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Deaths in hard-coal mining industry can be divided into: accidental (usually of a single character) and non-accidental-intentional (homicide, suicide) and natural (with a pathological background, 'without external factors'). The main cause of natural deaths is myocardial infarction (MI). Its risk is increased by environmental factors in working place, unhealthy life style, cigarette smoking and alcohol drinking, which is often an attempt at coping with chronic stress, so proper prevention, qualification and periodic examination of workers is indispensable. The aim of the study is to analyze cases of miners' cardiac deaths investigated in Department of Forensic Medicine in Katowice and the number of natural deaths in hard-coal mines in the years 1999-2010. There were 298 accidental and 122 natural deaths, the latter showing an increasing tendency in the years 2002-2004, 2006, 2008 and 2010. Natural deaths--in 95% sudden cardiac deaths--constituted 29% of all deaths in hard-coal mining industry. Autopsies supplemented by histopathological investigations often revealed advanced atherosclerosis and coronary heart disease, which should disqualify a candidate from working underground. A high number of natural deaths in hard-coal mining industry and morphological post mortem assessment of victims indicate insufficiency of occupational medicine services. We propose an improvement of its quality and a higher frequency of periodic examinations of workers (especially in groups with the highest risk of MI), as well as courses of Basic Life Support (BLS). Forensic medicine may be socially useful in assessing the efficiency of occupational medicine services in mining industry.

Pleural mesothelioma is an extremely rare neoplasm. Its etiology is related to professional or environmental exposure to asbestos dust. In the present research, the analysis of frequency and causes of death due to asbestos-related cancers in the district polluted with asbestos in comparison with the district free of such pollution has been performed. The increase has been highlighted in the mortality rate because of pleural mesothelioma among inhabitants of the area polluted with asbestos wastes.

A cohort study is the most important study design for analyzing industrial exposures. One of the sources of bias in industrial cohort studies is healthy worker effect (HWE). HWE consists of two selection processes: healthy worker hire and healthy worker survivor. In this article, methods of reducing HWE presented in the literature are compared and its limitations are discussed. The best method of reducing healthy worker hire effect is an internal reference group. But in the case of time related exposures (cumulative exposure) time from hire have to be controlled in the regression model. To minimize healthy worker survival effect internal reference group should be used and time from hire should be controlled.

In the study the mortality of Polish monks (Capuchins order) was analysed for the period 1946-2000, and for two pairs of sub-periods limited by the dates of the end of Vatican Council, Second, and democratic transformation in 1989. Statistical approach based on the follow-up method. Comparison with the reference population (Polish males from urban areas) was made by means of the standardised mortality ratios (SMRs) and their 95% confidence intervals. The studied cohort included 606 priests and 190 brothers contributing 13990.1 and 4148.7 person-years of observation, respectively. The total number of 154 deaths (105 priests and 49 brothers) was noted. Standardised mortality ratios for all the monks was 0.636 (95%CI: 0.539-0.744). Mortality of monks' cohort and priests' sub-cohort was found significantly lowered as related to the reference population, whereas for the brothers the observed decrease was statistically not significant. The influence of the Vatican Council and/or democratic transformation in 1989 on the Polish Capuchins order was observed. After 1989 the monks' mortality was decreased much more then previously, which is preferably correlated with the significant mortality reduction in the brothers' cohort.

The main goal of the study was to analyze thoroughly the results of a cohort study. Such an analysis renders it possible to eliminate certain neoplasms as those not related to the observed exposure. The cohort study was carried out in a group of workers, covering 11,342 persons (5472 men and 5870 women), employed for at least one year during the years 1945-1985 in a rubber footwear plant. The cohort study was continued until the end of December 1997. Of all the sites of malignant neoplasms observed in the cohort, significant, exposure-related excess mortality was found to be due to malignant neoplasms of larynx and lung in men, and malignant neoplasms of gallbladder and lung in women. For these neoplasms, the values of observed risk among those exposed were significantly higher than among non-exposed. Moreover, in a certain interval of employment duration, an increase in risk rates with increasing duration of employment under exposure was observed, which suggests the presence of dose-response relationship. For all these sites, a relevant trend was shown by the RR values calculated in relation to the group of persons non-exposed but employed in the same plant. The internal reference group used to calculate RR values allowed to eliminate the effect of confounding variables, which is not always possible when the general population is used as the reference group.

