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2.  Update on lung disease in coalminers. 
PMCID: PMC1007932  PMID: 3689723
4.  2-Cyanoethylmercapturic acid (CEMA) in the urine as a possible indicator of exposure to acrylonitrile. 
The aim of this study was to evaluate the efficiency of metabolism of acrylonitrile (ACN) to N-acetyl-S-(2-cyanoethyl)-L-cysteine (2-cyanoethylmercapturic acid (CEMA) in man, the kinetics of excretion of this metabolite, and the relation between the uptake of ACN and the excretion of CEMA in urine. Eleven experiments were performed on six male volunteers exposed for eight hours to ACN at concentrations of 5 or 10 mg/m3. The average respiratory retention of ACN was 52% and 21.8% of the retained ACN was excreted as CEMA in urine. Elimination approximated first order kinetics with half life of about eight hours. The best correlation between the uptake of ACN in the lungs and excretion of CEMA in urine was obtained when the concentration of CEMA in the urine fraction, collected between the sixth and eighth hours after the beginning of exposure, was adjusted to a specific gravity of 1.016 (y = 0.33x-13.3; r = 0.83). CEMA excretion, however, cannot be used as an individual index of exposure.
PMCID: PMC1007929  PMID: 3689720
5.  Occupational exposure to animals and antibodies against Pasteurella multocida. 
The relation between occupational exposure to cattle and prevalence of antibodies against Pasteurella multocida was evaluated in 680 workers. Three groups of exposed workers in abattoirs and slaughterhouses (S), in industrial breeding (I), and in traditional breeding (T) were compared with control workers not exposed to cattle or chicken (C). The prevalence of antibodies against capsular antigen A determined by indirect haemagglutination was significantly higher in the exposed groups (S: 26.2%; I: 29.0%; T: 32.1%) than in the control group (C: 14.0%). The prevalence of antibodies against capsular antigen D did not differ significantly between the groups. The prevalence of antibodies against one or more somatic antigens 1,2,3,7,8, or 9 was higher in the exposed groups with a significant difference only for group T versus group C (p less than 0.05). There was also a significant relation between antibodies against capsular antigen A and the contacts with pets. This high prevalence of antibodies against P multocida suggests that the infection is frequently subclinical and not only a disease associated with pets but also an occupationally related infection.
PMCID: PMC1007928  PMID: 3689719
6.  Small airway hyperreactivity among lifelong non-atopic non-smokers exposed to isocyanates. 
The development of isocyanate asthma is little understood. To gain more knowledge in this area, a group of 20 workers occupationally exposed to isocyanates, five subjects with clinical isocyanate asthma, and a control group of 10 people not exposed to isocyanate were examined with lung function tests and a methacholine provocation test. Forced expiratory volume in one second and tests aimed at detecting small airways obstruction such as volume of trapped gas, closing volume, and wash out volume were made. To detect abnormal airway reactivity, tests were made before and after inhalation of methacholine and of salbutamol. A significant increased reactivity to methacholine in the exposed and asthma groups was seen compared with the control group as measured by volume of trapped gas. The increase was reversed by inhaling salbutamol. In neither group could a statistically significant reaction be shown in the large airways. The study group had increased small airways reactivity of the same magnitude as the group with isocyanate asthma. The subjects in the study group had no clinical symptoms or spirometric abnormalities. The volume of trapped gas in combination with methacholine seems to disclose significantly altered reactivity of the small airways in workers exposed to isocyanate with no subjective symptoms of disease.
PMCID: PMC1007927  PMID: 3689718
7.  Lung function and respiratory symptoms in pig farmers. 
In a pilot study to investigate the health effects of swine confinement work on the respiratory tract pulmonary function tests and a questionnaire for respiratory symptoms were used. Complete data, including qualitative exposure information, were gathered for 132 owners of fattening, breeding, or closed pig farms. All measured pulmonary function values, except the FVC, were on average lower than the reference values of the European Committee for Coal and Steel. There were no significant associations between duration of exposure and pulmonary function. About 28% of the farmers had respiratory or flu-like symptoms during or shortly after confinement work; 14% reported symptoms four to eight hours after work. For the fattening farm the following elements of confinement management were negatively correlated with pulmonary function: fully slatted floor, an automatic feeding system, natural ventilation, and the use of dust masks. A significant association between lung disease of the pigs and pulmonary function of the pig farmers was observed.
