Mortality of short-term workers in two international cohorts

The purpose of this study was to compare the pattern of mortality of blue-collar workers employed less and more than 1 year in the man-made vitreous fiber (MMVF) and the reinforced plastic industries, the latter group being exposed to styrene. We conducted an analysis among 21,784 workers with less than 1 year of employment (short-term workers) and 19,117 workers with 1 or more years of employment (long-term workers) employed in eight European countries. We conducted analyses based on external as well as internal comparisons. In both cohorts, the standardized mortality ratio for all causes among short-term workers was approximately 40% higher, compared with that for longer-term workers. In internal comparisons, the difference was reduced to 9% in the MMVF cohort and 11% in the styrene cohort. Workers with less than 1 month of employment displayed an increased mortality in both cohorts and in most countries. The increased mortality among short-term workers was not concentrated shortly after they quit employment. In both cohorts, short-term workers had a higher mortality from external causes, while little difference was seen in mortality from ischemic heart disease and malignant neoplasms. Although extra-occupational factors may contribute to increase the mortality of short-term workers and, in particular, of those employed for less than 1 month, the difference observed in analyses adjusted for characteristics of employment suggested a relatively small difference in mortality from most causes.     

Do changes in cardiovascular risk factors explain the increasing socioeconomic difference in mortality from ischaemic heart disease in Finland?

STUDY OBJECTIVE: To estimate the extent to which changes in blood pressure, smoking, and serum cholesterol concentration explain the observed increase in socioeconomic differences in mortality from ischaemic heart disease (IHD) in Finland during the past 20 years. DESIGN: Predicted changes in mortality from IHD were calculated using logistic regression models with the risk factor levels assessed by cross sectional population surveys conducted in 1972, 1977, 1982, and 1987. The subjects included white collar and blue collar workers and farmers. The predicted changes were compared with the observed mortality changes in the same socioeconomic groups in the total population of the same geographical area. SETTING: North Karelia and Kuopio provinces, eastern Finland. PARTICIPANTS: 16,741 men and 16,389 women aged 30-59 randomly drawn from the population registers of the study areas. Mortality data were obtained from the total population in the same areas. MAIN RESULTS: In men, the changes in diastolic blood pressure, total serum cholesterol, and smoking predicted a 28% decline in the mortality from IHD among white collar workers, a 30% decline among blue collar workers, and a 33% decline in farmers. Observed declines in the same socioeconomic groups were 61%, 40%, and 37%, respectively. In women, the predicted decline was 41% among white collar workers, 35% among blue collar workers, and 39% among farmers. The respective observed declines were 57%, 43%, and 20%. CONCLUSIONS: Less than half of the decline in IHD mortality among white collar men was explained by the risk factor changes, while they explained 75% of the decline among blue collar men and 89% of the decline among male farmers. Changes in risk factors did not explain the increasing difference in IHD mortality between the socioeconomic groups, especially among men.     

Sociodemographic mortality differences among the oldest old in Finland

This study examined mortality differences and trends by several sociodemographic characteristics among the Finnish elderly aged 80 years or over during the period of 1971-90. The analyses were based on comprehensive data sets compiled by means of linking individual death records and census records for the entire population of Finland. Poisson regression was applied as the main statistical tool. For both sexes, life expectancy at age 80 was about 1 year longer among those with a higher education than among those with basic education. A similar difference was found between former upper nonmanual workers and manual workers. Slightly lower than average mortality was observed among the married, among those living in Western Finland, and among the Swedish-speaking population. Mortality declined during the study period in all subgroups, with no consistent signs of either convergence or divergence of mortality levels. The results suggest that at least some further decline of mortality even among the oldest old is possible.     

Occupational exposure to phenoxy herbicides and chlorophenols and cancer mortality in The Netherlands

