Shift work and mortality

Despite results linking shift work with ill health, only a few studies have addressed its relation with mortality. The purpose of the present study was to examine the hypothesis that shift work is a predictor of mortality. The study involved a sample of 22,411 individuals of the Swedish population. Data were obtained through annual phone interviews done between 1979 and 2000. Cox regression analysis was used to assess the association between shift work/day work as the independent variable and death/survival during the subsequent years as the dependent variable. Separate analyses were carried out for female and male white- and blue-collar workers, respectively. The results were adjusted for age, stress, physical work load, disease at the outset of the study, and smoking. Mortality was significantly increased for female white-collar workers, with a Hazard Ratio of 2.61 and a 95% confidence interval of 1.26-5.41. No other significant effects were found. It is concluded that blue-collar shift work is not related to mortality, but that risk of death is increased for women white-collar shift workers compared to women white-collar day workers.     

Division of Labour among Workers in the Termite,Reticulitermes fukienensis (Isoptera: Rhinotermitidae)

To investigate division of labour in Reticulitermes fukienensis, worker and larval subgroups were established in laboratory cultures and task performance patterns of different-sized workers and larvae were recorded. Five categories of subgroups were established based on head width differences: small larvae (SL); large larvae (LL); small workers (SW); medium workers (MW); and large workers (LW). Subgroups were compared for their ability to carry out the following tasks: tunnel construction; covered gallery construction; gallery repair; and feeding. Larval subgroups were found to carry out none of the tasks investigated. They did not feed or build covered galleries or underground tunnels. Temporal polyethism occurred among workers of different size groups. Covered foraging galleries were exclusively built and tunnels were predominantly built by older workers (i.e. MW and especially LW). Remarkably, most SW were apparently unable to burrow into the soil, something that all LW did within 3 d and 95% of MW did within 5 d. Surprisingly, LW ate 8.5 and 65.5 times as much food (i.e. filter paper) as MW and SW, respectively, although their average body weights were, respectively, only approximately two and four times that of MW and SW. MW carried out all four tasks that LW performed, although MW were typically less efficient. This contrasts with the hypothesis that different instars of termites should carry out different non-overlapping tasks. Large workers carried out most of all tasks compared with other worker sizes. The only exception was for gallery repair where repair rate by LW did not differ significantly from MW. The predominance of tasks carried out by larger (i.e. older) workers indicates a possible new pattern for division of labour in these lower termites. This contrasts with the pattern of organization of division of labour in the social Hymenoptera.     

Chromosomal aberration analysis of workers in tannery industries

A chromosomal aberration analysis was carried out on tannery workers and on matched controls. Workers were engaged in 2 different processing areas, the drum and the finishing workshop. A weak but significant increase in chromosomal aberration frequencies was shown in drum workers in comparison to controls, no difference was shown in finishers.     

Follow-up study of the genetic damage in lymphocytes of pharmacists and nurses handling antineoplastic drugs evaluated by cytokinesis-block micronuclei analysis and single cell gel electrophoresis assay

A follow-up study was carried out 4 years after an initial evaluation of the micronucleus frequency in 10 healthy individuals who had been occupationally exposed to antineoplastic drugs in a Brazilian hospital. Upon the first evaluation, these 10 exposed individuals were compared with 10 non-exposed individuals matched for age, sex and smoking habits; the results revealed that the frequency of micronucleated lymphocytes in individuals exposed to antineoplastic drugs was significantly higher (P=0.038) than in controls. The frequency of dicentric bridges was also increased, although not significantly (P=0.0545). After the first analysis, the workers handling antineoplastic drugs were advised to modify their work schedule to limit exposure, and the number of workers in the group was increased from 10 to 12 individuals. In the follow-up study, 12 individuals from the same work area were assessed. In addition to micronucleus frequency, alkaline single cell gel electrophoresis was also used to monitor genetic hazard. This exposed group was compared to 12 non-exposed workers from the same hospital, matched for age, sex and smoking habits. In the follow-up study, no statistical difference was found between exposed workers and controls in terms of micronucleus and dicentric bridge frequency with the Mann--Whitney U-test (P=0.129 and 0.373, respectively). However, the mean value of SCGE analysis was significantly higher in the exposed group than in the controls (P=0.0006). Although the micronucleus analysis seems to be less sensitive to assess DNA damage, it detects chromosome aberrations and not just repairable DNA breakage and alkali-labile sites. Combination of the alkaline single cell gel electrophoresis and cytokinesis blocked micronucleus assay appears to be commendable to monitor populations chronically exposed to genotoxic agents.     

