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Wolska A.,Central Institute for Labour Protection National Research Institute CIOP PIB | Sawicki D.,Warsaw University of Technology
International Journal of Occupational Medicine and Environmental Health | Year: 2014

Objectives: The aim of the study was to analyze discomfort glare sensation in subjects aged 50 years and more in comparison with younger subjects (i.e. younger than 35 years of age). Material and Methods: The experiments were performed on a computer workstation placed in controlled lighting environment where 2 discomfort glare conditions were modeled. Each participant performed for about 1 h specially designed visual tasks, including the tests with Landolt's rings presented on the screen by a computer program. The glare evaluation method consisted of subjective evaluation of discomfort glare on the semantic glare rating scale, tests of mesopic contrast and glare sensitivity, subjective assessment of lighting quality and asthenopic symptoms. The time needed to perform the task and the number of mistakes were also recorded. The subjective evaluation of glare was compared with the Unified Glare Rating (UGR) index calculated by the DIALux simulation program. Results: A higher percentage of the younger group subjects assessed glare after the experimental session as uncomfortable and intolerable than in the 50+ group, who more often assessed glare as acceptable. The assessment of discomfort glare in the younger group corresponded to higher UGR value compared to UGR value calculated by DIALux. In the 50+ group, such correlation was found only for lower discomfort glare (UGR = 19). The results showed that younger participants more frequently suffered from visual fatigue and assessed lighting as less comfortable. However, the mesopic glare sensitivity increased significantly after the experiments only in the 50+ group under both glare conditions. Conclusions: The obtained results showed that discomfort glare sensation changes with age. The younger population seems to be more sensitive and demanding than the older one in relation to discomfort glare limiting, in spite of the lack of significant objective measures of fatigue. The exposure of the elderly to bigger discomfort glare could adversely affect the objective measures of fatigue like mesopic glare sensitivity and visual performance. © 2014 Versita Warsaw and Springer-Verlag Wien.


Roman-Liu D.,Central Institute for Labour Protection National Research Institute CIOP PIB
International Journal of Occupational Safety and Ergonomics | Year: 2016

The purpose of this article is to gather results of studies on the relationship between median frequency (MF) and mean power frequency (MPF) and the level of muscle contraction, and to use those results to discuss the differences in the trends according to factors related to measurement technique and subject. Twenty-one studies with 63 cases for upper limb muscles and nine studies with 31 cases for lower limb muscles were analysed. Most results showed an increase in parameters with an increased level of muscle contraction, only some studies showed a decrease. The influence on parameters of the level of muscle contraction and factors such as subjects, type of contraction, muscle length and electrodes was analysed for each muscle. It was concluded that when analysing the influence of different factors on MF and MPF, because those factors interact they should be considered together, not separately. © 2016 Central Institute for Labour Protection – National Research Institute CIOP-PIB.


Mlynski R.,Central Institute for Labour Protection National Research Institute CIOP PIB | Kozlowski E.,Central Institute for Labour Protection National Research Institute CIOP PIB
International Journal of Occupational Safety and Ergonomics | Year: 2013

Determining the effectiveness of impulse noise attenuation with hearing protection devices (HPDs) is an important part of their selection. Measuring impulse noise parameters under an HPD would involve exposing subjects to impulses with a high peak sound pressure level. This paper presents a computational method of determining impulse noise parameters under the cups of earmuffs. Calculations are done using the transfer function of earmuffs, determined with Shaw's electrical equivalent of an HPD, taking into account the design parameters of earmuffs. The developed method was used for calculations in the presence of impulse noise generated by gunshots. To verify the computational method, the results of these calculations were compared with the results of measurements.


