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Objectives The aim of this study was to evaluate the effects of an mHealth intervention (intervention using mobile technology) consisting of tailored advice regarding exposure to daylight, sleep, physical activity, and nutrition, and aiming to improve health-related behavior, thereby reducing sleep problems and fatigue and improving health perception of airline pilots. Methods A randomized controlled trial was conducted among 502 airline pilots. The intervention group was given access to both the MORE Energy mobile application (app) with tailored advice and a website with background information. The control group was directed to a website with standard information about fatigue. Health-related behavior, fatigue, sleep, and health perception outcomes were measured through online questionnaires at baseline and at three and six months after baseline. The effectiveness of the intervention was determined using linear and Poisson mixed model analyses. Results After six months, compared to the control group, the intervention group showed a significant improvement on fatigue (β= -3.76, P

Background: Exposure to shift work has been associated with negative health consequences, although the association between shift work and sickness absence remains unclear. The aim of this study is to investigate associations between cumulative exposure to shift work and sickness absence among ground staff employees of an airline company. Methods: This study used data from the MORE (Monitoring Occupational Health Risks in Employees) cohort, which is a 5-year historic cohort. The population of the present study consisted of 7562 ground staff employees. For each employee, work schedules and sickness absence days between 2005 and 2009 were obtained from company records. For the exposure to different shift schedule types and to the cumulative number of night shifts, the association with long-term sickness absence (>7 consecutive sickness absence days) and the number of sickness absence episodes during 2009, was calculated using logistic and Poisson regression analyses. Socio-demographic variables, work-related variables, job classification variables, and previous sickness absence days were regarded as confounders. Results: After adjusting for previous sickness absence and job classification variables, only the group of employees that switched into working in a three-shift schedule, showed a significantly increased risk for long-term sickness absence (OR = 1.31, 95%CI 1.02-1.69). Night shift exposure was not significantly associated with long-term sickness absence. Exposure to shift work was negatively associated with more sickness absence episodes. Employees who were exposed to more than 46 night shifts also showed a lower risk for more sickness absence episodes. Subgroup analyses showed that single employees and employees without children had an increased risk for long-term sickness absence when exposed to a three-shift schedule, and when they had changed between shift schedule types. Conclusions: Cumulative exposure to shift work proved to be negatively associated with more sickness absence episodes, and was not associated with more long-term sickness absence, although selection bias could not be ruled out. Future research should explore the influence of household composition, and take into account both previous sickness absence and psychosocial and physical work factors to obtain a better estimation of the association between shift work and sickness absence.

Aim: To investigate differences in health perception and electromagnetic fields (EMF) between people within the general population reporting sensitivity or non-sensitivity to EMF, and people who registered themselves as sensitive to EMF at a non-governmental organisation (NGO). Methods: Correlations and regression analysis to compare a sample of the general population recruited via internet panel to individuals with idiopathic environmental intolerance to EMF (IEI-EMF) recruited via an interest group. Results: The general population sensitive group was more similar to the non-sensitive group in personal characteristics than to the NGO sensitive group. They experienced more – and more frequent – non-specific symptoms, reported higher perceived risk of EMF, and attributed their symptoms more to EMF than the non-sensitive group, but less than the NGO sensitive group. There was a positive association between attribution of symptoms to EMF and reported intensity of non-specific symptoms, which was stronger for the NGO sensitive subjects than for the general population. Conclusions: People sensitive to EMF and recruited via an internet panel differ from people sensitive to EMF and recruited via an NGO, who reported a higher frequency of non-specific symptoms. Attribution of symptoms to EMF is one of the predictors of the intensity of physical symptoms. Changing the perceived association between EMF and health problems in individuals with IEI-EMF might contribute to a better health experience.

The way health risks of electromagnetic fields are portrayed in the media may shape public concerns that the growing exposure to electromagnetic fields in daily life constitutes a health hazard. We analysed the content of information on electromagnetic fields and health in Dutch media to identify aspects that might be linked to the public perception of electromagnetic fields. A systematic search was performed on archives of five major Dutch newspapers (from March 2008 to March 2010) and on the internet (in April 2010). Content analyses included the identification of main characteristics and the context or frame in which the information can be clearly understood. We identified 155 newspaper articles and 23 relevant websites. Analyses showed that the media content often suggested a negative relationship between electromagnetic field exposure and health but lacked detailed information about research, technical aspects, possible biological mechanisms and regulation policy. Regional media predominantly feature...

