[Aggravating factors in teachers' work and fatigue]. / Czynniki obciazajace w pracy nauczycieli a zmeczenie.

BACKGROUND: Teachers are a occupational group in which, due to the type and specificity of work, it can be expected that the feeling of fatigue will be very intense. However, there has been little research into this problem. The aim of the research was to assess the level of fatigue after work and chronic fatigue in teachers, and to determine whether and to what extent it depends on occupational and non-occupational loads. MATERIAL AND METHODS: The stratified sampling model was used to select the sample, where the layers were the type of school and its location (size of a town/city). All teachers from selected schools were invited to participate. Overall, 650 questionnaires were distributed and 403 teachers returned completed questionnaires. Fatigue after work was assessed on the basis of answers to the following question: "Do you feel tired after work?" and chronic fatigue using the Fatigue Assessment Scale. A special questionnaire was developed to assess other factors that might affect the level of fatigue. The Subjective Stress Assessment at Work Questionnaire, Cohen's Perceived Stress Scale, a part of the Questionnaire of Professional Loads of the Teacher and a list of additional factors disturbing the work were used. RESULTS: The study involved 70 men aged 35-63 years and 333 women (24-64 years). The groups did not differ significantly in terms of mean age. The level of fatigue, regardless of gender, was mostly influenced by time pressure, rush, mismanagement of the pace of work to individual abilities, increasing workload, an excess of responsible tasks, a lack of support from superiors, a low prestige of the profession, a lack of pedagogical successes, a sense of the lack of meaning in work, and the negative impact of work on family life, as well as non-occupational loads and insufficient rest. CONCLUSIONS: The conducted study allowed for determining the profile and frequency of occupational and non-occupational factors affecting the level of fatigue in teachers. Med Pr. 2021;72(3):283-303.

Acetabular shape and orientation of the spastic hip in children with cerebral palsy.

AIM: To see if three-dimensional (3D) methods could bring new understanding to acetabular changes in shape and orientation in the spastic hip and in which direction(s) acetabular orientation might change, which is crucial for planning appropriate hip correction surgery. METHOD: We performed a retrospective study of pelvic computed tomography (CT) examinations in 20 consecutive patients (10 females, 10 males). The mean age of patients was 12 years 9 months (SD 2y; range: 9-16y) at the time of the CT examination. The control group consisted of 18 consecutive pelvic CT examinations (36 acetabula) of deceased individuals (six females, 12 males) aged 4 to 17 years (mean age: 10y 6mo; SD 5y 2mo) whose whole-body CT scans were taken shortly after their death. We compared 3D CT reconstructions of 28 unstable and dislocated hips in children with bilateral cerebral palsy (Gross Motor Function Classification System levels IV and V) with the unaffected side and typically developing controls to assess spatial orientation (inclination, anteversion, and tilt), acetabular volume, and surface area. Additionally, we analysed the multiple factors that may lead to structural and spatial changes of the acetabulum. RESULTS: Patients with dislocated and spastic hips had significantly lower anteversion (-3.2° and -1.4° respectively, p<0.001), increased inclination (85.2° and 85.3° respectively, p<0.001), and decreased tilt (24.6° [p=0.014] and 20.7° [p=0.013] respectively) compared with typically developing individuals. Regarding acetabular volume and surface area, dislocated and unstable hips had significantly lower volume (17.6ml vs 31.5ml respectively, p<0.001) and surface area (28.9cm2 vs 36.2cm2 respectively, p<0.001) than unaffected hips. Among several factors, only Reimer's migration index had an influence on acetabular orientation (i.e. anteversion, p=0.01), volume (p<0.001), and surface (p=0.004). INTERPRETATION: Acetabula in patients with spastic hip disease were severely retroverted with increased steepness; acetabular orientation was distorted superoposteriorly. In rare cases, acetabular orientation was distorted only superiorly or superoanteriorly. WHAT THIS PAPER ADDS: Acetabular orientation was distorted superoposteriorly in most patients with severe bilateral cerebral palsy. More pronounced acetabular changes were found in hips with a higher Reimer's migration index.

[The reaction of the circulatory system to stress and electromagnetic fields emitted by mobile phones - 24-h monitoring of ECG and blood pressure]. / Reakcja ukladu krazenia na stres i pole elektromagnetyczne emitowane przez telefony komórkowe ­ 24-godzinne monitorowanie EKG i cisnienia tetniczego.

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.

Analysis of bus drivers reaction to simulated traffic collision situations - eye-tracking studies.

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.

Radial Extracorporeal Shockwave Therapy and Ultrasound Therapy in the Treatment of Tennis Elbow Syndrome.

