Factors modifying the effect of environmental noise on sleep include sex, age, susceptibility, personality and the health status, including past and present history of disease. Objective: The effects of noise on sleep and habituation of sleep to noise were summarized. Results and conclusions: 1) The effect of noise on sleep is associated with physical changes, such as changes in heart rate, blood flow volume, breathing and the immune and neurocirculatory systems. During sleep, specific changes in these indicators are noted during different sleep stages. There are individual and sex differences, and it is important to understand the effects of noise on sleep considering several related factors. 2) Habituation to noise is also an important phenomenon that must be addressed while considering the effects of noise on sleep. Habituation is dependent on the type and sound level of the noise. In occupational fields, shift work and job stress should be considered to determine the association between noise and sleep, which is important to retaining a good quality of working life.
Objectives: The aim of this study was to determine the concentrations of respirable flour dusts and gliadin as well as gliadin-specific serum antibodies in exposed workers of Hamadan wheat flour mill factories. Methods: Blood samples from 95 exposed workers and 80 air samples from flour packing, husk packing, flour production and wheat unloading areas were collected. Respirable flour dust density was measured by a gravimetric method, and dust gliadin concentration as well as serum antibodies were determined by enzyme-linked immunosorbent assays. Results: The Time-weighted average (TWA) flour dust density was higher in all factories (1.56-4.68 mg/m3) compared with the threshold limit value (0.5 mg/m3) of ACGIH and showed a positive correlation with the gliadin concentration (p<0.05). Additionally, the respirable dust and gliadin concentrations were significantly higher at flour packing workstations compare with the other work areas. Moreover, the mean serum gliadin-specific IgA and IgG and total IgE antibodies were remarkably higher in exposed mill workers compared with the controls (p<0.05). Conclusion: We clearly demonstrated that workers in Hamadan flour mills are in exposed to a hazardous level of respirable flour dust, receiving the highest level of dust and gliadin in flour packing areas. Furthermore, dust-exposed workers showed upper levels of serum antibodies indicating exposure to higher amounts of allergens than controls.
Objectives: In order to measure occupational exposure concentrations of ethyl tertiary-butyl ether (ETBE), we developed a diffusive sampling method for monitoring ETBE and performed an ETBE exposure assessment. Methods: The applicability of diffusive samplers was examined by exposing the samplers to ETBE vapor in test chambers. The personal exposure levels of workers and airborne concentrations were measured at 4 gas stations. Results: The ETBE sampling rate for the diffusive samplers (VOC-SD, Sigma-Aldrich Japan) was 25.04 ml/min (25°C). Compared with the active sampling method, the diffusive samplers could be used for short-term measurements and in environments containing a mixture of organic solvents. The geometric mean (GM) of TWA-8h ETBE was 0.08 ppm (0.02-0.28 ppm) in 28 gas station workers and 0.04 ppm (0.01-0.21 ppm) in 2 gasoline tanker truck drivers. With regard to ETBE airborne concentrations, the GM was 4.12 ppm (0.93-8.71 ppm) at the handles of hanging pumps but dropped to less than 0.01 ppm (less than 0.01-0.01 ppm) at the side of a public road. Conclusion: The diffusive sampling method can be used for the measurement of occupational ETBE exposure. The threshold limit of TLV-TWA 5 ppm recommended by the ACGIH was not exceeded in any of the workers in this study.
Purpose: The aim of this study was to ascertain whether symptoms of respiratory disorders and lung functional impairments are associated with occupational inhalation exposure to carbon black (CB) in a group of rubber workers. Methods: The study population consisted of 72 male workers with a past history of and current exposure to CB and 69, randomly selected, healthy unexposed male office workers that served as the referent group. Subjects were interviewed and given standardized respiratory symptom questionnaires to answer. Furthermore, pulmonary function tests (PFTs) were performed before and after the work shift for exposed subjects and once during the work shift for referent subjects. Furthermore, to assess the extent to which workers were exposed to CB, using standard methods, inhalable and respirable dust fractions of CB were measured in different dusty worksites. Results: The levels of exposure to inhalable and respirable CB dust were estimated to be 6.2 ± 1.7 and 2.3 ± 0.29 mg/m3 respectively (mean ± SD). Respiratory symptom questionnaires revealed that regular cough, phlegm, wheezing and shortness of breath were significantly (p<0.05) more prevalent among exposed workers. Furthermore, significant decreases in some preshift and postshift parameters of pulmonary function of exposed workers with a spirometric pattern consistent with restrictive ventilatory disorder were found. Conclusion: The findings of this study provide circumstantial evidence to support the notion that exposure to CB exceeding its current TLV is associated with a significant increase in the prevalence of respiratory symptoms along with both acute, partially reversible and chronic irreversible significant decreases in some parameters of pulmonary function.