As part of the "IARC International Register of Persons Exposed to Phenoxy Herbicides and Contaminants," a cohort of workers who manufacture and prepare chlorophenoxy herbicides was recruited in The Netherlands. The cohort comprised 2,310 workers from two plants, operated by different companies, who were followed during the periods 1955-1985 and 1965-1986, respectively. In 1963, there had been an industrial accident in one factory with concomitant release of dioxin into the environment. Loss to follow-up was 3%. Mortality data on 963 exposed and 1,111 nonexposed men were evaluated by external and internal comparison. Compared with national rates, total mortality (94 deaths, standardized mortality ratio [SMR] = 101; 95% confidence interval [CI], 82-124) and cancer mortality (31 deaths, SMR = 107; 95% CI, 73-152) for exposed workers were not significantly increased. A statistically insignificant increase was observed for non-Hodgkin's lymphoma (2 deaths, SMR = 299; 95% CI, 36-1,078). No cases of soft-tissue sarcoma were encountered. There was no increase in either total mortality (25 deaths, SMR = 111; 95% CI, 72-163) or cancer mortality (10 deaths, SMR = 137; 95% CI, 66-252) among the 139 workers probably exposed to dioxins during the 2,4,5-trichlorophenol production accident or the subsequent clean-up operations. Compared with nonexposed workers, exposed workers did not exhibit a higher total mortality (rate ratio [RR] = 1.28; 95% CI, 0.89-1.82). Mortality due to all cancers (RR = 1.7; 95% CI, 0.9-3.4) and respiratory cancer (RR = 1.7; 95% CI, 0.5-6.3) was insignificantly elevated. These findings suggest that the increases in cancer mortality among workers exposed to phenoxy herbicides and chlorophenols may be attributable to chance. Lack of power prevented evaluation with respect to specific cancers.     

Risk profile of female sex workers who participate in a routine penicillin prophylaxis programme in Surabaya, Indonesia

We conducted a sexually transmitted disease (STD) prevalence survey of 1867 female sex workers in Surabaya, Indonesia, some of whom reported participation in a routine penicillin prophylaxis programme. In Surabaya, 34% of female sex workers had received a prophylactic penicillin injection programme from the government within 28 days. Sex workers who had received routine prophylaxis injection were more likely to be less educated, to work in brothel complexes, and to have more customers per week than other sex workers. The prevalence rates of syphilis, gonorrhoea, chlamydia, and trichomoniasis were higher among sex workers who received the routine penicillin treatment than among those who had not received antibiotic treatment in the last 28 days. However, after adjustment for age, education, fee per sex act, number of customers, and condom use in the previous 7 days, only trichomoniasis was still significantly different (adjusted odds ratio of 3.2). High-risk women were more likely to participate in the routine penicillin prophylaxis programme. The lack of a demonstrable individual-level protection from this prophylaxis treatment programme in this cross-sectional study appears due to differential uptake of penicillin prophylaxis by women at higher presumptive risk for STD. Randomized clinical trials and mathematical modelling, together with observational data such as presented here, all can contribute to optimal understanding of a complex intervention like mass chemoprophylaxis for STD among female sex workers.     

Socioeconomic and spatial differentials in mortality and means of committing suicide in New South Wales, Australia, 1985-91

Analysis of suicide mortality in New South Wales, Australia is undertaken with reference to marital status and occupational status between 1986-89/90 and with reference to the principal means of committing suicide. Not currently married male manual workers were particularly at risk although marital status variations were significant with both genders and at different ages. Between 1985-91 male suicide mortality rates were significantly higher in inland non-metropolitan regions, especially among younger men, and were higher in inner areas of metropolitan Sydney. While there were no significant variations by marital status in the means of committing suicide there were variations between genders, and there were regional and social class variations in the use of guns with males. The use of guns was a factor in the elevated suicide mortality levels among inland rural youth and men, and among farmers and transport workers while the use of poisons was also significant with these occupational groups. The use of poisons was greater among persons committing suicide in the areas of elevated mortality in inner Sydney and the use of guns much lower.     

Lung cancer mortality in a French cohort of hard-metal workers

A cohort mortality study was carried out among workers of a plant producing hard metals using cobalt as a binder. This study was aimed at assessing possible lung cancer risks in relation with cobalt exposure. Seven hundred nine male workers with at least 1 year of employment were included in the cohort and followed for mortality from 1956 to 1989. Job histories were provided by the administration of the plant, whereas smoking habits were collected from medical records and by interview. The causes of deaths were ascertained from hospital and general practitioner records. The observed numbers of deaths (obs) were compared with the expected based on national rates with adjustment for age, sex, and calendar time (standardized mortality ratio; SMR). The overall mortality did not differ from that expected (obs = 75, SMR = 1.05), whereas mortality due to lung cancer was in significant excess (obs = 10, SMR = 2.13). This excess was higher among workers employed in the areas with the highest exposure (obs = 6, SMR = 5.03). No trend was observed, however, with duration of employment or time since first employment. Smoking data were available for 81% of the workers and 69% of the deceased and showed that smoking alone does not account for these lung cancer excesses, yet, because of the small numbers involved, no firm conclusion should be drawn from this study.     

Premature separation of centromere and aneuploidy: an indicator of high risk in unaffected individuals from familial breast cancer families?

