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2.  Cotton bacterial endotoxin assessed by electron microscopy. 
A piece of bale cotton was incubated in nutrient broth. Electron microscopic inspection of the cotton and the broth showed Gram-negative bacteria with long flagella, loosely attached to the cotton fibres. Large amounts of endotoxin liberating from these bacteria were visible in the growth medium.
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PMCID: PMC1069296  PMID: 7032578
6.  Silicosis. 
PMCID: PMC1069297  PMID: 7317305
12.  A technique to prepare asbestos air samples for light and electron microscopy. 
The direct transfer technique used in preparing waterborne asbestos for analysis by transmission electron microscopy is also suitable for preparing airborne asbestos collected on polycarbonate filters for light microscopy, scanning, and transmission electron microscopy. The same area and even the same fibre may be examined by the three microscopic methods and individual fibres identified by optical and electron-optical techniques and by x-ray microanalysis.
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PMCID: PMC1069295  PMID: 7317304
13.  Non-invasive magnetopneumographic determination of lung dust loads in steel arc welders. 
Magnetopneumography was used to measure non-invasively the concentration of the ferrimagnetic fraction of retained welding fume in the thoraces of steel arc welders. This was done by measuring the remanent magnetic fields due to ferrimagnetic particles. The 11 welders studied had concentrations of thoracic ferrimagnetic mineral several orders of magnitude greater than three machinists, 16 former asbestos insulators and 24 control subjects. These concentrations correlated well with total years welding (p less than 0.01) and radiographic evidence of small rounded densities (p less than 0.05), but not with smoking history. There was a higher concentration of ferrimagnetic mineral over the hilar regions. Magnetopneumography offers a non-invasive indicator of the accumulation of welding fume in the thorax.
PMCID: PMC1069294  PMID: 7317303
14.  Screening for occupational vitiligo in workers exposed to hydroquinone monomethyl ether and to paratertiary-amyl-phenol. 
Two men reported previously with vitiligo after occupational exposure to hydroquinone monomethyl ether (HMME) have been reviewed after eight years. Repigmentation of significant degree was found in one man and of limited degree in the other. One hundred and sixty-nine men in the same works have been screened with Wood's light for evidence of vitiligo. No cases were found in the 148 men exposed to HMME (colleagues who screened 100 men exposed to HMME in two other factories also found no case) or in the 129 who had been exposed to paratertiary-amyl-phenol. Loss of light reflection on Wood's light examination was observed in 13 men due to scars or to other skin disorders.
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PMCID: PMC1069293  PMID: 7317302
15.  A study of the mortality of Cornish tin miners. 
Increased mortality from cancer of the lung has been found in several studies of miners exposed to high levels of radioactivity in underground air. In view of their exposure to raised levels of radiation, we have studied the mortality of a group of men recorded as Cornish tin miners in 1939. Using occupational description, a crude classification of exposure was derived for these miners. The meaningfulness of this classification was supported by differences in mortality from silicosis and silicotuberculosis. A twofold excess of cancer of the lung was found for underground miners, while for other categories mortality from this cause was less than expected. This supports the findings of previous studies on exposure to radon and its daughters. An excess of cancer of the stomach was also observed among underground miners.
PMCID: PMC1069292  PMID: 7317301
16.  Testicular function among epichlorohydrin workers. 
Epichlorohydrin (1,2-epoxy-3-chloropropane) (ECH) is a colourless liquid used in the production of insecticides, agricultural chemicals, epoxy resins, and many other productions. It is highly reactive and an alkylating agent suspected of possessing carcinogenic properties in man. The results of a clinical-epidemiological investigation to ascertain whether exposure to ECH may be associated with sperm count suppression among ECH production workers at two chemical plants are presented. Medical histories and physical examinations with special emphasis on the genitourinary tract were completed on each participant. Blood samples and three semen specimens were also obtained. Since no internal control group were available, the data arising from this effort were analysed for each plant (plant A, 44 men; plant B, 84 men) using a control group of 90 chemical plants workers unexposed to any agents known to be toxic to the tests who were included in previous studies. This study provides no evidence that exposure to ECH at the concentrations existing at the two plants studied is responsible for sperm count suppression.
