Derriennic F, Iwatsubo Y, Monfort C
… +1 more, Cassou B
Br J Ind Med
· 1993 Sep · PMID 8398880
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The relations between osteoarticular disorders and occupational exposure to heavy physical work factors were studied in a random sample of retired subjects living in the Paris area, all of whom had contributed to the sam...The relations between osteoarticular disorders and occupational exposure to heavy physical work factors were studied in a random sample of retired subjects living in the Paris area, all of whom had contributed to the same retirement pension fund. 627 subjects were originally seen in 1982-3 and 464 of them were seen again five years later. On both occasions, the same questionnaire was completed during a home interview. Osteoarticular disorders were evaluated by the presence of pain, with or without restricted joint movement, for at least six months before interview. The heavy physical work factors were those reported by the subject at the first interview, and only subjects who stated that they had been exposed to these factors for more than 10 years were considered as exposed persons. For those who were seen twice, the frequency of osteoarticular pain increased during the five years between the two interviews, from 52% to 65% in the men and 72% to 82% in the women. Among both sexes, these frequencies were significantly higher in those who stated that in the past they had to carry heavy weights and work in tiring positions. The increases in frequency of pain during the five year study period were also related to these occupational factors. In general, the frequencies for subjects not exposed to occupational factors caught up with those found for the exposed group. This interaction of age with the relation between exposure to heavy physical work factors and osteoarticular disorders does not seem to be explained by confounding factors, including age at the first interview, the fact of living alone, of being a former manual worker, of having a cardiorespiratory disorder, and smoking habits. The results of the survey suggest that working conditions are an important cause of osteoarticular disorders that last well beyond the end of working life.
Edling C, Anundi H, Johanson G
… +1 more, Nilsson K
Br J Ind Med
· 1993 Sep · PMID 8398879
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The results of this study suggest that exposure to styrene below the current Swedish permissible exposure limit of 20 ppm induces neurotoxic effects expressed as an increased number of neuropsychiatric symptoms. Twenty m...The results of this study suggest that exposure to styrene below the current Swedish permissible exposure limit of 20 ppm induces neurotoxic effects expressed as an increased number of neuropsychiatric symptoms. Twenty men exposed to styrene at a plastics factory participated. The reference group included 20 non-exposed men matched for age, working schedule, and physical work load. Exposure to styrene during one workday was assessed by personal air monitoring and biological monitoring. To evaluate the physical work load the pulse(heart) rate was measured. One week before the study each man completed a neuropsychiatric symptom questionnaire containing 16 items. Also 17 questions regarding acute symptoms of local irritation and symptoms of the central nervous system were presented after the psychometric tests were performed. The tests were simple reaction time, colour word vigilance, and symbol digit. A follow up with regard to the symptoms among the exposed men was done after their summer vacation, about two to five weeks after their last exposure. The mean eight hour time weighted average (TWA) concentration of styrene in air, measured by passive dosimetry was 8.6 ppm (range 0.04-50.4 ppm). The exposed men had significantly more symptoms than the referents although there were no significant differences for the psychometric tests. At the follow up the exposed men reported fewer symptoms. This study indicates that symptoms are earlier indicators of adverse effects than complex tests and underlines the importance of regular follow up of people exposed to styrene (and probably organic solvents in general).