Roman-Liu D.,Central Institute for Labour Protection National Research Institute CIOP PIB | Bartuzi P.,Central Institute for Labour Protection National Research Institute CIOP PIB
Gait and Posture | Year: 2013

This study investigates how altering wrist posture influences the relationship between the time and frequency measures of the electromyography (EMG) signal of extensor digitorum communis (EDC) and flexor carpi ulnaris (FCU). Thirteen participants exerted handgrip force related to maximum voluntary contraction (MVC) in four tests: 20%MVC and 50%MVC in neutral wrist posture and 20%MVC in full wrist flexion and extension. EMG measurements from EDC and FCU were used to calculate normalized values of amplitude (nRMS) and mean and median frequency of the power spectrum (nMPF, nMF). During muscle shortening (wrist flexion for FCU and wrist extension for EDC) nRMS was approximately twofold higher than in neutral posture for FCU and fourfold for EDC. All measures obtained at 20%MVC in neutral posture were significantly different from 20%MVC in wrist flexion for FCU and 20%MVC in wrist extension for EDC (p<0.05). Differences between 50%MVC and 20%MVC at neutral posture (nRMS) were significant for both muscles, although in nMPF and nMF for EDC only. Muscle shortening changed the pattern of statistical significance when the time and frequency domain measures were compared, whereas muscle lengthening did not. It can be concluded that muscle shortening caused by altering wrist posture influences the relationship between the time and frequency measures in both muscles. This suggests that in studies using EMG in different wrist postures, changes in the relationship between the time and the frequency measures should be considered. © 2012 Elsevier B.V.


Jachowicz M.,Central Institute for Labour Protection National Research Institute CIOP PIB
International Journal of Occupational Safety and Ergonomics | Year: 2015

Connectors are commonly found in personal equipment protecting against falls from a height. They are typically used outdoors and exposed to atmospheric factors, which can result in corrosion. This article presents the results of a study involving exposure of connectors to experimental corrosive media – neutral salt spray (NSS), acid salt spray (ASS), and seawater mist (for elements made of carbon steel and non-ferrous metals) – and to experimental conditions simulating the processes of pitting, stress, and intercrystalline corrosion (for equipment made of s‘tainless steel). The results indicate that the main effects of corrosion on connectors include impaired operation and reduced strength of their mobile elements. The article presents methods of testing connector operation developed for this purpose. Corrosive damage to connectors has been presented in relation to potential hazards for their users. © 2015 The Author(s). Published by Taylor & Francis.


Zradzinski P.,Central Institute for Labour Protection National Research Institute CIOP PIB
International Journal of Occupational Safety and Ergonomics | Year: 2015

Due to the various physical mechanisms of interaction between a worker’s body and the electromagnetic field at various frequencies, the principles of numerical simulations have been discussed for three areas of worker exposure: to low frequency magnetic field, to low and intermediate frequency electric field and to radiofrequency electromagnetic field. This paper presents the identified difficulties in applying numerical simulations to evaluate physical estimators of direct and indirect effects of exposure to electromagnetic fields at various frequencies. Exposure of workers operating a plastic sealer have been taken as an example scenario of electromagnetic field exposure at the workplace for discussion of those difficulties in applying numerical simulations. The following difficulties in reliable numerical simulations of workers’ exposure to the electromagnetic field have been considered: workers’ body models (posture, dimensions, shape and grounding conditions), working environment models (objects most influencing electromagnetic field distribution) and an analysis of parameters for which exposure limitations are specified in international guidelines and standards. © 2015 Central Institute for Labour Protection - National Research Institute (CIOP-PIB)..


Pawlowska Z.,Central Institute for Labour Protection National Research Institute CIOP PIB
International Journal of Occupational Safety and Ergonomics | Year: 2015

Improvement of occupational safety and health (OSH) management is closely related to the development of OSH performance measurement, which should include OSH outcomes (e.g., occupational accidents), OSH inputs (including working conditions) and OSH-related activities. The indicators used to measure the OSH outcomes are often called lagging indicators, and the indicators of inputs and OSH activities are leading indicators. A study was conducted in 60 companies in order to determine what kinds of indicators were used for OSH performance measurement by companies with different levels of OSH performance. The results reveal that the indicators most commonly used in all of the companies are those related to ensuring compliance with the statutory requirements. At the same time, the leading indicators are much more often adopted in companies with a higher performance level. These companies also much more often monitor on a regular basis the indicators adopted for the evaluation of their OSH performance. © 2015 The Author(s). Published by Taylor & Francis.