OBJECTIVES: Injury is the leading cause of death in the male working population of Brazil. An important fraction of these deaths are work related. Very few cohort studies of steel workers, and none from developing countries, have reported on mortality from injuries. This paper analyses mortality from work and non-work related injuries among Brazilian steel workers. METHODS: Deaths during employment from 1 January 1977 to 30 November 1992 were analysed in a cohort of 21,816 male steel workers. Mortality rates specific for age and calendar year among the workers were compared with those of the male population of the state where the plant is located. Work related injuries were analysed by comparing the mortality rates for different subgroups of the cohort. RESULTS: The number of deaths (391) was less than half that expected based on death rates of the general population. Over 60% (242) of deaths were due to injuries. Mortality from most causes was substantially below that in the general population, but that from unintentional injury, was 50% above that of the general population. Standardised mortality ratios (SMRs) were highest for the youngest and the oldest employees and for labourers and clerical workers. Mortality from motor vehicle injury was twice that expected from population rates (SMR = 209, 95% confidence interval (95% CI) 176-244). There was a 67% fall in the age adjusted mortality from occupational injuries in the study period. CONCLUSION: The healthy worker effect in this cohort was greater than that commonly found in studies of occupational groups in developed countries, probably because of a greater socioeconomic gap between employed and unemployed populations in Brazil, and unequal distribution of health care resources. Mortality was especially high for motor vehicle injuries. The fall in mortality from occupational injuries during the study period was probably due to improvement in safety standards, increased automation, and better medical care. There is a need to investigate risk factors for unintentional injuries among steel workers, especially those due to motor vehicle injuries. Prevention of occupational and nonoccupational injuries should be a main priority in Brazil.     

Features of work environment in open mining of gold-containing sand in the Far North

Up-to-date work conditions of open extraction of gold in Far North are characterized by some occupational hazards, among which noise and vibration are leaders. In severe climate conditions heat state of the workers was considered exceeding the allowable standards. The authors suggest recommendations to normalize working environment of the enterprises under study.     

Older workers in the construction industry: results of a routine health examination and a five year follow up

OBJECTIVE: To describe the health status of older construction workers and the occurrence of early retirement due to disability or of mortality within a five year follow up. METHODS: Firstly, a cross sectional study was performed among 4958 employees in the German construction industry, aged 40-64 years, who underwent standardised routine occupational health examinations in 1986-8. The study population included plumbers, carpenters, painters/varnishers, plasterers, unskilled workers, and white collar workers (control group). Job specific prevalence and age adjusted relative prevalence were calculated for hearing loss, abnormal findings at lung auscultation, reduced forced expiratory volume, increased diastolic blood pressure, abnormalities in the electrocardiogram, increased body mass index, hypercholesterolaemia, increased liver enzymes, abnormal findings in an examination of the musculoskeletal system, and abnormalities of the skin. Secondly, follow up for disability and all cause mortality was ascertained between 1992 and 1994 (mean follow up period = 4.5 y). Job specific crude rates were calculated for the occurrence of early retirement due to disability and for all cause mortality. With Cox's proportional hazards model, job specific relative risks, adjusted for age, nationality, and smoking were obtained. RESULTS: Compared with the white collar workers, a higher prevalence of hearing deficiencies, signs of obstructive lung diseases, increased body mass index, and musculoskeletal abnormalities were found among the construction workers at the baseline exam. During the follow up period, 141 men died and 341 men left the labour market due to disability. Compared with white collar workers, the construction workers showed a 3.5 to 8.4-fold increased rate of disability (P < 0.05 for all occupational groups) and a 1.2 to 2.1-fold increased all cause mortality (NS). CONCLUSIONS: This study shows the need and possibilities for further health promotion in workers employed in the construction industry, targeting both work related conditions and personal lifestyle factors. Rehabilitation measures should be enforced to limit the rate of disability among construction workers.     

Lung cancer mortality in Casale Monferrato (Italy) and attributable risk to occupations in the asbestos-cement production

The study presents mortality rates for lung cancer in the town of Casale Monferrato, where the largest Italian asbestos cement-plant was located. Cases of lung cancer dying in 1989-94 were exhaustively searched for in the register of deaths. Each case of lung cancer has been identified as ever or never employed in the factory with a linkage to the rosters of employees in the plant. Women were also identified as ever or never married to an asbestos-cement worker. The number of person-years at risk for asbestos cement workers and their wives was measured on the basis of the most recent follow-up. Mortality rates were computed separately for those exposed (workers and wives of workers) and for those with no evidence of exposure. Mortality rates for non-exposed were similar to rates in Piedmont (the region where Casale is located). The relative risk (ever exposed vs. never exposed) was 2.8 among men and 2.1 among women. Attributable risk among the exposed was 64.5% for men and 53.1% for women while among the general population it was 18.1% for men and 13.2% for women. The study confirms the dramatic effect of occupational asbestos exposure in Casale Monferrato but does not suggest an increase in lung cancer mortality among people with no occupational activity in the asbestos-cement production.     

