Elaboration of a quantitative job-exposure matrix for historical exposure to airborne exposures in the Polish rubber industry.

BACKGROUND: A job-exposure matrix (JEM) for inhalable aerosols, aromatic amines, and cyclohexane soluble matter (CSM) was elaborated based on measurements collected routinely between 1981 and 1996. METHODS: The data were grouped based on similarities in exposure levels and time trends in different departments, and were analyzed using smoothing splines and mixed effects models. RESULTS: Although higher than in western European countries, inhalable aerosol exposure decreased after changes in production volume and implementation of exposure reduction measures in mid-1980s. Aromatic amines concentrations first increased following the factory's production volume, but subsequently decreased in more recent years. CSM concentrations were uniformly distributed between departments. CONCLUSIONS: This JEM provides an overview of historical exposure levels in a large Polish rubber factory and will enable estimation of lifetime exposure for individual workers in a Polish rubber workers cohort and further investigation of the associations between specific exposures and cancer risk.

Direct transfer of IL-12 gene into growing Renca tumors.

We investigated the feasibility of transferring naked plasmid DNA containing a therapeutic gene (IL-12) into mice harboring growing Renca tumors. We found that naked DNA transferred into growing Renca and B16(F10) tumors gives higher expression level of reporter gene than complexes of DNA with DDAB/DOPE or DC-Chol/DOPE. Transfer of naked DNA carrying the IL-12 gene into growing Renca tumors causes a distinct therapeutic effect that depends on the time span between inoculation of mice with cancer cells and the beginning of the therapy. Therapy started on day 3 resulted in total cure (100%) of mice.

Combined delivery of an antiangiogenic protein (angiostatin) and an immunomodulatory gene (interleukin-12) in the treatment of murine cancer.

We investigated the feasibility of a novel therapeutic approach to treat neoplastic diseases in mice. This novel strategy consists in delivering a protein (angiostatin) with strong antiangiogenic properties, followed by administration of the interleukin 12 gene that is strongly immunomodulatory and has also some antiangiogenic effects. When angiostatin-mediated antiangiogenic therapy was used in combination with intratumor delivery of the IL-12 gene (a strategy much safer than IL-12 protein administration), this produced a synergistic therapeutic effect.

Mortality of workers at two asbestos-cement plants in Poland.

To assess mortality rate among workers occupationally exposed to asbestos, cohort studies were carried out in two asbestos cement plants operating since the 1960s. Asbestos cement sheets for roofing and siding have been manufactured there, using mostly chrisotile, and since 1985 also crocidolite for pressure pipes. In all, the cohort comprised 3,220 workers, including 2,616 male workers. Subject to consideration were the workers employed for at least three months in the period between the onset of the production and 1980. The vital status of the subjects was traced up to 31 December 1991. The availability of the cohort was 96.8%. Workers' mortality was analysed using standardized mortality ratio (SMR). The reference group was the general population of Poland. In the male cohort, 385 cases of death were recorded. Statistically significant excess of mortality from large intestine cancer (7 cases, SMR = 264) and pleural mesothelioma (5 cases, SMR = 2846) was found. In male workers who died from pleural mesothelioma the work history ranged from 12 to 26 years. An excess mortality from pleural mesothelioma was also noted among the female workers (2 cases, SMR = 11,275). No malignant neoplasms of other locations produced significant excess mortality either in the male or female workers.

A mortality study of workers with reported chronic occupational carbon disulfide poisoning.

A mortality cohort study was carried out on 2,291 workers, including 169 women, with chronic occupational CS2 poisoning diagnosed during the years 1970-90. Information on vital status was available for 98.2% as of December 31, 1992. Mortality assessment was based on the standardized mortality ratio using the person-years method. The general population of Poland was the reference population. The number of subjects who died during the period of observation accounted for 658 men and 21 women. The analysis of mortality in male subjects showed statistically significant excess of deaths from the circulatory system diseases (SMR = 139), in this from ischaemic heart disease (SMR = 137), cerebrovascular disease (SMR = 188) and colon cancer (SMR = 233). Over a two-fold increased risk of death from diseases of the nervous system and sense organs, although statistically insignificant, was also observed. Among women a statistically significant risk of death from atherosclerosis was noted (SMR = 286). An elevated risk of death from the circulatory system diseases and from ischaemic disease (IHD) agrees with the results of some other cohort studies carried out in the viscose rayon workers. The increased mortality from malignant neoplasms is an unusual finding in cohorts of workers exposed to CS2. Our own data reported here showed a significantly increased mortality from colon cancer (9 cases). All these cases were noted in workers of the two oldest rayon plants and they require a detailed analysis. Further survey is also needed to elucidate the excess of deaths from the nervous system and sense organs diseases.

