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Background Analysis of demographic trends indicates that there is an increasing proportion of people who can be described as elderly. In Poland, the population aged >60 years is expected to increase to 10.8 million in 2030 and to 13.7 million in 2050, i.e., around 40% of total population. In line with the general trend, the issue of the aging of the professionally active population is becoming more relevant. Material and Methods The average age of the world’s working population is steadily increasing. In the European Union, workers aged 55–64 years accounted for 50% of the total workforce in 2013, and already 59% in 2018. In Poland, in 2018, people aged 55–64 years accounted for 49% of the employed population. The low percentage of people working at this age is due, among other things, to employers’ attitudes towards employing older people, perceiving them as employees who are more difficult to manage and have health problems. Moreover, working conditions of seniors are not adapted to their age capabilities. Results It is necessary to reduce the burden of physical work, especially in awkward positions, carrying loads, monotonous work and piecework. It is important to create work organization in which it is possible to refer to the experience of older people, who should have freedom of action, without time pressure and the need to perform many tasks at the same time. The ever-increasing social dependence on information technology tools creates new problems for seniors. Taking into account age-related difficulties in acquiring new knowledge, it is important to provide them with simplified tools that are easier to use. Conclusions The scope of necessary actions to enable the aging population to work is very wide, ranging from legislative, technological and organizational changes, ending with education addressed both to people responsible for employee safety (including occupational health services) and to current and potential employees. Med Pr Work Health Saf. 2024;75(3):293–302

Occupational exposure to carcinogenic respirable crystalline silica and noise requires a deeper understanding and an assessment of the possible health risks caused by their combined action. Data on individual exposure to respirable crystalline silica (RCS) and occupational noise (ON) was collected among 44 open-pit miners. The study group was divided into two groups according to the job tasks performed. The individual exposure, exceeding of maximum admissible concentration/intensity, and predicted hearing thresholds (HTs) (according to ISO 1999:2013) were compared between the groups directly participating in the technological process (group 1; N = 23) and performing auxiliary, supervising, or laboratory activities (group 2; N = 21). All the analysed indices were significantly higher for group 1; therefore, the job category may predict ON and RCS exposure among open-pit miners. A statistically significant relationship (rs = 0.66, p < 0.05) was found between the time-weighted average (TWA) 8 h RCS and individual daily noise exposure levels. Exposure to noise in the course of employment causes the risk of hearing impairment (mean HTs for 2, 3, and 4 kHz > 25 dB) up to 74% and 4.4% (in the case of groups 1 and 2, respectively). Further studies are needed before conclusions concerning the effects of co-exposure to ON and RCS on open-pit miners can be made.

This paper summarizes the currently available knowledge on the impact of infrasound (IS) and low frequency noise (LFN) on human health and well-being. This narrative review of the literature data was based on the selected, mostly, peer-reviewed research papers, review articles, and meta-analyses that were published in 1971–2022. It has been focused on the results of epidemiological studies concerning the annoyance related to infrasound and low frequency noise, as well as their impact on the cardiovascular system and sleep disorders. Particular attention was also paid to the latest research results and specific sources of IS and LFN, i.e., wind turbines. Med Pr Work Health Saf. 2023;74(5):409–23.

Background The population ageing phenomenon is mainly attributable to the increasing proportion of people >60 years of age. This demographic situation requires more attention to the needs of the elderly. Given the lack of effective methods to expand the knowledge of and increase sensitivity to elderly people’s problems, especially among the younger generation, an attempt has been made to use virtual reality (VR) to prepare an educational tool focused on these problems. This paper will focus on the use of VR in depicting fundamental problems in the daily live of older people. Material and Methods For project purposes, a questionnaire (26 question) was developed, concerning data on socio-demographic situation, health and physical conditions; social, living and housing support needs. Additionally, qualitative interviews were conducted with elderly people regarding their needs about housing arrangements and daily activities. It was distributed to 100 people, 34 completed questionnaires were obtained from 30 women and 4 men. The study results were intended as information that would provide the basis for developing VR scenarios, not for the epidemiological purposes. Results The mean age of the respondents was 73.7±7.5 (60‒86 years). Different situations, as heavy housework, lifting/carrying heavy objects, lifting hands above the shoulder level, bending and squatting were identified that pose problems for elderly people. Based on these results, 3 scenario proposals were prepared, including situations: in the bathroom, in the supermarket, on a trip to the city. These scenarios were used to prepare the exercises in VR in the frame of European project – the Mixed Reality on Universal Design’s Secret Service (Mr. UD) Project. Conclusions The use of immersive technology such as VR can be beneficial for young people to be able to see perspectives of the elderly. Students from various fields (medicine, nursing, future engineers, designers, sociologists, etc.) may feel like the elderly and experience their daily challenges. Med Pr. 2023;74(3):159–70

Due to the controversy related to the necessity to wear protective masks and the negative perceptions of users, an attempt was made to analyze the available scientific research on the physiological consequences of wearing various types of masks. The literature review includes publications available in the PubMed bibliographic database, describing symptoms and complaints of mask users (e.g., the feeling of discomfort, fatigue, headaches), different physiological reactions depending on the type of mask (surgical masks, masks with an exhalation valve, with air flow, etc.) as well as the influence of air composition, temperature and humidity in the space under the mask. The impact of using the mask on the ability to exercise (maximal effort, moderate effort) and mental work was outlined. The consequences of wearing masks by people in a different physiological state (pregnancy) were discussed. Proposals for the organization of work were also presented in order to minimize the negative consequences for people wearing masks. The analysis of the presented studies shows that, regardless of the type of masks worn, they can intensify the body’s reactions to a varying degree, increasing the physiological cost of work and worsening the ability to make both physical and mental effort. In addition, the mask can contribute, among others, to more frequent headaches, symptoms of fatigue or the subjective feeling of discomfort. However, despite these adverse effects, the use of masks is important to protect people against harmful factors in the work and communal environments, and during the current SARS-CoV-2 pandemic, it has become a necessity. The discomfort of wearing a mask can be reduced by taking appropriate breaks. It should be emphasized that the rhythm of work and breaks in wearing the mask should take into account the individual limitations of the employee. Med Pr. 2021;72(5):569–89