PMCID: PMC1069291  PMID: 6797463
17.  Magnitude and distribution of trunk stresses in telecommunications engineers. 
The incidence of back injuries has been shown to be greater in occupations as heavy manual work than light manual work. To plan a programme aimed at reducing the incidence of back injuries in industry those workers at high risk of incurring handling accidents and back injuries need to be identified and a knowledge of the specific occupational factors causing such injuries sought. This has been achieved for telecommunications engineers using epidemiological and radio pressure pill methodologies. The results verify the correlation between the back injury rates and physical work stresses of different occupational groups. The magnitude and relative frequency of trunk stresses in hazardous tasks has been determined and compared with those with lower incidences of back disorders. The study has confirmed that in examining manual handling hazards in industrial male populations a critical value of truncal stress can be applied and used to determine the safety of occupational factors in relation to their potential causing or contributing to degenerative back diseases.
PMCID: PMC1069290  PMID: 7317300
18.  Occupational and individual factors in acute shoulder-neck disorders among industrial workers. 
Twenty workers, consecutively attending the industrial health care centre for the first time with acute shoulder-neck pains, were subject to extensive rheumatological and ergonomic examinations. In seven patients congenital malformations for diseases causing musculoskeletal symptoms, or both, were probable aetiological factors. In the remaining 13 patients a significantly higher load was found on both shoulders (assessed by biomechanical film analysis) than in matched control. Age, anthropometric measures, muscle strength, or HLAB27 did not appear as significant predisposing factors. Most patients could return to work within a year.
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PMCID: PMC1069289  PMID: 7317299
19.  Some observations on workers exposed to methylene chloride. 
An excess of self-reported neurological symptoms was found when a group of 46 men exposed to methylene chloride at concentrations below 100 ppm was compared with a non-exposed referent group. A follow-up study was then carried out to see whether there was any evidence of neuropsychological damage in the exposed men. Twenty-nine of the original group participated in this study. Age-matched controls controls were selected from among men working on a similar process but with no exposure to solvents. Each man in the study had a clinical examination; motor conduction velocities were measured in the ulnar and median nerves; an ECG was taken and a psychological test battery was designed to detect minimal brain damage was administered. No evidence was found of long-term damage that could be attributed to exposure to methylene chloride.
PMCID: PMC1069288  PMID: 7317298
20.  Acute behavioral effects of styrene exposure: a further analysis. 
Studies were carried out on two groups to styrene-based resin. Early morning urinary mandelic acid concentrations after two days without exposure correlated with reaction time measured on arrival at work. Men were found to differ considerably in their rate of clearance of mandelic acid-those with slow reaction times. After some months at reduced exposure, a small group of men with previously high mandelic acid concentrations has speeded up on the reaction time task.
PMCID: PMC1069287  PMID: 7317297
21.  Ventilatory function in workers exposed to tea and wood dust. 
Changes in ventilatory capacity during the work shift were studied in workers exposed to tea dust in tea-packing plants, wood dust in two furniture factories, and virtually no dust in an inoperational power station. The FEV1 and FVC in workers exposed to dust were found to decline during the work shift by a small but significant volume. The MMFR, Vmax 50% and Vmax 75% were to variable to display any trend. No dose-response relationship could be discerned between the fall in workers' ventilatory capacity and the concentrations of airborne dust or microbes to which they were exposed. Bronchodilators could reverse the fall in FEV1.
PMCID: PMC1069286  PMID: 7317296
22.  Sensitisation against environmental antigens and respiratory symptoms in swine workers. 
Adverse effects caused by airborne material to the respiratory tract are due either to non-specific irritation or to hypersensitivity. In this study 20 people employed in swine barns and 18 controls were tested for sensitisation against dusts present in the barn. Immunoprecipitation and enzyme-linked immunoassay (ELISA) were used to test for IgG antibodies; IgE antibodies against swine epithelium were tested using solid phase radioimmunoassay. Precipitins against swine antigens were found in two swine workers; while ELISA found six to be sensitised. Sensitisation against swine antigens correlated with exposure but not with the presence of symptoms. No IgE antibodies were found. Precipitins against feed antigens were detected in 12 workers; in nine of the 12 with symptoms, and in three of the eight asymptomatic workers. No single antigen was of special importance as an inducer of sensitisation. Sensitisation against feed dusts in barns, as indicated by the presence of circulating antibodies, suggests an immunological background for persistent symptoms. A large antigen penal should be used in testing for sensitisation because of the many immunogenic dusts present in the air in swine barns.
