PMCC PMCC

Search tips
Search criteria

Advanced
Results 1-25 (61)
 

Clipboard (0)
None
Journals
Year of Publication
Document Types
6.  Hand grip forces during chain saw operation and vibration white finger in lumberjacks. 
The hand grip forces at the front and rear handles of a chain saw were measured during work, in 89 professional lumberjacks. The symptoms caused by vibration to the upper limbs were compared with the hand grip force (HGF) during work. To allow better comparison between subjects we used the ratio of hand grip force (HGF) to the maximal voluntary compression force (MVC), HGF/MVC expressed as a percentage. The mean HGF during sawing varied from 5 to 12 N in all subjects. The variation in HGF was greater at the front handle than at the rear handle, during sawing. The lumberjacks who had vibration-induced white fingers (VWF), had a higher HGF/MVC in both hands than the lumberjacks without VWF. Those lumberjacks affected by VWF used over 12% of their MVC at work. Subjects without HGF/MVC ratio. The lumberjacks with and without numbness in their hands had equal HGF/MVC ratios.
PMCID: PMC1008612  PMID: 228695
7.  The distribution and metabolism of nickel carbonyl in mice. 
The distribution of 63Ni- and 14C-labelled nickel carbonyl was studied in mice by whole-body autoradiography and by liquid scintillation counting. Radioactivity from Ni(14CO)4 was found almost exclusively in the blood, probably because of the formation of 14CO-haemoglobin. After the administration of 63Ni(CO)4 the highest level of 63Ni was found in the lung. Other tissues accumulating a high amount of 63Ni were the brain and spinal cord, the heart muscle, the diaphragm, brown fat, the adrenal cortex and the corpora lutea of the ovaries. A high level of 63Ni was also present in the kidneys and the urinary bladder. Experiments designed to establish whether the nickel in the lung, the brain, the heart muscle and the blood was present in a non-ionised form, or as a cation, suggest that nickel is bound to these tissues in the cationic state (Ni++).
Images
PMCID: PMC1008611  PMID: 508645
8.  5-aminolevulinate dehydratase activity in blood of rabbits given tin or lead. 
The activity of 5-aminolevulinate dehydratase (ALAD) in rabbit blood is significantly inhibited by tin. Intravenous administration of tin (0.48 or 4.8 mumol/kg body weight) causes a decrease in the activity of the enzyme by 60% or 94% respectively. The effects of tin and lead on ALAD differ: inhibition by tin is not affected by pre-incubation at 50-60 degrees C, whereas the inhibitory effect of lead is increased by the same pretreatment. The optimum pH for rabbit blood ALAD is 6.8 in control rabbits. This optimum shifts to pH 5.8-6.0 in the blood of tin-treated rabbits, with or without pre-incubation at 60 degrees C for 5 min, while a similar shift is prevented by the same pre-incubation after lead treatment. Recovery to normal activity is faster after tin than after lead treatment.
PMCID: PMC1008610  PMID: 508644
9.  Occupational lead poisoning in the United States: clinical and biochemical findings related to blood lead levels. 
Dose-response relationships between blood lead levels and toxic effects have been evaluated in 160 lead workers in two smelters and a chemicals plant. Blood lead levels ranged from 0.77 to 13.51 mumol/litre (16-280 microgram/dl). Clinical evidence of toxic exposure was found in 70 workers (44%), including colic in 33, wrist or ankle extensor muscle weakness in 12, anaemia (Hgb less than 8.69 mumol/litre (Hb/4) or 14.0 gm/dl) in 27, elevated blood urea nitrogen (greater than or equal to 7.14 mmol/litre or 20 mg/dl) in 28, and possible encephalopathy in two. No toxicity was detected at blood lead levels below 1.93 mumol/litre (40 microgram/dl). However, 13% of workers with blood lead levels of 1.93 to 3.81 mumol/litre (40-79 microgram/dl) had extensor muscle weakness or gastrointestinal symptoms. Anaemia was found in 5% of workers with lead levels of 1.93-2.85 mumol/litre (40-59 microgram/dl), in 14% with levels of 2.90 to 3.81 mumol/litre (60-79 microgram/dl), and in 36% with levels greater than or equal to 3.86 mumol/litre (80 microgram/dl). Elevated blood urea nitrogen occurred in long-term lead workers. All but three workers with increased blood urea nitrogen had at least four years occupational lead exposure, and nine had received oral chelation; eight of this group had reduced creatinine clearance, and eight had decreased renal concentrating ability. These data support the establishment of a permissible biological limit for blood lead at a level between 1.93 and 2.90 mumol/litre (40-60 microgram/dl).