PMCID: PMC1007926  PMID: 3689717
8.  Determinants of chronic bronchitis and lung dysfunction in Western Australian gold miners. 
The relation of chronic bronchitis and respiratory dysfunction to age, tobacco smoking, and occupational exposure to surface and underground mining operations were examined in a cross sectional survey of 1363 men employed in the Kalgoorlie mining industry in 1985. Overall, the prevalence of chronic bronchitis was 14%. Eleven per cent of the workers had obstructive lung disorder (FEV1/FVC less than 0.70) and 9% had restrictive lung disorder (FVC less than 0.80 of predicted for height and age). There was little change in the prevalence of chronic bronchitis from that observed in a survey of the same industry in 1961-2. Only 1% of the workers in 1985 had radiographic signs of silicosis compared with 22% in 1961-2. Age, smoking, and underground mining experience all exerted strong effects on the development of chronic bronchitis with or without associated respiratory function abnormalities. After control of confounding by age and smoking, it was estimated that compared with a lifetime non-miner, the odds ratio (OR) of chronic bronchitis was 1.8 (95% confidence interval, 1.0-3.3) for one to nine years underground mining gold, 2.5 (1.2-5.2) for 10-19 years, and 5.1 (2.4-10.9) for 20 or more years. Underground mining of minerals other than gold was also associated with chronic bronchitis (OR = 5.1; 95% CI, 1.1-25.0) whereas exclusive surface mining had only a small empirical effect (OR = 1.3; 95% CI, 0.6-2.5). It is estimated that the proportion of cases of chronic bronchitis in working underground miners due to occupational factors is 50%. The results support the existence of an industrial cause of chronic bronchitis, although caution must be exercised in generalising the results to miners with progressive and sever respiratory impairment.
PMCID: PMC1007925  PMID: 3689716
9.  Mortality from lung cancer among a cohort of nickel cadmium battery workers: 1946-84. 
The lung cancer mortality experienced by a cohort of 3025 workers from a nickel cadmium battery factory during the period 1946-84 has been investigated. Occupational histories were described in terms of 75 jobs: eight with "high," 14 with "moderate" or slight, and 53 with minimal or zero exposure to cadmium oxide (hydroxide) dust. The Mantel-Haenszel technique applied to prospective (or historical prospective) studies was used to compare the estimated cadmium exposures (durations of exposed employment) of those dying from lung cancer with those of matching survivors in the same year of follow up, while controlling for sex and year, and age of starting employment. Among workers first employed in the period 1923-46, there was some evidence of an association between the risk of dying from lung cancer and duration of employment in "high or moderate" exposure jobs, although the evidence relied heavily on the findings for the single highest exposure category. Among workers first employed in the period 1947-75, there was no evidence whatsoever of such an association.
PMCID: PMC1007924  PMID: 3689715
10.  Respiratory cancer and air pollution from iron foundries in a Scottish town: an epidemiological and environmental study. 
A geographical association between respiratory cancer and air pollution from steel foundries has been shown previously in Scotland and elsewhere. In the present study the iron-founding town of Kirkintilloch was found to have standardised mortality ratios (SMRs) for respiratory cancer in 1959-63, 1964-8, and 1969-73 that were unexceptional in comparison with Scotland. Nevertheless, when SMRs were calculated for respiratory cancer for the period 1966-76 in five zones of the town arranged, a priori, according to probable exposure to fumes from two iron foundries, and in the individual enumeration districts of the 1971 census, higher SMRs were found in the residential areas most exposed to pollution from the foundries. The gradient of the zones' SMRs--high close to the foundries to low at some distance from them--persisted despite standardisation of the SMRs for social class. A survey of the concentrations of several metals in soil cores sampled at 51 sites throughout the town showed a pattern of pollution that probably illustrated the effects of prevailing winds and topography on the pollution plumes from the foundries. The value of sampling soil cores in investigations where historical sources of metallic air pollution are of epidemiological interest was emphasised by the detection of high concentrations of Ni in an area where a nickel refinery had been located many decades previously.