The objective of this study was to compare the mortality of Polish actors (males and females) with the general Polish population for the period 1981-1999 and for two sub-periods: 1981-1991 and 1992-1998. Initially the studied cohort included 3992 dramatic actors (2161 males, 1831 females) of age 18-80 years (at the moment of cohort entrance). After detailed data verification statistical analysis was made for 2120 actors and 1767 actresses, contributing 29477.1 and 24886.2 person-years of observation, respectively. A total of 633 deaths (368 males and 265 females) were noted during the analyzed period. Statistical approach based on the follow-up method. Comparison with the reference population (Polish males and females from urban areas) was made by means of the standardized mortality ratios (SMRs) and their 95% confidence intervals. Direct comparison of the selected subgroups' mortality based on the rate ratio analysis. Standardized mortality ratios were 0.739 (95%CI: 0.666-0.819) for the actors and 0.887 (95%CI: 0.784-1.001) for actresses. Mortality of the actors' cohort was found to be significantly lower than in the reference population during total analyzed period, whereas for actresses no significant differences were found. Age-specific SMR dependence was found. Statistically significant lowering of SMR was observed for actors up to 80 years old. Finally, it could be concluded that in contrast to the actresses' cohort the actors' mortality in 1992-1999 significantly decreased in relation to 1981-1991 period. Moreover, the decrease of the actors' mortality exceeded tendencies observed for Polish urban population.

The aim of the study was to assess the health risk of workers performing specific jobs in the process of the rubber footwear production by defining the cause and length of temporary work disability, as well as mortality causes and level. The analysis was carried out in the groups of workers performing the following jobs: mixing, mill operation, pressing and vulcanizing (A); semi-product preparation and calendaring (B); finishing and sorting (C); production of polyvinyl chloride footwear (D); and auxiliary works (E). The sickness absence study covered all workers (208 men and 315 women) employed in a large rubber footwear company and performing all above-listed jobs in 1995. Standardized sick days ratio was used to analyze the risk of temporary work disability. Mortality rate was estimated on the basis of the results of the cohort study performed in the same company among workers who had worked at least three months during the years 1945-1985. The follow-up continued until 31 December 1997. The present study included sub-cohorts composed of 5628 men and 7197 women, performing jobs listed above. The results of both studies indicated the enhanced risk of cardiovascular diseases among workers employed in the basic phases of the production process. The increased risk of the diseases of the digestive system was observed in men and women employed in: finishing, sorting and packing of the products (group C); in men involved in mixing, pressing and vulcanizing (group A); and in women engaged in auxiliary works (group E). In addition, the enhanced risk of sickness absence due to the diseases of the respiratory, digestive, or genitourinary systems was related to the enhanced risk of death from malignant neoplasms in a given site. The analysis showed that the temporary work disability may be regarded as a parameter useful in early assessment of health effects of the work environmental hazards.

