Diesel engine exhaust and lung cancer risks - evaluation of the meta-analysis by Vermeulen et al. 2014.

BACKGROUND: Vermeulen et al. 2014 published a meta-regression analysis of three relevant epidemiological US studies (Steenland et al. 1998, Garshick et al. 2012, Silverman et al. 2012) that estimated the association between occupational diesel engine exhaust (DEE) exposure and lung cancer mortality. The DEE exposure was measured as cumulative exposure to estimated respirable elemental carbon in µg/m(3)-years. Vermeulen et al. 2014 found a statistically significant dose-response association and described elevated lung cancer risks even at very low exposures. METHODS: We performed an extended re-analysis using different modelling approaches (fixed and random effects regression analyses, Greenland/Longnecker method) and explored the impact of varying input data (modified coefficients of Garshick et al. 2012, results from Crump et al. 2015 replacing Silverman et al. 2012, modified analysis of Moehner et al. 2013). RESULTS: We reproduced the individual and main meta-analytical results of Vermeulen et al. 2014. However, our analysis demonstrated a heterogeneity of the baseline relative risk levels between the three studies. This heterogeneity was reduced after the coefficients of Garshick et al. 2012 were modified while the dose coefficient dropped by an order of magnitude for this study and was far from being significant (P = 0.6). A (non-significant) threshold estimate for the cumulative DEE exposure was found at 150 µg/m(3)-years when extending the meta-analyses of the three studies by hockey-stick regression modelling (including the modified coefficients for Garshick et al. 2012). The data used by Vermeulen and colleagues led to the highest relative risk estimate across all sensitivity analyses performed. The lowest relative risk estimate was found after exclusion of the explorative study by Steenland et al. 1998 in a meta-regression analysis of Garshick et al. 2012 (modified), Silverman et al. 2012 (modified according to Crump et al. 2015) and Möhner et al. 2013. The meta-coefficient was estimated to be about 10-20 % of the main effect estimate in Vermeulen et al. 2014 in this analysis. CONCLUSIONS: The findings of Vermeulen et al. 2014 should not be used without reservations in any risk assessments. This is particularly true for the low end of the exposure scale.

Effectiveness of low emission zones: large scale analysis of changes in environmental NO2, NO and NOx concentrations in 17 German cities.

BACKGROUND: Low Emission Zones (LEZs) are areas where the most polluting vehicles are restricted from entering. The effectiveness of LEZs to lower ambient exposures is under debate. This study focused on LEZs that restricted cars of Euro 1 standard without appropriate retrofitting systems from entering and estimated LEZ effects on NO2, NO, and NOx ( = NO2+NO). METHODS: Continuous half-hour and diffuse sampler 4-week average NO2, NO, and NOx concentrations measured inside and outside LEZs in 17 German cities of 6 federal states (2005-2009) were analysed as matched quadruplets (two pairs of simultaneously measured index values inside LEZ and reference values outside LEZ, one pair measured before and one after introducing LEZs with time differences that equal multiples of 364 days) by multiple linear and log-linear fixed-effects regression modelling (covariables: e.g., wind velocity, amount of precipitation, height of inversion base, school holidays, truck-free periods). Additionally, the continuous half-hour data was collapsed into 4-week averages and pooled with the diffuse sampler data to perform joint analysis. RESULTS: More than 3,000,000 quadruplets of continuous measurements (half-hour averages) were identified at 38 index and 45 reference stations. Pooling with diffuse sampler data from 15 index and 10 reference stations lead to more than 4,000 quadruplets for joint analyses of 4-week averages. Mean LEZ effects on NO2, NO, and NOx concentrations (reductions) were estimated to be at most -2 µg/m(3) (or -4%). The 4-week averages of NO2 concentrations at index stations after LEZ introduction were 55 µg/m(3) (median and mean values) or 82 µg/m(3) (95th percentile). CONCLUSIONS: This is the first study investigating comprehensively the effectiveness of LEZs to reduce NO2, NO, and NOx concentrations controlling for most relevant potential confounders. Our analyses indicate that there is a statistically significant, but rather small reduction of NO2, NO, and NOx concentrations associated with LEZs.

Advantages of the JobReha discharge letter: an instrument for improving the communication interface in occupational rehabilitation.

