Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Healthy Worker Effect”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 271 records · Page 15Linked to original sources

Epidemiological survey of oil distribution centres in Britain.

A mortality study of workers employed for at least one year between 1 January 1950 and 31 December 1975 at oil distribution centres from three oil companies in Britain has been carried out. Ninety nine per cent of the population were successfully traced to determine their vital status at 31 December 1975. The mortality observed in the study population was compared with that which would be expected from the mortality rates for all the male population of England and Wales. The overall mortality observed was considerably lower than expected on this basis as was the mortality from stroke, hypertensive disease, bronchitis, and pneumonia. The observed number of deaths from all neoplasms was also much less than expected as were the observed deaths from lung cancer. The observed deaths from ischaemic heart disease approximately equalled those expected overall and in each of the companies, however, and there was no evidence of a "healthy worker effect" for this disease group. The ratio of observed over expected deaths from ischaemic heart disease tended to decrease with increasing age at death, and for most of the job groups overall, the observed and expected deaths were about the same. Raised mortality patterns from ischaemic heart disease were found in several subgroups of the population of one company. Mortality from myelofibrosis and diseases of the lymphatic and haematopoietic tissue was slightly raised overall. Only myelofibrosis showed an overall excess but raised mortality was found in subgroups of the population defined by company, job, and length of service in several of the other neoplasms making up this disease group. The numbers of deaths from these causes were all small, making it difficult to exclude chance effects. Further work would be required to ascertain whether these results are due to an occupational factor and if so to identify the physical or chemical nature of the risk.

Accidents, Traffic↗

Mortality of fire fighters in Western Australia.

All except 17 (1.7%) of 990 fire fighters employed by the Western Australian Fire Brigade between 1 October 1939 and 31 December 1978 were successfully followed up to 31 December 1978. Mortality from all causes was less than expected (SMR 0.80 with 95% confidence interval 0.67 to 0.96). There was evidence of the healthy worker effect but none that mortality increased with increasing duration of employment. A small proportional excess of deaths from road traffic accidents ( SPMR 1.66) appeared to be unrelated to fire service. Deaths from other accidents, poisonings, and violence were significantly less than expected (SMR 0.35 with 95% confidence interval 0.10 to 0.90) and may indicate an effect of training and experience on accident proneness. There was no evidence of increased mortality from cardiovascular or respiratory disease, or from any other cause.

Australia↗

Radiation, work experience, and cause specific mortality among workers at an energy research laboratory.

A retrospective cohort mortality study was conducted among 8375 white male employees who had worked at the Oak Ridge National Laboratory for at least one month between 1943 and 1972. This plant has been the site of energy related research, including uranium and plutonium reactor technology and radioisotope production. Radiation doses, primarily from gamma rays, were generally low; the median cumulative exposure for workers was 0.16 rems. Historical follow up was conducted for the years 1943-77 and ascertainment of vital status was achieved for 92.3% of the cohort. Standardised mortality ratios (SMRs) were computed to contrast the subjects' cause specific mortality experience with that of the United States white male population. The observed number of 966 deaths from all causes was 73% of the number expected. Mortality deficits were also seen for arteriosclerotic heart disease (SMR = 0.75; 344 observed) and all cancers (SMR = 0.78; 194 observed). These results are indicative of the healthy worker effect and the favourable influence on health of the cohort's relatively high socioeconomic status. Non-statistically significant raised SMRs were seen for all leukaemias (SMR = 1.49, 16 observed), cancer of the prostate (SMR = 1.16, 14 observed), and Hodgkin's disease (SMR = 1.10, 5 observed). Internal comparisons of mortality (standardised rate ratios, SRRs) were made between subgroups of the cohort according to radiation dose level and duration of employment in various job categories. No consistent gradients of cause specific mortality were detected for radiation exposure. Leukaemia mortality was highest among workers with greater than or equal to 10 years employment in engineering (SRR = 2.40) and maintenance (SRR = 3.12) jobs. The association of leukaemia with employment in engineering was unexpected; maintenance jobs entail potential exposures to radiation and to a wide range of organic chemicals; metals, and other substances.

Adolescent↗

Mortality of middle aged white South African gold miners.