OBJECTIVE: This systematic review aims to summarize the available evidence to elucidate the effects of shift work, which includes night work, on body weight change. METHODS: A systematic search strategy using longitudinal studies was performed. Articles were included based on strict inclusion criteria; methodological quality was assessed by a standardized quality checklist. The results were summarized using a levels of evidence synthesis. RESULTS: The search strategy resulted in eight articles that met the inclusion criteria. Five of them were considered to be high- and three of them low-quality studies. Seven studies presented crude results for an association between shift work exposure and change in body weight: five high- and two low-quality studies. There was strong evidence for a crude relationship between shift work and body weight increase. Five studies presented weight-related outcomes adjusted for potentially relevant confounders (age, gender, bodyweight at baseline, and physical activity). Two studies found a significant difference between groups in the same direction. Consequently, the evidence for a confounders-adjusted relationship between shift work exposure and body weight was considered to be insufficient. CONCLUSIONS: Strong evidence for a crude association between shift work exposure and body weight increase was found. In order to further clarify the underlying mechanisms, more and better high quality studies about this subject are necessary.

Background: Shift work research has shown that the relationship between exposure to irregular working times and sickness absence may differ between working populations. Not much is known about the prevalence of sickness absence in flight crews or about the relationship between exposure to different flight schedules and sickness absence in this population. Aims: To examine the association between cumulative exposure to different flight types and sickness absence in flight crew members. Methods: The study population consisted of flight crew members from a 5 year historic cohort. Flight schedule and sickness absence data were obtained from company records. The association between the cumulative exposure to different flight types and sickness absence episodes of >7 days was determined using univariate and multivariate logistic regression analyses. Adjusted models were obtained by adding potential confounders. Previous sickness absence was added to compose the fully adjusted models. Results: The records of 8228 employees were analysed. The fully adjusted univariate analyses showed that the numbers of medium-haul flights and flights with time zone crossings were associated with an increase in the odds for sickness absence. The fully adjusted multivariate analyses showed no significant associations between flight types and sickness absence. Conclusions: Cumulative exposure to flight types was not independently associated with sickness absence in flight crew members when previous sickness absence was taken into account. Because sickness absence in the past can predict future absence, preventive strategies targeted at flight crew members with a history of high sickness absence may be effective.

BACKGROUND: In 1992 a cargo aircraft crashed into apartment buildings in Amsterdam. In the troublesome aftermath rumours emerged on potential toxic exposures and health consequences. The aim of this study is to assess the long-term impact of this disaster on the health-related quality of life (HRQoL) of professional assistance workers.METHODS: Historic cohort study, using questionnaires to assess occupational disaster exposure, HRQoL (SF36), and background variables, at on average 8.5 years post-disaster. Participating were the exposed professional firefighters (n = 334) and police officers (n = 834) who reported disaster-related task(s), and their non-exposed colleagues who did not report such tasks (n = 194, and n = 634, respectively).RESULTS: Multivariate logistic regression analysis showed that exposed workers reported a significantly lower physical HRQoL and vitality than non-exposed workers. Exposed police officers also reported a lower mental HRQoL. Among exposed workers, a lower HRQoL was reported significantly more often by workers who had a close one affected by the disaster; by firefighters who rescued people, cleaned-up, or witnessed the immediate disaster scene; and by police officers who supported the injured. Exposed police officers who perceived the disaster as 'not bad' reported a lower HRQoL less often than those to whom it was 'the worst ever'.CONCLUSIONS: This study demonstrates that professional disaster assistance workers are at risk for a lower HRQoL, even after years.

The objective of this study was to compare sick leave data obtained from questionnaires with data from company records. During a period of 12 months, questionnaires were completed monthly for 6 months and then at 9 and 12 months. The sensitivity and specificity of questionnaires for detecting an episode of sick leave were determined, using the company records as a reference standard. In addition, the duration of sick leave episodes reported in the two data sets was compared. In this analysis, company records were not assumed to be superior, and agreement was assessed with intraclass correlation coefficients (ICCs). The sensitivity of questionnaires for detecting an episode of sick leave was 55% (95% CI = 0.50-0.60) and the specificity 83% (95% CI = 0.72-0.94). The ICC for all episodes was 0.58 (95% CI = 0.47-0.67). The only satisfactory ICC (0.87; 95% CI = 0.74-0.93) was found for the questionnaires at 9 and 12 months. No large systematic differences were found between the duration of episodes reported in the two data sets. In conclusion, in our study, the sensitivity of questionnaires for detecting an episode of sick leave was very low. Furthermore, when episodes were recalled, there was little agreement on the duration of the episode between questionnaire data and data in the company records. Based on these results and considering the risk of missing questionnaires, data on sick leave gathered from company records are clearly preferable as an outcome measure in research.