PURPOSE: Systematic collaboration between occupational physicians (OPs) and rehabilitation physicians (RPs) can improve occupational rehabilitation processes and outcomes. The JobReha discharge letter (JR-DL) is a key element of JobReha, a multilevel intervention for specific occupational rehabilitation of workers with musculoskeletal disorders. This feasibility study aims to analyse the perceived benefit and acceptance of the JR-DL as an instrument for improving the communication interface between RPs and OPs. METHODS: On the day of discharge from rehabilitation, the rehabilitation physician completed a JR-DL form containing relevant information on the rehabilitation measures undertaken during treatment and recommendations for return to work. The JR-DL was either transmitted to the patient's occupational physician directly or given to the patients to bring to the OP to support the reintegration process. The JR-DL as an instrument for improving the communication interface was evaluated using data from patient questionnaires (n = 250), JR-DLs (n = 247), OP questionnaires (n = 224) and RP questionnaires (n = 232). RESULTS: All rehabilitation physicians sent a JR-DL to the respective occupational physician on the day of discharge. OPs received the reports a median 2 days after discharge. The content quality and relevance of the JR-DL for the reintegration process were rated high to moderate by more than 97.0 % of the OPs; 92.3 % of the patients received a recommendation to return to their previous workplace; 43.3 % returned with minor limitation; and the remaining 31.6 % with a recommendation for individual reintegration; 74.0 % of the workers returned to work within 3 days of discharge. CONCLUSIONS: Use of the JR-DL for the improvement of communication and exchange of relevant information is feasible and supportive for both rehabilitation and occupational physicians. Its positive impact on reintegration and return to work was apparent. Delays in receipt of the JR-DL should be eliminated by appropriate quality assurance measures.

Mobile air quality studies (MAQS) in inner cities: particulate matter PM10 levels related to different vehicle driving modes and integration of data into a geographical information program.

BACKGROUND: Particulate matter (PM) is assumed to exert a major burden on public health. Most studies that address levels of PM use stationary measure systems. By contrast, only few studies measure PM concentrations under mobile conditions to analyze individual exposure situations. METHODS: By combining spatial-temporal analysis with a novel vehicle-mounted sensor system, the present Mobile Air Quality Study (MAQS) aimed to analyse effects of different driving conditions in a convertible vehicle. PM10 was continuously monitored in a convertible car, driven with roof open, roof closed, but windows open, or windows closed. RESULTS: PM10 values inside the car were nearly always higher with open roof than with roof and windows closed, whereas no difference was seen with open or closed windows. During the day PM10 values varied with high values before noon, and occasional high median values or standard deviation values due to individual factors. Vehicle speed in itself did not influence the mean value of PM10; however, at traffic speed (10 - 50 km/h) the standard deviation was large. No systematic difference was seen between PM10 values in stationary and mobile cars, nor was any PM10 difference observed between driving within or outside an environmental (low emission) zone. CONCLUSIONS: The present study has shown the feasibility of mobile PM analysis in vehicles. Individual exposure of the occupants varies depending on factors like time of day as well as ventilation of the car; other specific factors are clearly identifiably and may relate to specific PM10 sources. This system may be used to monitor individual exposure ranges and provide recommendations for preventive measurements. Although differences in PM10 levels were found under certain ventilation conditions, these differences are likely not of concern for the safety and health of passengers.

Reduced inclination of cervical spine in a novel notebook screen system - implications for rehabilitation.

BACKGROUND: Professional working at computer notebooks is associated with high requirements on the body posture in the seated position. By the high continuous static muscle stress resulting from this position at notebooks, professionals frequently working at notebooks for long hours are exposed to an increased risk of musculoskeletal complaints. Especially in subjects with back pain, new notebooks should be evaluated with a focus on rehabilitative issues. METHODS: In a field study a new notebook design with adjustable screen was analyzed and compared to standard notebook position. RESULTS: There are highly significant differences in the visual axis of individuals who are seated in the novel notebook position in comparison to the standard position. Also, differences are present between further alternative notebook positions. Testing of gender and glasses did not reveal influences. CONCLUSION: This study demonstrates that notebooks with adjustable screen may be used to improve the posture. Future studies may focus on patients with musculoskeletal diseases.

Carpal tunnel syndrome as an occupational disease.