BACKGROUND: Both ultrasound and radial shockwave therapies are used to treat tennis elbow syndrome. The aim of this study was to compare the therapeutic efficacy of both therapies by assessing the reduction in pain intensity and frequency, restoration of mobility, and reduction in the need for pain medication. MATERIAL AND METHODS: The study enrolled 60 people, who were randomly divided into two groups of 30 patients: those treated by radial shockwave therapy and those treated by ultrasound therapy. Radial shockwave therapy consisted of 3 sessions at weekly intervals. Ultrasound therapy consisted of 10 treatments performed daily. The clinical status of the patients before treatment, just after treatment, and after 8 weeks was assessed with the Leitinen questionnaire and a visual analogue scale (VAS). RESULTS: Pain reduction, as assessed by VAS scores, was observed in both groups, who were not different at baseline (p=0.807). While both therapies were effective (p<0.005), mean pain intensity assessed by VAS scores in patients treated by radial shockwave therapy was significantly lower compared to those treated by ultrasound therapy; this relationship was present just after treatment completion (p=0.001) and at 8 weeks after treatment completion (p=0.002). CONCLUSIONS: 1. Both radial shockwave and ultrasound therapies cause a reduction in the intensity and frequency of pain that persists for at least 8 weeks, reducing the need for pain medication and improving the function of the treated upper limb. 2. Ultrasound therapy is less effective than radial shockwave therapy.

[Prevention of cardiovascular diseases - Prophylactic program in a selected enterprise]. / Zapobieganie chorobom ukladu krazenia ­ program profilaktyczny wdrozony w wybranym przedsiebiorstwie.

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.

[Effect of stress and intesity of mobile phone using on the health and subjective symptoms in GSM workers]. / Wplyw stresu i intensywnosci rozmów przez telefon komórkowy na stan zdrowia i dolegliwosci subiektywne pracowników sieci GSM.

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.

Mobile phone use and risk for intracranial tumors and salivary gland tumors - A meta-analysis.

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.

[Neurological symptoms and syndromes in municipal transport drivers]. / Objawy i zespoly neurologiczne u kierowców pojazdów komunikacji miejskiej.

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 characterized 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.

Health risk to medical personnel of surgical smoke produced during laparoscopic surgery.

OBJECTIVES: During laparoscopic cholecystectomy, the removal of the gall bladder, pyrolysis occurs in the peritoneal cavity. Chemical substances which are formed during this process escape into the operating room through trocars in the form of surgical smoke. The aim of this study was to identify and quantitatively measure a number of selected chemical substances found in surgical smoke and to assess the risk they carry to medical personnel. MATERIAL AND METHODS: The study was performed at the Maria Sklodowska-Curie Memorial Provincial Specialist Hospital in Zgierz between 2011 and 2013. Air samples were collected in the operating room during laparoscopic cholecystectomy. RESULTS: A complete qualitative and quantitative analysis of the air samples showed a number of chemical substances present, such as aldehydes, benzene, toluene, ethylbenzene, xylene, ozone, dioxins and others. CONCLUSIONS: The concentrations of these substances were much lower than the hygienic standards allowed by the European Union Maximum Acceptable Concentration (MAC). The calculated risk of developing cancer as a result of exposure to surgical smoke during laparoscopic cholecystectomy is negligible. Yet it should be kept in mind that repeated exposure to a cocktail of these substances increases the possibility of developing adverse effects. Many of these compounds are toxic, and may possibly be carcinogenic, mutagenic or genotoxic. Therefore, it is necessary to remove surgical smoke from the operating room in order to protect medical personnel.

Testicular effect of a mixture of 2-methoxyethanol and 2-ethoxyethanol in rats.

BACKGROUND: 2-Methoxyethanol (ME) and 2-ethoxyethanol (EE) represent a large group of chemicals which are used separately or as mixtures. These compounds exert multidirectional toxic effects. The present studies aimed to demonstrate the effects of ME and EE alone and their mixture on the reproductive organs in the rats. METHODS: Male Wistar rats were treated subcutaneously with ME and EE alone (1.25-5.0mM/kg/day) or with their mixture (1:1) for 4 weeks. After completion of the experiment, the testes, epididymides, and prostate were weighed. In post-mitochondrial supernatant of the testes, the level of total protein, non-protein and protein sulfhydryl groups, malondialdehyde, total antioxidant status, and glutathione peroxidase and glutathione reductase activities were determined. RESULTS: Exposure to ME alone resulted in a dose-dependent decrease in the organ weights, the total protein, non-protein and protein sulfhydryl groups. EE alone led to less marked alterations. Co-exposure to ME and EE caused alterations similar as in the rats treated with ME alone. CONCLUSIONS: Marked testicular atrophy, decrease in epididymis and prostate weights are predominant effects of the repeated exposure to relatively low doses of ME and EE. A decrease in the total protein level, and protein sulfhydryl groups may be responsible for testicular atrophy. A significant depletion of non-protein sulfhydryl groups and occasionally elevated glutathione peroxidase activity may indicate that ME and EE resulted in disturbances of pro-oxidant/antioxidant balance. The study suggests that testicular toxicity in male rats co-exposed to ME and EE is mainly caused by the former compound.