PMCID: PMC1008609  PMID: 508643
10.  Mill effect and dose-response relationships in byssinosis. 
Four hundred and eighty-six textile workers in three cotton mills and one wool/synthetic mill were studied for symptoms and functional effects of workroom exposure to dust. Byssinosis was found in 5.7% of 386 cotton workers, with an apparent threshold level of 0.5 mg cotton dust/m3 of air. Mean post-shift functional declines were greater in workers exposed to greater than or equal to 0.2 mg/m3. Workers with byssinosis were unequally distributed, however, with respect to job category and mill; and these variables, rather than current dust exposure levels, accounted for the observed distribution of byssinosis prevalence rates. Variation in biological potency of different samples of cotton dust could be responsible for 'mill effect', the residual variation in response rates by mill after controlling for variation due to dust exposure. A number of other potential influencing variables that are likely to be distributed unequally by mill should also be considered. Mill effect should be assessed in large-scale studies of byssinosis, most of which have analysed biological response rates by combining mill and other variables to examine first-order effects of dust dosage. In such analyses, much of the observed variability may be due to factors other than dust dosage.
PMCID: PMC1008608  PMID: 508642
11.  Bacterial contamination of cotton as an indicator of respiratory effects among card room workers. 
The influence of the bacterial contamination of cotton dust on the development of pulmonary symptoms has been investigated. The pulmonary function of card room workers in 23 US cotton mills was tested before and after the Monday working shift. A significant relation was found between the delta FEV1.0 decrement and the vertical elutriator dust level in the different mills. An improved correlation was obtained when the number of Gram-negative bacteria cultured from the bale cotton used in the different mills was employed in the exposure description. The results support earlier epidemiological and experimental studies, which demonstrate the importance of the Gram-negative bacteria in the development of pulmonary symptoms among workers in cotton mills.
PMCID: PMC1008607  PMID: 389278
12.  Oral and pharyngeal cancer in the North-west and West Yorkshire regions of England, and occupation. 
Patients with oral or pharyngeal cancer in the two main textile regions of England were matched for age and sex with patients having cancers not known to be associated with textile work. Data were recorded on age, sex, cancer site, and smoking, chewing and drinking habits together with dental and occupational history. There were 102 and 61 matched pairs of males and 52 and 60 matched pairs of females in the North-west and West Yorkshire regions respectively. There were significantly (P less than 0.05) more textile workers in the cases compared with their matched controls for only the females in the North-west. No particular type of textile work occurred more frequently for the cases than the controls in all four matched comparisons. Only for the males in the North-west were there significant differences (P less than 0.05) in the proportions of textile workers in the three cancer sites of the tongue, mouth and pharynx. These results do not confirm the association between textile work and oral or pharyngeal cancer found by the mortality study of Moss and Lee (1974). The results for the association between oral or pharyngeal cancer and smoking, drinking, chewing and wearing of dentures are discussed.
PMCID: PMC1008606  PMID: 508641
13.  A cohort study of mortality and cancer incidence in ethylene oxide production workers. 
Ethylene oxide, important as an intermediate product in the chemical industry and for sterilising hospital equipment, is mutagenic in several organisms; carcinogenicity has been suspected although this had not been supported by clinical data. Ethylene oxide has been produced by a Swedish company since the beginning of the 1940s. This paper describes a cohort study of the mortality and the cancer incidence among full-time exposed workers in ethylene oxide production, a group of maintenance workers with intermittent exposure and a group of unexposed controls. Investigation of the production processes in the building at different times has shown that workers were exposed to ethylene dichloride, ethylene chlorohydrin, ethylene, and small amounts of bis-(2-chloroethyl) ether as well as to ethylene oxide and traces of other chemicals. The full-time exposed cohort shows a considerable excess mortality deriving mainly from increased mortality from tumours and also from diseases of the circulatory system. The cancer incidence study, including living persons with malignancies, showed a significant excess in the full-time cohort. Of the 16 patients with tumours in the two more exposed cohorts there were three cases of leukaemia, six of tumours in the alimentary tract and four of urogenital malignancy. The excess mortality and cancer incidence cannot be attributed to any particular chemical in the production process, but ethylene oxide and ethylene dichloride are the prime suspects.
PMCID: PMC1008604  PMID: 508639
14.  The Pearson Report--compromise or step towards effective and just compensation for disability? 
The setting up of the Royal Commission on Civil Liability and Compensation for Personal Injury, its terms of reference and report are discussed. The main recommendations are detailed with brief consideration of their possible impact. The proposals are assessed and the philosophy and principles behind the reform, explicit or implicit in the Report, are considered. Finally, the extent to which the proposals can be a blueprint for later reforms dealing with compensation for disability in general is discussed.
PMCID: PMC1008603  PMID: 159718
15.  UK Naval Dockyards asbestosis study: survey of the sample population aged 50-59 years. 
As part of a general morbidity study of all civilian employees in the four Royal Naval Dockyards, the clinical, radiological and physiological effects of exposure to asbestos in 1200 men aged 50-59 years were studied in detail. The sample included all men on the Register of Asbestos Workers, one in three of those currently in occupations where intermittent exposure to asbestos may occur, and one in 30 of the remainder. The conclusions are mainly in accord with those of the comprehensive morbidity study of all the civilian dockyard workers, and show that smoking played a large part in increasing prevalence rates of radiographic, clinical, and physiological abnormalities in this population. A sub-group of 39 men, who were working as asbestos laggers or sprayers before 1957, was identified. These men showed much more extensive disease than any other sub-group, yet, even so, the smokers were worse than the non-smokers. Of these smokers, 48% had small opacities of category 1/1 or more, 76% reported that they coughed during the day and 53% had crepitations; forced expiratory volume and transfer factor were also markedly reduced in these 21 smokers. Although asbestos exposure had been intermittent for the majority of the population, the prevalences of pleural thickening, small opacities, current respiratory symptoms and crepitations were shown to be related to duration of exposure to asbestos.