BACKGROUND: Carpal tunnel syndrome (CTS) has been listed since 2003 in the European Union's list of occupational diseases. In 2001, it took sixth place in frequency among all occupational diseases recognized in the European Union. It was not listed as an occupational disease in Germany until July 2009, when the medical expert advisory panel of the German Federal Ministry of Labour and Social Affairs issued an evaluative paper supporting its listing. METHODS: We selectively reviewed the literature on the potential causation of CTS by occupational activities. RESULTS: Repetitive manual work tasks involving flexion and extension at the wrist, forceful grip with the hand, and/or vibrations of the hand and arm, such as are induced (for example) by hand-held vibrating tools, can damage the median nerve and cause CTS. A combination of these exposures has been found to raise the risk of CTS with a more than additive effect. Harmful exposures arise in a wide variety of occupations; in judging whether a particular case of CTS is of occupational origin, the physician has to consider the actual manual tasks performed by the patient, rather than merely the job title. Working at a computer keyboard seems not to raise the risk of CTS. CONCLUSION: The causation of CTS by occupational activities, either alone or in combination with other factors, has been well documented by epidemiological data and is pathophysiologically plausible. In Germany, a physician who diagnoses carpal tunnel syndrome in an employee with a relevant, damaging occupational exposure is required to report the case to the German Social Accident Insurance.

Bidirectional Assessment of Stress, job satisfaction and work ability of Educators in day care centres: a real-time observation study - the study protocol (BASE).

BACKGROUND: Occupational demands of educators are not very well researched. Nevertheless their work is subject to several requirements. Whether these demands have an effect on the work ability and the health status of employees has also not been examined. Furthermore it is unclear if the ownership type of day care centres have an influence on job satisfaction and work ability of the pedagogical staff and what kind of resources do exist. Previous studies were mainly based on questionnaire data. Objective data does not exist. Therefore the aim of this investigation is to collect precise data relating to work of educators. METHODS: Effects of different types of ownership of day care centres on job satisfaction and work ability of educators will be assessed with the help of objective real time studies in combination with multi-level psycho diagnostic measurements. DISCUSSION: The present study is the first of its kind. Up to now there are no computer-based real time studies on workflow of pedagogical staff with regard to assess their work-related stress. Following an exhaustive documentation of educators work processes the day-to-day task can be estimated and approaches for prevention can be developed. This can substantially contribute to an overall improvement of child care in Germany.

The impact of shift work induced chronic circadian disruption on IL-6 and TNF-alpha immune responses.

AIM: Sleep disturbances induce proinflammatory immune responses, which might increase cardiovascular disease risk. So far the effects of acute sleep deprivation and chronic sleep illnesses on the immune system have been investigated. The particular impact of shift work induced chronic circadian disruption on specific immune responses has not been addressed so far. METHODS: Pittsburgh-Sleep-Quality-Index (PSQI) questionnaire and blood sampling was performed by 225 shift workers and 137 daytime workers. As possible markers the proinflammatory cytokines IL-6 and TNF-alpha and lymphocyte cell count were investigated. A medical examination was performed and biometrical data including age, gender, height, weight, waist and hip circumference and smoking habits were collected by a structured interview. RESULTS: Shift workers had a significantly higher mean PSQI score than day workers (6.73 vs. 4.66; p < 0.001). Day workers and shift workers had similar serum levels of IL-6 (2.30 vs. 2.67 resp.; p = 0.276), TNF-alpha (5.58 vs. 5.68, resp.; p = 0.841) or lymphocytes count (33.68 vs. 32.99, resp.; p = 0.404). Furthermore there were no differences in cytokine levels (IL-6 p = 0.761; TNF-alpha p = 0.759) or lymphocyte count (p = 0.593) comparing the sleep quality within the cohorts. When this calculation of sleep quality was stratified by shift and day workers irrespective of their sleep quality day workers and shift workers had similar serum levels of IL-6, TNF-alpha or lymphocytes count. Multiple linear regression analysis showed a significant correlation of lymphocytes count and smoking habits. CONCLUSION: Shift work induces chronic sleep debt. Our data reveals that chronic sleep debt might not always lead to an activation of the immune system, as we did not observe differences in lymphocyte count or level of IL-6 or TNF-alpha serum concentration between shift workers and day workers. Therefore chronic sleep restriction might be eased by a long-term compensating immune regulation which (in healthy) protects against an overstimulation of proinflammatory immune mechanisms and moderates metabolic changes, as they are known from short-term sleep deprivation or sleep related breathing disorders.