Pecillo M.,Central Institute for Labour Protection National Research Institute CIOP PIB
International Journal of Occupational Safety and Ergonomics | Year: 2015

Workers’ working conditions, work-related health problems and sickness absence are interdependent factors. Both workers’ health problems and their absence are adverse events which generate significant costs for both Poland’s Social Insurance Institution (ZUS) and employers. Despite the related burdens, it is difficult to assess the number of workers who experience work-related health problems, to indicate the share of those workers who have been unfit for work owing to such disorders and to indicate the types of workers’ disorders which are caused by factors the workers are exposed to in the working environment. This article presents the findings of surveys carried out in selected production and service-providing companies, assessing the scale and nature of work-related health problems and their links with workers’ sickness absence. © 2015 The Author(s). Published by Taylor & Francis.


Zradzinski P.,Central Institute for Labour Protection National Research Institute CIOP PIB
Electromagnetic Biology and Medicine | Year: 2013

According to international guidelines, the assessment of biophysical effects of exposure to electromagnetic fields (EMF) generated by hand-operated sources needs the evaluation of induced electric field (E in) or specific energy absorption rate (SAR) caused by EMF inside a worker's body and is usually done by the numerical simulations with different protocols applied to these two exposure cases. The crucial element of these simulations is the numerical phantom of the human body. Procedures of E in and SAR evaluation due to compliance analysis with exposure limits have been defined in Institute of Electrical and Electronics Engineers standards and International Commission on Non-Ionizing Radiation Protection guidelines, but a detailed specification of human body phantoms has not been described. An analysis of the properties of over 30 human body numerical phantoms was performed which has been used in recently published investigations related to the assessment of EMF exposure by various sources. The differences in applicability of these phantoms in the evaluation of E in and SAR while operating industrial devices and SAR while using mobile communication handsets are discussed. The whole human body numerical phantom dimensions, posture, spatial resolution and electric contact with the ground constitute the key parameters in modeling the exposure related to industrial devices, while modeling the exposure from mobile communication handsets, which needs only to represent the exposed part of the human body nearest to the handset, mainly depends on spatial resolution of the phantom. The specification and standardization of these parameters of numerical human body phantoms are key requirements to achieve comparable and reliable results from numerical simulations carried out for compliance analysis against exposure limits or within the exposure assessment in EMF-related epidemiological studies. © Informa UK Ltd.


Roman-Liu D.,Central Institute for Labour Protection National Research Institute CIOP PIB
International Journal of Industrial Ergonomics | Year: 2013

This paper presents a conceptual model of the interaction between the human body and external factors influencing the musculoskeletal system (biomechanical load, vibration and psychosocial factors). The interrelationship of parameters that define each external occupational or non-occupational factor and their combination creates exposure. Exposure influences the human body modelled as a mental system and a musculoskeletal system, and results in responses leading to improved or impaired structures of the musculoskeletal system. The reaction to external factors expressed as a response depends on personal traits. The results of this study are a basis for insights into how external physical and psychosocial risk factors influence the mechanisms responsible for whether body structures improve or are impaired. The model is intended to be filled in with mathematical equations that describe quantitatively phenomena related to processes caused by external load, with consideration of personal traits. This paper discusses ways leading to mathematical formulas, which would explain the phenomena included in the model quantitatively. Relevance to industry: The relevance of this study to industry consists in providing, through the use of the proposed model, after a quantitative verification, safety levels that can result in improved work and workers protect against MSDs. By considering both occupational and non-occupational activities, the model can help to protect workers holistically. © 2013 Elsevier B.V.

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