This paper describes a cohort study of the mortality among workers employed in one of Polish tyre plants. The scope of the study was limited to the analysis of mortality from main disease categories. Mortality from particular cancer sites will be discussed in a separate publication. The cohort comprised 17,747 workers (11,660 men and 6,087 women) employed during the years 1950-95 for at least three months in the tyre plant. As of 31 December 1995, the follow-up of the cohort was completed. A detailed analysis of mortality by causes was carried out using standardised mortality ratio (SMR) calculated by the person-years method. The general population of Poland was used as the reference. The results indicated general mortality significantly lower in the cohort (men: SMR = 72; women: SMR = 62), than in the reference population. The number of observed deaths from main disease categories was also lower than those expected. The analysis by specific causes revealed significant excess of deaths, due to hypertensive disease among men (36 deaths, SMR = 142; 95% CI: 99-197). SMRs were also calculated in sub-cohorts identified by activities performed (preparatory works: production of tyres and inner tubes; maintenance; storage; others). General mortality in sub-cohorts was similar to that in the total cohort. After analysis by causes of death, some non-significant excess mortality could be observed. It was very small or it applied only to single cases of death. Excess mortality from hypertensive disease in male maintenance workers (21 deaths, SMR = 262; 95% CI: 162-400) was the only exception. The absence of adverse health effects pronounced by significant excess mortality should be attributed to a relatively short period of exposure among the majority of the followed-up workers (over 58% of workers in the cohort employed in the plant for a period shorter than five years) and to their young age. Almost 56% of workers in the cohort were born in the 1950s or later which means that at the end of the follow-up they were not older than 45 years. In order to complete the final mortality assessment the follow-up should continue.

The cohort method was used in the study. A retrospective observation covered 4.556 males with occupational disease, manifested by lead poisoning, diagnosed during the years 1970-1992. Mortality risk analysis by causes was based on standardized mortality ratios (SMRs) calculated by person-years method. Their statistical significance was assessed by means of the test based on Poisson distribution. The general adult male population was adopted as the reference population. The state of the cohort as of 31 December 1992 was considered. The cohort accessibility was 95.6%. The study revealed increased total mortality among lead poisoned males (670 deaths; SMR = 108; 95% CI: 100-116). Significant excess mortality was observed in diseases of the digestive system (37 deaths; SMR = 148; 95% CI: 104-204), including chronic hepatitis and cirrhosis (19 deaths; SMR = 173; 95% CI: 104-270); malignant neoplasms of respiratory and intrathoracic organs (82 deaths; SMR = 135; 95% CI: 107-168), including malignant neoplasm of larynx (13 deaths; SMR = 213; 95% CI: 113-364). In the subcohort with high exposure, death risk was significantly enhanced in comparison to the general population (153 deaths; SMR = 129; 95% CI: 109-151). In addition, significant excess of malignant neoplasms was observed (43 deaths; SMR = 151; 95% CI: 109-203) including liver (4 deaths; SMR = 419; 95% CI: 114-1073) and respiratory and intrathoracic organs tumors (21 deaths; SMR = 175; 95% CI: 108-268).

After five successive years of observation the authors present a verified evaluation of the delayed health effects in the pulp and paper industry workers (with particular regard to mortality from malignant neoplasms). The cohort studied consisted of 10,460 workers employed for at least 12 months between 1967 and 1990 in the plants manufacturing sulfate pulp, paper, board and paper products. Subjects were assigned to three subcohorts according to the work areas: 1. pulp mill workers; 2. paper mill workers (paper and board as well as their products); 3. other workers. The workers were enrolled in the subcohort if they were employed for at least one year in one of these departments. One subject could be included in more than one subcohort. The vital status of the cohort was determined through a variety of sources over an observation period of 28 yrs (1967-95). Mortality data were analysed in terms of cause-specific standardized mortality ratios (SMRs) with expected deaths count based on the national mortality rates in Poland. The results of a twenty three-year cohort observation, published earlier, showed the lowered overall mortality (explained by a "healthy worker effect") and the excess of deaths from malignant neoplasms for some sites (peritoneum, prostate, brain). Due to a small number of deaths recorded, kind of exposure and its duration, were left out of the analysis. The results presented in this paper, obtained after five successive years of the male cohort observation, showed an excess of deaths from cancers of the respiratory tract and peritoneum. In the female cohort an excess of brain cancers was found. Only an excessive mortality from malignant neoplasms of the respiratory system was coherent with the exposure to higher concentrations of wood, paper and board dust. An excess mortality from diseases of the circulatory system was found in both males and females employed in paper production.