Scientometric analysis and combined density-equalizing mapping of environmental tobacco smoke (ETS) research.

BACKGROUND: Passive exposure to environmental tobacco smoke (ETS) is estimated to exert a major burden of disease. Currently, numerous countries have taken legal actions to protect the population against ETS. Numerous studies have been conducted in this field. Therefore, scientometric methods should be used to analyze the accumulated data since there is no such approach available so far. METHODS AND RESULTS: A combination of scientometric methods and novel visualizing procedures were used, including density-equalizing mapping and radar charting techniques. 6,580 ETS-related studies published between 1900 and 2008 were identified in the ISI database. Using different scientometric approaches, a continuous increase of both quantitative and qualitative parameters was found. The combination with density-equalizing calculations demonstrated a leading position of the United States (2,959 items published) in terms of quantitative research activities. Charting techniques demonstrated that there are numerous bi- and multilateral networks between different countries and institutions in this field. Again, a leading position of American institutions was found. CONCLUSIONS: This is the first comprehensive scientometric analysis of data on global scientific activities in the field of environmental tobacco smoke research. The present findings can be used as a benchmark for funding allocation processes.

Air pollution research: visualization of research activity using density-equalizing mapping and scientometric benchmarking procedures.

BACKGROUND: Due to constantly rising air pollution levels as well as an increasing awareness of the hazardousness of air pollutants, new laws and rules have recently been passed. Although there has been a large amount of research on this topic, bibliometric data is still to be collected. Thus this study provides a scientometric approach to the material published on this subject so far. METHODS: For this purpose, data retrieved from the "Web of Science" provided by the Thomson Scientific Institute was analyzed and visualized both with density-equalizing methods and classic data-processing methods such as tables and charts. RESULTS: For the time span between 1955 and 2006, 26,253 items were listed and related to the topic of air pollution, published by 124 countries in 24 different languages. General citation activity has been constantly increasing since the beginning of the examined period. However, beginning with the year 1991, citation levels have been rising exponentially each year, reaching 39,220 citations in the year 2006. The United States, the UK and Germany were the three most productive countries in the area, with English and German ranked first and second in publishing languages, followed by French. An article published by Dockery, Pope, Xu et al. was both the most cited in total numbers and in average citation rate. J. Schwartz was able to claim the highest total number of citations on his publications, while D.W. Dockery has the highest citation rate per publication. As to the subject areas the items are assigned with, the most item were published in Environmental Sciences, followed by Meteorology & Atmospheric Sciences and Public, Environmental & Occupational Health. Nine out of the ten publishing journals with more than 300 entries dealt with environmental interests and one dealt with epidemiology. CONCLUSIONS: Using the method of density-equalizing mapping and further common data processing procedures, it can be concluded that scientific work concerning air pollution and related topics enjoys unbrokenly growing scientific interest. This can be observed both in publication numbers and in citation activity.

Work-related musculoskeletal disorders in the automotive industry due to repetitive work - implications for rehabilitation.

BACKGROUND: Musculoskeletal disorders (MSDs) due to repetitive work are common in manufacturing industries, such as the automotive industry. However, it's still unclear which MSDs of the upper limb are to be expected in the automotive industry in a first aid unit as well as in occupational precaution examinations. It is also unclear which examination method could be performed effectively for practical reasons and under rehabilitation aspects. Additionally, it was to discuss whether the conception of unspecific description for MSDs has advantages or disadvantages in contrast to a precise medical diagnosis. METHODS: We investigated the health status of two study populations working at two automotive plants in Germany. The first part included 67 consecutive patients who were seen for acute or chronic MSDs at the forearm over a 4-month period at the plants' medical services. Information about patients' working conditions and musculoskeletal symptoms was obtained during a standardized interview, which was followed by a standardized orthopedic-chiropractic physical examination. In the second part, 209 workers with daily exposure to video display terminals (VDT) completed a standardized questionnaire and were examined with function-oriented muscular tests on the occasion of their routine occupational precaution medical check-up. RESULTS: The majority of the 67 patients seen by the company's medical services were blue-collar works from the assembly lines and trainees rather than white-collar workers from offices. Rates of musculoskeletal complaints were disproportionately higher among experienced people performing new tasks and younger trainees. The most common MSD in this group were disorders of flexor tendons of the forearm. By contrast, among the 209 employees working at VDT disorders of the neck and shoulders were more common than discomfort in the forearm. A positive tendency between restricted rotation of the cervical vertebrae and years worked at VDT was observed. In addition, only less than 8% of unspecific disorders of the upper limb (esp. wrist and forearm) were found. CONCLUSIONS: Functional tests for the upper limb seemed to be very helpful to give precise medical advice to the employees to prevent individual complaints. The results are also helpful for developing specific training programs before beginning new tasks as well as for rehabilitation reasons. There's no need to use uncertain terminology (such as RSI) as it may not be representative of the actual underlying disorders as diagnosed by more thorough physical examinations.

