[New methods for determining the relative load due to physical effort of the human body]. / Nowe metody wyznaczania wzglednego obcazenia wysilkiem fizycznym organizmu czlowieka.

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 VO,max. 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.

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.

[Can heaviness of the work for women be the same as for men?]. / Czy ciezkosc pracy dla kobiet moze byc taka sama jak dla meczyzn?

BACKGROUND: Considering recent suggestions that the same work heaviness should be made admissible for women and men, a study has been undertaken to assess to what extent does the fatigue, in terms of total index of physiological cost of work, differ in women and men performing a job of the same heaviness or at the same level of workload (%VO2 max). MATERIAL AND METHODS: The study group consisted of 147 women and 114 men performing jobs with dominant share of physical effort employed in a post-office, a chemical plant and a cold store. Their energy expenditure during work were determined and their maximum oxygen intake were assessed from the results of stress test. A questionnaire survey was performed to collect information about self-assessed work heaviness, work fatigue (0-100 scores) and chronic fatigue (Checklist Individual Strength--CIS20R Questionnaire), and also about frequency of abandoning, because of fatigue, some daily chore or "just for pleasure" activity. RESULTS: Mean energy expenditure during a work day in the study group of women was 504 kcal, while for men the respective value was 1204 kcal; the workload (%VO2 max) being 17.8% and 20.6%, respectively. However, the distribution of self-assessed work severity, work fatigue and chronic fatigue was similar in both groups, while the increase in work fatigue and chronic fatigue with growing energy expenditure was higher in women than in men. The frequency at which women and men abandoned their pleasure-motivated activities was similar; as to the "daily chore" activities, women used to abandon these more frequently than men, and they did so at a lower level of fatigue. CONCLUSIONS: Abolition of the regulations that prevent free accessibility of women to jobs requiring high physical effort is not advisable because it would result in their increased fatigue; it may also limit their ability to perform non-occupational duties as well as impair their health condition.

[Occupational and non-occupational determinants of work ability]. / Zawodowe i pozazawodowe determinanty zdolnosci do pracy.

BACKGROUND: Measurements of the work ability subjective assessment, using the work ability index (WAI), are widely applied in the examination of workers. The measurement results suggest that the low level of work ability, which is determined by work-burden factors, health condition, and lifestyles of persons under study, can be a predictor of earlier retirement. The aim of the study was to find out whether WAI can be used in Polish conditions and to identify personal traits and/or job characteristics and conditions of its performance that generate the risk of low work ability. MATERIALS AND METHODS: The cross-sectional study embraced 669 men and 536 women at the working age, representing different occupations and exposed to various factors. They self-assessed their work ability by completing a questionnaire that allows to determine WAI values. They also characterized their jobs in terms of physical burden, occupational stress, harmful and strenuous factors, work fatigue, chronic fatigue, and lifestyle. Based on the energy expenditure and health condition (number of diseases), the work burden was objectively defined. A model of multivariate logistic regression was used to assess the effect of the analyzed factors on the risk of low or moderate work ability. RESULTS: The level of work ability in the study group was lower than that observed in analogous occupational groups in other European countries. The results of the analysis indicate that job characterizing factors and workers' individual traits exert a stronger effect on the level of WAI components, which reflect a subjective assessment of work abilities, than factors concerning health conditions. Highly stressogenic work and low tolerance of work burden as well as personal traits (age, frequent alcohol consumption among men and non-occupational burdens among women) represented risk factors responsible for low or moderate VAI values. CONCLUSIONS: The measurement of work ability index is an indirect assessment of workers' physical state, and it slightly depends on objective work burdens.

[The CIS20R Questionnaire and its suitability for prolonged fatigue studies]. / Przydatnosc kwestionariusza CIS20R do badania zmeczenia przewleklego.

BACKGROUND: The aim of the study was to validate the Checklist Individual Strength (CIS20R) questionnaire for the assessment of prolonged fatigue in workers and to define its psychometric properties and fatigue standards for the population of Poland. The questionnaire contains 20 statements, scored on a seven-point scale (1-7), reflecting four aspects of fatigue: subjective feeling of fatigue, reduction of concentration, reduction of motivation, and reduction of physical activity. The outcome yielded by the questionnaire is expressed by the sum of all points scored in responding to all statements and mean values of its components. MATERIAL AND METHODS: The study was carried out in a group (325 men and 363 women) of workers employed in industrial plants, hypermarkets and municipal services; workers of research institutes (81 men and 205 women) and pregnant women (20 persons). Based on the calculated coefficients of correlation between responses to each statement and the total score, strong discriminative power of individual statements was observed. Crombach's alpha was used to assess the consistence of the questionnaire. The coefficient value for the total score was 0.912 and for the fatigue components it ranged from 0.611 to 0.879, which indicates satisfactory reliability of the method. In addition, norms were elaborated using a sten scale. The total value of 40 indicates the borderline between low and moderate and the value of 84 between medium and high level of fatigue. RESULTS: The level of the risk for chronic fatigue was estimated on the basis of investigations among industrial, trade and municipal services workers. In the group of men, the necessity of prolonged standing during work, high physical effort during work, lack of fitting to physical effort during work, and stress connected with responsibility (component of occupational stress) were the risk-increasing factors. In the group of women, they were: lack of fitting to physical effort during work, noise disturbing reasoning of speech and stress connected with psychic load and lack of social support (components of occupational stress). In both groups, sleep disturbances proved to be responsible for increasing risk of the incidence of chronic fatigue. In the group of men--the diet, and in the group of women - exercise during leisure time were found to be protective factors. CONCLUSIONS: The study revealed that the CIS20R questionnaire is a good research tool to study chronic fatigue. It was also found that the level of fatigue in the population of Poland is much higher than that in the Netherlands, the country where the questionnaire has been developed. In the Dutch studies, the value of 76 was found to be a borderline between "normal fatigue" and fatigue occurring in people with impaired health. In our studies this value corresponds with six stens, which means that it is still within the range of moderate values.