Cancer risk in workers of the pulp and paper industry in Poland. A continued follow-up.

A mortality cohort study was undertaken among Polish pulp and paper workers. This paper concentrates on neoplasms mortality among men and women employed continuously for at least one year in the factory producing sulphate pulp, paper board and paper products. A retrospective observation carried out till 31 December 1995 covered 10,460 workers employed during the years 1968-1990. The cohort accessibility was 99%. Cancer risk was evaluated on the basis of standardized mortality ratio (SMR) calculated according to the person-years method. The general population of Poland was the reference population. The results of a 23-year cohort observation, published earlier, showed a lowered overall mortality from all causes and from all malignant neoplasms, and a significant excess of death from peritoneum and prostate cancer among pulp mill male subcohort. The conclusion was drawn that a 'young' cohort and relatively short follow-up period might have affected the results. The results presented in this paper, obtained after further five years of observation showed in the male cohort an excess of deaths from cancer of respiratory tract and peritoneum (lung SMR = 122, nasal cavities SMR = 587, peritoneum SMR = 562). An approximate correction for smoking habits resulted in only 4 decreased risk estimates for lung cancer, indicating a small positive confounding effect of smoking in this material. In female cohort an excess of brain cancer was found (SMR = 355). Only the excess mortality from cancers of nose, lung and peritoneum was coherent with the exposure to higher concentrations of wood dust, pulp, paper and board dust. It may support a hypothesis that these factors as well as dust pollutants, not yet identified in this study, may be considered as one of the risk factors contributing to the incidence of neoplasms of these sites.

Environmental exposure to asbestos in asbestos cement workers: a case of additional exposure from indiscriminate use of industrial wastes.

The paper presents data on cancer risk, especially pleural mesothelioma and lung cancer, among the workers of asbestos cement plant who living in the vicinity of the plant, were also environmentally exposed to asbestos. In 1959 an asbestos cement factory was founded in the rural area of south-eastern Poland. Apart from chrysotile asbestos, crocidolite was used till 1985 chiefly for the manufacture of pressure pipes. The blue asbestos made up 15% of the mean annual tonnage of the processed asbestos. It was found that soon after asbestos production had started the process wastes were made available to local community, particularly to the workers of that factory. For over twenty years asbestos wastes of all kinds, both wet (process sludge) and dry (from pipe and sheet grinding) were exploited for the hardening of roads, paths, farmyards and sports fields and as construction material components. For the evaluation of cancer risk due to occupational exposure to asbestos a cohort of 1,526 workers employed in this factory was observed till the end of 1996. The cohort availability was 95.6%. Standardized mortality ratio (SMR) was calculated using the man-years method. The reference population was the general population of Poland. The results of the study demonstrated a statistically significant increase in the risk of a) pleural mesothelioma--over an 80-fold excess among males and over a 200-fold one among females; b) lung cancer in females--over a 6-fold excess; c) colon cancer in males--over a 3-fold excess. In the 1990 ten new cases of pleural mesothelioma in the cohort were reported. As compared to other asbestos-cement cohorts in Poland, observed at the same time, this cohort presented a very high risk of pleural mesothelioma. The analysis of 16 cases of pleural mesothelioma found in the cohort from 1987 to 1997 revealed 4 cases with very short employment period (3.5 months-5 years) including two cases with relatively short latency period (11-12 years). In order to find explanation of these findings, additional investigations were made. The epidemiological study indicated that all these persons were at the same time subject to non-occupational exposure associated with massive utilization of commonly available asbestos-cement wastes as road surface material.

Mortality in the cotton industry workers: results of a cohort study.