A cohort study was designed to evaluate the risk of death from malignant neoplasms among pulp and paper workers. This paper presents the evaluation of death risk among workers engaged only in the production of paper, paperboard and paper products. The cohort study covered 1,322 males and 1,914 females employed for, at least, one year in a big pulp and paper mill during the period 1968-90. The study of exposure to harmful factors revealed that concentrations of paper and paperboard dusts in this mill exceeded hygienic standards. The analysis of death risk by causes and gender of those under study was based on standardized mortality rate (SMR) calculated using the method of person-year observation. The general population of Poland was used as reference. The results do not confirm excess mortality from lung, stomach and hematopoietic cancers in paper mill workers reported by other authors. However, an elevated risk of bladder cancer in males (SMR = 491, two deaths) and brain cancer in females (SMR = 353, two deaths) was observed. Both SMR values were not statistically significant. Because of small number of deaths, risk according to exposure and latency was not evaluated.

The authors present the results of cancer risk evaluation in the cohort of men occupationally exposed to chrysotile asbestos dust in the plant involved in the production of asbestos packings, uneven fabric, yarn, cords, asbestos and rubber cardboards and friction materials. A retrospective observation, carried out till 31 December 1990, covered 2,403 men employed during the years 1945-73. The cohort accessibility accounted for 90.5%. Cancer risk was evaluated on the basis of standardized mortality ratio (SMR) calculated according to the person-years method. A slightly higher mortality from malignant neoplasms was found in the cohort than in the general population (160 deaths; SMR = 108). A significant excess mortality applied only to one site, namely large intestine (9 deaths; SMR = 232). In the subcohort of workers exposed to a high dose of asbestos dust, a significant increase in total cancer risk was revealed (30 deaths; SMR = 150), including neoplasm of stomach (8 deaths; SMR = 223), large intestine (3 deaths, SMR = 582) and liver (3 deaths, SMR = 373). No significant increase in mortality from lung cancer was observed.

The pulp mill workers are exposed to substances suspected of carcinogenic effect during production and bleaching of chemical paper-pulp. In order to assess the risk of death from malignant neoplasm, a cohort study covering 1,432 males and 546 females, employed in the sulfate pulp mills of a big cellulose and paper plant, was carried out. Those persons had worked in pulp mills during the years 1967-1990 for, at least, one year. The analysis of risk by causes and gender of those under study was based on standard mortality rate (SMR) calculated using the method of person-year observation. The general population of Poland was used as reference. Significant excess mortality from malignant neoplasm of peritoneum (SMR = 2530) and prostate (SMR = 854) was observed among males, however, the number of observed deaths in these groups was small. Excess female mortality was insignificant. It is rather doubtful whether an increased risk of death from some neoplasms, observed in this group (in this phase of exposure identification) could be linked with occupational exposure.

The author reviews in her paper results of 35 epidemiological surveys, including cohort studies, analysis of mortality and case-control studies. All of them focussed on the assessment of risk of neoplastic disease among workers of petroleum refineries and among persons engaged in the fuel distribution. The results yielded by the afore-said surveys, indicate a lower general mortality and mortality from all malignant neoplasms in the populations under study but a higher risk for the occurrence or death from malignant neoplasm of lymphatic and haematopoietic tissue as well as from malignant neoplasm of skin in the refinery workers. Data on risk of death from malignant neoplasm of digestive organs, kidneys, bones, prostate, brain and the central nervous system among the refinery workers and those on risk of death from malignant neoplasm of lymphatic and haematopoietic tissue, kidneys, stomach and lung in persons engaged in the fuel distribution are very often contradictory. It is most probable that confounding factors are responsible for these contradictions.

Mortality among workers of the rubber industry was assessed following the observation of the cohort comprised of 6,978 male workers who had started their employment in the plant producing rubber footwear during the years 1945-1973, and worked for, at least, three months. The condition of the cohort was assessed for December 31, 1990. Standardised mortality rate (SMR) was used as a measurement tool and it was calculated by means of the man-year method. The general population of Poland was taken as the reference population. General mortality in the cohort was significantly higher than in the reference population (2020 death, SMR = 110). Significant excess mortality due to atherosclerosis (205 deaths, SMR = 135) and cirrhosis of the liver (48 deaths, SMR = 170) was also noted. Total number of deaths due to malignant neoplasms-421-was slightly higher than expected. Significant excess of the bladder cancer (13 deaths, SMR = 357), the larynx cancer (23 deaths, SMR = 180) and the lung cancer (148 deaths, SMR = 122) was revealed. Significantly increased risk of the large intestine cancer (15 deaths, SMR = 242) was observed in the subcohort of workers employed in direct production departments.