Physiological reaction to work in cold microclimate.

OBJECTIVES: In Poland, occupational exposure to cold microclimate is quite common (5.1 workers/1000 occupationally active people). Reports on health effects of this exposure are rather scarce. The aim of the study was to evaluate the physiological reaction in workers occupationally exposed to cold microclimate. MATERIALS AND METHODS: Examinations were performed in a group of 102 workers (41 women and 61 men) employed at cold storage units. The mean age in the group was 39.1 +/- 9.9 years and the duration of employment under conditions of cold environment was over 12 years. The study population was divided into four groups, according to microclimate conditions (group I, ambient temperature -26 degrees C; group II, 10-14 degrees C; group III, 18-20 degrees C, control group; and group IV, 0-10 degress C). The workers underwent the following procedures: general medical examinations, cold pressor test, ambulatory blood pressure monitoring, and heart rate variability (HRV) analysis (time- and frequency-domain parameters). RESULTS: The results were adjusted for confounding factors (age, smoking and drinking habits). The analysis of HRV parameters did not reveal any significant differences between the study groups. However, systolic and diastolic blood pressure (BP) in the daytime and at night was significantly higher in group IV compared to group II. Mean heart rate (HR) in the daytime and at night and the BP and HR day/night ratio did not differ between the groups. The analysis of BP by gender revealed that in women, systolic BP during the day and at night was significantly higher in group IV than in group II. In the group of workers with hypertension (18 men and 5 women), men reacted to the cold pressor test either by increased or decreased BP while all the women reacted by the increased BP. CONCLUSIONS: Our findings indicated that in workers exposed to cold microclimate, the physiological reaction was dependent on gender and ambient temperature. Women seemed to be more sensitive to cold stress than men. However, this finding must be further investigated.

[Menstrual disorders. Is this a problem to be handled by occupational medicine physician?]. / Zaburzenia cyklu miesiecznego. Czy jest to problem, którym powinien sie interesowac lekarz sluzby medycyny pracy?

BACKGROUND: The aim of the study was to define the frequency of menstrual disorders and identify risk factors, especially those associated with the work environment. MATERIALS AND METHODS: The study group was composed of 142 women, aged 22-45 years. Some of them were employed in a cosmetics manufacture plant and a bank, others were hospital and ambulatory nurses and auxiliary personnel. RESULTS AND CONCLUSIONS: The study revealed irregular cycles in one third and prolonged bleeding in one fourth of the women. Long cycles were observed in one fifth of the women and short cycles were noted in every tenth women. It was found that occasional or frequent contact with ethylene oxide increased the risk of irregular cycles and oligomenorrhea, whereas work around X-ray apparatus was responsible for the risk of long cycles and heavy bleeding. Long rest pauses during work (in this study correlated with work load) were regarded as a factor inducing the risk of oligomenorrhea and prolonged bleeding. A randomly sampled group of 33 women measured morning temperature during two consecutive cycles. Of this number, 15 women (45.5%) showed ovulation in both cycles, 11 (33.3%) in one cycle only, and 7 both anovulatory cycles. The risk of ovulation disorders was enhanced by a two-shift work system (mostly night shift) and strong job stress. Energy expenditure for leisure time activity > 1000 kcal/week and smoking also contributed to an enhanced risk. In summing up, it should be stressed that because of varied frequency of irregular cycles determined by the intensity of environmental factors, occupational medicine physicians should gather data on the occurrence of such disorders and undertake relevant preventive measures.

[Working condition of pregnant women. Departures from regulation on occupations especially noxious or hazardous to women]. / W jakich warunkach pracuja kobiety bedace w ciazy? Zakres odstepstw od przepisów o pracach szczególnie uciazliwych lub szkodliwych dla kobiet.

