republic of China", the professionals of the above-mentioned area were sorted out and randomly stratified. The normative data were derived from a sample of 2 064 participants. The modified Occupation Stress Inventory Revised Edition (OSI-R) was used to test the targets' occupational stress level (including stressors, strain and coping resources).</p><p><b>RESULTS</b>(1) In these professionals, the sex ratio was about 1:1, average age (36.4 +/- 9.4) years, average length of service (15.9 +/- 10.0) years, 63.07% people were college educated and over 80% married. (2) Descriptive statistics for OSI-R scale scores for the total normative sample, for gender samples and for occupational group samples were modulated. (3) The gender norm showed that there were heavier role overload and stronger occupational strains in males than those in females (P < 0.01). The score of personal resources in the males was not different from that in females (P > 0.05). (4) In terms of different occupations, the scores of occupational role and personal strain among various groups indicated significant differences (P < 0.01). The score of personal resources did not manifest difference (P > 0.05). (5) The major factors influencing OSI-R were sex, occupation and length of service.</p><p><b>CONCLUSION</b>The norm established can basically represent the occupational stress on professionals in Chengdu and Chongqing area.</p>

The scale and application of the norm of occupational stress on the professionals in Chengdu and Chongqing area / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To establish the scale of the norm of occupational stress on the professionals and put it into practice.</p><p><b>METHODS</b>T scores were linear transformations of raw scores, derived to have a mean of 50 and a standard deviation of 10. The scale standard of the norm was formulated in line with the principle of normal distribution.</p><p><b>RESULTS</b>(1) For the occupational role questionnaire (ORQ) and personal strain questionnaire (PSQ) scales, high scores suggested significant levels of occupational stress and psychological strain, respectively. T scores >/= 70 indicated a strong probability of maladaptive stress, debilitating strain, or both. T scores in 60 approximately 69 suggested mild levels of maladaptive stress and strain, and in 40 approximately 59 were within one standard deviation of the mean and should be interpreted as being within normal range. T scores < 40 indicated a relative absence of occupational stress or psychological strain. For the personal resources questionnaire (PRQ) scales, high scores indicated highly developed coping resources. T scores < 30 indicated a significant lack of coping resources. T scores in 30 approximately 39 suggested mild deficits in coping skills, and in 40 approximately 59 indicated average coping resources, where as higher scores (i.e., >/= 60) indicated increasingly strong coping resources. (2) This study provided raw score to T-score conversion tables for each OSI-R scale for the total normative sample as well as for gender, and several occupational groups, including professional engineer, professional health care, economic business, financial business, law, education and news. OSI-R profile forms for total normative samples, gender and occupation were also offered according to the conversion tables.</p><p><b>CONCLUSION</b>The norm of occupational stress can be used as screening tool, organizational/occupational assessment, guide to occupational choice and intervention measures.</p>

Study on revising the criteria of classification of hazard conditions of productive dust / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To provide scientific basis data for revising the national hygiene criteria of "Classification of hazard conditions of productive dust" (GB5817-86).</p><p><b>METHODS</b>The data of the retrospective study and the field survey data were analyzed with correlation and regression analysis. The product of total dust concentration of respiratory exposure (mg/m(3)), total ventilation during exposure (m(3)/d per psrson), and level of free SiO(2) in dust (%) was the respiratory exposure dose of free SiO(2) (mg per day per person) which was used as dose criteria value of classification of hazard degree of dust.</p><p><b>RESULTS</b>Using free SiO(2) exposure dose and the dose-effect relationship, the hazard degrees of the dust were divided into 5 grades: 0, I, II, III, IV (0 - 8.0, 8.1 - 12.0, 12.1 - 16.0, > 24.1 mg per day per person).</p><p><b>CONCLUSION</b>The exposure dose of free SiO(2) is closely related to the pathogenesis of silicosis. Using the exposure dose of free SiO(2) as the classification indicator of hazard degree of dust is reliable, simple and easy to execute.</p>

Appraisal of occupational stress and its influential factors in nurses / 中华劳动卫生职业病杂志

<p><b>OBJECTIVE</b>To assess the occupational stress and its influential factors in nurses.</p><p><b>METHODS</b>A test of occupational stress, its influential factors, work ability were carried out for 248 nurses and 319 controls with revised occupational stress inventory (OSI-R) and work ability index (WAI).</p><p><b>RESULTS</b>The scores of personal cope resource (131.266 +/- 17.176) and work ability index (32.581 +/- 3.158) in nurse group were significantly higher than those in control group (126.931 +/- 19.108, 31.840 +/- 4.069) (P < 0.05). The main occupational stressors scores (role insufficiency, role clash, and responsibility) in nurses were higher than those in controls (P < 0.05). The stress response of interpersonal relationship in nurses was also higher. The items of personal cope resource, such as recreation, self-care and social support of nurses were superior to those of controls (P < 0.05). Stress response was positively correlated with occupational role (r = 0.512, P < 0.01), and negatively correlated with the personal cope resource (r = -0.475, P < 0.01). The primary influential factors of personal stress were recreation, social support, rational conduct, role insufficiency, role clash, responsibility, and poor work environment.</p><p><b>CONCLUSION</b>To strengthen social support, to improve work condition for nurses, so as to reduce the occupational stress and to enhance the work ability of nurses are important task in occupational health field.</p>