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1.  Hanford radiation study. 
PMCID: PMC1009130  PMID: 6824593
9.  Urinary hippuric acid and orthocresol excretion in man during experimental exposure to toluene. 
It is not known whether urinary excretion of hippuric acid (HA) or orthocresol (O-Cr) is to be preferred for the biological monitoring of workers with occupational exposure to toluene. To study this, 42 printing trade workers with more than 10 years' exposure to a mixture of organic solvents including toluene (0-20 ppm) and 43 control subjects matched by age, smoking habits, and living accommodation were investigated. Each matched pair was randomised to an experimental exposure of either 100 ppm or 0 ppm toluene for 6.5 hours under controlled conditions in an exposure chamber. Urinary excretion of HA and O-Cr was determined by high pressure liquid chromatography from samples obtained before exposure, during the first three hours, and during the last 3.5 hours of exposure. No difference in HA and O-Cr excretion was found between printing trade workers and controls. The median O-Cr excretion increased 29 times during exposure, whereas the HA excretion increased only five times. Thus only 3% of the O-Cr excretion originated from other sources than toluene whereas the corresponding value for HA was 19%. Standardisation of the concentrations of HA and O-Cr in relation to urinary creatinine reduced the relative variation by 29% and 56% respectively. This was not reduced further by expressing the excretions as average excretion rates based on total volume of urine collected. Background urinary O-Cr excretion was three to four times higher among smokers than non-smokers, probably due to the content of O-Cr in cigarettes. The O-Cr excretion in unexposed smokers was, however, 10 times lower that that of the non-smokers during the end of the experimental exposure to 100 ppm toluene.
PMCID: PMC1009223  PMID: 6626478
10.  Antipyrine clearance during experimental and occupational exposure to toluene. 
Exposure to toluene vapour enhances hepatic microsomal enzyme function in animals as assessed by the metabolism of the test drug antipyrine. Thirty six printing trade workers with long term occupational exposure to a mixture of organic solvents and 39 matched controls were randomly allocated into four groups. Eighteen printers and 21 controls were exposed to 100 ppm of toluene during 6.5 hours in an exposure chamber. The remaining 18 printers and 18 controls were exposed to 0 ppm of toluene under similar conditions. The salivary clearance of antipyrine was measured immediately after the stay in the exposure chamber to investigate a possible acute change in liver function and was repeated two weeks later, shortly before the summer vacation. Antipyrine clearance was measured again at the end of the summer vacation-four weeks after exposure. To study a possible effect of chronic exposure on antipyrine clearance 12 printing trade workers with 17 years (median) of occupational exposure to toluene vapour at concentrations of about 100 ppm were investigated before and four weeks after cessation of exposure. No difference in antipyrine clearance was found either within the groups or between the groups at any of the measurements.
PMCID: PMC1009222  PMID: 6626477
11.  Interference with the pacemakers of two workers at electricity substations. 
Pacemaker function was tested in two electricity substation workers exposed to high tension electric fields. High intensity electric fields induced reversion to the interference mode, producing in one case competitive rhythm and in the other inappropriately slow pacing which resulted in asymptomatic pauses of up to 2.5 s. A suit designed to shield the body from the effects of high intensity electric fields was tried and proved to be effective in protecting the pacemaker, allowing it to function normally in the substations.
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PMCID: PMC1009221  PMID: 6626476
12.  Reversibility of skeletal fluorosis. 
At two x ray examinations in 1957 and 1967, 17 cases of skeletal fluorosis were identified among long term cryolite workers in Copenhagen. In 1982 four of these patients were alive, eight to 15 years after exposure had ended. Radiographs were obtained, and the urinary fluoride excretion was measured. A similar picture emerged in all four cases: extensive fading of the sclerosis of trabecular bone in ribs, vertebral bodies, and pelvis, whereas cortical bone thickening and calcification of muscle insertions and ligaments remained virtually unchanged. The fluoride excretion was increased in three cases (with the shortest exposure free period). These findings indicate that with continuous remodelling of bone tissue trabecular sclerosis is slowly reversible and the excess fluoride is excreted in the urine.
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PMCID: PMC1009220  PMID: 6626475
13.  Industrial gassing poisonings due to trichlorethylene, perchlorethylene, and 1-1-1 trichloroethane, 1961-80. 
During the period 1961-80, 384 cases of industrial gassing poisonings by trichlorethylene, perchlorethylene, and 1-1-1 trichloroethane (methylchloroform) were reported to HM Factory Inspectorate. A study of these data, which have been collated and analysed with particular reference to sex, age, clinical manifestations, and circumstances of the incident, is presented. Possible bias of the data owing to its source and method of extraction is discussed. The study shows the hazards inherent in the use of these narcotic solvents and discusses the circumstances that appear most likely to produce problems. The vulnerability of the younger worker is shown. Toxic effects were most commonly exerted on the central nervous system but no good evidence of cardiac or hepatic toxicity was found. In nine cases evidence of deliberate sniffing of solvent was reported. The problem of solvent abuse in an industrial context is discussed.