Swennen B, Buchet JP, Stánescu D
… +2 more, Lison D, Lauwerys R
Br J Ind Med
· 1993 Sep · PMID 8398878
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Several organs (lung, skin, thyroid, heart, bone marrow) are potential targets of cobalt (Co). Whereas there is no doubt that inhalation of Co alone may cause bronchial asthma, its role in the occurrence of hard metal di...Several organs (lung, skin, thyroid, heart, bone marrow) are potential targets of cobalt (Co). Whereas there is no doubt that inhalation of Co alone may cause bronchial asthma, its role in the occurrence of hard metal disease is still controversial because most cases were reported in workers exposed not only to Co but also to other substances such as tungsten carbide, titanium carbide, iron, silica and diamond. To assess whether exposure to pure Co dust (metal, oxides, or salts) may lead to adverse health effects a cross sectional study was carried out among 82 workers in a Co refinery. The results were compared with those in a sex and age matched control group. The Co group had been exposed for 8.0 years on average (range 0.3-39.4). The geometric mean time weighted average exposure assessed with personal samplers (n = 82) was about 125 micrograms/m3 and 25% of the values were higher than 500 micrograms/m3. The concentrations of Co in blood and in urine after the shift were significantly correlated with those in air. Concentration of Co in urine increased during the workweek. A slight interference with thyroid metabolism (decreased T3, T4, and increased TSH), a slight reduction of some erythropoietic variables (red blood cells, haemoglobin, packed cell volume) and increased white cell count were found in the exposed workers. The exposed workers complained more often of dyspnoea and wheezing and had significantly more skin lesions (eczema, erythema) than control workers. Within the exposed group a dose-effect relation was found between the reduction of the forced expiratory volume in one second/vital capacity and the intensity of current exposure to Co assessed by the measurement of Co in air or in urine. The prevalence of dyspnoea was related to the dustiness of the workplace as reflected by statistically significant logistic regression between this symptom and the current levels of Co in air and in urine. No difference between lung volumes, ventilatory performances, carbon monoxide diffusing capacity, and serum myocardial creatine kinase and procollagen III peptide was found between the Co and control groups and no lung abnormalities were detected on the chest radiographs in both groups. The results suggest that exposure to high airborne concentrations of Co alone is not sufficient to cause pulmonary fibrosis. This finding is compatible with experimental studies indicating that interaction of other airborne pollutants with Co particles play a part in the pathogenesis of parenchymal lung lesions.
Br J Ind Med
· 1993 Sep · PMID 8398877
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A cohort study of workers exposed to formaldehyde in the British chemical industry in any one of six factories has been extended after the earlier published report in 1984. A further eight years of follow up to the end o...A cohort study of workers exposed to formaldehyde in the British chemical industry in any one of six factories has been extended after the earlier published report in 1984. A further eight years of follow up to the end of 1989 have been included for the originally reported 7660 workers first employed before 1965, and a first follow up to the same date has been carried out for 6357 workers first employed since 1964. Extensive checking of the database has taken place including records at the factories, the MRC Environmental Epidemiology Unit, and the National Health Service Central Register. The updated findings include one death from nasal cancer compared with 1.7 expected in this number of men during the follow up period--which gives no support to the original hypothesis based on animal experimental data that formaldehyde may be a nasal carcinogen in humans. There have been no cases of nasopharyngeal cancer in the cohort compared with an estimated 1.3 expected--which gives no support to the findings in a similarly designed study in the United States of an excess of cancers of the nasopharynx associated with exposure to formaldehyde. There has been a slight excess of about 12% for lung cancer with 402 deaths compared with about 359 expected. This is similar to that found in the United States study, but higher than we reported earlier before the checking procedures and extended follow up. Further analysis gives no definitive indication of this excess of lung cancer being clearly related to formaldehyde exposure, and the increase is within that generally thought consistent with possible confounding effects of cigarette smoking (although no data are available on this point).
Br J Ind Med
· 1993 Sep · PMID 8398876
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An investigation was conducted to examine the reliability (reproducibility) of self reported occupational histories obtained from a cohort of 326 capacitor manufacturing workers who had participated in an epidemiological...An investigation was conducted to examine the reliability (reproducibility) of self reported occupational histories obtained from a cohort of 326 capacitor manufacturing workers who had participated in an epidemiological study relating health abnormalities to exposure to polychlorinated biphenyls (PCBs). For a subsample of the cohort (n = 164) in which occupational histories were obtained twice (in 1976 and 1979), reliability of cumulative exposure to PCBs ranged from 93.6% for the early PCB period (1947-70) to 95.7% for the late PCB period (1971-6). These respective reliabilities were lower, however, for workers who changed jobs often. Workers above the median value of a weighted job change index had early and late reliabilities of 89.9% and 83.6% respectively. Reliability is a relevant factor when calculating power or sample size during the planning stage of epidemiological studies, for interpretation or adjustment of estimates in the analysis stage, or for determination of study feasibility.
