Electrocardiographic changes in workers occupationally exposed to lead.

BACKGROUND: The significance of heavy metals in pathogenesis of the circulatory system diseases remains unresolved. The aim of the study was to evaluate electrocardiographic changes in workers occupationally exposed to lead without clinical presentation of cardiac involvement. METHODS: A group of 60 smelters and refiners and 45 healthy men, as a control group, were enrolled. Twelve-lead electrocardiogram (ECG) and 24-hour Holter monitoring were performed. Further analysis included heart rate variability (HRV) in time and frequency domains and heart rate turbulence (HRT). RESULTS: Analysis of 12-lead ECG recordings revealed various pathologies in 27 out of 60 men occupationally exposed to lead. Twenty-four-hour ECG Holter monitoring showed the higher mean heart rate in copper smelters than in healthy subjects (85.8 ± 14.1 bpm vs 72.6 ± 9.2 bpm; P < 0.05) and more premature supraventricular and ventricular contractions (298 ± 235 vs 27 ± 45; P < 0.05 and 152 ± 138 vs 18 ± 18; P < 0.05, respectively). The majority of time domain and frequency domain HRV parameters were significantly lower, and the LF:HF ratio was higher when compared with the control group. Turbulence onset was abnormal in six copper smelters and turbulence slope in five men exposed to lead. CONCLUSIONS: Electrocardiographic evaluation showed that various heart rhythm disorders were more frequent in metallurgists, as compared to the control group, and the decreased HRV and abnormal parameters of HRT were observed. Noninvasive electrocardiographic evaluation could be a valuable method of the early prediction of cardiovascular disorders in men occupationally exposed to lead.

The influence of the call with a mobile phone on heart rate variability parameters in healthy volunteers.

It is possible that electromagnetic field (EMF) generated by mobile phones (MP) may have an influence on the autonomic nervous system (ANS) and modulates the function of circulatory system. The aim of the study was to estimate the influence of the call with a mobile phone on heart rate variability (HRV) in young healthy people. The time and frequency domain HRV analyses were performed to assess the changes in sympathovagal balance in a group of 32 healthy students with normal electrocardiogram (ECG) and echocardiogram at rest. The frequency domain variables were computed: ultra low frequency (ULF) power, very low frequency (VLF) power, low frequency (LF) power, high frequency (HF) power and LF/HF ratio was determined. ECG Holter monitoring was recorded in standardized conditions: from 08:00 to 09:00 in the morning in a sitting position, within 20 min periods: before the telephone call (period I), during the call with use of mobile phone (period II), and after the telephone call (period III). During 20 min call with a mobile phone time domain parameters such as standard deviation of all normal sinus RR intervals (SDNN [ms]--period I: 73.94+/-25.02, period II: 91.63+/-35.99, period III: 75.06+/-27.62; I-II: p<0.05, II-III: p<0.05) and standard deviation of the averaged normal sinus RR intervals for all 5-mm segments (SDANN [ms]--period I: 47.78+/-22.69, period II: 60.72+/-27.55, period III: 47.12+/-23.21; I-II: p<0.05, II-III: p<0.05) were significantly increased. As well as very low frequency (VLF [ms2]--period I: 456.62+/-214.13, period II: 566.84+/-216.99, period III: 477.43+/-203.94; I-II: p<0.05), low frequency (LF [ms(2)]--period I: 607.97+/-201.33, period II: 758.28+/-307.90, period III: 627.09+/-220.33; I-II: p<0.01, II-III: p<0.05) and high frequency (HF [ms(2)]--period I: 538.44+/-290.63, period II: 730.31+/-445.78, period III: 590.94+/-301.64; I-II: p<0.05) components were the highest and the LF/HF ratio (period I: 1.48+/-0.38, period II: 1.16+/-0.35, period III: 1.46+/-0.40; I-II: p<0.05, II-III: p<0.05) was the lowest during a call with a mobile phone. The tone of the parasympathetic system measured indirectly by analysis of heart rate variability was increased while sympathetic tone was lowered during the call with use of a mobile phone. It was shown that the call with a mobile phone may change the autonomic balance in healthy subjects. Changes in heart rate variability during the call with a mobile phone could be affected by electromagnetic field but the influence of speaking cannot be excluded.

[New image of occupational medicine--current problems, future solutions]. / Nowe oblicze medycyny pracy--aktualne problemy, przyszle rozwiazania.

Current problems in occupational medicine result mainly from the situation in which existing structures are not appropriately adapted to the changes in economy, work market structures and social and demographic trends, which rapidly appeared within the last decade. The Act of Occupational Medicine Service in force precisely defines the duties of occupational medicine services. However, although the legal powers seem clear and detailed, the possibility of real actions is not put in order and encounters many barriers. The changes in structures of economy, enterprises and work market result in the situation in which despite the obligatory preventive examination system, there is a large group of people that are not subject to them. Care of workers in bigger companies or institutions is also the source of problems concerning mainly the examination range, but also the identification of new threats connected with ergonomics, psychological or biological factors; their limiting, monitoring and prevention. A broad issue of provided service qualities is closely connected with the problems mentioned above. Another question is defining the quality control system, the execution of post-control suggestions and the possibility of applying possible sanctions. A significant task is also to modify the examining and specialisation acquirement system. In the creation of the new image of occupational medicine in Poland the most significant issue is to correct the current legal grounds by introducing new standards of health protection for working people, enable to provide high- quality services, create the conditions for functioning of multidiscipline teams preventively caring of working people, being a guarantee of health and economic benefits for the society.