PMCID: PMC1009219  PMID: 6626474
14.  Allergy to laboratory animals: a retrospective and a prospective study. 
Twenty four volunteers who had been allergic to laboratory animals for some years were examined by means of a questionnaire paying particular attention to symptoms associated with rats and by serological and skin tests with extracts of rat urine (retrospective study). Nasal and eye symptoms were reported by 21 and 16 individuals respectively: 13 had asthma. Positive skin tests and high levels of specific IgE antibody to rat urine extract were found in 17 of the more severely affected individuals and this group included 12 of those with asthma. Latent periods of work with animals before symptoms appeared varied from 0.5 to 12 years. Also 148 individuals were studied during their first year of work with animals (prospective study). Symptoms developing during the year were reported by 15%, asthma by 2%. IgE antibody levels to rat urine were raised in 40% of affected and 6% of the unaffected individuals but there was no significant correlation between symptoms and either antibody levels or positive skin tests. Allergic symptoms developing during the first year of postemployment were, on the whole, much milder than those seen in the retrospective study. A tentative conclusion is that most individuals who become allergic to laboratory animals develop the condition in a mild form during their first year of employment but it appears probable that atopic individuals, although having an equal chance of developing allergy as compared with non-atopic individuals, may eventually progress to a more severe form of the disease.
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PMCID: PMC1009218  PMID: 6626473
15.  Blood pressure, flow, and peripheral resistance of digital arteries in vibration syndrome. 
The peripheral circulation was studied in 19 lumberjacks and in 12 control subjects. Twelve of the lumberjacks were free from vascular symptoms and seven had vibration induced white finger (VWF). Using the strain-gauge plethysmographic technique, the digital circulation was examined at rest, during cooling of the upper body, and during heating of the upper body. At rest and during vasodilatation no significant differences were found between the lumberjacks and the controls. During reflexive vasoconstriction, digital blood flow in the upper body was more reduced in lumberjacks with VWF than in control subjects. Furthermore, digital blood pressure of the lumberjacks with VWF fell more than in the control group. The peripheral resistance also increased more, but this difference was not statistically significant. There was no evidence that the exaggerated vasoconstriction of VWF resulted from a narrowing of the lumen of arterioles due to hypertrophy of the vessel wall. The present findings suggest that VWF is produced by the highly sensitive responsiveness of the affected vessel to normal vasoconstrictor stimuli.
PMCID: PMC1009217  PMID: 6626472
16.  Vibration syndrome and vibration in pedestal grinding. 
At one Finnish foundry all the workers had typical symptoms of vibration induced white finger (VWF) after they began using a new type of pedestal grinding machine. The objectives of this study were to establish the severity of the symptoms and the difference in vibration exposure between the new and the old machines. Vibration detection thresholds and grip forces were measured, as well as the vibration in the casting and in the wrist simultaneously. The mean latency for VWF among the grinders was 10.3 months after the change of pedestal grinding machines. All the grinders had numbness in their hands. The vibration detection threshold was significantly higher for the grinders than for their referents. At the same circle speed, the new wheels caused vibration levels up to 12 dB more than the old wheels. The circle speed had a slight influence on the vibration. The vibration levels of light (0.5 kg) casting were up to 25 dB higher than the heavy (5 kg) casting. The use of a pneumatic pressing device decreased the vibration levels in the wrist by 5-10 dB. The increase in vibration, which occurred when the new wheels were taken into use, was too small to explain such a dramatic outbreak of VWF. This led to the conclusion that some other feature such as the impulse character of the vibration also contributed to the effects of vibration.
PMCID: PMC1009216  PMID: 6626471
17.  Cadmium in blood and urine related to present and past exposure. A study of workers in an alkaline battery factory. 
Blood and urinary cadmium concentrations together with cadmium in air concentrations from the breathing zone of 18 male workers in an alkaline battery factory were determined at regular intervals for 11 consecutive weeks. Nine of the workers examined were smokers and nine non-smokers. Smokers and non-smokers did not differ in age or years of employment. Cadmium in air concentrations varied, but no definite trend was observed. The concentrations of cadmium in the blood and urine were found to be stable. Exposure to airborne cadmium was identical for smokers and non-smokers but average cadmium concentrations in the blood and urine of smokers were approximately twice as high as those in non-smokers. For the whole group, urinary cadmium was significantly correlated with years of employment, but no correlation was found between blood cadmium concentrations and exposure. For non-smokers, the correlation between cadmium in blood and years of employment was statistically significant (p less than 0.001). This finding indicated that blood concentrations of cadmium reflect body burden in non-smokers at current low exposure levels.