A cohort of 3971 white miners in South Africa, born between 1 January 1916 and 31 December 1930 who were alive on 1 January 1970 and currently working in the East Rand-Central Rand-West Rand mining areas, was followed up for nine years, when the 3426 survivors were aged from 48 to 62. Fifteen (0.4%) had been lost to view and 530 had died (13.4% of the 3956 whose vital status was determined). Based on the occupational histories of a 30% sample of the cohort it was known that the vast majority were gold miners. An estimated 93% had worked more than 85% of their mining service in gold mines. Standardised mortality ratios were calculated as the ratios of the deaths observed in the cohort to those expected on the basis of concurrent mortality in the reference population--the total white male population in the Republic of South Africa. There was little sign of a "healthy worker effect"; of several possible reasons, one is that the white miner in South Africa had adopted certain unhealthy life styles, another is that the reference population was otherwise inappropriate. The SMR for all causes of death (117.6) was raised because of excess mortality due to the following causes: lung cancer (161.2), chronic respiratory diseases (165.6), and acute and chronic nephritis (381.0). A case-referent analysis was carried out on those miners in the cohort who had spent at least 85% of their service in gold mines. For lung cancer, smoking was the main contributory factor towards disease. For chronic respiratory diseases bronchitis, emphysema, asthma, pneumoconiosis, and pulmonary heart disease), smoking was also the main risk factor, but there was an association wih cumulative dust exposure. Raised blood pressure, smoking, and adiposity were associated with ischaemic heart disease as was the duration of service underground. Study of comprehensive medical histories in all 530 deaths, including necropsy in most cases, showed that none was directly due to pneumoconiosis or to tuberculosis.

Chronic Disease↗

Census based mortality study of pharmaceutical industry workers.

This study was designed to investigate whether the mortality of British pharmaceutical industry workers showed any evidence of occupationally related patterns associated with particular sections of the industry with special emphasis on cancers and respiratory diseases. The data were extracted from census schedules by the Office of Population Censuses and Surveys using occupational categories recorded by pharmaceutical workers at the 1961 and 1971 censuses of England and Wales. Subsequent mortality was ascertained through the National Health Service Central Registry. Both cohorts, followed up to the end of 1981, showed a "healthy worker effect," with overall SMRs ranging from 0.77 to 1.04, though comparison with the employed populations of the longitudinal study reduced this effect by 25%. Evidence of inconsistent excess mortality was noted in small numbers for suicide (SMR 0.91 to 2.79) and cancer of the large intestine (SMR 1.09 to 2.38). There was no clear association between the type of industry and the causes of death investigated. Although the census based study has several methodological shortcomings, there was no evidence, on the basis of this study, to suggest any excess mortality risk from employment in the pharmaceutical industry.

Adult↗

Population based mortality surveillance in carbon products manufacturing plants.

The utility of a population based, corporate wide mortality surveillance system was evaluated after a 10 year observation period of one of the company's divisions. The subject population, 2219 white male, long term employees from Union Carbide Corporation's carbon based electrode and specialty products operations, was followed up for mortality from 1974 to 1983. External comparisons with the United States male population were supplemented with internal comparisons among subgroups of the study population, defined by broad job categories and time related variables, adjusting for important correlates of the healthy worker effect. Significant deficits of deaths were observed for all causes and the major non-cancer causes of death. The numbers of deaths due to malignant neoplasms and respiratory cancer were less than, but not statistically different from, expected. There was a non-significant excess of deaths from lymphopoietic cancer, occurring predominantly among salaried employees. When specific locations were examined, operations with potential exposure to coal tar products exhibited a mortality pattern similar to that of the total cohort. The risk for lung cancer was significantly raised (five observed, 1.4 expected) in one small, but older, location which did not involve coal tar products during the period of employment of these individuals, but which historically used asbestos materials for several unique applications. Although these findings are limited by small numbers and a short observation period, the population based surveillance strategy has provided valuable information regarding the mortality experience of the population, directions for future research, and the allocation of epidemiological resources.

Carbon↗

Prevalence rates and odds ratios of shoulder-neck diseases in different occupational groups.