This study examined the use of health care by police officers after the air disaster in Amsterdam. On average 8.5 years post-disaster, involved police officers (n = 834, who reported disaster-related tasks), and their non-involved colleagues (n = 634) completed questionnaires on disaster involvement and health care in the preceding 12 months. Logistic regression showed that involved police officers more often used drugs on their own initiative, sleeping pills or tranquillisers, and consulted a general practitioner or medical specialist, a paramedical specialist, and a privately practicing psychologist or psychiatrist. Thus, even after years, police officers involved in disaster work may use more self-initiated health care. © The Author 2007. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

Background A considerable percentage of flight crew reports to be fatigued regularly. This is partly caused by irregular and long working hours and the crossing of time zones. It has been shown that persistent fatigue can lead to health problems, impaired performance during work, and a decreased work-private life balance. It is hypothesized that an intervention consisting of tailored advice regarding exposure to daylight, optimising sleep, physical activity, and nutrition will lead to a reduction of fatigue in airline pilots compared to a control group, which receives a minimal intervention with standard available information. Methods/design The study population will consist of pilots of a large airline company. All pilots who posses a smartphone or tablet, and who are not on sick leave for more than four weeks at the moment of recruitment, will be eligible for participation. In a two-armed randomised controlled trial, participants will be allocated to an intervention group that will receive the tailored advice to optimise exposure to daylight, sleep, physical activity and nutrition, and a control group that will receive standard available information. The intervention will be applied using a smartphone application and a website, and will be tailored on flight- and participant-specific characteristics. The primary outcome of the study is perceived fatigue. Secondary outcomes are need for recovery, duration and quality of sleep, dietary and physical activity behaviours, work-private life balance, general health, and sickness absence. A process evaluation will be conducted as well. Outcomes will be measured at baseline and at three and six months after baseline. Discussion This paper describes the development of an intervention for airline pilots, consisting of tailored advice (on exposure to daylight and sleep-, physical activity, and nutrition) applied into a smartphone application. Further, the paper describes the design of the randomised controlled trial evaluating the effect of the intervention on fatigue, health and sickness absence. If proven effective, the intervention can be applied as a new and practical tool in fatigue management. Results are expected at the end of 2013. Trial registration Netherlands Trial Register: NTR2722

OBJECTIVES: To determine the effectiveness of a weight-management program with personal counseling by phone or e-mail. METHODS: A randomized controlled trial of a 6-month program comparing two modes of intervention delivery (phone, n = 462; Internet, n = 464) with self-directed materials (control, n = 460), among overweight employees. Change in body weight after 2 years was the main outcome. RESULTS: Among complete cases, weight loss in the Internet group was 1.2 kg (95% confidence interval [CI], -1.9 to -0.4) and in the phone group 0.8 kg (95% CI, -1.5 to 0.03), compared with the control group. Multiple imputation of missing body weight resulted in comparative weight losses of -0.9 kg (95% CI, -2.0 to 0.3) and -0.4 kg (95% CI, -1.4 to 0.7). CONCLUSIONS: Among complete cases, the Internet intervention showed modest long-term weight loss, but among all participants neither program version was more effective than self-help. ©2011The American College of Occupational and Environmental Medicine.