In 2017, preparations were made in Poland to provide all citizens with access to the Internet at a speed of at least 30 Mb/s, and at a speed of at least 100 Mb/s for 50% of households. This goal is to be realized, among others, by means of the fifth generation (5G) radio-communication networks. This work presents the assumptions of the 5G network structure and estimates of the level of population exposure toelectromagnetic fields related to their rational use. It was also analyzed whether, from the technical point of view, 5G networks could be implemented while respecting the currently acceptable level of electromagnetic field intensity in Poland (7 V/m), taking into account the current environmental exposure caused by antennas of cellular base stations. This is a contribution to the ongoing discussion on the need to change the requirements in Poland in order to limit the level of population exposure to electromagnetic fields. Based on the available documentation of the proposed technical standards, the theoretical analysis of environmental exposure to the electromagnetic field emitted by 5G systems shows that, with rational power management, obtaining the expected (compatible with 5G standards) quality of connections via base stations installed outside of buildings and using intelligent antenna systems with controlled beams, it will be possible to maintain the electric field strength and power density below the current limit values in places accessible to the public (

Chronic diseases (ChDs) pose an essential problem from an individual, social and economic point of view. It is estimated that they account for 60% of all deaths worldwide, and this share is expected to rise to 72% by 2020. The most prevalent are cardiovascular diseases (30%), cancers (13%), respiratory diseases (7%), and diabetes (2%). Their major risk factors include unhealthy diet, the lack of physical activity, and tobacco smoking. Of significance are also occupational and environmental hazards. Among teachers, the factor with the highest impact is noise, reported by 25% of male and 38% of female teachers. In Poland, there are no databases on ChDs or risk factors in teachers; only voice disorders are well-recognized as an occupational disease. Only a few studies of health and lifestyle were conducted among teachers in Poland, but they cannot be generalized because they were carried out with different methods, in small groups of people and in various regions in the country. A representative study carried out by Statistics Poland (GUS) among education employees (with no separate data for teachers) revealed that the most prevalent were musculoskeletal disorders, including back-pain (21.9%), as well as painfulness of the neck, shoulder, hand, hip and leg (10% in each case). Headaches and eye fatigue were found in 14.6%; stress, anxiety and depression in 7.3%; and cardiovascular disorders in 4.6% of the study population. Defining health problems in this professional group is an important public health issue which should enable reducing the prevalence and adverse health effects of ChDs. Med Pr. 2020;71(2):221–31

There is an ongoing discussion about electromagnetic hazards in the context of the new wireless communication technology – the fifth generation (5G) standard. Concerns about safety and health hazards resulting from the influence of the electromagnetic field (EMF) emitted by the designed 5G antennas have been raised. In Poland, the level of the population’s exposure to EMF is limited to 7 V/m for frequencies above 300 MHz. This limitation results from taking into account the protective measures related not only to direct thermal hazards, but also to diversified indirect and long-term threats. Many countries have not established legal requirements in this frequency range, or they have introduced regulations based on recommendations regarding protection against direct thermal risks only (Council Recommendation 1999/519/EC). For such protection, the permissible levels of electric field intensity are 20–60 V/m (depending on the frequency). This work has been created through an interdisciplinary collaboration of engineers, biologists and doctors, who have been for many years professionally dealing with the protection of the biosphere against the negative effects of EMF. It presents the state of knowledge on the biological and health effects of the EMF emitted by mobile phone devices (including millimeter waves which are planned to be used in the 5G network). A comparison of the EU recommendations and the provisions on public protection being in force in Poland was made against this background. The results of research conducted to date on the biological effects of the EMF radiofrequency emitted by mobile telecommunication devices, operating with the frequencies up to 6 GHz, do not allow drawing any firm conclusions; however, the research evidence is strong enough for the World Health Organization to classify EMF as an environmental factor potentially carcinogenic to humans. At the moment, there is a shortage of adequate scientific data to assess the health effects of exposure to electromagnetic millimeter waves, which are planned to be used in the designed 5G devices. Nevertheless, due to the fact that there are data indicating the existence of biophysical mechanisms of the EMF influence that may lead to adverse health effects, it seems necessary to use the precautionary principle and the ALARA principle when creating environmental requirements for the construction and exploitation of the infrastructure of the planned 5G system. Med Pr. 2020;71(1):105–13

Background The aim of the study was to compare the musculoskeletal system load assessed using the rapid office strain assessment (ROSA) and rapid upper limb assessment (RULA) methods in computer operators, and to determine the correlation of the obtained results with the occurrence and intensity of musculoskeletal complaints (MSCs) in these individuals. Material and Methods In a group of 72 persons (38 women and 34 men) working with a computer for > 4 h/day, the ROSA and RULA methods were used to assess the load, while a questionnaire modeled on the Standardized Nordic Questionnary was used to assess the frequency and severity of MSCs. Results Musculoskeletal complaints occurred in about 66% of the investigated women and 62% of the investigated men within the previous year. The results of the ROSA and RULA methods were not convergent. The final result of the ROSA method (scale 1−10 pts) was 2−6 pts (M = 3.51±1.09), while the final result of the RULA method (scale 1−7 pts) ranged 2−4 pts (3.00±0.17). The values of partial and final scores in the ROSA method were correlated with the number of concurrent ailments and intensity of complaints in various regions of the musculoskeletal system. The assessment of the position of particular parts of the body during work, performed using the RULA method, in people with or without MSCs was almost identical. Conclusions The use of the ROSA method has shown that it is a useful and easy-to-use tool for assessing computer workstations and can be successfully disseminated. Med Pr. 2019;70(6):675–99