Cytogenetic biomonitoring of workers from laboratories of clinical analyses occupationally exposed to chemicals

A cytogenetic monitoring study was carried out on a group of workers in clinical analysis laboratories to investigate the risk of occupational exposure to chronic low levels of chemicals.Thirty-four clinical laboratories have been involved in the study. In these laboratories, toxicants and analytical procedures utilized have been characterized. The individual occupational exposure of workers was assessed by use of a questionnaire concerning the chemical substances utilized. About 300 different chemicals have been identified.Cytogenetic analyses (chromosomal aberration and micronucleus tests) were carried out on a strictly selected group of 50 workers enrolled from these laboratories and compared to 53 controls (healthy blood donors) matched for gender and age.The exposed group shows a significantly higher frequency of genetic damage than the control group. Both chromatid and chromosome aberration frequencies in workers appear significantly higher than in controls. Similarly, comparison between micronucleated cells rates of exposed and unexposed groups show significantly higher frequencies of binucleated cells with micronucleus (BNMN) and of total micronuclei (MN tot) in workers than in controls.     

Support measures to improve night and shift work conditions in Thailand: a case study in a glass factory

The present study aimed to examine the working conditions of shift workers in a multinational enterprise in Thailand and to identify practical support measures for improvements. A multinational, glass-manufacturing factory employing 1,500 workers was selected as the research site. Three shift systems in three teams were adopted. A direct observation study and a fatigue feeling monitoring study were carried out to compare the differences between different shifts. A 10-day time-budget study was conducted for 30 shift workers to know their work and sleep patterns. The direct observation study identified safety and health risks during the night work periods. The risks included insufficient lighting, height gaps on the floor, excessive exposure to heat, inappropriate workstations, and sleepiness and fatigue feelings among shift workers. Working consecutive double shifts and overtime work was often seen. An advisory meeting was held based on the study findings to assist managers and workers in improving their working conditions. A follow-up visit six months later confirmed that the glass factory implemented several improvements to help night and shift workers. It was concluded that the direct observation methods associated with the time-budget study were helpful for identifying practical action points and strengthening workplace initiatives.     

Genetic effect of low doses of radiation in occupationally exposed workers in coal mines and in coal fired plants

Summary Analyses of structural aberrations of chromosomes and of the body burden of lead-210 were carried out in a group of workers occupationally exposed to chemical pollutants and low doses of ionizing radiation during a technological process in which coal is used as fuel. A parallel study was performed in a control group of workers.In the exposed group the percentage of chromatid and chromosome aberrations and the results of radiochemical analyses were higher than in the control group.This paper is based on work performed under International Atomic Energy Agency contract No. 2346/RB     

Cytogenetic biomonitoring of workers from laboratories of clinical analyses occupationally exposed to chemicals

A cytogenetic monitoring study was carried out on a group of workers in clinical analysis laboratories to investigate the risk of occupational exposure to chronic low levels of chemicals.Thirty-four clinical laboratories have been involved in the study. In these laboratories, toxicants and analytical procedures utilized have been characterized. The individual occupational exposure of workers was assessed by use of a questionnaire concerning the chemical substances utilized. About 300 different chemicals have been identified.Cytogenetic analyses (chromosomal aberration and micronucleus tests) were carried out on a strictly selected group of 50 workers enrolled from these laboratories and compared to 53 controls (healthy blood donors) matched for gender and age.The exposed group shows a significantly higher frequency of genetic damage than the control group. Both chromatid and chromosome aberration frequencies in workers appear significantly higher than in controls. Similarly, comparison between micronucleated cells rates of exposed and unexposed groups show significantly higher frequencies of binucleated cells with micronucleus (BNMN) and of total micronuclei (MN tot) in workers than in controls.     