PMCID: PMC1007923  PMID: 3689714
11.  Anyone for teno? 
PMCID: PMC1007922  PMID: 3689713
12.  Erythrocyte membrane microviscosity and phospholipid composition in lead workers. 
The microviscosity and fluidity of erythrocyte ghost membranes from lead workers and control subjects was measured by fluorescence polarisation using the fluorophore, 1,6-diphenyl-1,3,5-hexatriene (DPH). Increased lead was associated with a significant decrease in the average microviscosity of resealed and unsealed erythrocyte membranes. Since DPH fluorescence reflects the organisation of lipids in the central core of the membrane, two aspects of phospholipid metabolism were investigated. Phospholipids were extracted from red blood cell ghost membranes and identified by high performance liquid chromatography. The ratio of phosphatidyl choline to phosphatidyl ethanolamine, an established correlate of membrane fluidity, was significantly increased in lead workers. This is attributed to the known increases in red blood cell cholesterol in lead workers and the structural incompatibility of phosphatidyl ethanolamine and cholesterol, which result in a compensatory increase of phosphatidyl choline. Erythrocyte ghost membranes from control subjects were resealed with the intermediates in phospholipid synthesis that increase with a lead inhibited decrease in red blood cell pyrimidine 5'-nucleotidase. Membrane fluidity was not modified by incubation with cytidine triphosphate, uridine triphosphate, cytidine diphosphate choline, or cytidine diphosphate ethanolamine. Alterations in the microviscosity of the lipid regions of the hydrophobic core of the erythrocyte membrane bilayer and in the phospholipid composition of the membrane may be defects which contribute to the clinical and biochemical instability of the red blood cell on exposure to lead.
PMCID: PMC1007930  PMID: 3689721
14.  Malignant mesothelioma in Singapore. 
PMCID: PMC1007920  PMID: 3689712
15.  Exposure to benzene in Turkey between 1983 and 1985: a haematological study on 231 workers. 
A study was performed to determine the content of benzene in the air and solvents and thinners used by 231 workers in 40 small or large workplaces in Istanbul and Izmit. The benzene value in the air of a tyre cord manufacturing factory where two cases of acute leukaemia were recorded in a six year period was 110 ppm. In nine of 47 thinners (19.1%) the benzene content ranged between 0% and 6.4% whereas it was between 0.7% and 7.64% in 26 of 34 solvents used. A haematological study on 231 workers showed that there were mild abnormalities in 14 workers including leucopaenia in nine (3.9%), thrombocytopaenia in four (2.16%), and pancytopaenia in one (0.54%). This study shows that despite the considerable decrease in the content of benzene in the solvents and thinners available in Istanbul and Izmit the percentages of benzene in most of the materials are still above permissible limits.
PMCID: PMC1007919  PMID: 3689711
16.  Factor analysis of clinical data from asbestos workers: implications for diagnosis and screening. 
Clinical data from 624 asbestos exposed workers were analysed by factor analysis. Fifteen clinical variables were found to reflect several underlying factors: "obstruction," "interstitial disorder," "x ray change," "air tapping," and "age/exposure." Scoring individual subjects along these axes can facilitate identifying early cases and avoiding false diagnosis. The analysis suggests that screening should be multimodal and that radiographic abnormality need not imply physiological impairment.