The elimination of mercury (Hg) in blood was investigated in 14 chloralkali workers exposed to metallic Hg vapour for 1-24 (median 10) years. Blood and urine samples were collected on several (median eight) occasions dur...The elimination of mercury (Hg) in blood was investigated in 14 chloralkali workers exposed to metallic Hg vapour for 1-24 (median 10) years. Blood and urine samples were collected on several (median eight) occasions during a period of 17-26 days. The initial Hg concentrations were about 80 nmol/l in whole blood (B-Hg) and 17 nmol/mmol creatinine in urine (U-Hg). The decrease in Hg in whole blood, plasma (P) and erythrocytes (Ery) was best characterised by a two compartment model. In a model with a common half life for all subjects, the best fit for B-Hg was obtained with half lives of 3.8 days for a fast phase and 45 days for a slow phase. The half life of the fast phase was shorter for P-Hg than for Ery-Hg, whereas the opposite was the case for the slow phase. The half lives of the slow phases in whole blood and plasma were longer, and the relative fractions of the slow phases were higher (about 50%) after long term exposure than those (about 20%) reported after brief exposure. Slower elimination indicates higher accumulation of Hg in organs with long half lives, and possibly the presence of at least one additional, even slower compartment. The U-Hg fluctuated substantially during the sampling period, and average concentrations decreased only slightly.
Bruch J, Rehn B, Song W
… +2 more, Gono E, Malkusch W
Br J Ind Med
· 1993 Sep · PMID 8398874
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Silicon carbide (SiC) dust and other dusts for comparison were injected intratracheally at a high dose (50 mg) into rats and the response of the lungs and the lymph nodes was studied after an appropriate experimental per...Silicon carbide (SiC) dust and other dusts for comparison were injected intratracheally at a high dose (50 mg) into rats and the response of the lungs and the lymph nodes was studied after an appropriate experimental period. The indices studied were: histological changes in the lung and lymph nodes, organ weights, the formation of collagenous fibres, and the appearance of quartz typical areas. According to several epidemiological investigations and previous experimental animal studies, SiC produces silicogenic (fibrogenic) effects. No changes in the tissues studied in terms of damaging fibrogenic effects could be found after eight months (first series) and three and 12 months (second series). In particular, the histological findings and the absence of quartz typical areas as well as the quantitative determination of collagen fibres show that SiC had no harmful effects on tissues. Based on these results, the extent to which other exposures during the production of SiC can be responsible for the established radiological alterations is discussed. Without doubt the following may be confounders: SiC fibres, crystalline SiO2 (quartz, cristobalite, tridymite), and possibly gaslike emissions (SO2). From the hygienic medical point of view the workplaces during SiC manufacture should be examined carefully. The substance SiC dust as such can be considered as inert from the experimental results based on qualitative and extremely sensitive procedures. A revision of the present threshold value for SiC in ther German MAK list is called for.
Bruch J, Rehn B, Song H
… +2 more, Gono E, Malkusch W
Br J Ind Med
· 1993 Sep · PMID 8398873
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The question of lung damage as a result of exposure to silicon carbide (SiC) was investigated by inhalation experiments to obtain information on the qualitative response of lung tissue to the test substance (SiC). For co...The question of lung damage as a result of exposure to silicon carbide (SiC) was investigated by inhalation experiments to obtain information on the qualitative response of lung tissue to the test substance (SiC). For comparison, quartz, kaolinite, and tempered clay dusts were used. The indices for the effects of the dusts studied were organ weights, numbers of bronchoalveolar cells, lung surfactant phospholipid concentrations including subfractions, and lung clearance. Exposure to the test samples was carried out according to the Essen inhalation model in two independent series. The results of the two series were similar: Compared with sham controls, exposure to SiC did not affect the indices studied. Even at a low dose (a quarter of the SiC dose) quartz gave pronounced deviations in all indices. In particular, an increase in granulocytes indicated toxic properties of the dust. The long term elimination of quartz from the lung was worse than that of SiC. The kaolinite and tempered clay dusts were intermediate between SiC and quartz based on several of the indices studied. It is concluded that SiC is deposited practically inert in the lung.