The aim of the present study was to evaluate the association and impact of occupational exposure and diseases of the shoulder and neck. Prevalence rates, odds ratios, aetiological fractions, and their confidence intervals were computed for pooled and non-pooled data of previous published reports. By comparison with office workers and farmers, dentists had an increased odds ratio for cervical spondylosis (two studies) and for shoulder joint osteoarthrosis. Meat carriers, miners, and "heavy workers" also had significantly higher rates of cervical spondylosis compared with referents. Compared with iron foundry workers, civil servants had a significant odds ratio (4.8) of cervical disc disease and a 0.79 aetiological fraction. Whether this was due to exposure or healthy worker effect was not clear. In four occupational groups with high shoulder-neck load an odds ratio of 4.0 was found for thoracic outlet syndrome with an aetiological fraction of 0.75. Rotator cuff tendinitis in occupational groups with work at shoulder level (two studies) showed an odds ratio of 11 and an aetiological fraction of 0.91. Keyboard operators had an odds ratio of 3.0 for tension neck syndrome (five studies). Unfortunately, owing to the scanty description of the work task, the exposure could be analysed only by job title. Examination of published reports shows clearly that certain job titles are associated with shoulder-neck disorders. High rates and aetiological fractions for rotator cuff tendinitis and tension neck syndrome suggest that preventive measures could be effective. Although job descriptions are brief, the associations noted suggest that highly repetitive shoulder muscle contractions, static contractions, and work at shoulder level are hazardous exposure factors. In reports of cross sectional studies of occupational shoulder-neck disorders presentation of age, exposure, and effect distribution may help for future meta-analysis.

Adult↗

Hydrocarbon exposure, pancreatitis, and bile acids.

The data on hydrocarbon induced pancreatitis are conflicting. This question was therefore studied in a non-selected population exposed to hydrocarbons and in "formerly" exposed workers. Neither the past clinical history nor the pancreatic tests provided any evidence for a causal relation between exposure and pancreatitis. No signs of hydrocarbon induced liver damage were seen either. As a healthy worker effect cannot be totally excluded, however, a case-control study in a group of patients suffering from non-alcohol induced pancreatitis could give useful indications for finally excluding the possibility of pancreatitis being induced by hydrocarbons.

Alcohol Drinking↗

A multicentre mortality study of workers exposed to ethylene oxide.

A multicentre cohort study was carried out to study the possible association between exposure to ethylene oxide and cancer mortality. The cohort consisted of 2658 men from eight chemical plants of six chemical companies in the Federal Republic of Germany who had been exposed to ethylene oxide for at least one year between 1928 and 1981. The number of subjects in the separate plants varied from 98 to 604. By the closing date of the study (31 December 1982) 268 had died, 68 from malignant neoplasms. For 63 employees who had left the plant (2.4%) the vital status remained unknown. The standardised mortality ratio for all causes of death was 0.87 and for all malignancies 0.97 compared with national rates. When local state rates were used the SMRs were slightly lower. Two deaths from leukaemia were observed compared with 2.35 expected (SMR = 0.85). SMRs for carcinoma of the oesophagus (2.0) and carcinoma of the stomach (1.38) were raised but not significantly. In one plant an internal "control group" was selected matched for age, sex, and date of entry into the factory and compared with the exposed group. In both groups a "healthy worker effect" was observed. The total mortality and mortality from malignant neoplasms was higher in the exposed than in the control group; the differences were not statistically significant. There were no deaths from leukaemia in the exposed group and one in the control group.

Cause of Death↗

Respiratory mortality among firefighters.

Although firefighters have been shown in some studies to suffer chronic respiratory morbidity from their occupational exposures, an increased risk for dying from non-malignant respiratory diseases has not been documented in any previous retrospective cohort mortality study. In order to assess the possibility that an unusually strong "healthy worker effect" among firefighters might mask this increased risk, a mortality analysis of firefighters was carried out in three cities in relation to the United States population and also to a comparison cohort of police officers. The firefighters were employed between 1945 and 1980 and experienced 886 deaths by 1 January 1984; compared with the United States population they had a significantly reduced risk of dying from all causes (SMR = 82, 95% confidence interval, 77-87), and from non-malignant circulatory diseases (SMR = 81, 95% confidence interval 73-89), but no significant difference in risk of non-malignant respiratory diseases (SMR = 88, 95% confidence interval 66-117). Compared with police, the firefighters experienced a trend toward improved mortality outcomes for all causes investigated (SMR = 82), but they had an excess of deaths from non-malignant respiratory diseases (SMR = 141). The results indicate that firefighters are probably at increased risk for dying from non-malignant respiratory diseases; this increased risk may have been missed in previous studies because of the limitations of using a general reference population.