Background: The World Health Organization (WHO) and the International Labour Organization (ILO) are developing joint estimates of the work-related burden of disease and injury (WHO/ILO Joint Estimates), with contributions from a large number of individual experts. Evidence from mechanistic data suggests that occupational exposure to noise may cause cardiovascular disease (CVD). In this paper, we present a systematic review and meta-analysis of parameters for estimating the number of deaths and disability-adjusted life years from CVD that are attributable to occupational exposure to noise, for the development of the WHO/ILO Joint Estimates. Objectives: We aimed to systematically review and meta-analyse estimates of the effect of any (high) occupational exposure to noise (≥85 dBA), compared with no (low) occupational exposure to noise (

Objectives Only a few studies have been undertaken to analyze the dietary habits of people with cardiovascular diseases. The aim of this study was to evaluate the dietary behaviors of working people who were hospitalized due to experiencing the first acute cardiovascular incident. Material and Methods In the study, the Functional Activity Questionnaire was used. The study was conducted in 2 groups. The first group included all the men hospitalized during 1 year (January–December 2009) in 2 clinics of cardiology, who were professionally active until the first myocardial infarction (MI). It comprised 243 men aged 26–70 years. The reference group consisted of 403 men, blue- and white-collar workers, aged 35–65 years. Results The body mass index of the MI patients was significantly higher (p = 0.006). The frequency of consumption of particular products in the MI group and in the reference group differed significantly for 11 of 21 products. The MI patients significantly less frequently reported the daily consumption of fruit, raw vegetables, cheese, vegetable oils and fish. In this group, the consumption of salty (p = 0.0226) or fatty (p < 0.0001) foods was significantly higher. It was shown that, after adjusting for age, education and the type of work, the daily consumption of fish, salads and cooked vegetables, as well as fruit and vegetable oils, significantly reduced the risk of myocardial infarction. An increased MI risk was, in turn, associated with obesity and preference for fatty foods. Conclusions The authors found that diet significantly modified the MI risk in the examined workers. This indicates that an important aspect of prevention activities among working people should involve education about proper dietary habits. Int J Occup Med Environ Health. 2019;32(6):853–63

Road accidents are among the main fatalities worldwide and drowsy driving is a significant cause of road deaths where drivers are at fault. There are well known diseases which impair sensory and cognitive functions and can cause sleepiness during driving. Such diseases can be an important contraindication to driving because they may have an adverse effect on its safety. Thus, medical examinations for drivers should also be directed at identifying any possible conditions posing risks for driving safety. Occupational medicine specialists should look for symptoms of locomotor and sleep-related breathing disorders as these are medical conditions which could preclude a person from driving. In this case report, the authors describe a professional driver with chest deformity and present a pioneering attempt at assessing his medical fitness to drive. It is also explained why scoliosis can impair driving ability and how it should be diagnosed and treated. Finally, the authors describe how they used driving simulator tests as part of their diagnosis and suggest a relevant treatment regimen. Int J Occup Med Environ Health. 2019;32(5):735–45

Background Experimental studies have shown cardiovascular effects of electromagnetic fields (EMF) emitted by mobile phones (e.g., prolonged QTc interval and abnormal blood pressure [BP] values). Also, stress may have an impact on the cardiovascular function. However, there are practically no data regarding the joint effect of exposure to stress and EMF, with both factors pertaining, e.g., to employees of mobile network operators. Material and Methods Out of 208 subjects who had taken part in survey research, 55 workers agreed to undergo resting ECG, 24-h ECG and ambulatory blood pressure monitoring (ABPM). Their health condition, occupational and life-stress levels and EMF exposure were also assessed. Results Among the workers using mobile phones for more than 60 min daily, the systolic BP values in office measurement and at night-time in ABPM were significantly higher than among the workers spending less time talking on mobile phones (p = 0.04 and p = 0.036, respectively). The workers with the highest level of occupational stress showed significantly higher systolic 24-h BP (p = 0.007) and at day-time (p = 0.002), both during work (p = 0.010) and after work (p = 0.005), and higher diastolic BP values at day-time (p = 0.028). Cardiovascular response was strongly gender-related: males showed more BP abnormalities while females displayed more impairments in ECG records. The heart rate from 24 h was significantly correlated with the level of occupational stress, after adjusting for gender, life-stress and EMF. Conclusions The findings obtained thus far have indicated the need to conduct in-depth studies on the impact of stress and EMF emitted by mobile phones on the health effects, in order to clarify the observed gender-related differences in cardiovascular response to the combined exposure to stress and EMF. Med Pr. 2019;70(4):411–24