The cohort consisted of persons found on the payroll of one of the Lódz cotton plants in 1964-1993 who were employed in the plant for at least 10 years. Death risk by causes was analysed using standardised mortality ratios (SMRs) calculated by the person-years method. The general population of Poland was used as the reference. In all, 7892 people were observed. As of December 31, 1995, the follow-up was completed for 7545 people (2852 men and 4693 women), i.e. the availability of the cohort was 95.6%. A total of 2069 deaths were recorded; the information on the cause of death was available for 97% of the subjects. In the male cohort, the level of the general mortality was the same as in the general population (SMR = 99). However, there was a significant increase in the number of deaths from diseases of the digestive system (SMR = 142) and larynx cancer (SMR = 188). The analysis of the results by production departments revealed in the weaving department significantly higher mortality from atherosclerosis (SMR = 141), peritoneal carcinoma (SMR = 1057) and melanoma (SMR = 677); and in the spinning department the increased risk of the hypertensive disease (SMR = 239), atherosclerosis (SMR = 175), and Hodgkin's disease (SMR = 768). Mortality in the female cohort was lower than that in the general population (SMR = 88). None of the disease groups or tumour sites caused statistically significant excess deaths either in the total cohort or in subcohorts selected according to departments. Special attention was paid to the chemical processing departments where chemicals used could contribute to the increased risk of death from cancer. Our analysis did not reveal any significant increase either in the total cohort of the workers employed in those departments or in the cohorts analyzed by duration of employment. Our results confirm the lower risk of lung cancer in the analysed group as compared with that in the general population. The numerous, but statistically insignificant increases in the incidence of malignant tumours at some specific sites detected in the subcohorts, distinguished according to the duration of employment or department, confirm the reported findings on the incidence of oral cavity, nose, throat, and larynx tumours among people exposed to harmful agents in the cotton industry.

Cancer mortality among pulp and paper workers in Poland. A cohort study.

Mortality among workers in the Polish pulp and paper industry was evaluated in a cohort study of 10,460 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. Three subcohorts were formed according to the work areas. A standardized mortality ratio (SMR) analysis was used to compare death rates for each group exposed with Polish national rates. Mortality from all causes and from all malignant neoplasms, both in the female and in male cohorts was lower than that observed in the general population. In the pulp male subcohort a significantly elevated risk of death from peritoneum cancer (2 obs, SMR = 2,530) and prostate cancer (4 obs, SMR = 854) was recorded, although overall mortality from all causes and from all malignant neoplasms was lower than expected. The excess of deaths from neoplasms in other sites was statistically nonsignificant in all subcohorts. This study did not confirm the excess mortality from lung, stomach and lymphatic cancers found by other authors. The "young" cohort and a relatively short follow-up period (23 years) might have affected the results.

Cancer mortality in rubber tire workers in Poland.

The study aimed at assessing cancer risk in a cohort of workers employed in the rubber tire production. The cohort consisted of 17,747 workers (11,660 men and 6087 women) employed in a rubber tire plant for at least three months during the years 1950-1995. The cohort follow-up was completed on December 31, 1995. Deaths by causes were analyzed using standardized mortality ratio (SMR) calculated by the person-years method. The mortality pattern of the general population of Poland was used as the reference. The study indicated significantly lower total mortality in the cohort (men: SMR = 72; women: SMR = 62) as compared to the general population, which is an example of a well known "healthy worker effect". The number of deaths from malignant neoplasms was also lower than expected (men: SMR = 67; women: SMR = 64). Only in a very small sub-cohort of men involved in dosing and mixing of raw material for the production of rubber, an excess of total mortality (SMR = 104) and from all cancers (SMR = 115) was found. Mortality from all neoplasms was enhanced (SMR = 108) in the sub-cohort of women employed in the technical service work area. When analyzing individual cancer sites in men of the whole cohort or sub-cohorts, the observed number of deaths from cancers of the lip, tongue, pharynx, stomach, gallbladder, pancreas, peritoneum, articular cartilage, connective tissue, skin, testis, prostate, bladder, kidney, brain, as well as from Hodgkin's disease, multiple myeloma and leukemia was larger than the expected number. Among women the excess mortality was due to cancers of the large myeloma and leukemia. The SMR calculated for these sites were statistically insignificant. The cohort under study was "young" and thus relatively small numbers of deaths were recorded. The excess mortality, based quite frequently on single cases of selected cancer sites, cannot be regarded as a basis for final conclusions. Nevertheless, the fact that these observations are in agreement with the findings of other authors who carried out studies in the rubber industry of other countries justifies the need to follow-up this cohort in the future.