Background Overweight (Body Mass Index [BMI] ≥ 25 kg/m2) and obesity (BMI≥ 30 kg/m2) are associated with increased cardiovascular risk, posing a considerable burden to public health. The main aim of this study was to investigate lifestyle intervention effects on cardiovascular risk factors in healthy overweight employees. Methods Participants were 276 healthy overweight employees (69.2% male; mean age 44.0 years [SD 9.2]; mean BMI 29.7 kg/m2 [SD 3.1]). They were randomized to one of two intervention groups receiving a six month lifestyle intervention with behavior counseling by phone (phone group) or e-mail (Internet group), or to a control group receiving usual care. Body weight, height, waist circumference, sum of skinfolds, blood pressure, total cholesterol level and predicted aerobic fitness were measured at baseline, at 6 and at 24 months. Regression analyses included the 141 participants with complete data. Results At 6 months a significant favorable effect on total cholesterol level (-0.2 mmol/l, 95%CI -0.5 to -0.0) was observed in the phone group and a trend for improved aerobic fitness (1.9 ml/kg/min, 95%CI -0.2 to 3.9) in the Internet group. At two years, favorable trends for body weight (-2.1 kg, 95%CI -4.4 to 0.2) and aerobic fitness (2.3 ml/kg/min, 95%CI -0.2 to 4.8) were observed in the Internet group. Conclusions The intervention effects were independent of the used communication mode. However short-term results were in favor of the phone group and long-term results in favor of the internet group. Thus, we found limited evidence for our lifestyle intervention to be effective in reducing cardiovascular risk in a group of apparently healthy overweight workers. Trial registration ISRCTN04265725

Background The work setting provides an opportunity to introduce overweight (i.e., Body Mass Index ≥ 25 kg/m2) adults to a weight management programme, but new approaches are needed in this setting. The main purpose of this study was to investigate the effectiveness of lifestyle counselling by phone or e-mail on body weight, in an overweight working population. Secondary purposes were to establish effects on waist circumference and lifestyle behaviours, and to assess which communication method is the most effective. Methods A randomized controlled trial with three treatments: intervention materials with phone counselling (phone group); a web-based intervention with e-mail counselling (internet group); and usual care, i.e. lifestyle brochures (control group). The interventions used lifestyle modification and lasted a maximum of six months. Subjects were 1386 employees, recruited from seven companies (67% male; mean age 43 (SD 8.6) y; mean BMI 29.6 (SD 3.5) kg/m2). Body weight was measured by research personnel and by questionnaire. Secondary outcomes fat, fruit and vegetable intake, physical activity and waist circumference were assessed by questionnaire. Measurements were done at baseline and after six months. Missing body weight was multiply imputed. Results Body weight reduced 1.5 kg (95% CI -2.2;-0.8, p < 0.001) in the phone group and 0.6 kg (95% CI -1.3; -0.01, p = 0.045) in the internet group, compared with controls. In completers analyses, weight and waist circumference in the phone group were reduced with 1.6 kg (95% CI -2.2;-1.0, p < 0.001) and 1.9 cm (95% CI -2.7;-1.0, p < 0.001) respectively, fat intake decreased with 1 fatpoint (1 to 4 grams)/day (95% CI -1.7;-0.2, p = 0.01) and physical activity increased with 866 METminutes/week (95% CI 203;1530, p = 0.01), compared with controls. The internet intervention resulted in a weight loss of 1.1 kg (95% CI -1.7;-0.5, p < 0.001) and a reduction in waist circumference of 1.2 cm (95% CI -2.1;-0.4, p = 0.01), in comparison with usual care. The phone group appeared to have more and larger changes than the internet group, but comparisons revealed no significant differences. Conclusion Lifestyle counselling by phone and e-mail is effective for weight management in overweight employees and shows potential for use in the work setting. Trial registration ISCRTN04265725.

No general, theoretical framework exists for exposure monitoring strategies for epidemiological purposes nor for the analysis of these data. It is, however, recognized that the variation in exposure over time and between workers is an important element of consideration in the design of measurement strategies and the analysis of exposure data. In this paper, the partitioning of exposure variability is discussed for two types of monitoring strategies. First, a monitoring strategy is considered in which all members of the study population are monitored on various occasions. In this strategy, the ratio of within and between worker variance gives information about the magnitude of underestimation of the exposure-response relationship. The second strategy discussed is one based on “homogeneous” exposure categories. This strategy is illustrated with a study among animal feed workers in The Netherlands. It is shown that the grouping which results from this strategy can be applied for epidemiological purp...