Objectives The aim of the study was to establish whether the driver’s visual strategy may influence a driver’s behavior to avoid a crash in a high-risk situation. Any published papers on drivers’ visual strategies just before a crash were not found. Material and Methods Tests were performed using a high-tech driving bus simulator. Participants comprised 45 men drivers, aged 43.5±7.9 years old, seniority as a bus driver of 13.3±8.6 years. The tests were preceded by medical examinations: general, neurological and ophthalmological. Each participant drove the same city route for approximately 40 min (entire route – ER). In the final phase, a collision situation was simulated (a phantom car blocked the participant’s right of way). Driver’s visual strategy was analyzed using the FaceLab device with 2 cameras during ER and just before collision. The field-of-view covered by camera 1 was divided into 8 regions, by camera 2 into 10 regions. The distribution of gazes in regions was a criterion of visual strategy. Results Thirty-five drivers completed the simulated driving test, 14 escaped the collision, 21 crashed. These groups differed only in resting systolic blood pressure before the test. The analysis of covariance, after adjusting to this factor, indicated that during the ER visual strategy recorded by camera 1 did not differ between groups, in camera 2 the drivers in the crash group fixed their gaze more frequently (p = 0.049) in region 3 (close part of the road in front of the windshield). Just before the collision drivers who escaped the collision fixed their gaze significantly more often in region 6 (left side of the road) in camera 1 and in region 6 (in front of the windshield,) and region 10 (right side) in camera 2. Conclusions The visual strategy has an impact on the road safety. The analysis of visual strategies may be a useful tool for the training of drivers. Int J Occup Med Environ Health. 2019;32(2):161–74

Background: The World Health Organization (WHO) and the International Labour Organization (ILO) are developing a joint methodology for estimating the national and global work-related burden of disease and injury (WHO/ILO joint methodology), with contributions from a large network of experts. In this paper, we present the protocol for two systematic reviews of parameters for estimating the number of deaths and disability-adjusted life years from cardiovascular disease attributable to exposure to occupational noise, to inform the development of the WHO/ILO joint methodology. Objectives: We aim to systematically review studies on exposure to occupational noise (Systematic Review 1) and systematically review and meta-analyse estimates of the effect of occupational noise on cardiovascular diseases (Systematic Review 2), applying the Navigation Guide systematic review methodology as an organizing framework, conducting both systematic reviews in tandem and in a harmonized way. Data sources: Separately for Systematic Reviews 1 and 2, we will search electronic academic databases for potentially relevant records from published and unpublished studies, including Medline, EMBASE, Web of Science and CISDOC. We will also search electronic grey literature databases, Internet search engines and organizational websites; hand search reference list of previous systematic reviews and included study records; and consult additional experts. Study eligibility and criteria: We will include working-age (≥15 years) workers in the formal and informal economy in any WHO and/or ILO Member State, but exclude children (

Background In the studies investigating the potential health effects of occupational exposure to electromagnetic fields (EMF), the key problem is the assessment of workers’ exposure. Electromagnetic fields exposure assessment requires determining maximum EMF levels, for the acute effect, and the dose absorbed, for the cumulative effect. A study was undertaken to determine EMF exposure in workers at broadcasting centers (BCs) in Poland. It was the first part of a comprehensive project on health effects of occupational exposure to EMF. Material and Methods The study was conducted in 4 selected BCs. Spot measurements of electric field strength (E), and the results of E measurements that were made in the past for occupational hygiene assessments, were used for determining workers’ exposure to electric field. The parameters considered were the maximum E value (E max ), the weighted average E value (E avg ) and the E lifetime dose (E lifetime dose ). Results In the group of workers examined, the E values did not exceed 16.7 V/m for Emax (the occupational exposure limit (OEL) for work shift in Poland is 20 V/m), 2.9 V/m for E avg and 1 500 000 (V/m) 2 ×h for E lifetime dose . Conclusions In view of the lack of dosimetry data, a retrospective assessment of BC workers’ exposure to very high frequency and ultra-high frequency EMF was conducted, which made it possible to estimate EMF lifetime dose for the workers. Since the EMF exposure levels at BCs did not exceed the admissible values, they can be considered safe to the workers’ health, according to the approach used for developing OELs for EMF exposure. Med Pr 2018;69(5):477–482

Background: In Poland cardiovascular diseases (CVD), classified as work-related diseases, are responsible for 25% of disability and cause 50% of all deaths, including 26.9% of deaths in people aged under 65 years. The aim of the study was to analyze employee expectations regarding CVD- oriented prophylactic activities in the selected enterprise. Material and Methods: A questionnaire, developed for this study, consists of: socio-demographic data, job characteristics, occupational factors, and questions about the respondents’ expectations concerning the prevention program. The study group comprised 407 multi-profile company employees aged (mean) 46.7 years (standard deviation (SD) = 9.1), including 330 men (81.1%), mean age = 46.9 (SD = 9.2) and 77 women (18.9%), mean age = 45.9 (SD = 8.2) The study was performed using the method of auditorium survey. Results: Employees declared the need for actions related to physical activity: use of gym, swimming pool, tennis (56.5%), smoking habits – education sessions on quitting smoking (24.6%). A few people were interested in activities related to healthy diet. According to the majority of the study group, the scope of preventive examinations should be expanded. Based on our own findings and literature data CVD- oriented preventive program, addressed to the analyzed enterprise was prepared. The program will be presented in another paper. Conclusions: The results showed significant quantitative and qualitative differences in the classic and occupational CVD risk factors between men and women, as well as in preferences for participation in prevention programs. Therefore, gender differences should be taken into account when planning prevention programs. Med Pr 2017;68(6):757–769

This paper presents a camera-based prototype sensor for detecting fatigue and drowsiness in drivers, which are common causes of road accidents. The evaluation of the detector operation involved eight professional truck drivers, who drove the truck simulator twice—i.e., when they were rested and drowsy. The Fatigue Symptoms Scales (FSS) questionnaire was used to assess subjectively perceived levels of fatigue, whereas the percentage of eye closure time (PERCLOS), eye closure duration (ECD), and frequency of eye closure (FEC) were selected as eye closure-associated fatigue indicators, determined from the images of drivers’ faces captured by the sensor. Three alternative models for subjective fatigue were used to analyse the relationship between the raw score of the FSS questionnaire, and the eye closure-associated indicators were estimated. The results revealed that, in relation to the subjective assessment of fatigue, PERCLOS is a significant predictor of the changes observed in individual subjects during the performance of tasks, while ECD reflects the individual differences in subjective fatigue occurred both between drivers and in individual drivers between the ‘rested’ and ‘drowsy’ experimental conditions well. No relationship between the FEC index and the FSS state scale was found.