Selected factors determining a way of coping with stress in type 2 diabetic patients.

OBJECTIVES: The aim of the study was to examine factors which determine stress coping styles in type 2 diabetic (T2D) patients, with regard to selected demographic variables, clinical diabetes-related variables and selected psychical variables (anxiety level and assessment of depressive disorders). METHODS: 50 T2D patients, aged 59.9 ± 10.2 years were assessed by Coping Inventory for Stressful Situations (CISS), Spielberger State-Trait Anxiety Inventory (STAI), and Beck Depression Inventory (BDI). In the statistical analysis simple and multivariable logistic regression models were used. RESULTS: Variables significantly increasing the selection risk of stress coping style different from preferred task-oriented strategy in a simple logistic regression model are: hypoglycemia within three months prior to the research: odds ratio (OR) = 6.86 (95% confidence interval (CI) 1.25-37.61), taking antidepressants or neuroleptics: OR =15.42 (95% CI 2.42-98.33), severe depression in Beck's scale: OR = 84.00 (95% CI 6.51-1083.65), high state-anxiety level: OR = 9.60 (95% CI 1.08-85.16), and high trait-anxiety level: OR = 18.40 (95%CI 2.96-114.31), but in a multivariable model, diagnosed depression is the strongest factor: OR = 32.38 (95% CI 4.94-212.13). CONCLUSIONS: In T2D patients, the strategy to cope with stress appears to be mostly influenced by psychical predisposition.

The risk of subjective symptoms in mobile phone users in Poland--an epidemiological study.

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.

Cardiovascular changes in workers exposed to fine particulate dust.

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/m(3) and the FPD (fine particulate dust) concentration amounted to 11.5±1.6 mg/m(3). 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.

[Cardiovascular risk factors and life and occupational stress among policemen]. / Czynniki ryzyka chorób ukladu krazenia (CVD) a stres zyciowy i zawodowy u policjantów.

BACKGROUND: Several studies have shown an association between work-related stress and risk factors for cardiovascular disease. ever, 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 LDI, 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 34.914.8 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.

Heart rate variability (HRV) analysis in radio and TV broadcasting stations workers.

OBJECTIVES: The aim of the study was to assess the mechanism of cardiovascular impairments in workers exposed to UHF-VHF radio frequency electromagnetic fields (EMF). MATERIALS AND METHODS: Heart rate variability (HRV) was analysed using 512 normal heart beats registered at rest. The analysis concerned time-domain (STD R-R) and frequency-domain (VLF, LF, HF) parameters of HRV. Fifty nine workers (group I) with low-level and 12 workers (group II) with high-level exposure were examined. The mean age of the subjects was 47 ± 9 years and 41 ± 14 years, and mean exposure duration 19.1 ± 8.8 years and 13 ± 4 years, in groups I and II, respectively. The groups were divided according to: E(max), E(dose), E(mean) for frequencies UHF, VHF and UHF+VHF: The control group consisted of 42 non-exposed subjects, aged 49 ± 8 years. Statistical analysis comprised one-way analysis of variance, covariance analysis and logistic regression models. RESULTS: In the exposed groups, the heart rate was higher than in the control one. Standard deviation of R-R intervals (STD R-R) was found to be significantly (p = 0.0285) lower in group I (42.5 ± 24.7 ms) compared to the control group (62.9 ± 53.5 ms). The risk of lowered STD R-R was significantly increased (OR = 2.37, p = 0.023) in group II. Both exposed groups presented significantly higher VLF and LF values than the control group (p = 0.005 and p = 0.0025, respectively). The EMF-exposed groups were characterised by the dominance of the sympathetic system (LF/HF 1.3 ± 0.35). CONCLUSIONS: The results indicate that exposure to radiofrequency EMF may affect the neurovegetative regulation.

Hematological effects of exposure to mixtures of selected ethylene glycol alkyl ethers in rats.