Objective: To study whether the methods used to select participants in research on prevalence rates of the health effects of exposure to a disaster may cause bias. This study compared background characteristics, disaster exposure, and complaints reported by (1) police officers who participated in an epidemiological study and underwent a medical examination, and (2) police officers who only participated in an epidemiological study. Design and Setting: In 2000, an epidemiological study was started to investigate the health status among police officers who were involved in assistance work related to the air disaster in Amsterdam: the epidemiological study air disaster Amsterdam (ESADA). These police officers were personally invited to participate in the epidemiological study and were additionally offered a medical examination, providing them with the opportunity to have their health checked by a medical doctor. Participants: Of the total group of involved police officers who were invited, 834 (70%) participated in the ESADA: 224 (26.9%) only participated in the study, but 610 (73.1%) also underwent the medical examination. Main results: Police officers who underwent a medical examination significantly more often reported one or more musculoskeletal complaints, skin complaints, general or non-specific complaints, had more often experienced an event with potentially traumatic impact, or had performed one or more potentially traumatic tasks. Conclusions: The methods of selection of participants are important in research on health effects after disasters and can result in an overestimation of some of the effects, on average, by a factor of 1.5 to 2.

BACKGROUND: On 4 October 1992, a cargo aircraft crashed into apartment buildings in Amsterdam, the Netherlands. Fire-fighters and police officers assisted with the rescue work.OBJECTIVES: To examine the long term health complaints in rescue workers exposed to a disaster.METHODS: A historical cohort study was performed among police officers (n = 834) and fire-fighters (n = 334) who performed at least one disaster related task and reference groups of their non-exposed colleagues (n = 634 and n = 194, respectively). The main outcome measures included digestive, cardiovascular, musculoskeletal, nervous system, airway, skin, post-traumatic stress, fatigue, and general mental health complaints; haematological and biochemical laboratory values; and urinalysis outcomes.RESULTS: Police officers and fire-fighters who were professionally exposed to a disaster reported more physical and mental health complaints, compared to the reference groups. No clinically relevant statistically significant differences in laboratory outcomes were found.CONCLUSIONS: This study is the first to examine long term health complaints in a large sample of rescue workers exposed to a disaster in comparison to reference groups of non-exposed colleagues. Findings show that even in the long term, and in the absence of laboratory abnormalities, rescue workers report more health complaints.

Background In 1992 a cargo aircraft crashed into a residential area of Amsterdam. A troublesome aftermath followed, with rumors on potential toxic exposures and health consequences. Health concerns remained even though no excess morbidity was predicted in retrospective risk evaluations. This study aimed to assess to what extent the rescue workers attribute long-term physical complaints to this disaster, including its aftermath, and to examine associations between such attribution and types of exposure and background variables. Methods Historic cohort study that collected questionnaire data on occupational disaster exposure, attribution of physical complaints, and background variables on average 8.5 years post-disaster. For the present study the workers who were exposed to the disaster were selected from the historic cohort, i.e. the professional firefighters (n = 334), police officers (n = 834), and accident and wreckage investigators (n = 241) who performed disaster-related tasks. Results Across the three occupational groups, a consistent percentage (ranging from 43% to 49%) of exposed workers with long-term physical complaints attributed these to the disaster, including its aftermath. Those with more physical complaints attributed these to a stronger degree. Multivariate logistic regression analyses showed that attribution was significantly more often reported by firefighters who rescued people, and by police officers who reported the identification and recovery of or search for victims and human remains, clean-up, or security and surveillance of the disaster area; who witnessed the immediate disaster scene; who had a close one affected by the disaster; and who perceived the disaster as the worst thing that ever happened to them. Age, sex and educational level were not significantly associated with attribution. Conclusion This study provides further cross-sectional evidence for the role of causal attribution in post-disaster subjective physical health problems. After on average 8.5 years, almost a third (32%) of all the exposed workers, and almost half (45%) of the exposed workers with physical complaints, attributed these complaints to the disaster, including its aftermath. The similarity of the results across the occupational groups suggests a general rather than an occupation-specific attribution process. Longitudinal studies are needed to determine whether causal disaster attribution leads to persistence of post-disaster complaints and health care utilization.

The effectiveness of return-to-work intervention for subacute low-back pain on work absenteeism, pain severity, and functional status was examined by means of a systematic review of randomized controlled trials. Publications in English that met the selection criteria were identified in a computer-aided search and assessed for methodological quality. A best-evidence synthesis was performed instead of statistical data pooling, because of the heterogeneity of the interventions and study populations. Five of nine studies comparing return-to-work intervention with usual care were identified as methodologically high-quality studies. Strong evidence was found for the effectiveness of return to work intervention on the return-to-work rate after 6 months and for the effectiveness of return-to-work intervention on the reduction of days of absence from work after > or = 12 months. It can be concluded that return-to-work interventions are equal or more effective regarding absence from work due to subacute low-back pain than usual care is.