Fatigue affects multiple aspects of cognitive performance among drivers. However, even after fatigue builds up, some are still able to maintain the level of behavioral performance. To evaluate these adaptations on the neural network level, we utilized functional magnetic resonance imaging (fMRI). Seventeen male professional drivers underwent two fMRI sessions, once while rested and once in a fatigued condition after 10-h of overnight driving. The cognitive task used in the study involved the detection of visual feature conjunctions, namely the shape and the color. There were no significant differences in the task performance between the conditions except for longer reaction times in the fatigued condition. However, we observed substantial differences in the activation patterns during the cognitive task involving selective attention between the conditions. On the global level, we observed a general decrease in activation strength in the fatigued condition, which appeared to be more pronounced in the left hemisphere. On the local level, we observed a (spatially) extended activation of the medial prefrontal regions in the fatigued condition, which reflected increased cognitive control mechanisms compensating for the diminished efficiency of mechanisms involved in meeting task demands.

Background: There are no available data on the health consequences that may result from the synergistic effects of electromagnetic fields (EMF) and stress. Understanding the mechanisms of the simultaneous exposure will make it possible to develop procedures to minimize adverse health effects in professionals using mobile phones. Material and Methods: A questionnaire survey was conducted in 600 randomly selected people to obtain data on their health status and the prevalence of subjective symptoms related to the mobile phones using. Among them, there were 208 GSM Network employees, to whom the Perceived Stress Scale and Assessment of Stress at Work Questionnaire were sent. Eighty-nine completed questionnaires were returned (response rate – 42.8%). Results: The mean age of respondents was 30.3 years (standard deviation (SD) = 7.7), time of occupational use of mobile phone – 4.1 years (SD = 1.7), the level of occupational stress – 95.3 (SD = 19.1). A significant percentage of people (62.8%) complained of the frequent difficulties in coping with problems of everyday life, and 57.4% had a fairly frequent problems with managing their own affairs. Significant differences in the life stress were detected between groups with different time of phone use (p = 0.03), and in occupational stress level, significant differences were noted between the 2 groups differing in the length of the conversation (p = 0.05). The risk of headache, associated (odds ratio (OR) = 4.2, p = 0.008) or not associated (OR = 2.97, p = 0.04) with calls on mobile phone, adjusted for stress, was significantly higher in people speaking via mobile more than 60 min/day than in those talking less. Conclusions: The study indicates that both stressors acting at the same time (EMF from cell phone and stress) adversely affect the well-being of workers and increase the risk of subjective symptoms. Med Pr 2017;68(5):617–628

Results of epidemiological studies on the association between use of mobile phone and brain cancer are ambiguous, as well as the results of 5 meta-analysis studies published to date. Since the last meta-analysis (2009), new case-control studies have been published, which theoretically could affect the conclusions on this relationship. Therefore, we decided to perform a new meta-analysis. We conducted a systematic review of multiple electronic data bases for relevant publications. The inclusion criteria were: original papers, case-control studies, published till the end of March 2014, measures of association (point estimates as odds ratio and confidence interval of the effect measured), data on individual exposure. Twenty four studies (26 846 cases, 50 013 controls) were included into the meta-analysis. A significantly higher risk of an intracranial tumor (all types) was noted for the period of mobile phone use over 10 years (odds ratio (OR) = 1.324, 95% confidence interval (CI): 1.028–1.704), and for the ipsilateral location (OR = 1.249, 95% CI: 1.022–1.526). The results support the hypothesis that long-term use of mobile phone increases risk of intracranial tumors, especially in the case of ipsilateral exposure. Further studies are needed to confirm this relationship. Int J Occup Med Environ Health 2017;30(1):27–43

Nervous system is the most “electric” system in the human body. The research of the effects of electromagnetic fields (EMFs) of different frequencies on its functioning have been carried out for years. This paper presents the results of the scientific literature review on the EMF influence on the functioning of the human nervous system with a particular emphasis on the recent studies of the modern wireless communication and data transmission systems. In the majority of the analyzed areas the published research results do not show EMF effects on the nervous system, except for the influence of GSM telephony signal on resting EEG and EEG during patients’ sleep and the influence of radiofrequency EMF on the cardiovascular regulation. In other analyzed areas (EMF impact on sleep, the evoked potentials and cognitive processes), there are no consistent results supporting any influence of electromagnetic fields. Neurophysiological studies of the effect of radio- and microwaves on the brain functions in humans are still considered inconclusive. This is among others due to, different exposure conditions, a large number of variables tested, deficiencies in repeatability of research and statistical uncertainties. However, methodological guidelines are already available giving a chance of unifying research that definitely needs to be continued in order to identify biophysical mechanisms of interaction between EMFs and the nervous system. One of the EMF research aspects, on which more and more attention is paid, are inter-individual differences. Med Pr 2016;67(3):411–421