[Results of the control of the reliability of toxicological analyses of biological specimens 1980-1984]. / Wyniki akcji kontroli wiarygodnosci analiz toksykologicznych materialu biologicznego za okres 1980-1984.

Within the programme of the National Specialist Group relating to Industrial Medicine the Department of Laboratory Diagnostics, Institute of Occupational Medicine in Lódz, carries on biological material reliability control. This paper has been aimed at an evaluation of the work carried on by laboratories basing on the results of determinations of control samples of lead, mercury, phenol, trichloroacetic acid and deltaminolevulinic acid.

[Selection of a statistical model for the evaluation of the reliability of the results of toxicological analyses. II. Selection of our statistical model for the evaluation]. / Dobór modelu statystycznego dla oceny wiarygodnosci wyników analiz toksykologicznych.

Part II presents a statistical model devised by the authors for evaluating toxicological analyses results. The model includes: 1. Establishment of a reference value, basing on our own measurements taken by two independent analytical methods. 2. Selection of laboratories -- basing on the deviation of the obtained values from reference ones. 3. On consideration of variance analysis, t-student's test and differences test, subsequent quality controls and particular laboratories have been evaluated.

[Selection of a statistical model for evaluation of the reliability of the results of toxicological analyses. I. Discussion on selected statistical models for evaluation of the systems of control of the results of toxicological analyses]. / Dobór modelu statystycznego dla oceny wiarygodnosci wyników analiz toksykologicznych. Czesc I. Omówienie wybranych modeli statystycznych sluzacych dla oceny systemów kontroli wyników analiz toksykologicznych.

2 statistical models for evaluation of toxicological studies results have been presented. Model I. after R. Hoschek and H. J. Schittke (2) involves: 1. Elimination of the values deviating from most results-by Grubbs' method (2). 2. Analysis of the differences between the results obtained by the participants of the action and tentatively assumed value. 3. Evaluation of significant differences between the reference value and average value for a given series of measurements. 4. Thorough evaluation of laboratories based on evaluation coefficient fx. Model II after Keppler et al. As a criterion for evaluating the results the authors assumed the median. Individual evaluation of laboratories was performed on the basis of: 1. Adjusted test "t" 2. Linear regression test.

[Absenteeism as an indicator of health status of patients with long-term and frequent diseases]]. / Absencja chorobowa jako miernik stanu zdrowia w grupach osób dlugo i czesto chorujacych.

Results of the feasibility analysis of using sickness absenteeism as a measure of worker health condition, especially in long (above 30 days p.a.) and often (above 3 cases p.a.) ailing workers have been reported. Information on health condition of 5197 random-selected textile industry workers and their sickness absenteeism over one year period served as teh basis of the study. Sensitivity, specificity, negative and positive predictive value of the sickness absenteeism due to most frequently diagnosed illnesses in the investigated population were employed. Sickness absenteeism has proved to be a specific, but not very sensitive health condition measure. In the groups of long and frequently ailing persons, sickness absenteeism has proved to be the more sensitive but less specific measure than in the whole investigated group. Among the frequently ailing group, the percentage of persons absent because of digestive system diseases, circulatory system diseases and back diseases satisfactorily approximates the percentage of the chronically sick.

[Problem of cigarette smoking in the epidemiological studies of lung cancer risks among industrial populations]. / Problem palenia papierosów w badaniach epidemiologicznych ryzyka raka pluca w populacjach przemyslowych.

The concept of the confounding factor is discussed in relation to epidemiological studies, in particular, cigarette smoking is presented as a possible confounding factor in the determination of lung cancer risk in the populations with occupational exposure to carcinogens in their everyday work. In the light of the results of own investigations of a cohort exposed to asbestos dust the confounding effect of smoking on risk of lung cancer risk in this cohort is evaluated.

[Health status and working conditions of female workers in the textile industry in Lódz]. / Stan zdrowia i warunki pracy kobiet zatrudnionych w przemysle wlókienniczym w Lodzi.