Background In 1992, a cargo aircraft crashed into apartment buildings in Amsterdam, killing 43 victims and destroying 266 apartments. In the aftermath there were speculations about the cause of the crash, potential exposures to hazardous materials due to the disaster and the health consequences. Starting in 2000, the Epidemiological Study Air Disaster in Amsterdam (ESADA) aimed to assess the long-term health effects of occupational exposure to this disaster on professional assistance workers. Methods/Design Epidemiological study among all the exposed professional fire-fighters and police officers who performed disaster-related task(s), and hangar workers who sorted the wreckage of the aircraft, as well as reference groups of their non-exposed colleagues who did not perform any disaster-related tasks. The study took place, on average, 8.5 years after the disaster. Questionnaires were used to assess details on occupational exposure to the disaster. Health measures comprised laboratory assessments in urine, blood and saliva, as well as self-reported current health measures, including health-related quality of life, and various physical and psychological symptoms. Discussion In this paper we describe and discuss the design of the ESADA. The ESADA will provide additional scientific knowledge on the long-term health effects of technological disasters on professional workers.

Background: Long-term health consequences of disasters have not been studied extensively, one reason amongst others is that no pre-disaster observation is available. This study focuses on an aeroplane crash on an Amsterdam suburb. The ongoing Longitudinal Aging Study Amsterdam has one pre-disaster and several post-disaster observations, making it possible to study changes in health, taking pre-disaster health characteristics into account. Methods: Three exposure groups are distinguished: those living within a radius of 1km from the disaster (initial n = 39), those living between a radius of 1 and 2km from the disaster (initial n = 56), and those living in the rest of the city of Amsterdam (initial n = 508). Health measures include general health, health in comparison with age peers, functional limitations, disability and cognitive functioning. These measures are based on self-ratings, interviewer observations, or both. Results: Older persons living closest to the disaster area are likely to experience health decline in the wake of a disaster, over and above the health decline that would occur normally with aging. The disaster-associated health decline is small, and most obvious in the ability to perform actions (such as mobility), but is not observed in either disability in daily functioning, nor in self-perceptions of health. Cognitive functioning even shows a short-term improvement. Conclusion: These findings suggest substantial resilience in older adults, despite their common health problems. © The Author 2005. Published by Oxford University Press on behalf of the European Public Health Association. All rights reserved.

The study describes results of the first part of a follow-up study among 50 animal feed and grain elevator workers. The initial results suggest that the change in lung function over a 5 year period is related to the dust exposure. Workers in the high exposure category showed a greater decline in lung function than workers in the low exposure category. The decline in lung function was strongest for workers who were low exposed at the beginning of the study and who became high exposed during the follow-up period.

The benefits of using linear mixed-effects models for occupational exposure assessment were studied by re-analysing three data sets from two published surveys with repeated exposure measurements. The relative contributions of particular characteristics affecting exposure levels were assessed as in a multiple regression model, while controlling for the correlation between repeated measurements. While one-way ANOVA allows one only to estimate unconditioned variance components, a mixed model enables estimation of between- and within-worker variance components of exposure levels while accounting for the fixed effects of work characteristics. Consequently, we can identify the work characteristics affecting each variance component. Mixed models were applied to the data sets with repeated measurements and auxil iary information on work characteristics. The between-worker variance components were reduced by 35, 66 and 80%, respectively, in the three data sets when work characteristics were taken into account. The within-worker (day-to-day) variability was reduced only in the pig farmer data set, by 25%, when accounting for work activities. In addition, coefficients of work characteristics from the mixed model were compared with coefficients resulting from originally published multiple linear regression models. In the rubber manufacturing data, the coefficients of the mixed model showed similar relative importance, but were generally smaller than the coefficients from regression models. However, in the pig farm data, only the coefficients of work activities were somewhat reduced. The mixed model is a helpful tool for estimating factors affecting exposure and suitable variance components. Identifying the factors in the working environment that affect the between-worker variability facilitates a posteriori grouping of workers into more uniformly exposed groups. Identifying the factors that affect the within-worker variance is helpful for hazard control and in designing efficient sampling schemes with reference to time schedule.