Adolescent↗

Malignant melanoma of the skin among workers in a telecommunications industry: mortality study 1976-83.

An incidence study of malignant melanoma of the skin (MMS), conducted previously among the workers of four plants of a large telecommunications industry located in Montreal, Canada, showed a standardised incidence ratio of 2.7 (95% confidence interval (95% CI) 1.3-5.02) for the years 1976 to 1983. To describe more precisely the magnitude of the problem a mortality study was started among the same population (n = 9590) for the same period (1976-83). At the end of 1983, 9180 workers were alive, 261 were dead, and 149 (1.5%) were not traced. Standardised mortality ratios (SMRs) for all causes of death were surprisingly low for men (SMR = 0.57; 95% CI 0.50-0.64) and women (SMR = 0.56; 95% CI 0.37-0.82). The SMRs for major causes of death were also less than expected. These results may be explained by a pronounced selection bias (healthy worker effect) and by the short duration of follow up (eight years). For MMS, two deaths occurred among men (SMR = 2.00; 95% CI 0.24-7.22) and one among women (SMR = 4.81; 95% CI 0.12-26.78). A third man who died of MMS was miscoded as having a primary pulmonary melanoma. Including this case increased the SMR for MMS to 3.00 (95% CI 0.62-8.77; p = 0.08). Polyvinyl chloride and polychlorinated biphenyls were used in the plants and some of the workers did soldering. A planned case-control study will investigate other possible exposures at work.

Canada↗

Mortality in retired coke oven plant workers.

A previous study on 536 retired coke oven plant workers in Lorraine Collieries (France) reported an excess of deaths from lung cancer (standardised mortality ratio (SMR) = 251) compared with the French male population. Occupational exposures during working life were retraced for each subject, but the number of deaths during the observation period (1963-82) was small, and smoking habits were known only for dead subjects. In 1988, the cohort was re-examined (182 deaths occurred between 1963 and 1987) and smoking habits were determined for all the subjects. This study confirmed the excess of lung cancer (SMR = 238, p < 0.001). It showed an excess of mortality from all causes (SMR = 141, p < 0.001), overall cancers (SMR = 133, p < 0.05), and cardiovascular diseases (SMR = 133, p < 0.05). A significant excess of deaths was found for subjects who worked near the ovens for all causes (145, p < 0.01), lung cancer (SMR = 252, p < 0.01), colon cancer (SMR = 381, p < 0.05), and cardiovascular diseases (SMR = 155, p < 0.05). A significant excess mortality was also found from all causes (176, p < 0.05) and stomach cancer (SMR = 538, p < 0.01) in subjects who worked in byproducts, from lung cancer (SMR = 433, p < 0.001) in those in the workshops, and from cirrhosis of the liver and alcoholism (SMR = 360, p < 0.01) in those underground; but, due to small numbers, these figures were not robust. An excess of mortality from all causes (SMR = 163, p<001), lung cancer (SMR = 228, p<0.05) and cardiovascular diseases (SMR = 179, p<0.01) was shown also for non-exposed or slightly exposed subjects. The fact that, on the whole, mortality of various exposed groups was similar to that of non-exposed or slightly exposed workers may be explained in part by the selection at hiring and the healthy worker effect. As an increased risk of lung cancer was noted among subjects who worked in the old generations of plant compared with the other workers (although the relative risk was not significant) it is concluded that the role of occupational hazards could not be excluded.

Cardiovascular Diseases↗

Cancer incidence and mortality in the Swedish polyurethane foam manufacturing industry.