PMCID: PMC1009215  PMID: 6626470
18.  Effects of lead exposure on peripheral nerve in the cynomolgus monkey. 
The relationship between blood lead concentration and nerve conduction velocity has been examined, using the cynomolgus monkey as a model for human lead poisoning, with lead dose and blood lead concentration maintained under controlled conditions, to determine whether nerve conduction velocity could be used as an objective measure of the effects of lead on the nervous system at subclinical concentrations. Five cynomolgus monkeys were maintained at a blood lead concentration of 90-100 micrograms Pb/100 ml for nine months by daily oral dosing with lead acetate (12-15 mg Pb/kg body weight). Motor nerve conduction velocity in the ulnar nerve was measured, together with blood lead concentrations. Blood lead concentrations were proportional to lead intake, reaching a stable level within one to two weeks. Lead did not accumulate in the blood, and blood lead concentrations were found to decrease to a maintained plateau from initial high concentrations during the first seven days of dosing. The animals showed no clinical or behavioural evidence of lead poisoning at any time during the study, although there was a progressive decrease in blood packed cell volume, haemoglobin concentration, and erythrocyte concentration. The maximal motor nerve conduction velocity of the ulnar nerve remained constant throughout the study, although changes were observed in the conduction velocity of slowly conducting nerve fibres. At termination, intranuclear inclusions were found in the renal tubular cells of all animals as were focal areas of myelin degeneration in the ulnar and sciatic nerves.
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PMCID: PMC1009213  PMID: 6626468
19.  A brief history of scrotal cancer. 
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PMCID: PMC1009212  PMID: 6354246
20.  Lung cancer associated with chloromethyl methyl ether manufacture: an investigation at two factories in the United Kingdom. 
The prevalence of deaths from lung cancer, other cancer, and all other causes was studied in workers and former workers at two factories (A and B) in the United Kingdom at which chloromethyl methyl ether has been manufactured, at one since about 1948 and at the other since 1956. At factory A in South Wales 571 men were traced and at factory B in the north east of England 1196. A statistically significant excess of observed deaths from lung cancer but not other cancer compared with the number expected was found in factory A when the death rates for the population of Glamorgan were applied. The deaths from lung cancer at factory A were related to risk in terms of total exposure time, and average exposure rate and dosage. The degree of exposure was more important than the duration of exposure. There has so far been no demonstrable excess of deaths from lung cancer in employees working at factory A since the process was changed in 1972. In factory B the risk was low over the whole period, and there was no excess of lung or other cancers compared with the rates for the Tyneside conurbation. Despite improvements in the process in both factories continued surveillance of the workers is needed for some years yet.
PMCID: PMC1009211  PMID: 6226309
21.  Tobacco consumption and asbestos exposure in patients with lung cancer: a three year prospective study. 
During the three years 1979-81, all patients with bronchial carcinoma of World Health Organisation types I to IV were given a questionnaire to determine occupation, smoking habits, and exposure to asbestos. Chest x rays were screened for the presence of pleural plaques. Of the men, 96.2% were current or ex-smokers, as were 71% of the women. In those who had never smoked 70% had an adenocarcinoma. In smokers the risk of getting other types was greater, but the risk of getting an adenocarcinoma was also considerably increased compared with the normal population. Of the men, 35.8% were occupationally exposed to asbestos and 15.6% were carriers of radiological plaques, a frequency five to six times greater than expected. Practically all asbestos exposed patients with lung tumours were smokers or ex-smokers and their total tobacco consumption was as high as that of non-exposed patients. The average latency from first exposure to asbestos to diagnosis of the lung tumour was 37 years. Even if strict regulations are warranted for the use of asbestos, this cannot prevent future asbestos cancers resulting from exposure that has already occurred. Elimination of smoking seems the only way to reduce such tumours.
PMCID: PMC1009210  PMID: 6626467
22.  Fibre type and concentration in the lungs of workers in an asbestos cement factory. 
The predominant asbestos fibre type used in the production of asbestos cement is chrysotile. The use of asbestos in relation to fibre type in a Norwegian asbestos cement plant during 1942-80 was 91.7% chrysotile, 3.1% amosite, 4.1% crocidolite, and 1.1% anthophyllite respectively. Electron microscopy and x ray microanalysis of lung tissue samples of asbestos cement workers who had died of malignant pleural mesothelioma or bronchogenic carcinoma showed a completely inverse ratio with regard to fibre type. The percentage of chrysotile asbestos in lung tissue varied between 0% and 9% whereas the corresponding numbers for the amphiboles were 76% and 99%. These differences are discussed with respect to the behaviour of different fibre types in the human body and to the occurrence of malignant mesothelioma in this asbestos cement factory.