Within a cross-sectional representative study of textile industry workers in Lódz, the rate of chronic diseases in particular occupational groups of women, as related to age, socio-living conditions and work environment, has been analysed. Furthermore, a representative gynaecologic examination has been carried out in a randomly selected group of women and occupational and non-occupational workload has been estimated. The study delivered ample information on the health conditions and revealed a number of disadvantageous phenomena inherent in the population and in the gynecologic care system for the women employed in the test plants.

[Problems related to studies on the mortality of industrial workers exemplified by observations of persons exposed to asbestos dust]. / Problemy badan umieralnosci w kohortach przemyslowych na przykladzie obserwacji kohort narazonych na pyl azbestu.

The most significant problems strictly connected with studies of mortality in industrial cohorts are: selection of reference population, obtention of data for cohorts in historically prospective studies (completeners and reliability of sources of information on employment and death), determination of exposure in retrospective cohorts, disturbing factors, methods of statistical analyses. Basing on literature and their own experience the authoresses thoroughly analysed the first three methodological issues related to studies of mortality rates in industrial cohorts.

[Occupational lead poisoning in Poland]. / Problemy zawodowych zatruc oøowiem w Polsce.

During the years 1970-1996, 8,414 cases (8,176 among men and 238 among women) of lead poisoning, recognised as occupational disease, were registered with the peak in 1972-1976 (500-800 cases per year). An in-depth analysis of 7,893 (men) reported in the period between 1970 and 1992 revealed that repeated poisonings in the same person were observed quite frequently. Among 4,556 men poisoned by lead during the period under study, in every third men the disease was diagnosed at least twice. Almost half of men with occupational lead poisoning received the occupational disease certification after the exposure lasting less than five years. The majority of persons poisoned by lead (64.3%) were employed in plants located in the Katowice voivodship. More than half of men with occupational lead poisoning (54.1%) was exposed to maximum concentrations of lead, exceeding MAC values by two hundred times. A diminishing number of occupational lead poisoning observed during the 1990s does not reflect a real-level of occupational exposure. The majority of cases reported apply to large plants or industrial complexes where the prevention of poisonings is rather well organised. But dispersed small production and service enterprises, where acute cases of poisoning may lead to irreversible organic changes create a great problem. One of the prerequisites for effective prevention of occupational lead poisoning is to identify and to make a complete inventory of workplaces where lead occurs, as well as to identify workposts hazardous to worker's health, and to monitor lead concentrations in the air.

[Health risk among workers employed in rubber footwear plant]. / Ryzyko zdrowotne wsród pracowników zakladu obuwia gumowego.

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.

[Neoplasm risk in men occupationally exposed to asbestos dust]. / Ryzyko choroby nowotworowej u mezczyzn zawodowo narazonych na pyl azbestu.

To evaluate the magnitude of cancer risk in those occupationally exposed to asbestos dust, a historically prospective cohort has been investigated. The observation covered 2403 men employed for at least 3 months, within 1945-1973, in a factory producing various asbestos products--including chrysotile. The cohort availability on 31 Dec. 1981 was 91.3%. The risk analysis was based on the standardized mortality ratio (SMR) calculated by the man-years method. The reference group was composed of general men population in Poland. Totally, in the test cohort 401 deaths were certified, in this 73 due to malignant tumours and 31 due to the respiratory system cancer. The total standardized mortality ratio (SMR) came to 85, for malignant tumours, SMR = 104.8 for the respiratory system cancer SMR = 144.7, lung cancer-139.5%. Those values were not statistically significant. In the cohort of those employed during 1945-1955, selected due to a very high concentration of asbestos dust at this time and long observation time from the first contact with asbestos dust, the total SMR was 90.7, the one for malignant tumours-136.2 (p less than 0.05). In this cohort 21 deaths for the respiratory system cancer were observed, the total SMR = 191.1 (p less than 0.01), in this 18 for the lung cancer, SMR = 187.1 (p less than 0.05). The other cancer groups did not exhibit any statistically significant standardized mortality rate. The analysis points to a considerable lung cancer risk in those occupationally exposed to asbestos dust at the time of high non-controlled asbestos dust concentrations.