PMCID: PMC1008605  PMID: 508640
20.  Carboxyhaemoglobin levels in workers in Leicestershire garages. 
Blood carboxyhaemoglobin (HbCO%) levels were measured in 61 workers in 35 garages in Leicester and Leicestershire. Of 26 workers in large garages in winter, 44% of the non-smokers and 20% of the smokers had increased CO absorption, the highest HbCO% being 26.0 in a non-smoker. Of 35 workers in 24 smaller, randomly chosen garages visited throughout the year (two per month) the corresponding figures were 43% and 14%, the highest HbCO% being 21.0. The possible relevance of these findings to coronary heart disease in garage workers is discussed.
PMCID: PMC1008572  PMID: 91618
21.  The time course of mandelic and phenylglyoxylic acid excretion in workers exposed to styrene under model conditions. 
Urinary excretion of mandelic and phenylglyoxylic acids by two technicians building glass-reinforced plastic boats has been measured over a 7-day period. Peak excretion of both metabolites occurred several hours after the end of exposure. There was little relationship between urinary mandelic acid concentrations measured at the end of shift and the maximum excretion observed in samples collected after this time. It is suggested that sampling strategies devised to monitor workers exposed to styrene should reflect maximum excretion rates of urinary mandelic acid.
PMCID: PMC1008571  PMID: 500784
22.  Partition coefficients of some aromatic hydrocarbons and ketones in water, blood and oil. 
Water/air, blood/air, oil/air, oil/water, and oil/blood partition (or solubility) coefficients of 17 aromatic hydrocarbons and ketones were measured by a newly developed vial-equilibration method, which needs no direct measurements of the concentration either in the liquid or in the air phase, but only the gas chromatographic peak heights of the air in the sample (in which a test material is contained) and reference vessels (containing no test material). It was found that the blood/air partition coefficients for aromatic hydrocarbons are correlated closely with the product of water/air and oil/air partitiion coefficients, whereas those for ketones are almost in the same range as the water/air, irrespective of the oil/air partition coefficients.
PMCID: PMC1008570  PMID: 500783
23.  Amount and distribution of fume contaminants in the lungs of an arc welder post mortem. 
This study describes various post-mortem examinations of the lungs of a shipyard arc welder. These investigations comprised morphological methods, including gross pathology and radiography, histological and ultrastructural examinations, chemical analysis of lung tissue, and sensitive magnetic measurements, which can now be used to detect magnetic contaminants, such as welding fume, in human tissue. Such methods can also show the distribution of contaminants. The amount of welding-fume contaminants was low, only 110 mg. The contaminant iron seemed to represent only 10% of the total iron chemically analysed in lung tissue. The concentration of the total iron was 4-10 times higher than that in control tissue. Contaminants tended to collect in the central areas of the lungs. Two concentration centres could be observed in each lung, one anterior and one posterior. There was slight fibrosis around pigmented areas. Histological findings were similar to those of previous studies. Transmission electron micrographs showed that enlarged lysosomes of macrophages contained electron-dense granules, 450 nm to less than 5 nm in diameter, which formed aggregates and short chains, and resembled welding-fume particles in the breathing zone. Our results show the value of studying the same material by a number of inter-related methods.
Images
PMCID: PMC1008569  PMID: 500782
24.  A clinical survey of paraquat formulation workers. 
A group of 18 male Caucasian workers from the United Kingdom and a further group of 18 male mixed race (mainly Malay) workers from Malaysia employed in the formulation of paraquat-based herbicides were examined for evidence of chronic ill health after long-term exposure to paraquat. Clinical records were examined, medical and occupational histories were obtained and a clinical examination, particularly of the skin, was undertaken. Skin rashes, nail damage and epistaxes were encountered by most workers as a result of direct contact of skin and mucous membranes with paraquat. These conditions subsided rapidly and no worker reported any sequelae. There was no clinical evidence of long-term effects on skin, mucous membranes or general health following exposure to paraquat over several years in these workers.
PMCID: PMC1008568  PMID: 500781
25.  Lung function in sisal ropemakers. 
Lung function was measured by spirometry in 66 workers in a sisal ropemaking factory, and in their matched controls. The major atmospheric contaminant was the lubricant (or a component part thereof) used to soften the fibre. The concentration of airborne matter was generally less than 1 mug m--3. There was no difference in lung function between the two groups before the start of the working shift, that is, the mixture of softening lubricant and sisal caused no long-term effects. Although there was no change in lung function over the working shift in the group making sisal rope, the control group did show a significant increase in lung function over the same period. This suggests that an effect attributable to the lubricant and sisal dust did exist. In previous studies little mention has been made of the softeners used in the processing of sisal fibre. These additives may exert a significant effect on ventilatory capacity and may act in conjunction with sisal dust.
PMCID: PMC1008567  PMID: 500780

Results 1-25 (61)