Br J Ind Med
· 1993 Sep · PMID 8398872
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OBJECTIVE: To study the general and specific incidence of occupational asthma within a defined geographic area; to audit the diagnosis of occupational asthma; to determine proposed mechanisms of asthma; and to determine...OBJECTIVE: To study the general and specific incidence of occupational asthma within a defined geographic area; to audit the diagnosis of occupational asthma; to determine proposed mechanisms of asthma; and to determine the employment state of workers at diagnosis. DESIGN: A surveillance scheme of physicians likely to see cases of occupational asthma. SETTING: The West Midlands Region of the United Kingdom. SUBJECTS: Workers with occupational asthma diagnosed within the boundaries of the West Midlands Region. MAIN MEASURES: Demographic data, employer, agent to which exposed, date of diagnosis, method of diagnosis, proposed mechanism of asthma, and employment state. RESULTS: A recognised incidence of 43 (95% confidence interval CI 35-52) new cases per million general workers per year was detected. Specific occupational incidences varied from 1833 (95% CI 511-2990) per million paint sprayers to eight per million clerks. Specific incidence by District Health Authority varied from 103 in Solihull to 14 per million general workers in South Warwickshire. Agents to which workers were exposed at the time of diagnosis were generally well recognised (isocyanates 20.4%, flour 8.5%, colophony 8.3%). The most commonly used method of diagnosis was serial peak expiratory flow (PEF) measurement. Its use varied (specialist unit 72%, general chest physicians 50%, compensation board 48%). Workers were still exposed and therefore could have usefully performed PEF readings in 4% of cases where they were omitted from the specialist centre, 16% seen by chest physicians, and 2% seen by the Compensation Board. Other methods of diagnosis were used only infrequently outside the specialist unit. Fifty six per cent of reporting physicians considered that the mechanism of asthma was allergy compared with 18% who believed that it was irritation. Twenty eight per cent of workers were exposed to the suspected causative agent at the time of diagnosis, 38% were either on long term sickness absence, had retired, or had become unemployed. More workers (38%) who were exposed to agents recognised for statutory compensation before the 1991 changes seen at the specialist centre reach compensation and were reported to the scheme by the Compensation Board than those seen by chest physicians (9%). CONCLUSIONS: These recognised incidences are likely to be an underestimate of the true incidence. They highlight at risk occupations and suggest underdiagnosis in some District Health Authorities. They suggest that diagnostic methods are underused outside specialist centres and that the mechanism of asthma is generally considered to be allergic.
Br J Ind Med
· 1993 Sep · PMID 8398871
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The mortality from ischaemic heart disease was studied in a prospective cohort of 1725 shipyard workers exposed to asbestos. The analyses were stratified for age and smoking habits and restricted to men. In agreement wit...The mortality from ischaemic heart disease was studied in a prospective cohort of 1725 shipyard workers exposed to asbestos. The analyses were stratified for age and smoking habits and restricted to men. In agreement with other findings, men with impaired lung function had a significantly higher risk (relative risk (RR) = 3.5) of dying from ischaemic heart disease than men with normal lung function. Men with asbestosis or suspected asbestosis had a significantly higher risk (RR = 3.1) of dying from ischaemic heart disease than men without asbestosis. Thus asbestosis or suspected asbestosis also seemed to be a risk factor for ischaemic heart disease. This finding was independent of respiratory function. There was no increased risk for ischaemic heart disease in men with compared with men without pleural plaques. Men with production of phlegm or sputum and wheezing or whistling had no increased risk for ischaemic heart disease compared with men without these symptoms. In the group with normal lung function men with dyspnoea had a significantly higher risk of dying from ischaemic heart disease than men without dyspnoea. The findings for men with asbestosis or suspected asbestosis indicated a further risk factor besides impaired lung function, in persons exposed to asbestos. Perhaps this risk factor is due to lesions of the pericardium with consequences for heart function.
Magnani C, Terracini B, Ivaldi C
… +4 more, Botta M, Budel P, Mancini A, Zanetti R
Br J Ind Med
· 1993 Sep · PMID 8398870
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The study investigates mortality from cancer and other diseases in a cohort of wives of asbestos cement workers in Casale Monferrato (northwest Italy). After the exclusion of women with an occupational record in the asbe...The study investigates mortality from cancer and other diseases in a cohort of wives of asbestos cement workers in Casale Monferrato (northwest Italy). After the exclusion of women with an occupational record in the asbestos cement industry, the cohort comprised 1964 women. Their domestic exposure was estimated according to their husbands' periods of employment in the plant: 1740 had a period of domestic exposure whereas the remaining 224 married an asbestos cement worker only after he definitely stopped his activity in the asbestos cement plant; these have, therefore, been considered as unexposed. The cohort of wives was constructed entirely through official records in the town offices and is both exhaustive and unaffected by recall bias. At the end of follow up (1988) 1669 women were alive, 270 were dead and 25 (1.2%) were untraced. Main mortality analyses were only up to age 79 to reduce the misclassification of causes of death. Expected mortality was based on local rates. Mortality analyses were limited to the period 1965-88 due to the availability of local rates: in that period 210 deaths occurred among women with domestic exposure v 229.1 expected. There were four deaths from pleural tumours (one diagnosed as mesothelioma at necropsis) and six from lung cancer v. 0.5 and 4.0 expected respectively. Two further cases of mesothelioma were diagnosed by histological examination after the end of follow up. None of the three wives with histologically diagnosed mesothelioma had been engaged in industrial activities. Corresponding information for the other three cases could not be traced.