A room for reflection: self-observation and transformation in participatory HIV prevention work

This article looks at HIV prevention projects in which established stigmatized and stigmatizing roles were actively reversed and manipulated in pursuit of HIV harm reduction. In two Norwegian projects, sex workers and drug users carried out harm-reduction activities with other drug users and sex workers. Although HIV-related harm reduction was the aim of the projects, termination or reduction of drug use or sex work was not. Such changes nevertheless occurred among the sex workers and drug users who took active part in the project. The article considers these changes in order to reflect on the meanings and roles of participation in HIV prevention work. In particular, the discussion theorizes on possible ways in which alteration of roles and subject positions may produce self-reflective effects with transformative potentials.     

Possibilities of earlier evidence of the lead load

A total of 138 workers of a motorcar transportation plant were examined to show a degree of lead damage. The analysis of obtained results was conducted from the two points of view: 1) according to employment time in plant; 2) according to work groups. The following laboratory examinations were carried out: delta-aminolevulin acid and coproporphyrin urinary excretion; determination of serous transaminase of glutaminoxalacetic acid and glutamin and piruvic acid, leucinaminopeptidase, whole protein, albumin-globulin coefficient, protein fractions (albumin alpha 1-, alpha 2-, beta 1-, beta 2, gamma) as well as of dehydratase activity of delta-aminolevulin acid in erythrocytes. In conformity with literary data an increased urinary excretion of delta-aminolevulin acid and of coproporphyrin to a different degree, as well as a decrease of dehydratase content of delta-aminolevulin acid in erythrocytes were detected. In the authors' view attention is to be drawn to a minor or greater extent to proportional increase of leucinaminopeptidase content however, in all the age groups and all the professional categories. The results of present examinations are considered by authors an important and sensitive parameter to evidence of lead damage.     

Sickness absence and shift work among Japanese factory workers

To investigate the effect of shift work on long-term sickness absence (more than 7 calendar days), an 8-year follow-up study was carried out in a factory in Japan. The participants were male employees aged 18-54 years who were engaged in manufacturing sites. Shift patterns were classified by the number of non-daytime working days during the previous one-year. The causes of sickness absence were classified into three groups, 1) causes except injury, diseases of the musculoskeletal system and connective tissue, 2) injury, 3) diseases of the musculoskeletal system and connective tissue. The analysis of long-term sickness absences was based on the first occurrence. The age-adjusted incidence of sickness absence among shift workers who were on non-daytime shifts more than two-thirds of working days during the previous one year was significantly higher than that among other workers. After adjusting for confounding factors, a significant high risk still existed for this group of workers taking sickness absence for all causes and causes except for injury and the musculoskletal disorders. These findings suggest that shift workers who are engaged on a particular shift schedule are more likely to take leave due to sickness.     

Knowledge of and Attitudes to Influenza Vaccination in Healthy Primary Healthcare Workers in Spain, 2011-2012

Annual influenza vaccination is recommended for healthcare workers, but many do not follow the recommendation. The objective of this study was to investigate the factors associated with seasonal influenza vaccination in the 2011–2012 season. We carried out an anonymous web survey of Spanish primary healthcare workers in 2012. Information on vaccination, and knowledge and attitudes about the influenza vaccine was collected. Workers with medical conditions that contraindicated vaccination and those with high risk conditions were excluded. Multivariate analysis was performed using unconditional logistic regression. We included 1,749 workers. The overall vaccination coverage was 50.7% and was higher in workers aged ≥ 55 years (55.7%), males (57.4%) and paediatricians (63.1%). Factors associated with vaccination were concern about infection at work (aOR 4.93; 95% CI 3.72–6.53), considering that vaccination of heathcare workers is important (aOR 2.62; 95%CI 1.83–3.75) and that vaccination is effective in preventing influenza and its complications (aOR 2.40; 95% CI 1.56–3.67). No association was found between vaccination and knowledge of influenza or the vaccine characteristics. Educational programs should aim to remove the misconceptions and attitudes that limit compliance with recommendations about influenza vaccination in primary healthcare workers rather than only increasing knowledge about influenza and the characteristics of the vaccine.     

Low-back pain among electric power supply workers and their attitude toward its prevention and the treatment.