Toluene diisocyanate (TDI) and methylene diphenyldiisocyanate (MDI) are used in large quantities in the polyurethane foam manufacturing industry. Both substances are mutagenic and at least TDI is carcinogenic to animals, but the occupational hazard with respect to cancer is not known. Cancer incidence and mortality patterns were therefore investigated in a cohort of 4154 workers from nine Swedish plants manufacturing polyurethane foam, employed for at least one year. Each workplace and job task in the nine plants was categorically assessed for each calendar year by an experienced occupational hygienist, for "no exposure", "low or intermittent exposure", or "apparent exposure" to TDI and MDI. The observed deficit for all cause mortality (standardised mortality ratio (SMR) 0.78, (95% confidence interval (95% CI) 0.66-0.93) became smaller (SMR 0.92) excluding the first 10 years since the start of exposure and was ascribed to a healthy worker effect. No increased risk for death from bronchial obstructive diseases was found. An almost statistically significant deficit occurred for all malignant neoplasms (standardised incidence ratio (SIR) 0.81, 95% CI 0.63-1.02); slight (not significant) increased risks were found for rectal cancer (SIR 1.66) and non-Hodgkin's lymphoma (SIR 1.53). The SIR for non-Hodgkin's lymphoma increased to 2.80 (95% CI 0.76-7.16) when the first 10 years since first exposure were excluded from the observation period. The corresponding figure for rectal cancer was 1.92 (95% CI 0.52-4.92). Further restricting the analysis to those who had experienced an apparent exposure to TDI or MDI increased the SIR for both rectal cancer (3.19, 95% CI 0.66-9.33), and non-Hodgkin's lymphoma (3.03, 95% CI 0.37-10.9). These estimates were based, however, on few incident cases. As the cohort is still young and little time has elapsed since the start of exposure, future follow ups will enable a more conclusive evaluation.

Adult↗

Further follow up of mortality in a United Kingdom oil distribution centre cohort.

Results of an extension of follow up (1976 to 1989) of a cohort of workers employed for at least one year between 1 January 1950 and 31 December 1975 at oil distribution centres in Britain are presented. Over 99% of the workers were successfully traced to determine their vital status at 31 December 1989. The mortality observed was compared with that expected from the death rates of all the male population of England and Wales. The mortality from all causes of death for the total study population was less than that of the comparison population, and reduced mortality was also found for many of the major non-malignant causes of death. No healthy worker effect was found for ischaemic heart disease, and raised mortality from this disease was found in particular for one company and in several job groups. Raised mortality was also found for aortic aneurysm. Mortality from all neoplasms was lower than expected overall, largely due to a deficit of deaths from malignant neoplasm of the lung. Raised mortality patterns from all neoplasms, malignant neoplasm of the lung, and several non-malignant disease groups were found for general manual workers although the mortality from many of these diseases for all men in this social class in the national population is also high. There was increased mortality from malignant neoplasms of the larynx and prostate but these tended to be in isolated subgroups. Mortality from malignant neoplasm of the kidney was raised overall and in drivers in particular. Mortality from leukaemia was high at one company and in drivers overall.

Adult↗

Mortality and incidence of cancer among sewage workers: a retrospective cohort study.

To study the incidence of and mortality from cancer among sewage workers a retrospective analysis was performed on a cohort of 656 men employed for at least one year at any one of 17 Swedish sewage plants during the years 1965-86. Assessment of exposure was done by classification of work tasks. Lower than expected total mortality (standardised mortality ratio (SMR) = 0.75, 95% confidence interval (95% CI) 0.58-0.97) and cardiovascular mortality (SMR = 0.61, 95% CI 0.39-0.91) was found. This was interpreted as a result of the healthy worker effect. For all cancers combined the mortality (SMR = 1.08, 95% CI 0.68-1.67) and morbidity (SMR = 1.02, 95% CI 0.72-1.38) were comparable with those of the general population. There were increased incidences for brain tumours (SMR = 2.19, 95% CI 0.45-6.39), gastric cancers (SMR = 2.73, 95% CI, 1.00-5.94), and renal cancers (SMR = 1.68, 95% CI = 0.35-4.90). For lung cancer the risk was reduced (SMR = 0.70, 95% CI 0.15-2.05). Allowance for a latency period of 10 years from the start of exposure did not change the pattern. Logistic modelling was used to search for exposure-response relations. In a logistic model with the confounder age forced in, renal cancer had a significant positive relation with a weighted sum of employment times, where the weights describe the classification of exposure. No exposure-response relations were found for brain tumors or gastric cancers. The increased risks are based on small numbers of cases. A future follow up will add more conclusive power to the study. Specific exposures need to be identified to allow for a better dose-response analysis.