PMCID: PMC1007918  PMID: 3689710
17.  Gastric cancer in coalminers: final report. 
A matched case-control study was conducted to investigate the risk of gastric cancer in coalminers in the southern part of Limburg, The Netherlands. All 683 male cases of gastric cancer were identified at the five pathology departments in the area, all histologically confirmed by a pathologist. For each case a control patient, free of gastric cancer, was selected from the same pathology department, matched on date of birth. Of the 1366 patients enrolled in the study, an occupational history was collected regarding previous employment in a Dutch coal mine. Of the patients with gastric cancer, 28% had been employed as underground workers in a coalmine compared with 25% of the control group. The odds ratio for underground coalmining and gastric cancer was 1.15 (95% confidence limits: 0.89-1.47). There was no evidence for the existence of a dose-response relation. It was concluded that the study did not provide support for the hypothesis that underground coalmining increases the risk of gastric cancer.
PMCID: PMC1007917  PMID: 3689709
18.  Occupation and five cancers: a case-control study using death certificates. 
A case-control approach has been used to examine mortality from five cancers--oesophagus, pancreas, cutaneous melanoma, kidney, and brain--among young and middle aged men resident in three English counties. The areas studied were chosen because they include major centres of chemical manufacture. By combining data from 20 years it was possible to look at local industries with greater statistical power than is possible using routine national statistics. Each case was matched with up to four controls of similar age who died in the same year from other causes. The occupations and industries recorded on death certificates were coded to standard classifications and risk estimates derived for each job category. Where positive associations were found the records of the cases concerned were examined in greater detail to see whether the risk was limited to specific combinations of occupation and industry. The most interesting findings to emerge were risks of brain cancer associated with the production of meat and fish products (relative risk (RR) = 9.7, 95% confidence interval (CI) 2.6-36.8) and with mineral oil refining (RR = 2.9, CI 1.2-7.0), and a cluster of four deaths from melanoma among refinery workers (RR = 16.0, CI CI 1.8-143.2). A job-exposure matrix was applied to the data but gave no strong indications of further disease associations. Local analyses of occupational mortality such as this can usefully supplement national statistics.
PMCID: PMC1007915  PMID: 3689708
19.  Levels of short (1-15 ms) electrical shocks from a 50 Hz supply inducing ventricular fibrillation in hyperbaric helium and oxygen. 
An investigation was undertaken to determine the ventricular fibrillation (VF) threshold of anaesthetised dogs subjected to external application of electric shocks between a foreleg and a hindleg. The shocks were 2-15 ms sections of 50 Hz sine waveform starting at peak current and were applied at a known time in the heart cycle. The object of the experiment was to determine if there was an increase in cardiac susceptibility to electrically induced VF at 31 atmospheres absolute (atm abs) in a helium and oxygen environment. The duration and position of that part of the cardiac cycle most vulnerable to induction of VF by electrocution was found (seven animals) using 4 ms shocks and then the minimum fibrillating current for shocks of 2-15 ms (min FC2-15) delivered at the most vulnerable point of the cycle (five animals). Body resistance was calculated from the data so gathered. Fibrillation thresholds were not changed by compression and there were no significant changes in the vulnerable period of the cardiac cycle. Min FC2 was significantly higher than for other durations under both control (3.21 A, SD 1.08) and test conditions (3.26 A, SD 0.39), p = 0.001. There was no difference in body resistance at 31 atm abs (395.5, SD 12.9) from control values at 1 atm abs (396.7, SD 10.9). From these data it was concluded that the heart is no more susceptible to the induction of VF at 31 atm abs in a helium oxygen environment and additional safety factors are unnecessary from this point of view.
PMCID: PMC1007914  PMID: 3689707
20.  Experimental studies with palygorskite dusts. 
As the preliminary results of experimental studies on dust from the palygorskite group have led to some confusion a detailed description of the completed investigation is given for clarification. As in other experiments the biological effects have been shown to be associated with the physical characteristics of the fibres in these specimens. Samples of sepiolite and attapulgite from Spain and a single sample of palygorskite from the United Kingdom have been studied. Serious abnormalities were produced only by the palygorskite and one of the attapulgite dusts. The palygorskite is of no commercial interest and the attapulgite was from one small deposit and was used only in the preparation of drilling mud in the exploration of oil deposits.