Mortality among workers in the Polish pulp and paper industry was evaluated in retrospective cohort study of 10460 workers who had been employed continuously for at least one year between 1968 and 1990 in the factory producing sulphate pulp, paper, board and paper products. A standardized mortality ratio (SMR) analysis was used to compare death rates for the exposure group with Polish national rates. For all the subjects death due to all causes and all malignant neoplasms were lower than the number expected. The only significantly increased risks were those of malignant neoplasm of brain among women (4 cases, SMR = 318) and of retroperitoneum and peritoneum among men (2 cases, SMR = 659), exposed to high level of wood dust and irritant sulphur compounds. The authors could not find any etiological explanation of the excessive mortality from brain and peritoneum cancers.

The aim of the study was: 1. to choose health indicators related with hazards caused by chemicals in order to identify areas of the greatest health hazards, following the criteria proposed in Part I; 2. to apply different methods of variable aggregation, to evaluate their efficency and to choose a method most useful for identifying the areas most hazardous for health because of chemicals present in the environment. On the basis of the analysis performed, according to criteria proposed, and the analysis of the frequency of individual phenomena, the following health indicators were chosen to assess chemical hazards: incidence of low birth weight (under 2500), mortality of infants with low birth weight; male and female mortality from diseases of the circulatory system, and male mortality from lung and stomach neoplasm in the 30-59 age groups; mortality females above 60 years od age, and the rate of premature deaths in the 30-64 age group. For a comprehensive assessment of negative health effects three synthetic measures were applied: according to Hellwig, Strahl and Klima and Wydymus. Upon the analysis of rank concordance according to measures obtained and the sum of ranks of individual indicators based on correlation coefficient od Spearman's rank, the measure according to Strahl proved to be most accurate. This measure has been proposed for identifying areas most hazardous for the population health because of chemicals present in the environment.

The paper presents a review of morality studies for workers occupationally exposed to lead. The authors highlighted the limitations which most of the reviewed analyses suffer from and which are due mainly to incomplete characteristics of the exposure in question. As follows from the results of morality studies carried out so far, lead-exposed workers are subject to an increased risk of death from stomach and lung cancer, though the epidemiologic evidence for the latter is not quite explicit. The single reports on the risk of cerebrovascular diseases probably concerns only the high-level exposure. Relatively best documented is the death risk due to nephritis. The authors believe that further research is necessary in order to evaluate delayed health effects of chronic exposure to lead.

The results of the study of a cohort of 2403 men occupationally exposed to chrysotile asbestos dust during the manufacture of various asbestos products have been reported. The study covered the period 1945-1985. Cohort availability was 91%. Risk estimates were based on SMR and SRR calculated by the man-year method. The general Polish male population served for the reference. The analysis was performed for sub-cohorts selected according to the period of employment in the plant, taking into account the dust dose and the age at the moment of the beginning of employment under exposed conditions. A significantly increased risk of pulmonary carcinoma (SMR: 238.0-211.0) and of gastric carcinoma (SMR: 197.9-238.5) was found in men exposed to high doses of the asbestos dust (above 50 mg/m3 x years). No statistically significant increases in the mortality rates either from cancer in general or from the cancer varieties specified above were detected in men exposed to low doses of dust. One case of death from pleural mesothelioma was reported.

The present paper covers the third part of a larger work concerning mortality measures applied in the studies on industrial cohorts. The aim of this paper is to discuss the problems of testing the trends of standardized relative risks (SRR). In spite of its advantages the standardized relative risk (SRR) is not often used in empirical works to assess mortality. If it is used at all, it is usually based on the chi-square test. The authors of this paper must state that, as it results from their own experience, a non-parametric test is more useful in evaluating mortality than chi-square or F test.