Socioeconomic differences in 'avoidable' mortality in Sweden 1986-1990

BACKGROUND: 'Avoidable' mortality is commonly studied as an indicator of the outcome of health care. In this study socioeconomic differences in avoidable mortality in Sweden from 1986 to 1990 are analysed and related methodological issues discussed. METHODS: The 1985 Swedish Population and Housing Census was linked to the National Cause of Death Register 1986-1990. Mortality from potentially 'avoidable' causes of death was analysed for the age group 21-64 years. Analyses were performed for different socioeconomic groups, blue-collar workers, white-collar workers and the self-employed as well as for individuals outside the labour market. Standardized Mortality Ratios were calculated using standardization by age and sex. RESULTS: For all indicators studied, the death rates for those not in work were higher than for people at work. The largest differences were found for chronic bronchitis, diabetes, bacterial meningitis, ulcer of the stomach and duodenum, chronic rheumatic heart disease, asthma and hypertensive and cerebrovascular disease. For these causes of death the risk of dying was between 3.1 and 7.5 times greater in the non-working population than in the work-force. The differences in avoidable mortality between blue-collar workers and white-collar workers and the self-employed were, however, much smaller. For most of the indicators no significant differences were found. For ulcers of the stomach and duodenum, however the death rate for blue-collar workers was 2.8 times higher than those for other categories in work. CONCLUSIONS: The small difference in mortality outcome for different socioeconomic groups within the work-force indicates an equal quality of care for these groups. The greatly increased risk among the non-working population, however, is a warning sign. These results may be due to a 'healthy worker' effect. The measurement of socioeconomic differences in mortality may be dependent on the time-period chosen between occupational exposure and mortality outcome.     

Effect of gonadotrophin on cell and matrix retention and expression of metalloproteinases and their inhibitor in cultured human granulosa cells modelling corpus luteum function

A retrospective cohort study in 1794 male ceramic workers in the Netherlands was carried out to analyze the lung cancer risk in relation to crystalline silica exposure and silicosis. They had all been employed for two years or longer in ceramic industries between 1972 and 1982. During a health survey, 124 cases of simple pneumoconiosis were diagnosed; after 14 years of follow-up, 161 deaths had occurred. No increased overall and cause-specific mortality was found in the total group of ceramic workers, and a statistically significant cumulative dose-response relation for silica exposure and lung cancer did not emerge. An excess lung cancer mortality appeared among workers with simple pneumoconiosis. The authors conclude that the disease process resulting in silicosis in the ceramic industry carries an increased risk of lung cancer, which is supportive of a nongenotoxic pathway.     

Gorham massive osteolysis

The training of health workers in breastfeeding and lactation management is to enable them make correct breastfeeding recommendations to mothers. This study aims to provide answers to two research questions: what components of breastfeeding training are easily achieved with extension health workers, and what health worker variables affect these outcomes. Multivariable analysis of the outcomes of a controlled breastfeeding training programme for community health workers (CHW) in rural communities of Osun State, Nigeria, was performed by logistic regression. The results show that the training was the most powerful predictor of correct CHW recommendations on breastfeeding (OR = 60.25, p-0.0000), and of 'perfect' breastfeeding knowledge (OR = 192.49, p = 0.0000). Younger CHWs (in the age bracket 20 to 29 years) were significantly more likely to make correct recommendations on exclusive breastfeeding (OR = 3.02, p = 0.0304). Other CHW variables such as sex, experience, job status, and marital status did not make consistently significant independent contributions to the outcomes. The results suggest that breastfeeding education can enhance CHW professional recommendations on breastfeeding and should be extended to all categories of health workers.     

Mandibular fractures following third molar extraction. A retrospective clinical and radiological study

Health care workers (HCW) are at risk of occupationally acquiring Mycobacterium tuberculosis (TB) infection. The Centers for Disease Control and Prevention has published guidelines for health care facilities to protect HCW. One of the recommended elements is TB infection surveillance among HCW using purified protein derivative (PPD) skin testing and analysis of the data by occupational group and work location to determine areas of increased risk of infection. At the military medical center (MMC) we studied, occupational groups with statistically significant (p < 0.05) above-average PPD conversion risk (> 1.1%/year) included respiratory therapists (15.6%/year), nursing technicians (2.3%/year), and military personnel (1.6%/year). Maintenance and engineering workers (2.6%/year), food service workers (2.5%/year), laboratory workers (2.0%/year), custodial workers (1.8%/year), and practical nurses (1.7%/year) had above-average, but not statistically significant, risk. The fourth floor of the MMC had 39% (21/54) of the converters. The surveillance program also uncovered 235 individuals who had not completed adequate prophylactic therapy, and a case of active TB in a laboratory worker.     