Objective - To assess the effectiveness of lumbar supports, education, and exercise in the prevention of back pain in industry. Methods - A computerised search for controlled clinical trials was conducted. A criteria list was used to assess the methodological quality of the studies. The available evidence for the effectiveness of the interventions was graded with a rating system for the level of evidence. Effect sizes of individual studies were combined if the studies were sufficiently similar. Results - 11 studies were identified for the review. The methodological quality of all studies was low, with a maximum score of three out of seven for internal validity. There was no evidence for the effectiveness of lumbar supports due to contradictory outcomes of the studies. Five of the six studies on education reported no effect. Thus there is limited evidence that education does not help to prevent back pain. All three studies on exercise reported a positive result, indicating limited evidence for the effectiveness of exercise. The combined effect size for exercise was 0.53, which is a medium sized effect. Conclusions - Although widely used, there is little evaluative research on the preventive measures studied here. The review showed that there is limited evidence that exercise has some effect in the prevention of back pain and that education is not effective. No conclusive evidence was found for or against the effectiveness of lumbar supports. Research of higher methodological quality is needed before firm conclusions on the effectiveness of lumbar supports, education, and exercise in the prevention of back pain in industry can be drawn.

Reported respiratory and related symptoms during work were compared between 265 exposed animal feed workers and a control group consisting of 175 external controls and nonexposed workers in the animal feed industry. Symptoms indicating respiratory and nasal irritation were significantly increased in the animal feed workers. Prevalences ranged from 9% (cough) to 21% (sneezing). Reported cough after work was also significantly increased. In 119 workers, a total of 457 across-shift spirometric lung function changes were measured. Almost all lung function variables showed a decrease during the work shift, as could be expected since the circadian rhythm is in a downward phase during the measurement period (2 p.m.-10 p.m.). When the workers were grouped into dust and endotoxin exposure categories according to their job titles, and exposure-response trend was seen for maximum mid-expiratory flow (MMEF) and maximum expiratory flow rate at 50% of vital capacity (MEF50). The effect of endotoxin was stronger than that of dust, both in magnitude and significance. For the same lung function variables and for forced expiratory volume in 1 second (FEV1) and MEF25, a significant across-week change was also detected. The results of this study are in concordance with other studies that indicate acute effects on lung function and elevated prevalences of respiratory symptoms during work caused by exposure to grain dust.

In the Dutch animal feed industry, approximately 6000 workers are exposed to organic dust, originating mainly from raw materials such as grain, pulses (peas and beans), and waste products from the vegetable oil and starch industries. In this study, 79 stationary dust samples and 530 personal dust samples from eight animal feed production facilities were analyzed. The stationary total dust samples showed gravimetric concentrations ranging from 0.2 to 25 mg/m3 (geometric mean [GM] 1.3 mg/m3). Concentrations of smaller particle fractions (respirable, thoracic, and inspirable dust) were considerably lower. Personal inspirable dust concentrations were considerably higher than stationary concentrations and were strongly related to job titles. Pooled personal inspirable dust concentrations ranged from 0.2 to 450 mg/m3 (GM = 2.4 mg/m3). After adjusting for differences between inspirable and total dust, 25% of the measurements exceeded the Dutch maximum allowed concentration (MAC) for total nuisance dust (10 mg/m3) and 42% exceeded the American Conference of Governmental Industrial Hygienists' threshold limit value for grain dust (4 mg/m3). Endotoxin concentrations ranged from 0.2 to 1870 ng/m3 inspirable dust (GM = 5.1 ng/m3). Endotoxin appeared to be less prevalent in respirable dust than in larger dust fractions. Concentrations in dust appeared to be related to stages in the production process. Colony-forming units (cfu) of fungi ranged from 130 to 15,300 cfu/m3 (GM = 2300 cfu/m3) and were in parallel measurements more strongly related to endotoxin concentrations than to dust concentrations. Clearly, workers in the Dutch animal feed industry are frequently exposed to dust levels above recommended Dutch and American levels. Exposure levels to endotoxin and to fungi are quantified.(ABSTRACT TRUNCATED AT 250 WORDS)

An influenza-like illness appeared recently among workers in a plant processing synthetic yarn. A humidifier, a cold-water spraying system, was the suspected cause. Lung function changes over the day and week and changes in blood leucocytes were studied among the workers from the suspected department and two reference populations. Exposure to colony-forming units of bacteria and fungi and to endotoxins was also monitored. The workers from the suspected department had statistically significantly lower lung functions on the first workday of the week than the referents. Their blood leucocytes were also raised statistically significantly. The exposure to fungi, bacteria, and endotoxins differed significantly between the various departments, but the measured levels were low. It was concluded that the observed effects were suggestive of a "Monday morning fever" type of reaction and that adverse effects occurred at exposure levels lower than those found to date in the literature.