Psychosocial work characteristics including high demands, lack of control and poor social support have consistently been linked to poor health as has poor general mental ability (GMA). However, less is known about the relationships between stable individual factors such as GMA, psychosocial work characteristics and health. Objective: The present study investigated how childhood mental ability and psychosocial work characteristics relate to health in terms of mental distress, neck/shoulder pain (NSP) and self-rated health (SRH). Methods: Data on childhood GMA, occupational level, self-reports of demands, control and social support and health (mental distress, NSP and SRH) in midlife came from working women (n=271) and men (n=291) included in a Swedish school cohort. Hierarchical regression analyses, controlling for occupational level, were used to examine associations between childhood GMA, self-reports of high demands, low control and poor social support and the three health indicators. Taking into consideration the gendered labor market and variations in health patterns between women and men, gender specific analyses were performed. Results: There were no significant associations between childhood GMA and health indicators. Further, there were no significant interactions between GMA and psychosocial work factors. As regards the strength of the associations between GMA, psychosocial work factors and health, no consistent differences emerged between women and men. Conclusions: In a cohort of healthy and working middle-aged women and men, self-reports of current psychosocial work characteristics seem to be more strongly linked to health, than are stable childhood factors such as GMA.
Objective: To examine the impact of globalization on employee psychological health and job satisfaction via job characteristics (i.e., job demands and job resources) in an emerging economy, that of Malaysia. As external factors are regarded as influences on the working environment, we hypothesized that global forces (increased pressure and competition) would have an impact on burnout and job satisfaction via increased demands (role conflict, emotional demands) and reduced resources (supervisor support, coworkers support). Methods: Data were collected using a population based survey among 308 employees in the state of Selangor, Malaysia. Participants were approached at home during the weekend or on days off from work. Only one participant was selected per household. Structural equation modelling was used to analyse the data. Nearly 54% of respondents agreed that they need to work harder, 25% agreed that their job was not secure and 24% thought they had lost power and control on the job due to global trade competition. Results: Consistent with our predictions, demands mediated the globalization to burnout relationship, and resources mediated the globalization to job satisfaction relationship. Conclusions: Together, these results support the idea that external factors influence work conditions and in turn employee health and job satisfaction. We conclude that the jobs demands-resources framework is applicable in an Eastern setting and that globalization is a key antecedent of working environments.
Background: Emergency departments (EDs) workers are at increased risk of exposure to occupational violence. The prevalence of occupational violence is potentially higher and consequences are more serious in areas with poor security conditions. Objectives: We investigated the prevalence, characteristics and factors associated with the exposure of ED workers to violence at Lebanese hospitals. Methods: All ED employees at six tertiary hospitals in Lebanon were surveyed using a cross-sectional design. The survey instrument included four sections collecting demographic/professional information and measuring exposure to violence, degree of job satisfaction and degree of professional burnout. The questionnaire was distributed to all ED employees at participating hospitals and was completed by 256 ED workers (70.3% response rate). Multinomial and binary logistic regressions were used to investigate factors significantly associated with verbal and physical violence. Results: Over the past 12 mo, four in five ED employees were verbally abused and one in four was physically assaulted. Exposure to verbal abuse was associated with serious outcomes including significantly higher levels of occupational burnout and an increased likelihood to quit current job. Exposure to physical violence was associated with increased likelihood-to-quit, nurse status and "public hospital" employment. Conclusion: Violence largely prevails at Lebanese EDs. Most vulnerable are nurses and employees of public hospitals who are disproportionally exposed to violence. ED stakeholders must work collaboratively to investigate the root causes of violence and devise and implement effective antiviolence policies and measures. Such measures will be necessary to protect the well-being and decrease the turnover of ED workers.
Objectives: This study evaluated a simple workplace intervention that used visual messages to create awareness of two highly specific recommendations for good health. Methods: Four worksites were recruited in Iwakuni, Japan. The 4-month intervention used three promotional media—A2-size posters, A4-size flyers and displays on the company intranet. The visual messages were designed with silhouettes, pictograms and slogans. Knowledge acquisition concerning the two recommendations (daily vegetable intake of 350 g and 23 exercises weekly) was evaluated using questionnaires. In addition, recall of media and attitudes toward health behavior were assessed. Results: Of the 2,322 workers, 827 responded to both the pre- and postintervention surveys. Correct responses at the four worksites increased from initial levels of 36-48% to 38-73% for the vegetable intake questions and from 7-14% to 7-59% for the physical activity questions. Media recall results were 35-73% for posters, 20-43% for flyers and 19% for intranet. The workers who recalled the posters and flyers had more correct answers on knowledge questions than those who did not recall the posters or flyers (p<0.01). In multivariate analyses, seeing the visual messages was associated with a positive change in response to physical activity questions (odds ratio=1.49-2.03), and the number of media recalled was also significant (odds ratio=1.16-1.17). Conclusions: Interventions with a combination of media and simple visual messages should be considered for health promotion among general populations at worksites.