Background: The aim of the study was to analyze the hearing status of employees of a furniture factory with respect to their exposure to noise and the presence of additional risk factors of noise-induced hearing loss (NIHL). Material and Methods: Noise measurements, questionnaire survey and assessment of hearing, using pure tone audiometry, were carried out in 50 male workers, aged 20–57 years, directly employed in the manufacture of furniture. The actual workers’ hearing threshold levels (HTLs) were compared with the predictions calculated according to PN-ISO 1999:2000 based on age, gender and noise exposure. Results: Workers under study were exposed to noise at daily noise exposure levels of 82.7–94.8 dB (mean: 90.9 dB) for a period of 3–14 years. In all subjects, mean HTL at 500 Hz, 1000 Hz, 2000 Hz and 4000 Hz did not exceed 25 dB. Nevertheless, high frequency notches were found in 11% of audiograms. The actual workers’ HTLs at 3000–6000 Hz were similar to those predicted using PN-ISO 1999:2000. There were statistical significant differences between HTLs in subgroups of people with higher (> 78 mm Hg) and lower (≤ 78 mm Hg) diastolic blood pressure, smokers and non-smokers, and those working with organic solvents. Hearing loss was more evident in subjects affected by the additional risk factors specified above. Conclusions: The results confirm the need to consider, in addition to noise, also some other NIHL risk factors, such as tobacco smoking, elevated blood pressure, and co-exposure to organic solvents when estimating the risk of NIHL and developing the hearing conservation programs for workers. Med Pr 2016;67(3):337–351

Recording and analyzing eye movements provide important elements for understanding the nature of the task of driving a vehicle. This article reviews the literature on eye movement strategies employed by drivers of vehicles (vehicle control, evaluation of the situation by analyzing essential visual elements, navigation). Special focus was placed on the phenomenon of conspicuity, the probability of perceiving an object in the visual field and the factors that determine it. The article reports the methods of oculographic examination, with special emphasis on the non-invasive technique using corneal reflections, and the criteria for optimal selection of the test apparatus for drivers in experimental conditions (on a driving simulator) and in real conditions. Particular attention was also paid to the helmet – or glass-type devices provided with 1 or 2 high definition (HD) camcorders recording the field of vision and the direction of gaze, and the non-contact devices comprising 2 or 3 cameras and an infrared source to record eye and head movements, pupil diameter, eye convergence distance, duration and frequency of eyelid blinking. A review of the studies conducted using driver eye-tracking procedure was presented. The results, in addition to their cognitive value, can be used with success to optimize the strategy of drivers training.

Background: Bus drivers are a special group of professional drivers who are at a very high risk of fatigue. The aim of the study was to examine whether the driver’s subjective assessment of fatigue allows for the determination of its level and identification of its causes. Material and Methods: The study group comprised 45 randomly selected bus drivers (mean age – 43.7±7.9 years, period of employment as drivers – 14.7±8.6 years). Examinations were performed in all subjects four times – before and after work on the “easy” route (outside the city center, small traffic intensity) and before and after work on the “difficult” route (city center, heavy traffic). The fatigue test questionnaire, based on the list of symptoms of fatigue prepared by the Japan Research Committee of Fatigue, was used in the study. Results: The rating of fatigue after the work was significantly higher than that before the work. The profile of fatigue after work was not influenced by the type of route, but the assessment of most symptoms of fatigue reached a higher level after the “difficult” routes and the differences were statistically significant for 7 symptoms. Only the ratings of leg fatigue, feeling of heaviness, and the necessity to squint eyes and gaze with effort reached the higher levels after driving the “easy” routes. It has been found that the level of fatigue was significantly correlated with the job characteristics (driving time, the length of the route, number of stops, etc.) and with the abundance of food ingested and type of beverage (coffee vs. others) drunk prior to driving. Conclusions: The questionnaire used in our study to assess the subjective feeling of fatigue has proved to be a sensitive and useful tool for indicating the level and causes of fatigue. The relationship between the symptoms of fatigue and the characteristics of job and lifestyle shows that actions must be taken by both the employers and employees to prevent fatigue in bus drivers. Med Pr 2015;66(5):661–677

Background: The way the municipal transport drivers perform their job contributes to varied burdens linked with the body posture at work, stress, shift work, vibration, noise and exposure to chemical agents. The aim of the study was to assess the condition of the nervous system (NS) in municipal transport drivers. Material and Methods: The study covered 42 men, aged 43.4 years (standard deviation (SD): 8.3), employed as bus drivers in the municipal transport enterprise. The duration of employment was 11.8 years on average (SD: 8.6). The condition of the nervous system was assessed on the basis of clinical neurological examinations. Results: Chronic lumbosacral syndrome was found in 54.8% of the subjects. A significant relationship between the incidence of lumbosacral syndrome and the duration of employment (p = 0.032) was observed; significantly higher in drivers employed for 11–15 years (90.9%) in comparison to the remaining groups. Nervous system functional disorders were niejedcharacterized by the increased emotional irritability (47.6%), sleep disorders manifested by excessive sleepiness (33.3%) or insomnia (28.6%) and headaches (3%), mostly tension headaches. Excessive daytime sleepiness was significantly age-dependent (p = 0.038). Conclusions: The evidenced NS disorders indicate the need to undertake preventive measures tailored for the occupational group of bus drivers. Med Pr 2015;66(3):333–341

Impedance cardiography seems to be a very good, although underappreciated diagnostic method. What may distinguish it from among the many research methods is the fact that it enables non-invasive monitoring of cardiac output, stroke volume and systemic vascular resistance. Holter recording of the hemodynamic parameters makes it possible to study them not only in stationary (hospital, outpatient clinic) conditions, but also during household or professional activities, e.g., during road vehicle driving. Assessment of the trends of changes in the circulatory system of the employee at work makes it possible to judge whether the type of work performed by the worker is well tolerated – whether it is not too hard or too stressful. This is important, therefore, impedance cardiography can be extensively used in occupational medicine. Provision of preventive care to workers according to current standards requires, on the one hand, the use of the latest diagnostic methods while, on the other hand, the methods must be inexpensive, because otherwise the employer would not be able or willing to pay the associated costs. Impedance cardiography meets those criteria; however, few data is available in literature worldwide on the use of this method in the research on the impact of occupational work on cardiovascular responses of the employees. This work reports the use of impedance cardiography in studies on the various aspects of work environment.