Spirometric lung-function measurements were conducted 5 days before and after the work shift of 11 welders of zinc-coated steel, ten nonwelders who were indirectly exposed to welding fumes, and 17 controls. The exposure to dust and zinc of all participants was monitored personally using PAS-6 samplers. Geometric mean concentrations for welders were 0.91 mg/m3 (dust) and 34.0 micrograms/m3 (zinc). Cross-sectional analysis of Monday morning values showed no differences in lung-function parameters between groups. However, the number of years the participants were engaged in welding was of borderline statistical significance and correlated negatively with values of FEV1 and FEV1/FVC. Changes in lung function over a work shift or a working week were not related to the exposure level.

The performance of sampling for fungi using four widely used microbiological air sampling devices and three broad spectrum media was compared in seven occupational settings. Total colony forming units counts ranged from 10 to 3700 CFU/m3. The sampling efficiencies of the Andersen N-6 sampler, slit sampler, and Reuter centrifugal air sampler (RCS) were comparable, whereas the SAS sampler underestimated CFU counts by approximately 50%. The correlation between the RCS results and the other three samplers used was lower compared to their mutual correlations. There were no large differences in performance of the three media tested: malt extract agar, dichloran glycerol (18) agar, and dichloran rose bengal chloramphenicol agar. Coefficients of variation of duplicate samples were large compared to commonly used methods for sampling dust and chemicals. It is concluded that the N-6 and slit sampler perform best, although RCS is useful in probes because it is easy to handle. The three media tested yielded similar results. Further testing of DG-18 is recommended, as it inhibits fast growing genera and, thus, counting colonies is easier.

Background The amount of exposure to electromagnetic fields (EMF) at work is mainly determined by an individual's occupation and may differ from exposure at home. It is, however, unknown how different occupational groups perceive possible adverse health effects of EMF. Methods Three occupational groups, the general Dutch working population (n = 567), airport security officers who work with metal detectors (n = 106), and MRI radiographers who work with MRI (n = 193), were compared on perceived risk of and positive and negative feelings towards EMF in general and of different EMF sources, and health concerns by using analyses of variances. Data were collected via an internet survey. Results Overall, MRI radiographers had a lower perceived risk, felt less negative, and more positive towards EMF and different sources of EMF than the general working population and the security officers. For security officers, feeling more positive about EMF was not significantly related to perceived risk of EMF in general or EMF of domestic sources. Feeling positive about a source did not generalize to a lower perceived risk, while negative feelings were stronger related to perceived risk. MRI radiographers had fewer health concerns regarding EMF than the other two groups, although they considered it more likely that EMF could cause physical complaints. Conclusions These data show that although differences in occupation appear to be reflected in different perceptions of EMF, the level of occupational exposure to EMF as such does not predict the perceived health risk of EMF.

Background: New high-voltage power transmission lines will be introduced due to increasing demand for reliable and renewable energy supplies. Some residents associate non-specific health complaints with exposure to electromagnetic fields from nearby power lines. This study protocol describes the design and rationale of a prospective study investigating whether the introduction of a new power line triggers health responses in residents living nearby. Methods/Design. The study is designed as a quasi-experimental field study with two pretests during the construction of a new power line route, and two posttests after it has been put into operation. Key outcomes are self-reported non-specific somatic and cognitive health complaints, and attribution of these health complaints to a power line. The main determinant is proximity to the new power line route. One member of every household (n = 2379) residing in close proximity (0-500 meters) to the overhead parts of a new power line route in the Netherlands is invited to participate, as well as a sample of household members (n = 2382) residing farther away (500-2000 meters). Multilevel analysis will be employed to test whether an increase in key outcome measures is related to proximity to the line. Longitudinal structural equation models will be applied to test to what extent health responses are mediated by psychosocial health mechanisms and moderated by negative oriented personality traits. Discussion. This is the first study to investigate health responses to a new power line route in a prospective manner. The results will provide theoretical insight into psychosocial mechanisms operating during the introduction of an environmental health risk, and may offer suggestions to policymakers and other stakeholders for minimizing adverse health responses when introducing new high-voltage power lines. © 2014 Porsius et al.; licensee BioMed Central Ltd.