Br J Ind Med
· 1993 Aug · PMID 8398864
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Several studies suggest that work in electrical occupations is associated with an increased risk of cancer, mainly leukaemia and brain tumours. These studies may, however, not be representative if there is a publication...Several studies suggest that work in electrical occupations is associated with an increased risk of cancer, mainly leukaemia and brain tumours. These studies may, however, not be representative if there is a publication bias where mainly positive results are reported. To study an unselected population the incidence of cancer was followed up over a 17 year period (1970-87) in a cohort of 2.8 million Danes aged 20-64 years in 1970. Each person was classified by his or her industry and occupation in 1970. Before tabulation of the data on incidence of cancer, each industry-occupation group was coded for potential exposure to magnetic fields above the threshold 0.3 microT. Some 154,000 men were considered intermittently exposed and 18,000 continuously exposed. The numbers for women were 79,000 and 4000 respectively. Intermittent exposure was not associated with an increased risk of leukaemia, brain tumours, or melanoma. Men with continuous exposure, however, had an excess risk of leukaemia (observed (obs) 39, expected (exp) 23.80, obs/exp 1.64, 95% CI 1.20-2.24) with equal contributions from acute and other leukaemias. These men had no excess risk of brain tumours or melanoma. A risk for breast cancer was suggested in exposed men but not in women. The risk for leukaemia in continuously exposed men was mainly in electricians in installation works and iron foundry workers. Besides electromagnetic fields other exposures should be considered as possible aetiological agents.
Camner P, Boman A, Johansson A
… +2 more, Lundborg M, Wahlberg JE
Br J Ind Med
· 1993 Aug · PMID 8398863
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Two groups, each of six guinea pigs, were sensitised by the application of cobalt chloride (CoCl2) on the skin on day 0, 2, 7, and 9 and the establishment of contact allergy was confirmed by patch testing on day 21. A fu...Two groups, each of six guinea pigs, were sensitised by the application of cobalt chloride (CoCl2) on the skin on day 0, 2, 7, and 9 and the establishment of contact allergy was confirmed by patch testing on day 21. A further six animals were not sensitised. Starting on day 42 one sensitised group and the non-sensitised group were exposed by inhalation to 2.4 (0.8) mg (mean (SD)) Co in the form of CoCl2 for six hours a day for two weeks. After exposure the lungs were lavaged and the cells obtained were studied by light and electron microscopy. In the sensitised exposed group much more lavage liquid was retained in the lungs than in the other two groups; although more liquid was instilled in the lungs of this group, on average only 5 (range 2.5-10) ml were recovered compared with 10 ml in all animals in the other two groups. In the sensitised exposed group, the percentage of neutrophils and eosinophils tended to be higher than in the non-sensitised exposed group. The results indicate that the lungs of guinea pigs allergic to contact with Co react differently to inhaled Co compared with those of non-sensitised ones.
Ellingsen DG, Holland RI, Thomassen Y
… +3 more, Landro-Olstad M, Frech W, Kjuus H
Br J Ind Med
· 1993 Aug · PMID 8398862
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The concentrations of total mercury (B-Hg), inorganic mercury (B-IHg), and methyl mercury (B-MeHg) in whole blood, urinary mercury (U-Hg), and selenium in urine (U-Se) and whole blood (B-Se) were determined in 74 chloral...The concentrations of total mercury (B-Hg), inorganic mercury (B-IHg), and methyl mercury (B-MeHg) in whole blood, urinary mercury (U-Hg), and selenium in urine (U-Se) and whole blood (B-Se) were determined in 74 chloralkali workers previously exposed to Hg vapour, and compared with 51 age matched referents. Dental amalgam state, fish consumption, and exposure related indices were studied with regard to the determined elements. A significant relation between the surface of dental amalgam and U-Hg (Pearson's r = 0.63, p < 0.001) was found among the referents. Mean U-Se was significantly lower (p < 0.001) among the subjects previously exposed to Hg (34.1 nmol/mmol creatinine) compared with that for the referents (42.6 nmol/mmol creatinine). A significant negative relation between the cumulative Hg dose and U-Se was also found. The mechanisms and the clinical significance of these findings are not clear. No relation between current U-Hg and previous occupational exposure to Hg was found among subjects in whom exposure had ceased more than one year before the study.