Monitoring of cardiovascular hemodynamic changes requires a very expensive and highly specialized equipment and skilled medical personnel. Up to the present time, an inexpensive, non-invasive and easy-to-use method which, like Doppler echocardiography, magnetic resonance angiography or radionuclide imaging, would assess hemodynamics of the cardiovascular system was not available. A method known as impedance cardiography (ICG) or thoracic electrical bioimpedance cardiography (TEBC) meets those criteria. It is non-invasive, which is of a particular advantage over the conventional methods that require catheterization. As a result, the patient is not at risk of possible complications and the procedure is less expensive and easier. Impedance cardiography, despite its non-invasive character, has not been so far extensively used for monitoring of hemodynamic parameters in hospitalized patients. Various authors report that attempts have been continued to compare the results from ICG and those obtained by other diagnostic methods. This paper presents the use of impedance cardiography in diagnosis of hypertension, cardiac insufficiency, differentiating the causes of acute dyspnea, as well as in assessing the effects of cardiac rehabilitation in patients with heart failure.

Cardiopulmonary exercise testing is a method used to assess the exercise capacity. It is used in cardiology to define the diagnostic and prognostic information, the treatment and its effectiveness. This method is also useful in sport medicine and in occupational medicine. The cardiopulmonary exercise test involves measuring of gas exchange during exercise testing. The article presents the main parameters assessed during the test and the indications and contraindications for conducting the test. It also reveals the results of recently published clinical trials on the use of cardiopulmonary exercise test in patients with cardiovascular disease and in the working population. The study included variability of respiratory parameters during the cardiopulmonary exercise test and after its completion, as well as their impact on the prognostic value. In addition, the results of a study involving an optimal choice of interval training on the basis of oxygen consumption at peak exercise are summarized. Med Pr 2014;65(5):665–674

Objectives: To assess the type and incidence of subjective symptoms related to the use of mobile phones in Polish users. Material and Methods: The study was conducted in 2005 using a questionnaire survey. Although it has been quite a long time, up to now, no such data have been published for Poland. The questionnaire consisted of 53 questions concerning sex, age, education, general health, characteristics of a mobile phone (hand-held, loud-speaking unit) as well as the habits associated with its use (frequency and duration of calls, text messages, etc.) and complaints associated with using a mobile phone. Results: As many as 1800 questionnaires were sent. The response was obtained from 587 subjects aged 32.6±11.3 (48.9% women, 51.1% men); the age did not differ significantly between men and women. The subjects owned a cell phone for an average of 3 years. Majority of the respondents used the phone intensively, i.e. daily (74%) or almost daily (20%). Headaches were reported significantly more often by the people who talked frequently and long in comparison with other users (63.2% of the subjects, p = 0.0029), just like the symptoms of fatigue (45%, p = 0.013). Also, the feeling of warmth around the ear and directly to the auricle was reported significantly more frequently by the intensive mobile phone users, compared with other mobile phone users (47.3%, p = 0.00004 vs. 44.6%, p = 0.00063, respectively). Most symptoms appeared during or immediately after a call and disappeared within 2 h after the call. Continuous headache, persisting for longer than 6 h since the end of a call, was reported by 26% of the subjects. Conclusions: Our results show that the mobile phone users may experience subjective symptoms, the intensity of which depends on the intensity of use of mobile phones.

Background: The relative physical load (% VO2max) is the quotient of oxygen uptake (Vo2) during physical effort and maximum oxygen uptake (VO2max) by the human body. For this purpose the stress test must be performed. The relative load shows a high correlation with minute ventilation, cardiac output, heart rate, stroke volume, increased concentrations of catecholamines in the blood, inner temperature, weight, height and human body surface area. The relative load is a criterion for the maximum workloads admissible for healthy and sick workers. Besides, the classification of effort can be more precise when based on the relative load than on the energy output. Material and Methods: Based on our own and international empirical evidence and the laws of heat transfer and fluid mechanics, a model of temperature control system has been developed, involving the elements of human cardiovascular and respiratory systems. Using this model, we have been able to develop our own methods of determining the relative load, applying only the body core temperature (TW) or heart rate within one minute (HR), body mass (m), height (H), and body surface area (AD) instead of VO2max. Results: The values of the relative physical load (% VO2max) obtained by using our own methods do not differ significantly from those obtained by other methods and by other researchers. Conclusions: The developed methods for determining the relative physical load (% VO2max) do not require the exercise test to be performed, therefore, they may be considered (after verification in an experimental study) a feasible alternative to current methods. Med Pr 2014;65(2):189–195

