Workers' exposure to electric fields during the task 'maintenance of an operating device of circuit breaker from a service platform' at 110-kV substations.

The objective of the study was to investigate occupational exposure to electric fields during the task 'maintenance of an operating device of circuit breaker from a service platform' at 110-kV substations. The aim was also to compare the results to Directive 2013/35/EU. At 16 substations, 255 electric field measurements were performed. The highest mean value of the electric fields was 9.6 kV⋅m-1. At 63% of substations the maximum values were over 10.0 kV⋅m-1, and at 31% of the substations the 75th percentiles were over 10.0 kV⋅m-1, which is the low action level (AL) according to Directive 2013/35/EU. All measured values were below the high AL (20.0 kV⋅m-1). In the future, it is important to take into account that the measurements were only taken at Finnish 110-kV substations; therefore, it is not possible to generalize these results to other countries and different types of substations.

Solar Radiation Exposure and Outdoor Work: An Underestimated Occupational Risk.

A considerably high number of outdoor workers worldwide are constantly exposed for the majority of their working life to solar radiation (SR); this exposure is known to induce various adverse health effects, mainly related to its ultraviolet (UV) component. The skin and the eye are the principal target organs for both acute and long-term exposure. Actinic keratosis, non-melanoma skin cancers, and malignant melanoma are the main long-term adverse skin effects, whereas in the eye pterygium, cataracts, and according to an increasing body of evidence, macular degeneration may be induced. Despite this, SR exposure risk is currently undervalued, if not neglected, as an occupational risk factor for outdoor workers. SR exposure is influenced by various environmental and individual factors, and occupation is one of the most relevant. For a better understanding of this risk and for the development of more effective prevention strategies, one of the main problems is the lack of available and adequate methods to estimate SR worker exposure, especially long-term exposure. The main aims of this review were to provide a comprehensive overview of SR exposure risk of outdoor workers, including the UV exposure levels and the main methods recently proposed for short-term and cumulative exposure, and to provide an update of knowledge on the main adverse eye and skin effects. Finally, we also outline here preventive interventions to reduce occupational risk.

Self-reported wrist and finger symptoms associated with other physical/mental symptoms and use of computers/mobile phones.

Recently, computer, mobile phone and Internet use has increased. This study aimed to determine the possible relation between self-reported wrist and finger symptoms (aches, pain or numbness) and using computers/mobile phones, and to analyze how the symptoms are specifically associated with utilizing desktop computers, portable computers or mini-computers and mobile phones. A questionnaire was sent to 15,000 working-age Finns (age 18-65). Via a questionnaire, 723 persons reported wrist and finger symptoms often or more with use. Over 80% use mobile phones daily and less than 30% use desktop computers or the Internet daily at leisure, e.g., over 89.8% quite often or often experienced pain, numbness or aches in the neck, and 61.3% had aches in the hips and the lower back. Only 33.7% connected their symptoms to computer use. In the future, the development of new devices and Internet services should incorporate the ergonomics of the hands and wrists.

Near Retirement Age (≥55 Years) Self-Reported Physical Symptoms and Use of Computers/Mobile Phones at Work and at Leisure.

The aim of this research is to study the symptoms and use of computers/mobile phones of individuals nearing retirement age (≥55 years). A questionnaire was sent to 15,000 Finns (aged 18-65). People who were ≥55 years of age were compared to the rest of the population. Six thousand one hundred and twenty-one persons responded to the questionnaire; 1226 of them were ≥55 years of age. Twenty-four percent of the ≥55-year-old respondents used desktop computers daily for leisure; 47.8% of them frequently experienced symptoms in the neck, and 38.5% in the shoulders. Workers aged ≥55 years had many more physical symptoms than younger people, except with respect to symptoms of the neck. Female daily occupational users of desktop computers had more physical symptoms in the neck. It is essential to take into account that, for people aged ≥55 years, the use of technology can be a sign of wellness. However, physical symptoms in the neck can be associated with the use of computers.

Peak exposures to main components of ash and gaseous diesel exhausts in closed and open ash loading stations at biomass-fuelled power plants.