Low-back pain among electric power supply workers and their opinions about the ways to prevent and relieve the disorder were investigated. A questionnaire study revealed that 38.7% of 6,272 electric power supply workers were suffering from low-back pain, including severe pain resulting in frequent absenteeism or requiring occasional rest from work. Chronological analysis of the occurrence of the disorder revealed that the incidence of gradually developing pain has increased and that improper working posture and overwork have become more important as etiological factors. Rest from work was found to be the most effective way of relieving pain, while any medical treatment which did not include rest was useless. Low-back pain among these workers is believed to have resulted from rapid and intensified work as required by increasing demand and mechanization, greater mental stress and improper working posture. As preventive measures, it is necessary to improve working hours and to lighten the rate of work. In order to relieve pain, the employers should permit the workers to absent themselves from work quickly following an attack. Discrepancy between workers' opinions and both actual causation of low-back pain and actual effectiveness of medical treatment is discussed.     

Chromosomal monitoring of chromium-exposed workers

A cytogenetic analysis was carried out on peripheral blood lymphocytes of workers exposed to chromite in a ferrochromium plant, to evaluate the possible existence of genetic damage. A quantitatively limited increase in aberrant cell frequencies was detected in subjects working in the furnace sector. The data were analyzed by several statistical approaches.     

Radiation and nonradiation factors in thyroid pathology development for Chernobyl cleanup workers--residents of Mayak PA affected zone

Thyroid state study was been carried out for Chernobyl NPP accident liquidators living in Ozyorsk, the city, located in the nuclear facility affected zone (Mayak PA). In total 531 individuals were examined. Thyroid assessment was made basing on physical examination, on ultrasound study and on hormones measurement of thyroid stimulating hormone, free thyroxine and thyroid peroxidase antibody. Screening revealed thyroid pathology for 27% of clean-up workers. As a result of the study carried the following conclusions were made: thyroid disease prevalence among the Ozyorsk residents participated in the breakdown elimination after Chernobyl accident was not differ from the individuals who didn't take part in this work; the prevalence of thyroid disease in liquidators was significantly connected with non radiation risk factors: with gender (for women compared to men), RR = 4.0, 95% CI 2.9-5.5; with age (over 60 years old vs under 60 years old), RR for women was 1.7; 95% CI 1.0-3.0 and for men -1.9; 95% CI 1.1-3.2; with hereditary predisposition, RR for autoimmune thyroiditis was 3.3, 95% CI 1.4-7.9.     

金毛弓背蚁行为谱与社会分工的研究

本研究在室内模拟自然蚁巢的结构和条件下,使用个体标记和直接观察法对一巢金毛弓背蚁Componotus tonkinus的行为类型和社会分工进行了研究。共34只来自同一巢穴的工蚁被标记。在持续一周的观察过程中对每只蚂蚁所执行的每种行为的频率进行了统计和聚类分析。结果表明：金毛弓背蚁可以区分出12种基本行为类型;该蚂蚁的成员大致可以分为5个功能组, 即繁殖（蚁后1个）、觅食（由10个工蚁组成,主要负责觅食）、巢穴内的维护及护育（由16个工蚁组成,主要负责巢穴的维修、清理及护育）、巢穴的防卫（包括3个工蚁,行巢穴防卫）及不活跃型（含5个工蚁）。     

The influence of visual display terminal use on the physical and mental conditions of administrative staff in Japan

Visual display terminals (VDT) are standard equipment for many office workers. Their use, however, may increase the risk of developing adverse conditions related to vision, the musculoskeletal system, and mental health. We carried out a survey among 3070 workers aged 18 to 67 years (mean, 39.9 years) at a prefectural administrative office, in which 76% of subjects were visual display terminal (VDT) users. We examined the relationship between duration of daily VDT use and eyestrain, neck or upper extremity pain, back pain, and mental health, and estimated the effect of breaks and rest during VDT work on these symptoms. The 12-item General Health Questionnaire (GHQ-12: total scores ranged from 0 to 12) was used to identify potential poor mental health status, and subjects with 4 or more were considered to have symptoms of psychological distress. Seventeen percent of subjects reported eyestrain, 19.1% reported upper extremity pain, 11.6% reported back pain, and 17% of subjects had GHQ-12 scores of 4 or higher. Logistic regression analysis showed that duration of daily VDT use and lack of breaks and rest during VDT work were significantly associated with eyestrain, neck or upper extremity pain, back pain, and psychological distress. In order to protect users from the adverse effects associated with VDT work, reducing daily VDT exposure, taking breaks, and rest during VDT work are important.     