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PMCID: PMC1009209  PMID: 6313034
23.  Dust exposure and mortality in an American factory using chrysotile, amosite, and crocidolite in mainly textile manufacture. 
This report describes the second in a series of three parallel cohort studies of asbestos factories in South Carolina, Pennsylvania, and Connecticut to assess the effects of mineral fibre type and industrial process on mortality from malignant mesothelioma, respiratory cancer, and asbestosis. In the present plant (in Pennsylvania) mainly chrysotile, with some amosite and a small amount of crocidolite, were used primarily in textile manufacture. Of a cohort of 4137 men comprising all those employed 1938-59 for at least a month, 97% were traced. By the end of 1974, 1400 (35%) had died, 74 from asbestosis and 70 from lung cancer. Mesothelioma was mentioned on the certificate in 14 deaths mostly coded to other causes. All these deaths occurred after 1959, and there were indications that additional cases of mesothelioma may have gone unrecognised, especially before that date. The exposure for each man was estimated in terms of duration and dust concentration in millions of dust particles per cubic foot (mpcf) from available measurements. Analyses were made both by life table and case referent methods. The standardised mortality ratio for respiratory cancer for the whole cohort was 105.0, but the risk rose linearly from 66.9 for men with less than 10 mpcf.y to 416.1 for those with 80 mpcf.y or more. Lines fitted to relative risks derived from SMRs in this and the textile plant studied in South Carolina were almost identical in slope. This was confirmed by case referent analysis. These findings support the conclusion from the South Carolina study that the risk of lung cancer in textile processing is very much greater than in chrysotile production and probably than in the friction products industry. The much greater risk of mesothelioma from exposure to processes in which even quite small quantities of amphiboles were used was also confirmed.
PMCID: PMC1009208  PMID: 6313033
24.  Dust exposure and mortality in an American chrysotile textile plant. 
Three parallel cohort studies of asbestos factory workers were undertaken to investigate the effects of mineral fibre type and industrial process on malignant mesothelioma, respiratory cancer, and asbestosis. This report describes the mortality of a cohort of 2543 men, defined as all those employed for at least a month from 1938 to 1958 in a textile plant in South Carolina in which chrysotile was the only type of asbestos used. Of these, 863 men (34%) had died before 31 December 1977, one from malignant mesothelioma. Twenty one deaths were ascribed to asbestosis and 66 to cancer of the lung. Compared with the number expected from South Carolina, there was an excess of 30 deaths from respiratory cancer (ICD 160-164) in men 20 or more years after first employment (SMR 199.5). In men employed five years or more, no SMRs for this category rose above 300. Individual exposures were estimated (in mpcf X years) from recorded environmental measurements. Life table analyses and "log-rank" (case-control) analyses both showed a steep linear exposure-response that was some 50-fold greater at similar accumulated dust exposures than in Canadian chrysotile mining and milling. These findings agree closely with those from another study in this plant and confirm that mesothelioma is rarely associated with chrysotile exposure. Cigarette smoking habits did not greatly differ between the textile workers and the Canadian miners and millers. The far greater risk of lung cancer in the textile industry, if not attributable to other identified cocarcinogens, may be related to major differences in the size distribution of fibres in the submicroscopic range which are not detected by the usual fibre or particle counting procedures.
PMCID: PMC1009207  PMID: 6313032
25.  Effect of occupational exposure to elemental mercury on short term memory. 
Previous studies have indicated that exposure to elemental mercury is associated with increased short term memory scanning time. In an effort to provide converging evidence that short term memory is one locus of the neurotoxic effect of mercury, two measures of short term memory capacity were used in this study. The first measure, the Wechsler digit span forward, was too imprecise and unreliable to detect any adverse effects. The second measure, an estimate of the worker's 50% threshold for correct serial recall, was more satisfactory and provided evidence of a statistically significant decrease in short term memory capacity associated with increasing exposure to elemental mercury (based on a group of 26 workers, urinary mercury average 0.20 mg/l, range 0.0-0.51 mg/l). A replication study of another group of 60 workers was performed to confirm this apparent mercury related effect. Despite lower urinary mercury concentrations in this second group (0.11 mg/l average), a statistical association was again observed relating urine mercury to reduced short term memory capacity.
PMCID: PMC1009214  PMID: 6626469

Results 1-25 (81)