Fly and bottom ashes are collected at power plants to reduce the environmental effects of energy production. However, handling the ashes causes health problems for operators, maintenance workers and truck drivers at the power plants. Hence, we evaluated ash loaders' peak inhalation exposures to the chemical components of ash and diesel exhausts in open and closed ash loading stations at biomass-fuelled combined heat and power plants. We also carried out chemical and morphological analyses of the ashes to evaluate their health hazard potential in order to find practical technical measures to reduce workers' exposure. On the basis of X-ray diffraction analyses, the main respirable crystalline ash compounds were SiO2, CaSO4, CaO, Ca2Al2SiO7, NaCl and Ca3Al2O6 in the fly ashes and SiO2, KAlSi3O8, NaAlSi3O8 and Ca2Al2SiO7 in the bottom ashes. The short-term exposure levels of respirable crystalline silica, inhalable inorganic dust, Cr, Mn, Ni and nitric oxide exceeded their Finnish eight hours occupational exposure limit values in the closed ash loading station. According to our observations, more attention should be paid to the ash-moistening process, the use of tank trucks instead of open cassette flatbed trucks, and the sealing of the loading line from the silo to the truck which would prevent spreading the ash into the air. The idling time of diesel trucks should also be limited, and ash loading stations should be equipped with exhaust gas ventilators. If working conditions make it impossible to keep to the OEL values, workers must use respirators and protect their eyes and skin.

Measuring Occupational Exposure to Extremely Low-Frequency Electric Fields at 220 kV Substations.

Earlier studies conducted at 400 and 110 kV substations in Finland have shown that the occupational exposure to electric fields can exceed the action levels (ALs) set by Directive 2013/35/EU. This is a case study investigating the level of occupational exposure experienced by workers at 220 kV substations in order to determine if the actions levels are being exceeded. The measurements were conducted at two old 220 kV substations in Finland. The higher AL of 20 kV m-1 was exceeded at both substations.

The biomechanical overload of the upper limb: a neglected occupational hazard in animal facility operators.

Data on biomechanical overload of the upper limb in animal facility operators are currently scanty. We decided to study this risk in a university animal facility. Eleven different tasks performed by operators were identified. For each of them, the biomechanical overload of the upper limb was evaluated by applying 4 different methods frequently used, hypothesising a task duration of 4 and 8 h. Then two 'typical' real working days of the examined facility were reconstructed, and the risk for operators was calculated using the OCRA Index, Checklist and Mini-Checklist. Considering the specific tasks, the results show some difference among methods, but the overall results show an acceptable/slight risk of biomechanical overload of the upper limb in animal facility operators during typical working days. Practitioner Summary: Upper limb biomechanical overload (UL-BO) is a neglected risk in animal facilities. In a university facility, 11 different tasks were identified, and 2 typical working days were analysed. Even if some task at increased risk may exist, during typical working days,  the overall results show that the risk of UL-BO in operators can be considered usually acceptable or, at worst, slight.

Self-Reported Ache, Pain, or Numbness in Feet and Use of Computers amongst Working-Age Finns.

The use of the computers and other technical devices has increased. The aim of our work was to study the possible relation between self-reported foot symptoms and use of computers and cell phones using a questionnaire. The study was carried out as a cross-sectional study by posting a questionnaire to 15,000 working-age Finns. A total of 6121 responded, and 7.1% of respondents reported that they very often experienced pain, numbness, and aches in the feet. They also often experienced other symptoms: 52.3% had symptoms in the neck, 53.5% in had problems in the hip and lower back, and 14.6% often had sleeping disorders/disturbances. Only 11.2% of the respondents thought that their symptoms were connected to the use of desktop computers. We found that persons with symptoms in the feet quite often, or more often, had additional physical and mental symptoms. In future studies, it is important to take into account that the persons with symptoms in the feet may very often have other symptoms, and the use of computers can influence these symptoms.

The Possibility of Decreasing 50-Hz Electric Field Exposure near 400-kV Power Lines with Arc Flash Personal Protective Equipment.