Exposure to various ethylene glycol monoalkyl ethers (EGAEs) is known to result in hemolytic effect caused by their metabolites, appropriate alkoxyacetic acids, generated via both alcohol dehydrogenase and aldehyde dehydrogenase. It has been shown in many studies that administration of single doses of EGAEs to rats lead to dose- and time-dependent hemolytic anemia. The repeated exposure to isopropoxyethanol (IPE), and butoxyethanol (BE), contrary to methoxyethanol (ME) and ethoxyethanol (EE), resulted in significantly less pronounced hematological changes. While the majority of hematological effects were dramatic at the beginning of the exposure, later these changes clearly regressed despite continued weekly exposure to these ethers. The gradual recovery from the hemolytic anemia may be associated with tolerance development to the hemolytic effect of IPE and BE. ME demonstrated high hematotoxicity, which increased progressively and reached a maximum at the end of 4 week exposure, whereas EE revealed moderate hematological effects. It might be suspected that ME and EE may modified of IPE hemolytic activity in rats simultaneously treated with these compounds. In the rats co-exposed to IPE and ME subcutaneously at a relatively low doses of 0.75 mM + 0.75 mM for 4 weeks, a significantly less pronounced hematological changes at the beginning of the exposure in comparison with animals treated with IPE (0.75 mM) alone were observed. At the later period, i.e., at the end of 4 weeks exposure, the hematological alterations in the same animals were markedly pronounced and progressively elevated with exposure time, except for mean corpuscular volume (MCV) values, which were significantly lower in comparison with IPE group. ME at the higher dose of 1.25 mM/kg and EE at both doses of 0.75 and 1.25 mM/kg did not modify the hematotoxicity of IPE (at doses of 0.75 mM and 1.25 mM) at the beginning of the exposure, whereas increased its harmful effects at the end of the treatment. The amelioration in the majority of the hematological parameters at the beginning of the exposure may be caused by inhibitory effect of ME on IPE metabolism. On the contrary, an accumulation of the methoxyacetic acid and ethoxyacetic acid, toxic metabolites of ME and EE, respectively, and no tolerance development to the hemolytic effect of these two chemicals may be responsible for elevated hematological alterations at the end of the exposure.

Changes in tympanic temperature during the exposure to electromagnetic fields emitted by mobile phone.

OBJECTIVE: Mobile phones generate microwave radiation which is absorbed by exposed tissue and converted into heat. It may cause detrimental health effects. The aim of the experiment was to check if exposure to EMF emitted by mobile phone influenced the tympanic temperature. MATERIAL AND METHODS: Human volunteer study was performed on ten healthy young men, aged 22.1±4.7 years, examined three times: 1. on a day with 2×60 min of no exposure (sham day), 2. on a day with continuous, 60 min exposure and 60 min of no exposure, 3. on a day with intermittent exposure (4×15 min "on" and 4×15 min "off"). Exposure was generated by mobile phone (frequency 900 MHz, SAR 1.23 W/kg). The study was double-blind, performed under controlled conditions (at 24°C and 70% humidity). The tympanic temperature (T(ty)) was monitored every 10 sec by a thermistor probe placed close to the aural canal membrane in the ear opposite the one in contact with mobile phone (contralateral position). Multivariate repeated-measures analysis of variance was used to calculate the results. RESULTS: The mean T(ty) in the whole group during continuous exposure was significantly higher than during sham exposure (p = 0.0001). During intermittent exposure the temperature was lower than during sham day (difference was up to 0.11°C). Within an hour after continuous exposure, T(ty) was higher by 0.03°C and after intermittent exposure T(ty) was lower by 0.18°C in comparison with sham day. Two hours after exposure T(ty) was significantly lower (p = 0.0001) than after sham exposure (0.06°C and 0.26°C respectively). The trends in T(ty) during experiment differed significantly in relation to exposure conditions (p < 0.05). CONCLUSIONS: The results of this analysis indicate that the physiological response to EMF exposure from mobile phone was mostly related to type of exposure (continuous or intermittent).

Behavioral effects following repeated exposure to hexachloronaphthalene in rats.

Polychlorinated naphthalenes (PCNs), including hexachloronaphthalene (HxCN), are widespread global environmental contaminants. Our experiments were aimed at assessing HxCN effects on motor behavior, long-term memory, pain sensitivity, magnitude of stress-induced analgesia, auditory function and sensorimotor gating, following repeated intragastric administration (28 days) of HxCN at 0.3 and 1.0 mg/kg body weight. Three weeks after the exposure termination, male Wistar rats were subjected to the neurobehavioral tests battery performed in the following order: open-field test, passive avoidance test, hot-plate test and acoustic startle response test. Repeated administration of HxCN induced disorders of motivational processes manifested by: anorectic effect caused by aphagia and adipsia; significantly reduced motor activity (hypokinesia); impaired long-term memory and acquired passive avoidance reaction; reduced pain threshold and shortened duration of anxiety reaction after pain stimulus (sensory neglect). Some of these neurobehavioral effects (impaired long-term memory, reduced pain threshold and stress-induced analgesia) were observed at 0.3 mgHxCN/kg body weight without any signs of overt toxicity. The outcome of our study shows that HxCN, like other compounds of the persistent organic pollutants (POPs) group, creates a potential risk of behavioral changes in the central nervous system in the general population as a result of environmental exposure.

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

OBJECTIVES: The 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 METHODS: Our study was performed in housing estates located in five regions of Lódz. 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. RESULTS: 181 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). CONCLUSIONS: The 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.