To define the range and kind of discrepancies between regulations and actual state of working conditions and occupations performed by women during pregnancy, a survey was carried out in the population of 2649 women, a representative group of occupationally involved pregnant women in the region of Lódz. The questionnaire analysis provided information on the kind and arduousness of work performed, working hours and conditions in the work environment. Having verified the data obtained from 10% of women, a very high consistency between working conditions described by respondents and evaluated by experts was noted. Its was found that almost 60% of women under study indicated that their working conditions depart from those defined as admissible for women during pregnancy. Of the women who worked only during the first month of pregnancy, 75% of them were employed at workposts, which did not meet the requirements, and nearly half of women who worked during the whole period of pregnancy were employed in inappropriate conditions. The noxiousness most frequently reported by respondents applied to body posture: bending and position with rotated spine (about 40%). This was followed by lifting and carrying various objects (about 30%), prolonged working hours (about 20%), shift work, including night shifts (about 12%), work at conveyor belt and forced work pace (about 20%). Noise that makes it difficult to communicate, local vibration and work with computers over 4 hours daily was reported by 30% and 15% of respondents, respectively. The most common solution to limit the potential effect of hazardous and noxious working conditions on pregnant women was to remove them from work by issuing a sick leave certificates, while the modification of working conditions or shifting them to another post applied only to 14% of women. The results of the study showed that working conditions of pregnant women differed from those described by the State Labor Inspectorate. The discrepancy can be explained by different method of data collection.

[Perimenstrual complaints--is this a problem to be handled by occupational medicine physicians]. / Dolegliwosci zwiazane z miesiaczkowaniem. Czy jest to problem, którym powinien sie interesowac lekarz sluzby medycyny pracy?

BACKGROUND: The aim of the study was to define associations between intensity of perimenstrual complaints, the type of job performed and working conditions, taking also account of non-occupational factors. The study preceding the development of a preventive program was carried out in a group of women employed in work settings different in the character and burden of adverse agents. MATERIALS AND METHODS: The group was composed of 142 women, aged 21-45 years, employed in a cosmetics manufacture plant (27%) and a bank (27%), as well as of hospital and ambulatory nurses and auxiliary personnel (50%). A questionnaire on premenstrual and menstrual complaints, working conditions, characteristics of the women and their household duties load was the main tool of the study. RESULTS: The study revealed that about 80% of women experienced premenstrual and about 75% menstrual symptoms, which were strongly intensified in 40% of women. After applying logistic regression, it was found that physical workload and occupational stress were the major occupational risk factors, whereas chronic diseases, age, household duties load and alcohol consumption were the major non-occupational risk factors. CONCLUSIONS: The evidenced relationship between complaints and adverse agents typical of the job performed should prompt occupational medicine physicians to more comprehensive analysis of individual jobs in view of reducing occupational load.

[Risk of certain obstetric pathologies in women employed in working conditions non-complying with the current legal status on work load and working conditions appropriate for pregnant women]. / Ryzyko wybranych patologii polozniczych (wczesniactwo, hipotrofia) u ciezarnych zatrudnionych w warunkach pracy niezgodnych z aktualnym stanem prawnym dotyczacym ksztaltowania intensywnosci pracy i warunków pracy dla kobiet w ciazy.

BACKGROUND: The aim of the study was to define the incidence of prematurity and small-for-gestational age (SGA) infants in occupationally involved pregnant women, and to find out how far working conditions departing from binding regulations contribute to the risk of the development of these pathologies. MATERIALS AND METHODS: The study was carried out on a representative sample of 3050 women employed for longer than one week during pregnancy in the Lódz district. An interview conducted with the subjects few days after delivery was the source of information about working conditions. The obtained information was compared with the real situation in about 10% of randomly selected workposts. A high level of consistence was observed. RESULTS: The study revealed that almost 60% of women work in conditions, which do not comply with the Labor Code provisions setting working conditions permissible for pregnant women. In the study group, 4.68% of prematurity and 6.15% of SGA were recorded. A 66% excess in the risk of delivering SGA infants in case of at least one factor not complying with regulations was revealed. The excess was growing with the increased number of departures from regulations and continuation of employment during pregnancy. It was estimated that the number of SGA cases would decrease by 28% if the working conditions would have met the requirements. A prolonged time of work, local vibration for > 4h/shift, forced work pace, excessive effort and forced body position during the work performance contributed mostly to the risk of pathology. Interestingly, the risk of premature delivery was lower by about 40% in women working in unsatisfactory conditions, which is attributed to termination of work immediately after the occurrence of pregnancy-threatening symptoms. Only those women whose pregnancy was not threatened with pathology could continue their work. CONCLUSIONS: The study revealed a quite large number of workplaces not complying with regulations on working conditions permissible for pregnant women. Therefore, studies in this area should be continued by physicians attending pregnant women, under programs aimed at preventing prematurity, and they should be expanded to include the detection of SGA during gestation and the implementation of relevant prophylactics.