The paper presents the risk of life-loss at work due to ionizing radiation, as compared to work in other professions. Average life-expectancy loss in exposure to ionizing radiation, mean annual dose of 0,5 radium, comes to 12 days, whereas in other industries life-expectancy reduction comes to 500 days.

The investigation was carried out in an asbestos plant producing yarn, cords, gaskets and frictional products. Only chrysotile asbestos was used in the production process. The follow-up covered a cohort composed of 2403 men and 1190 women employed in the plant of various asbestos products for at least 3 months during 1945-1973. The availability was 91.3% for men and 89.6% for women. Due to considerably changed working conditions in the plant, resulting from modernization carried out in 1956, the results were analysed for a subcohort employed during 1945-1955, composed of 670 men and 349 women. Men demonstrated increased standardized mortality rates (SMR) from malignant tumours of respiratory organs and thorax under increased dust concentrations. SMR = 243,2 was statistically significant only in the subcohort of men employed during 1945-1955 in a group with a mean asbestos dust concentration considerably exceeding TLVs. The risk analysis, depending on the dose, exhibited in the subcohort of men working during 1945-1955 who were affected by the highest dose of dust, increased, over 3-fold, the risk of death from lung cancer (SMR = 327.9). In the subcohort of women the risk of death from malignant tumours was higher only in the group of high dust concentration, as compared to the reference population (SMR = 210.2). A significant increase in the risk of death from cancer of the digestive organs and peritoneum as well as malignant tumours of the liver and pancrease was found in the group of high and low dust concentrations alike.(ABSTRACT TRUNCATED AT 250 WORDS)

Presented in the paper are the features of standardized mortality rates (SMR) related to their comparability in different categories of exposure factor as well as features of standardized relative risk (SRR) of the possibility of evaluating the significance of the calculated value of relative risk and possibility of comparing SRR values in different categories of exposure factor. The method of calculating and interpreting SRR was based on the materials of the authors' own cohort study on mortality in a cohort of workers exposed to asbestos dust.

Deaths due to the lung cancer has been investigated among the Cracow inhabitants in years 1980-1985. The control group consisted of men died to other causes than diseases and neoplasms of the respiratory tract. Data on smoking habits and habitation place of the investigated and the control group were received from family members of subjects studied. It has been stated that relative risk of death due to the lung cancer in subjects working in metallurgical industry increases parallely to the time of work and the class of workers employed more than 30 years and in these groups the relative risk of death to above cancer was equal to 2.66 (95% PU 1.37-5.42). The relative risk associated with occupational exposure has also been significant in subject working more than 20 years in other industry branches. The cigarette smoking has been determined as most significant etiologic factor of the lung cancer.

In order to estimate the risk of death due to cancer in those occupationally exposed to asbestos dust, 1190 women--workers of an asbestos producing plant--employed for at least 3 months during 1945-1973, were examined. The cohort availability for 31 December 1981 was 89.6%. The risk was analyzed basing on the standardized mortality ratio (SMR) calculated by the man-years method. The reference group was that of the general population of women in Poland. In the test cohort, 136 deaths occurred (SMR = 93.3), in this 46 were caused by malignant tumours (SMR = 162.0), 25 by malignant tumours of the digestive organs and peritoneum (SMR = 226.9), 13 by malignant tumours of the liver and pancreas (SMR = 360.9). The mortality due to the above mentioned causes was significantly higher than that of the general population. In the subcohort of women employed during 1945-1955 selected for the very high concentration of asbestos dust 95 deaths occurred in this period (SMR = 111.1). Significantly higher than in the reference population was mortality of: malignant tumours totally (32 deaths, SMR = 206.1), malignant tumours of the digestive organs and peritoneum (20 deaths. SMR = 311.0), and malignant tumours of the liver and pancreas (12 deaths, SMR = 541.5).