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PMCID: PMC1007913  PMID: 2961365
21.  Excess mortality among Swedish chimney sweeps. 
In a cohort study of 5464 union organised Swedish chimney sweeps employed at any time between 1918 and 1980 mortality was studied from 1951 to 1982 with national statistics used as a reference. Follow up was possible for 98.6% of the individuals: 717 deaths were observed against 540 expected. There was an increased mortality from coronary heart disease, respiratory diseases, and several types of malignant tumours. Lung cancer mortality was significantly increased and positively correlated to the number of years employed. A fivefold risk increase for oesophageal cancer and liver cancer was found. The increased mortality could be attributed to exposure to combustion products in the work environment but not to smoking habits.
PMCID: PMC1007911  PMID: 3689705
22.  Mortality among flavour and fragrance chemical plant workers in the United States. 
Vital status on 1 January 1981 was determined for a cohort of 1412 white men employed in a flavour and fragrance chemical plant between 1945 and 1965 in order to investigate the risks from fatal diseases among men exposed to multiple chemicals in the manufacture of fragrances, flavours, aroma chemicals, and other organic substances. Cause specific standardised mortality ratios (SMRs) were calculated for the entire study population and for several subsets by likelihood of exposure to chemicals, duration of employment, and year of hire. SMRs for rectal cancer and ischaemic heart disease were raised among white male employees whose jobs were in production, maintenance, laboratory, or other jobs that would involve exposure to multiple chemicals used and produced in the plant. The excess of rectal cancer was confined to employees who had worked as chemical operators and mortality was significantly raised among men who worked for ten or more years. Traces of dioxin were recently found in and around plant buildings that used trichlorophenol in the production of hexachlorophene. The study group was small and had limited power to detect excess risk of rare causes of death; however, no soft tissue sarcomas were observed during the study period.
PMCID: PMC1007910  PMID: 3689704
23.  Employers, the government, and industrial fatigue in Britain, 1890-1918. 
The evolution of the concept of industrial fatigue and the responses of employers and the government in Britain to research initiatives in this field of industrial medicine up to the end of the first world war is explored. The discussion dovetails in with the broader debate about the characteristics and dissemination of scientific labour management in Britain. The first section focuses on attitudes towards human energy expenditure and overwork in the nineteenth century. Following this is a discussion of the shorter hours movement of the 1890s, the important experiment at the Manchester engineering firm of Mather and Platt, and the reaction of British employers and the government to this. Finally, a brief analysis is made of the progress in research into workers' health, fatigue, and efficiency during the 1914-8 war, particularly concentrating on the role of the Health and Munition Workers Committee in pioneering the scientific study of industrial medicine. This led directly to the establishment of the Industrial Fatigue Research Board in 1918. Though there are significant caveats, it is argued that before the first world war a wide gap existed between research findings, best practice, and the common workshop experience and that in general British management (with some notable exceptions) grossly neglected the human element in production, ignored human physiological and psychological limitations, and hence both created and exacerbated serious problems of mental and physical fatigue and overstrain.
PMCID: PMC1007909  PMID: 3318915
25.  Occupational lead exposure and blood pressure. 
Recent community studies have suggested that low level lead exposure is significantly associated with blood pressure in the general population. This finding is inconsistent with the results of recent occupational studies of lead exposed workers, although the occupational studies contained serious methodological weaknesses. The present study examined the relation between occupational lead exposure and diastolic and systolic blood pressure in randomly selected samples of 270 exposed and 158 non-exposed workers. Four exposure indicators were examined: employment at a lead battery plant nu a control plant, current blood lead value, current zinc protoporphyrin value, and time weighted average blood lead value. After controlling for other known risk factors such as age, education, income, cigarette usage, alcohol consumption, and exercise, the associations between exposure and blood pressure were small and non-significant. In the absence of a biologically feasible hypothesis regarding the mechanism by which low level lead exposure would influence blood pressure the present findings challenge the validity of the general population association.
PMCID: PMC1007912  PMID: 3689706

Results 1-25 (158)