Objectives: Epidemiological studies provide evidence that airborne particulate matter may contribute to the increased incidence and mortality rates due to pulmonary and cardiovascular diseases. Only some of them address the problem of occupational exposure to particulate air pollution. The aim of our study was to assess cardiovascular reaction and autonomic regulation in workers exposed to fine particles. Materials and Methods: All workers had medical examination, resting ECG with heart rate variability analysis (HRV), 24-h ECG, and ambulatory blood pressure monitoring (ABPM) performed. The subjects were 20 male workers (mean age: 32.14.0 year) of a ceramic ware factory exposed to the dust and 20 workers who were not exposed (mean age: 39.4±7.8 year). The period of employment under exposure amounted to 5.6±2.1 year. Dust exposure was measured using individual dosimeters. Results: The geometric mean total dust concentration was 44±1.5 mg/m3 and the FPD (fine particulate dust) concentration amounted to 11.5±1.6 mg/m3. No abnormalities were noted in the resting ECG in both groups, in 24-h ECG 2 subjects, both from exposed and control groups, had ventricular heart rhythm and repolarization disturbances. Blood pressure in ABPM, both systolic as well as diastolic, was normal and did not differ between the groups. Resting heart rate in the exposed group was significantly lower (p = 0.038) than in the control group. In the exposed group STD R-R from short-term records was significantly higher (p = 0.01). Fast Fourier Transform (FFT) analysis showed that the low frequency power spectrum (LF) did not differ in the exposed and the control group, while high frequency (HF) was significantly higher in the exposed group. LF/HF ratio was significantly lower in the exposed in comparison with the control group. Conclusions: Although we did not reveal significant abnormalities in ECG as well as in ABPM in the exposed group, it seems that neurovegetative disturbances (parasympathetic predominance) may serve as an early indicator of fine particulate dust effect on cardiovascular system.

Background: The aim of this work was to assess the load on the musculoskeletal system and its effects in the collectors of solid refuse. The rationale behind this study was to formulate proposals how to reduce excessive musculoskeletal load in this group of workers. Material and Methods: The study group comprised 15 refuse collectors aged 25 to 50 years. Data about the workplace characteristics and subjective complaints of workers were collected by the free interview and questionnaire. During the survey the photorecording of the workpostures, the distance and velocity by GPS recorders, measurements of forces necessary to move containers, energy expenditure (lung ventilation method), workload estimation using the Firstbeat system and REBA method and stadiometry were done. Results: The distance walked daily by the collectors operating in terms of 2 to 3 in urban areas was about 15 km, and in rural areas about 18 km. The most frequent musculoskeletal complaints concerned the feet (60% subjects), knees, wrists and shoulders (over 40% subjects). After work-shift all examined workers had vertebral column shorter by 10 to 14 mm (11.4 mm mean). Conclusions: The results of our study show that the refuse collectors are subjected to a very high physical load because of the work organization and the way it is performed. To avoid adverse health effects and overload it is necessary to undertake ergonomic interventions, involving training of workers to improve the way of their job performance, active and passive leisure, technical control of the equipment and refuse containers, as well as the renegotiation of contracts with clients, especially those concerning non-standard containers. Med Pr 2013;64(4):507–519

Background: Several studies have shown an association between work-related stress and risk factors for cardiovascular disease. However, only a few studies concerned the police. The aim of this study was to assess the relationship between the general and work-related stress, and the functioning of the circulatory system in the police staff. Material and Methods: The study group consisted of 126 policemen (aged 37.8±7.3 years), with average employment duration of 14.4±7 years. The study comprised the assessment of health status based on the medical examination and medical history of identified diseases, cardiovascular risk factors and symptoms, dietary habits, physical activity, intake of drugs, data on the family history, determinations of serum total cholesterol, HDL and LDL fractions, triglycerides, and fasting glycemia. The stress level was assessed using the Questionnaire for the Subjective Assessment of Work and Perceived Stress Scale. Results: On medical examination hypertension was found in 36% of the people under study. Chest discomfort was reported by 60% of the subjects. Average body mass index (BMI), serum cholesterol and LDL were elevated (22.7±4.1, 222.6±41.7 mg/dl and 142.7±39.7 mg/dl, respectively). Mean triglyceride, HDL fraction and fasting glucose levels were normal in the whole group. The levels of general and occupational stress were 34.9±4.8 and 128.0±33.3, respectively, being higher than in other occupational groups. In the group with the highest level of stress, there were significantly more people with circulatory problems (81%), drinking strong alcohol at least once a week (27%), working in a 3-shift system (40.5%) and working overtime (44%). Conclusions: The results show that the police are a group at high risk of developing cardiovascular diseases due to work-related stress. Med Pr 2013;64(3):335–348

Introduction: The paper reports the results of the determinations of UMTS EMF distributions in the driver's cab of motor vehicle simulators. The results will serve as the basis for future research on the influence of EMF emitted by mobile phones on driver physiology. Materials and Methods: Two motor vehicle driving simulators were monitored, while an EMF source was placed at the driver's head or on the dashboard of the motor vehicle driving simulator. For every applied configuration, the maximal electric field strength was measured, as were the values at 16 points corresponding to chosen locations on a driver's or passenger's body. Results: When the power was set for the maximum (49 mW), a value of 27 V/m was measured in the vicinity of the driver's head when the phone was close to the head. With the same power, when the phone was placed on the dashboard, the measured maximum was 15.2 V/m in the vicinity of the driver's foot. Similar results were obtained for the passenger. Significant perturbations in EMF distribution and an increase in electric field strength values in the motor vehicle driving simulator were also observed in comparison to free space measurements, and the electric field strength was up to 3 times higher inside the simulator. Conclusions: This study can act as the basis of future studies concerning the influence of the EMF emitted by mobile phones on the physiology of the driver. Additionally, the authors postulate that it is advisable to keep mobile phones at a distance from the head, i.e. use, whenever possible, hands-free kits to reduce EMF exposure, both for drivers and passengers.

Sight is the basic sense for drivers. Condition of the eye determines correct, comfortable and safe performance of the work as drivers. This article presents various factors influencing the sight condition. There are two groups of factors, external (environment, the kind and time of work, stress caused by work) and internal (systemic and local disorders). All these factors can reduce significantly visual functions, such as visual acuity, field of vision, color vision, strereoscopic vision, twilight vision and glare sensitivity. There are also presented actual requirements for drivers and causes of the car accidents in various age groups. Impairments in vision functions can be dangerous for both the driver and other road users. Med Pr 2013;64(3):419–425