Various guidelines for the protection of human beings against possible adverse effects resulting from exposure to electromagnetic fields (EMFs) have been published with a view towards continual improvement; therefore, decreasing exposure is an important research area. The aim of this study was to investigate the possibility of decreasing electric field exposure with arc flash rated personal protective equipment (PPE), which in this case was a set of coveralls, and to compare the measurement results to calculations using the helmet-mask measuring system. We collected the data under a 400-kV power line. The test person stood on isolated aluminum paper, and the current between the ground and the aluminum paper was measured. When the test subject wore the arc flash PPE, the current to the ground was only 9.5% of the current measured when wearing normal clothes, which represents a clear decrease in exposure.

Subjective symptoms in Magnetic Resonance Imaging operators: prevalence, short-term evolution and possible related factors.

BACKGROUND: The number of Magnetic Resonance Imaging (MRI) operators is rapidly increasing. In these workers, a high prevalence of certain subjective symptoms has been described but until now scant research is available on this topic. OBJECTIVES: To assess the prevalence and the evolution of symptoms over time in a group of operators recently engaged in MRI, also considering the possible role played by factors such as age, gender and occupational stress. METHODS: In 17 physicians exclusively engaged in MRI - 6 working with 1.5 T scanners only and 11 with both 1.5 and 3T - subjective symptoms were evaluated at the beginning of MRI activity and after 2 months by using an ad hoc questionnaire. The questionnaire also included items on occupational stress. RESULTS: At the start of MRI activity, 81% of the subjects reported at least one of the investigated symptoms; after 2 months, 85% of the symptomatic operators reported the regression of one or more symptoms. In operators with high exposure (1.5 and 3 T scanners), the mean number of symptoms tended to be higher compared with those with lower exposure (1.5 T only), and the reduction after 2 months was significantly greater. In the whole group, occupational stress was significantly correlated with the total number of symptoms and to some of the symptoms more specifically. As stress did not differ between highly- and lowly- exposed, there is no reason to assume an influence on the observed differences in the prevalence and reduction of symptoms. CONCLUSIONS: Our data suggest that MRI operators may experience various symptoms at the beginning of activity, rapidly reversible in a few weeks. The trend over longer periods deserves further study. Occupational stress may play a role in symptoms. The duration of previous MRI work (particularly short-term) as well as work-related stress should be adequately addressed in future studies on subjective symptoms in operators.

Current densities and total contact currents during forest clearing tasks under 400 kV power lines.

The aim of the study was to analyze all values of electric currents from measured periods while performing tasks in forest clearing. The objective was also to choose and analyze measurement cases, where current measurements successfully lasted the entire work period (about 30 min). Two forestry workers volunteered to perform four forest clearing tasks under 400 kV power lines. The sampling frequency of the current measurements was 1 sample/s. The maximum values of the current densities were 1.0-1.2 mA/m(2) (calculated internal EFs 5.0-12.0 mV/m), and the average values were 0.2-0.4 mA/m(2) . The highest contact current was 167.4 µA. All measured values during forest clearing tasks were lower than basic restrictions (0.1 V/m and 0.8 V/m) of the International Commission on Non-Ionizing Radiation Protection. Bioelectromagnetics. 37:423-428, 2016. © 2016 The Authors. Bioelectromagnetics published by Wiley Periodicals, Inc.

Simple estimation of induced electric fields in nervous system tissues for human exposure to non-uniform electric fields at power frequency.

Most results regarding induced current in the human body related to electric field dosimetry have been calculated under uniform field conditions. We have found in previous work that a contact current is a more suitable way to evaluate induced electric fields, even in the case of exposure to non-uniform fields. If the relationship between induced currents and external non-uniform fields can be understood, induced electric fields in nervous system tissues may be able to be estimated from measurements of ambient non-uniform fields. In the present paper, we numerically calculated the induced electric fields and currents in a human model by considering non-uniform fields based on distortion by a cubic conductor under an unperturbed electric field of 1 kV m(-1) at 60 Hz. We investigated the relationship between a non-uniform external electric field with no human present and the induced current through the neck, and the relationship between the current through the neck and the induced electric fields in nervous system tissues such as the brain, heart, and spinal cord. The results showed that the current through the neck can be formulated by means of an external electric field at the central position of the human head, and the distance between the conductor and the human model. As expected, there is a strong correlation between the current through the neck and the induced electric fields in the nervous system tissues. The combination of these relationships indicates that induced electric fields in these tissues can be estimated solely by measurements of the external field at a point and the distance from the conductor.