Pariah capitalism and the overseas Chinese of Southeast Asia: Problems in the definition of the problem

This paper explores how current shifts in racial discourse and demographics are reflected within the negotiation of paid domestic work. Various scholars have pointed out that racism in the United States has become increasingly covert and institutionalized, void of racial terminology and invisible to most whites. This shift has been institutionalized in the negotiation of domestic work, as alternative racial markers such as language and citizenship replace explicit racial terminology. Through an analysis of thirty interviews with white women who employ domestic workers this research examines contemporary negotiations of racial privilege and subordination in domestic work. Overall, white employers insisted that race did not matter when making hiring decisions; however other cultural markers such as language mattered greatly, at times even resulting in firing. In addition, complex and contradictory narratives about immigration were used to simultaneously both vilify immigrant workers and romanticize their work experiences.     

Cancer morbidity and mortality among the liquidators of the Chernobyl accident: estimation of radiation risks

The work focuses on the results of the analysis of the cancer incidence among the Chernobyl emergency workers residing in Russia during 1991-2001. The analysis is based on the data for the cohort of male emergency workers from 6 regions of Russia including 55718 persons with documented external radiation doses in the range of 0.001-0.3 Gy who worked within the 30-km zone in 1986-1987. The mean age at exposure for these persons was 34.8 years old and the mean external radiation dose 0.13 Gy. In this cohort 1370 cases of solid cancer were diagnosed. Three follow-up periods were considered: 1991-1995, 1996-2001 and 1991-2001. The second follow-up period was chosen to allow for a minimum latency period of 10 years. Risk assessments were performed for two control groups: the first control group ("external") represented incidence rates for corresponding ages in Russia in general and the second control group ("internal") consisted of emergency workers. The estimated standardized incidence ratio (SIR) is in good agreement with that of the control within 95% CI. The values of the excess relative risk per unit dose 1 Gy (ERR/Gy) for solid malignant neoplasms have been estimated to be 0.33 (95% CI: -0.39, 1.22) (internal control) for the follow-up period 1991-2001 and 0.19 (95% CI: -0.66, 1.27) for 1996-2001. The analysis of cancer morbidity was carried out for the cohort of 29003 emergency workers who took part in liquidation of the consequences of the Chernobyl accident from 26 April 1986 to 25 April 1987. It was shown that the excess relative risk of cancer deaths per unit dose 1 Sv (ERR/Sv) is equal to 1.52 (95% CI: 0.20, 2.85).     

Integrated ergonomics approach toward designing night and shift work in developing countries based on experiences in Bali, Indonesia

Recently, the effort in carrying out an integrated ergonomics approach known as "SHIP" (systemic, holistic, interdisciplinary and participatory) approach has been intensively undertaken in Bali with the aim of sustaining improvements being done. The People's Consultative Assembly of the Republic of Indonesia issued for the 1999-2004 period a "SHIP" Act on the Macro Guidelines of Tourism Development in which ergonomics and other factors must be considered comprehensively to attain sustainable development in tourism. Therefore the night and shift work that is recently increasingly applied in the tourism industry must also be designed and organized through this approach. In fact, however, economic factors have still been the predominant reason for workers to accept any type of night and shift work decided by the management, without taking into account possible impacts and consequences. For example, rapid forward rotation schemes seem more adapted to the hotel industry instead of traditional 6-6-6 rotation. Further, inter-city bus drivers are approved to work a 24-hour shift followed by one day off. These drivers often work an additional risky night shift after two consecutive night shifts so as to meet needed expenses for the family. Cultural or religious activities still presented constraints for workers as they carried out subsequently the night work. Therefore, proactive steps should be taken in a timely manner through the integrated SHIP approach in designing night and shift work so as to achieve work schedules compatible with both social life of shiftworkers and business concerns.