Rheumatoid arthritis: scientific development from a critical point of view.

Rheumatoid arthritis (RA) is classified as a chronic, progressive, systemic autoimmune disorder leading to inflammation, stiffness, defective position and destruction of joints. Finally a complete loss of mobility and functioning can be the result. The fraction of disability varies strongly, for example, a systematic review shows a 50% disability in a period from first occurrence to disability from 4.5 to 22 years. Scientific efforts focused strongly on therapeutic and diagnostic methods during recent years. So far, there is no scientometric approach of the topic rheumatoid arthritis available although there is an increased need to evaluate quality and quantity of scientific research. Density-equalizing algorithms, scientometric methods and large scale data analysis were applied to evaluate the quality and quantity of scientific efforts in the field of rheumatoid arthritis. Data were gained from Pubmed and ISI-Web. During the period 1901-2007, 78,128 items were published by 129 countries including the USA, UK and Germany being the most productive suppliers, representing 45.7% of all publications. Another 23 countries published more than 100 items. In terms of international cooperation the USA proved to be the most successful partner. "Arthritis and Rheumatism", "Annals of the Rheumatic Diseases" and the "Journal of Rheumatology" are the most prolific journals. The current study is the first analysis of "rheumatoid arthritis" research activities and output. Our analysis revealed single areas of interest, the most prolific journals, authors and institutions dealing with the topic. Nevertheless, statements concerning the scientific quality should be considered critical due to a bias according to self-citation and co-authorship.

Correlates shift work with increased risk of gastrointestinal complaints or frequency of gastritis or peptic ulcer in H. pylori-infected shift workers?

AIM: There is an ongoing discussion whether work under shift work conditions enhances the ulcerogenic potential of Helicobacter pylori infections. This may be induced by a disruption of the circadian rhythm. The present study assessed whether there is an association between H. pylori infection and an increased risk of gastrointestinal complaints or frequency of gastritis or peptic ulcer in H. pylori-infected shift workers. METHODS: We analyzed 615 workers divided in shift and daytime. Upper gastrointestinal diseases, medication or operation, unspecific gastrointestinal complaints, smoking habits, subjective job strain and private stress factors were monitored. The H. pylori status was analyzed using IgA and IgG antibody concentration in blood and qualitative ELISA for feces. RESULTS: It was observed that 27.6% of all workers, 34.6% of the shift workers and 16% of daytime workers were Hp positive (P = 0.004). Shift workers reported reflux or pyrosis less frequently than daytime workers. No increased lifetime prevalence for gastritis, ulcus or eradication therapy was found for shift workers. Analysis revealed a weak regression between age and Hp-positive gastritis or upper gastrointestinal complaints, smoking habits were a major confounding factor for ulcus disease. Clinical manifestation of gastritis or ulcus disease did not correlate with shift work or especially shift work including night work. CONCLUSIONS: As a result of the present study, it cannot be confirmed that there is a causal connection between shift work and upper or unspecific gastrointestinal complaints or gastritis or peptic ulcer in dependency of a H. pylori colonization.

Development and evaluation of a computer-based medical work assessment programme.