Occupational exposure to electric and magnetic fields during tasks at ground or floor level at 110†kV substations in Finland.

The aim was to investigate occupational exposure to electric and magnetic fields during tasks at ground or floor level at 110 kV substations in Finland and to compare the measured values to Directive 2013/35/EU. Altogether, 347 electric field measurements and 100 magnetic field measurements were performed. The average value of all electric fields was 2.3 kV/m (maximum 6.4 kV/m) and that of magnetic fields was 5.8 µT (maximum 51.0 µT). It can be concluded that the electric and magnetic field exposure at ground or floor level is typically below the low action levels of Directive 2013/35/EU. The transposition of the directive will not create new needs to modify the work practice of the evaluated tasks, which can continue to be performed as before. However, for workers with medical implants, the exposure may be high enough to cause interference.

Possible Influences of Spark Discharges on Cardiac Pacemakers.

Exposure to spark discharges may occur beneath high voltage transmission lines when contact is initiated with a conductive object (such as a motor vehicle) with the spark discharge mediated by the ambient electric field from the line. The objective of this study was to assess whether such exposures could interfere with the normal functioning of implanted cardiac pacemakers (PMs). The experiment consisted of PMs implanted in a human-sized phantom and then exposed to spark discharge through an upper extremity. A circuit was designed that produced spark discharges between two spherical electrodes fed to the phantom's left hand. The circuit was set to deliver a single discharge per half cycle (every 10 ms) about 10 µs in duration with a peak current of 1.2-1.3 A, thus simulating conditions under a 400-kV power line operating at 50 Hz. Of 29 PMs acquired, all were tested in unipolar configuration and 20 in bipolar configuration with exposure consisting of 2 min of continuous exposure (one unit was exposed for 1 min). No interference was observed in bipolar configuration. One unit in unipolar configuration incorrectly identified ventricular extra systoles (more than 400 beats min(-1)) for 2 s. The use of unipolar configuration in new implants is extremely rare, thus further minimizing the risk of interference with the passage of time. Replication of this study and, if safety for human subjects can be assured, future testing of human subjects is also advisable.

Self-reported depression and anxiety symptoms and usage of computers and mobile phones among working-age Finns.

The aim of the work is to study self-reported depression and anxiety symptoms among working-age Finns using logistical regression models. The study was carried out as a cross-sectional study by posting a questionnaire to 15,000 working-age persons. The responses (6121) revealed that 101 (1.7%) Finnish working-age persons suffered depression very often and 77 (1.3%) suffered anxiety very often during the last 12 months. Symptoms uncovered in the comparative analysis of respondents who had quite often or more often depression to respondents who had less depression showed differentiation. The same result was obtained in the analysis of self-reported anxiety symptoms. With the logistical regression models (from depression and anxiety), we found associations between physical symptoms (in shoulder) and depression and between different mental symptoms and anxiety or depression. In the future, it is important to take into accout that persons with physical symptoms can also have mental symptoms (depression or anxiety).

Cardiac pacemakers in magnetic fields of a shunt reactor at a 400†kV substation.

The use of cardiac pacemakers (PMs) increases in Western countries. The aim of the study is to investigate cardiac pacemakers (PMs) using a human-shaped phantom in magnetic fields of a shunt reactor at a 400 kV substation. We performed seven PM experiments using a phantom. Two locations close to the shunt reactors were chosen. The magnetic field exposure was over 1000 µT in one location and over 600 µT in the other one. The magnetic field exposure did not disturb the tested five different PMs (in unipolar or bipolar configurations). It can be stated that in our experiment, the magnetic field exposure (over 600 µT and over 1000 µT) did not disturb the PMs (in unipolar or bipolar configurations). Since we only studied some PMs, it is possible that the magnetic field exposure at 400 kV substations can cause disturbances to other PMs. However, the risk of disturbances does not seem to be high.