Cause of Death↗

Disorders of the neck and upper limbs in women in the fish processing industry.

OBJECTIVE: The aim was to study the association between personal factors and physical and psychosocial work environment factors and disorders of the neck or upper limbs among women in the fish processing industry. METHODS: A cross sectional study was performed on 206 women in the fish processing industry and 208 control women. Several physical and psychosocial work environment factors were evaluated. Subjective complaints about the neck or upper limbs were assessed by questionnaire and by a clinical examination. RESULTS: The study showed a high prevalence (35%) of diagnoses in the neck or shoulders of the exposed women. All prevalence odds ratios (POR's) were substantially higher in young women. There was a pronounced dose-response relation between disorders of the neck or shoulders and duration of employment for women < 45 years old. When studying 322 former workers, the proportion who claimed musculoskeletal complaints as the reason for leaving was highest among the older women. Muscular tension, stress or worry, work strain, and the largest fraction of the work time spent with highly repetitive work tasks were clearly associated with disorders of the neck or shoulders. The measurements of the wrist movements also showed that the work was performed almost without any pauses and that the median flexion and extension velocity was high (41 degree/s). The results of observation showed good agreement with the measurements of wrist motion. CONCLUSION: Work in the fish processing industry is a risk factor for disorders of the neck and upper limbs. Due to the homogenity of the physical work load in the exposed group, we could not show any associations between the objective measurements and disorders. In cross sectional studies the risk may be underestimated due to a healthy worker effect.

Adolescent↗

A case-control study of chronic neuropsychiatric disease and organic solvent exposure in automobile assembly plant workers.

A case-control study of chronic neurological and psychiatric disease and occupational exposure to solvents was carried out in eight automobile assembly plants. Cases included 299 subjects who were granted medical disability retirement in 1980-8. Two control groups were selected, the first from those granted retirement in the same period because of medical disability from causes unrelated to solvent exposure. The second included hourly employees from the plant population. In these facilities, solvent exposures tended to be short term and low level, although common: the average duration of exposure was 2.3 years; about 41% experienced at least one day of exposure. Of those exposed, 46% had less than one year of exposure. Results for all psychiatric disease combined (273 cases) suggested that cases had lower exposures than either control group, regardless of how exposure was expressed. Results could not be explained by conventional confounding exposures or characteristics or by usual manifestations of the healthy worker effect. By contrast, chronic neurological disease, and multiple sclerosis in particular, seemed to be associated with exposure, although few cases were identified and observed increases in risk were not statistically significant.

Adult↗

Cancer mortality among local authority pest control officers in England and Wales.

OBJECTIVE: To examine cancer mortality by tumour site among local authority pest control officers. METHODS: Prospective mortality study, and follow up to the end of 1994, of 1485 male pest control officers aged between 17 and 69 and employed in 296 local authorities in England and Wales for at least six months between January 1980 and April 1984. Observed numbers of deaths were compared with those expected on the basis of the rates for relevant calendar year, cause, sex, and age specific groups for England and Wales. RESULTS: 200 deaths occurred during the follow up period of which 65 were certified as due to malignant neoplasms. No tumour type showed significantly more deaths than expected. Total all cause, lung cancer, and respiratory disease mortality were significantly lower than expected. CONCLUSIONS: 15 year follow up of a group of men handling a wide range of pesticides did not show any significant risk of cancer. This may be partially explained by the healthy worker effect and also the limited power of the study to detect significant increases in the less common tumours. Further long term follow up of this cohort will continue. Chemical control of pests that can cause human disease and can contaminate food and water has been, and will continue to be, a major public health measure. It is important to ensure that the health of those applying pesticides is not at excess risk. Negative results are important.

Adolescent↗