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PMCID: PMC1069285  PMID: 7032577
23.  Respiratory cancer in a cohort of nickel sinter plant workers. 
A study was undertaken of a cohort of nickel refinery workers from a sinter plant that operated from 1948 to 1962. A complete follow-up of the 495 workers has been carried out by searching death records and other measures. Incidence cases known to the Workmen's Compensation Board of Ontario have been included. Fifty-four cases of lung cancer and eight of sinus cancer (including two in men who subsequently developed primary lung cancer) were located. The risk of lung and sinus cancer was much higher in the earlier days of operation of the plant, with an increase rate of over 40% for those employed in the first year of operation. The dose-response relationship has been examined by regressions of standardised morality ratios (SMR) and standardised incidence ratios (SIR). The SIR suggests that the risk doubled at levels of exposure of 12 months (six months in the earlier years).
PMCID: PMC1069282  PMID: 7317295
24.  Factors predisposing to the development of progressive massive fibrosis in coal miners. 
Altogether 238 759 miners employed by the National Coal Board were examined in the third of the Board's radiological surveys from 1969 to 1973 inclusive. Excluding those diagnosed as having progressive massive fibrosis (PMF) on that occasion, 210 847 were in collieries still operating at the time of the fourth survey four to five years later 132 728 attended for radiography at the same colliery on the second occasion, and were used to study the attack rate of PMF. In all groups in the age range 35-54 and having category 2 simple pneumoconiosis (SPN) or less, 80% or more had a second radiograph. It was found that the probability of developing PMF increased sharply with rising category of SPN; however, half the cases occurred in men having SPN categories 0 or 1, who were in the majority. Current coalface work had no significant effect on the attack rate. Age increased the attack rate of PMF within each major SPN category (0, 1, 2, and 3), especially the higher categories. All or part of this effect may have been due to the fact that SPN in younger men with categories 1 and 2 tends to lie in the lower range within these categories. Similarly, a lower distribution of SPN within each category associated with a low overall local prevalence may account wholly or in part for the great difference between the attack rates of PMF supervening on each category of SPN in Scotland and South Wales. The rank (quality) of coal mined had no effect on the attack rate.
PMCID: PMC1069281  PMID: 7317294
25.  Relationship between type of simple coalworkers' pneumoconiosis and lung function. A nine-year follow-up study of subjects with small rounded opacities. 
One hundred and twenty-five men who were identified in 1968 as having the simple pneumoconiosis of coalworkers were re-examined nine years later when their mean age was 59.6 years. On both occasions the lung function and response to exercise were assessed. There was no evidence for progression of simple pneumoconiosis between the surveys, but 14 had developed small irregular opacities on their chest radiographs and 28 showed early changes of progressive massive fibrosis (PMF). After allowing for the effects of smoking and of exposure to coal dust, subjects with both p and r types of simple pneumoconiosis exhibited a reduced transfer factor compared with subjects having q-type opacities; subjects with r-type opacities also showed an increased pulmonary elastic recoil pressure. The presence of irregular opacities, independent of rounded opacities, was associated with a low transfer factor and decreased slope of phase III of the single breath oxygen test. Subjects who developed PMF between 1968 and 1978 had p or r opacities more often than q opacities: these subjects had an increase pulmonary elastic recoil pressure. The development of PMF was also associated with physiological evidence of airways obstruction. The changes in subjects with r opacities are consistent with the presence of space occupying lesions that may progress to PMF. Subjects with p opacities have physiological evidence of emphysema as do some subjects with established PMF. Irregular opacities may reflect the presence of both emphysema and diffuse fibrosis. There is need for more morbid anatomical evidence on the underlying pathology.
PMCID: PMC1069280  PMID: 7317293

Results 1-25 (74)