[Coexistence of pneumoconiosis with myelodysplastic syndrome in a coal miner occupationally exposed to coal dust]. / Przypadek pylicy pluc wspotistniejacy z zespolem mielodysplastycznym u górnika narazonego na pyl weglowy.

Pneumoconiosis is the most common occupational disease of the respiratory system. The aim of this paper is presentation of case of pneumoconiosis coexisting with myelodysplastic syndrome in a former coal miner occupationally exposed to coal dust. In a mineral coal miner, aged 56 year, with a 15-year duration of work underneath, suffering from pneumoconiosis, pancytopenia was detected. He was admitted to the hospital, where myelodysplastic syndrome was diagnosed. The patient's condition was gradually worsening, even though chemotherapy was applied, he died from thrombocytopenia manifested by bleeding from the digestive tract in a relatively short time since diagnosis. The presented case seems to be interesting not only in view of possible development of pneumoconiosis as a result of occupational exposure to coal dust, typical in this case, but also in view of the occurrence of clonal disease of blood several years after cessation of exposure.

[Genotoxicity effect of chronic lead exposure assessed using the comet assay]. / Genotoksyczny efekt przewleklej ekspozycji na olów w tescie kometkowym.

BACKGROUND: Lead, an important xenobiotic, is globally well distributed. The IARC has classified inorganic lead compounds as possibly carcinogenic to humans. The study was designed to assess genotoxic effects in workers occupationally exposed to Pb. MATERIALS AND METHODS: The study comprised 62 male workers with chronic exposure to lead and 22 matched non-exposed men. DNA damage was assessed by single cell gel electrophoresis (known as comet assay) using peripheral blood lymphocytes. The level of DNA damage was determined as the percentage of cells with comets. RESULTS: Mean blood Pb (PbB) concentrations in workers exposed to lead were significantly higher than in controls (422.6 +/- 181.2 microg/l vs. 81.0 +/- 37.84 microg/; p< 0.01). The level and the grade of DNA damage were significantly higher in workers exposed to lead (total--12.55 +/- 7.93%; grade 1--9.05 +/- 5.78%; grade 3--1.05 +/- 1.28%; p < 0.05) than in controls (total--6.63 +/- 3.05%; grade 1--5.68 +/- 2.32%; grade 3--0.35 +/- 1.04%; p < 0.05). The highest level and the degree of DNA damage were observed in workers with PbB over 500 microg/l and the lowest in workers with PbB lower than 200 microg/l. CONCLUSIONS: Our results suggest that lead, particularly in people with chronic occupational Pb exposure and high PbB may induce DNA damage in peripheral lymphocytes detected by the comet assay, and thus should be regarded as a potential agent harmful to the human chromosome. The comet assay can be used to monitor and evaluate biological toxic effects in humans occupationally exposed to lead.

[Coexistence of occupational exposure to lead and sleep apnea syndrome as a cause of hypertension and arrhythmias. A case report]. / Wspólistnienie zawodowego narazenia na dzialanie olowiu oraz zespolu bezdechu sennego przyczyna nadcisnienia tetniczego i zaburzen rytmu serca. Opis przypadku.

A case of a 54-year-old man occupationally exposed to lead with diagnosed obstructive sleep apnea, hypertension and implanted artificial pacemaker due to atrioventricular dissociation of the third degree and pauses in sinus rhythm is presented.

[Individual protection devices--opinion and practice of occupational medicine physician]. / Srodki ochrony indywidualnej w aspekcie dzialalnosci lekarza medycyny pracy.

Technological developments have led to changes in work conditions and the character of work itself that modify the responsibilities and tasks of occupational medicine physicians. Their major task is to protect workers' health through primary prevention, which means the employment of all available measures to prevent adverse health effects resulting from working conditions unfavorable to human health. Statistical data on the incidence of occupational diseases and accidents at work in Poland show that despite many beneficial changes, better labor organization or new technologies in production and services, social and economic consequences of exposure-related diseases induced by so called hard harmful agents in the work environments are still the major problem, hence the significance of prevention. Activities aimed at preventing hazards at workplace should be carried out by employers, safety and work hygiene services and physicians involved in prophylactics. In addition, the selection and supply of individual protectors as well as their use by workers to protect themselves against dangerous and harmful factors occurring in the work environment play an essential role. The authors discuss the significance of using individual protectors from the viewpoint of occupational medicine physicians, and the tasks of this group of physicians in the light of epidemiology of occupational diseases induced by various agents present in the work environment.