Agata Szyjkowska

Subjective complaints of people living near mobile phone base stations in Poland

ObjectivesThe aim of our study was to assess the health conditions and subjective symptoms of the inhabitants living in the base stations vicinity and to analyse the relationship between the complaints and level of exposure to electromagnetic fields (EMF).Materials and MethodsOur study was performed in housing estates located in five regions of Łódź. The electric field measurements were performed in the buildings located closest to the azimuth of the antennas. Respondents were selected by trained interviewers using an uniform procedure. The number of the households to be examined was set at a minimum of 420. The questionnaire contained: demographic data, occupational and environmental exposure to EMF, health condition, subjective complaints. Results were adjusted for confounders (age, gender, EMF at the workplace and EMF emitted by household equipment) using multiple regression model.Results181 men and 319 women from 500 households were examined. Electric field above 0.8 V/m was recorded in 12% of flats. There was no significant correlation between electric field strength and the distance of examined flats from the base stations. To make possible comparison with relevant literature, we analysed also the frequency of the reported symptoms vs. the distance. Headache was declared by 57% people, most frequently (36.4%) living 100–150 m away from the base station compared to people living at longer distances (p = 0.013). 24.4% subjects, mostly living at a distance above 150 m, declared impaired memory. Difference was statistically significant in comparison with people living at other distances (p = 0.004).ConclusionsThe explanation why we did not find any correlation between the electric field strength and frequency of subjective symptoms but found a correlation between subjective symptoms and distance from base station needs further studies. Maybe new metrics of exposure assessment should be adopted for this purpose.

The risk of subjective symptoms in mobile phone users in Poland – An epidemiological study

ObjectivesTo assess the type and incidence of subjective symptoms related to the use of mobile phones in Polish users.Material and MethodsThe 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.ResultsAs 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.ConclusionsOur results show that the mobile phone users may experience subjective symptoms, the intensity of which depends on the intensity of use of mobile phones.

WORK-RELATED RISK FACTORS OF MYOCARDIAL INFARCTION

OBJECTIVES The aim of the study was to find out which occupational factors account for the risk of the myocardial infarction. MATERIAL AND METHODS A questionnaire survey was performed during the period of one calendar year in all patients (1053 subjects, 692 men and 361 women) hospitalized at the Medical University of Łódź because of the first myocardial infarction. The questionnaire was prepared especially for the purpose of this study and consisted of two parts. The first part comprised: demographic data, health status at admittance, traditional risk factors for the ischaemic heart disease and was filled-in by physicians. Part II was done by occupational hygiene specialists and referred to education, job title and characteristics, employment data, self assessment of work-related and general stress, fatigue, socio-economic status, physical activity, alcohol intake, tobacco smoking, dietary habits. RESULTS Mean age in the study group was 59.9 ± 10.4 years (26-85 years), 58.7 ± 10.0 (26-84 years) for men and 62.3 ± 10.7 (32-85 years) for women, employment duration was 32.9±8.8 (4-65 years), for men 34.0 ± 8.6 (5-65 years), for women 30.7 ± 8.8 (4-60 years. Most of myocardial infarction cases both in the group of men and women were noted in the age interval 56-60 years, 22.3% vs. 17.4%, respectively. The majority of examined men were farmers, low and middle management and self-employed workers. Among women prevailed clerks, seamstresses and farmers. The most frequent occupational risk factors were: work-related stress, experienced by 54.2% of the examined subjects, occupational noise (45,5%), dust (41,7%) and various chemical factors (33%). A majority of the study group (76.5% women and 54.4% men) linked the cardiac infarction with stress, while 39.1% men vs. 16.5% women correlated it with physical effort. CONCLUSION Our studies indicate that, among a wide spectrum of occupational factors, stress, noise and fine particulate dust are major contributors to the increased risk of myocardial infarction.

Cardiovascular changes in workers exposed to fine particulate dust

ObjectivesEpidemiological 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 MethodsAll 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.ResultsThe 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.ConclusionsAlthough 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.

1244 Electroencephalographic studies among drivers before and after test on bus simulator

Introduction The aim of the study was to evaluate the effect of the test on the simulator on the bioelectric activity of the brain of professionally active drivers. Methods Electroencephalography registration was performed with the 32-channel recorder. Electrodes locations were specified by the International 10–20 system. The records were performed before the start of the test on the simulator, which enables full simulation of real road conditions (Exam I) and after its completion (Exam II). A recording was performed, with eyes closed, for 30 min. At 2,5,6,23,25 min of the test, the eye was opened and closed, at the 8th min. – a test of deep breathing (hyperventilation test – 3 min) and intermittent photic stimulation. We used stimulation with frequencies of 3, 6, 9, 12, 15, 18, 21, 24, 27, 30 Hz and back. 45 subjects were enrolled to study. All subjects were bus drivers aged 31–58 years (43.5±7.9 years), seniority as a bus driver of 13.3±8.6 years. The frequency and amplitude of the basic activity of the brain was analysed and compared between left and right homologous EEG channels in Exam I and II. Results The basic activity brain parameters were analysed at rest, 2–3 min hyperventilation and after activation attempts. In the Exam I hyperventilation revealed a statistically significant difference between basic rhythm frequencies (p=0.043). In the left-side channels, the mean value was significantly higher than in the right-side channels (10.49±1.34 vs 10.30±1.19), the difference was not observed in the Exam II (10.46±1.66 vs 10.29±1.64, p=0.397). Discussion This difference could not be explained by the physiological response to hyperventilation. There were no differences between the baseline rhythm recorded at rest at both the first and second test. The explanation of these results requires further studies.

335 Eye-tracking as a method for evaluation of the driver’s visual strategy

Introduction One of the most important parameters of interest in the study of drivers on the driving simulator is the oculometric data obtained during driving. Using this method we have a direct view of the driver’s eye path and ability to analyse it. The purpose of the study was to trace the places where the driver’s eyes focus when driving on a bus simulator. Materials and methods The study was conducted in a group of randomly selected 45 city bus drivers. Thanks to the use of appropriate infrared cameras, scene cameras and specialised software, data has been obtained and selected using special programs and statistical analysis. By collecting this data we are able to analyse the driver’s eye-path in different situations on the road (urban driving, off-road driving, and stress-based driving). Methods FaceLab was used to track the visual path with infrared cameras. We also use scene cameras and Eyeworks (Record, Analyse) and Captive programs. These programs enabled the visual path to be taken in the form of saccades and fixations applied to a video file with recorded driving data and data from the simulator. Then the image from the scene camera (what the driver saw) was divided into regions (areas in front of the driver’s eye or side mirror surfaces) so it was possible to analyse the individual regions of all the drivers taking part in the experiment. Results The driver during 28.77% of the driving time on the simulator focused on the area of the road directly in front of the vehicle and on the right-hand mirror it was 2.27% of the driving time. Discussions The obtained data confirm that the driver is most likely to look at the road ahead and the area surrounding the right mirror (which is affected by stops at the bus stops).

Effect of stress and intesity of mobile phone using on the health and subjective symptoms in GSM workers

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.