Examples of occupational exposure to electric and magnetic fields at 110-kV gas-insulated substations (GISs).

The objectives of the study were to present examples of occupational exposure to electric and magnetic fields at gas-insulated substations (GISs) and to analyse the exposure according to the new European Directive 2013/35/EU. The aim was also to describe the details of the measurements of this study at GISs. Electric and magnetic fields were measured (45 measurements in total) at two GISs in the Tampere region of Finland. Inside the GISs, magnetic field values varied from 0.4 to 43.0 µT, and electric fields from 5 to 90 V m(-1). In the cable room of GIS B, the maximum value was 250 µT (very near the cables). The values did not exceed the low or high action levels of the new Directive 2013/35/EU. In conclusion, it can be stated that at 110-kV GISs, workers are not exposed to electromagnetic fields (EMFs) higher than the new European Directive 2013/35/EU.

Current densities and total contact currents for 110 and 220 kV power line tasks.

The aim of this study was to analyze all values of electric current from measured periods while performing tasks on 110 and 220 kV power lines. Additionally, the objective was to study the average current densities and average total contact currents caused by electric fields in 110 and 220 kV power line tasks. One worker simulated the following tasks: (A) tested insulation voltage at a 110 kV portal tower, (B) checked the wooden towers for rot at a 110 kV portal tower, (C) tested insulation voltage at a 220 kV portal tower, and (D) checked the wooden towers for rot at a 220 kV portal tower. The highest average current density in the neck was 2.0 mA/m(2) (calculated internal electric field was 19.0-38.0 mV/m), and the highest average contact current was 234 µA. All measured values at 110 and 220 kV towers were lower than the basic restrictions (0.1 and 0.8 V/m) of the International Commission on Non-ionizing Radiation Protection.

Upper limb musculoskeletal disorders in healthcare personnel.

The literature on upper limb musculoskeletal disorders (UL-MSD) in different groups of healthcare workers was reviewed: 65 relevant studies were collected. In dentists, the neck was the most frequently affected segment, with prevalences up to 73% and exceeding 50% in 7 out of 12 studies. In dental hygienists and in laboratory technicians, the hand/wrist had the highest prevalence in the majority of the studies. In nurses, the most seriously affected anatomic sites were the neck and shoulders. Physiotherapists had the lowest prevalence of UL-MSD. A high prevalence of upper limb disease, mainly carpal tunnel syndrome, was reported in dentists, dental hygienists, anesthesia nurses and endoscopists. The high prevalence of upper limb disorders/diseases reported in health personnel supports the hypothesis of a significant risk in these workers. However, the possible role of biomechanical overload, as much as that of stress or other personal factors, cannot be currently assessed. Practitioner Summary: Published studies support the hypothesis of a significant risk of upper limb musculoskeletal disorders in healthcare activities. The neck was the most frequently affected segment in dentists, the hand/wrist in dental hygienists and in laboratory technicians, and the neck and shoulders in nurses. Lower prevalence was reported in physiotherapists. A high prevalence of carpal tunnel syndrome was also observed in various healthcare activities.

Comparison of electric field exposure measurement methods under power lines.

The object of the study was to investigate extremely low frequency (ELF) electric field exposure measurement methods under power lines. The authors compared two different methods under power lines: in Method A, the sensor was placed on a tripod; and Method B required the measurer to hold the meter horizontally so that the distance from him/her was at least 1.5 m. The study includes 20 measurements in three places under 400 kV power lines. The authors used two commercial three-axis meters, EFA-3 and EFA-300. In statistical analyses, they did not find significant differences between Methods A and B. However, in the future, it is important to take into account that measurement methods can, in some cases, influence ELF electric field measurement results, and it is important to report the methods used so that it is possible to repeat the measurements.