Epidemiologic-hygienic aspects of the assessment of carcinogenic risk in methacrylate production

The authors studied oncologic mortality among the workers exposed to some acryl monomers. The oncologic risk was estimated for the individuals exposed to acrylonitrile, methyl methacrylate, methyl- and butyl acrylate, methacrylic acid. Occurrence of the malignancies appeared to depend on the dose of methyl methacrylate.     

Stronger occipital cortical activation to lower than upper visual field stimuli. Neuromagnetic recordings

This article present the results of the extension of the follow-up of a cohort of workers employed in an Italian oil refinery. 1,583 workers employed in 1949-1982 in a northern Italy oil refinery plant were followed-up for mortality as of May 31, 1991. Environmental measurements documented potential exposure to benzene. Standardized mortality ratios (SMR) and their 95% confidence intervals (95% CI) were calculated using as references national (1949-1968) and regional mortality rates (1969-1991). Elevated mortality from lymphoma (seven deaths, SMR 190, 95% CI 76-391) and leukemia (eight deaths, SMR 225, 95% CI 97-443) was observed. No consistent trends by length of employment or time since first exposure were apparent. Nonetheless, the excess risk was particularly and significantly increased among workers with 15 or more years of employment, and 30 or more years since first employment. The findings of elevated mortality from leukemia and lymphoma are in agreement with those of other oil refinery studies. Chance, confounding, or other biases might have played a marginal, if any, role in determining the results. Exposure to benzene is a biologically plausible explanation.     

Human immunodeficiency virus infection, Part II

The acceptance of highly active antiretroviral therapy (HAART) among patients and health care providers has had a dramatic impact on the epidemiology and clinical characteristics of many opportunistic infections associated with human immunodeficiency virus (HIV). Previously intractable opportunistic infections and syndromes are now far less common. In addition, effective antibiotic prophylactic therapies have had a profound impact on the risk of patients developing particular infections and on the incidence of these infections overall. Most notable among these are Pneumocystis carinii, disseminated Mycobacterium avium complex, tuberculosis, and toxoplasmosis. Nevertheless, infections continue to cause significant morbidity and mortality among patients who are infected with HIV. The role of HAART in many clinical situations is unquestioned. Compelling data from clinical trials support the use of these therapies during pregnancy to prevent perinatal transmission of HIV. HAART is also recommended for health care workers who have had a "significant" exposure to the blood of an HIV-infected patient. Both of these situations are discussed in detail in this article. In addition, although more controversial, increasing evidence supports the use of HAART during the acute HIV seroconversion syndrome. An "immune reconstitution syndrome" has been newly described for patients in the early phases of treatment with HAART who develop tuberculosis, M avium complex, and cytomegalovirus disease. Accumulating data support the use of hydroxyurea, an agent with a long history in the field of myeloproliferative disorders, for the treatment of HIV. Newer agents, particularly abacavir and adefovir dipivoxil, are available through expanded access protocols, and their roles are being defined and clarified.     

Renal biopsy diagnosis in children presenting with haematuria

OBJECTIVES: This study considers the cause-specific mortality from cancer among art glass workers employed in 17 industrial facilities in Tuscany, Italy. METHODS: A cohort of 3390 workers, 3180 men and 210 women, employed at least 1 year, was taken from company payrolls. It was followed between the year each factory started operation, mostly the mid-1950s, and 31 December 1993. The cause-specific expected mortality from cancer was computed for men relative to Tuscany rates, specified for gender, 5-year age groups, and calendar year. Separate analyses were carried out for the job title of maker and former and for batch mixers. RESULTS: For 3180 men, the observed mortality was above the expected for larynx [standardized mortality ratio (SMR) 166, 90% confidence interval (90% CI) 90-282], lung (SMR 123, 90% CI 100-151), stomach (SMR 105, 90% CI76-142), and brain (SMR 150, 90%CI 71-282) cancer. Increases for these causes were also found for the makers and formers. Mortality from larynx and lung cancer increased with latency, and significantly increased SMR values were observed for > or =21 years since first exposure. The increasing pattern was also present after adjustment for smoking. CONCLUSIONS: The results showed consistently increased mortality from larynx and lung cancer in the overall cohort and among makers and formers. Stomach and brain cancer was also increased in the overall cohort and among the makers and formers.     

Risk of death from malignant neoplasms among paper mill workers

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.