BACKGROUND: There are several ways to conduct a job task analysis in medical work environments including pencil-paper observations, interviews and questionnaires. However these methods implicate bias problems such as high inter-individual deviations and risks of misjudgement. Computer-based observation helps to reduce these problems. The aim of this paper is to give an overview of the development process of a computer-based job task analysis instrument for real-time observations to quantify the job tasks performed by physicians working in different medical settings. In addition reliability and validity data of this instrument will be demonstrated. METHODS: This instrument was developed in consequential steps. First, lists comprising tasks performed by physicians in different care settings were classified. Afterwards content validity of task lists was proved. After establishing the final task categories, computer software was programmed and implemented in a mobile personal computer. At least inter-observer reliability was evaluated. Two trained observers recorded simultaneously tasks of the same physician. RESULTS: Content validity of the task lists was confirmed by observations and experienced specialists of each medical area. Development process of the job task analysis instrument was completed successfully. Simultaneous records showed adequate interrater reliability. CONCLUSION: Initial results of this analysis supported the validity and reliability of this developed method for assessing physicians' working routines as well as organizational context factors. Based on results using this method, possible improvements for health professionals' work organisation can be identified.

Occupational medical prophylaxis for the musculoskeletal system: A function-oriented system for physical examination of the locomotor system in occupational medicine (fokus(C)).

Occupational physicians are very often confronted with questions as to the fitness of the postural and locomotor systems, especially the spinal column. Occupational medical assessment and advice can be required by patients with acute symptoms, at routine check-ups, by persons who have problems doing certain jobs, and for expert medical reports as to the fitness of persons with chronic disorders or after operations. Therefore, for occupational medical purposes a physical examination must aim primarily to investigate functions and not structures or radiologic evidence. The physical examination should be structured systematically and according to regions of the body and, together with a specific (pain) anamnesis should provide a basis for the medical assessment.This paper presents a function-oriented system for physical examination of the locomotor system, named fokus(C) (Funktionsorientierte Koerperliche Untersuchungssystematik, also available on DVD). fokus(C) has been developed with a view to its relevance for occupational medical practice and does not aim primarily to provide a precise diagnosis. Decisive for an occupational medical assessment of disorders of the musculoskeletal system is rather information about functional disorders and any impairment of performance or mobility which they can cause. The division of the physical examination into a rapid screening phase and a subsequent more intensive functional diagnostic phase has proved its practicability in many years of day-to-day use. Here, in contrast to the very extensive measures recommended for orthopaedic and manual diagnosis, for reasons of efficiency and usability of the system in routine occupational medical examinations the examination is structured according to the findings. So it is reduced to that which is most necessary and feasible.

Shift work and pathological conditions.

Shift work exerts major influences on the physiological functions of the human body. These are primarily mediated by the disruption of circadian rhythms since most body functions are circadian rhythmic. Next to the disturbances caused by changes in the circadian system, shift work has also been suggested to be related to a number of other health disorders. The present study summarizes recently published data on the potential relationship between disorders and shift working.

Comparison of the aerosol velocity and spray duration of Respimat Soft Mist inhaler and pressurized metered dose inhalers.

Apart from particle size distribution, spray velocity is one of the most important aerosol characteristics that influence lung deposition of inhaled drugs. The time period over which the aerosol is released (spray duration) is also important for coordination of inhalation. Respimat Soft Mist Inhaler (SMI) is a new generation, propellant-free inhaler that delivers drug to the lung much more efficiently than pressurised metered dose inhalers (pMDIs). The objective of this study was to compare the velocity and spray duration of aerosol clouds produced by Respimat SMI with those from a variety of chlorofluorocarbon (CFC) and hydrofluoroalkane (HFA) pMDIs. All inhalers contained solutions or suspensions of bronchodilators. A videorecording method was used to determine the aerosol velocity. For spray duration, the time for generation of the Soft Mist by Respimat SMI was initially determined using three different methods (videorecording [techniques A and B], laser light diffraction and rotating disc). Videorecording was then used to compare the spray duration of Respimat SMI with those from the other inhalers. The Soft Mist produced by Respimat SMI moved much more slowly and had a more prolonged duration than aerosol clouds from pMDIs (mean velocity at a 10-cm distance from the nozzle: Respimat SMI, 0.8 m/sec; pMDIs, 2.0-8.4 m/sec; mean duration: Respimat SMI, 1.5 sec; pMDIs, 0.15-0.36 sec). These characteristics should result in improved lung and reduced oropharyngeal deposition, and are likely to simplify coordination of inhaler actuation and inhalation compared with pMDIs.