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Biomedical subjects

R G Love

Publications and source records attributed to R G Love.

11 recordsLinked to original sources
PubMed1991

The characteristics of respiratory ill health of wool textile workers.

The relations of lung function and chest radiographic appearances with exposure to inspirable dust were examined in 634 workers in five wool textile mills in west Yorkshire, randomly selected to represent fully the range of current exposures to wool mill dust. Most of these workers could be categorised into three large sex and ethnic groups; European men, Asian men, and Asian women. Exposures to inspirable dust had been measured at a previous survey and time spent in current job, and in the industry were used as surrogates for lifetime cumulative exposures. Chest radiographs were interpreted on the International Labour Office (ILO) scale by three medically qualified readers, and the results combined. Profusions of small opacities of 0/1 on the ILO scale, or greater, were present in only 6% of the population, and were not positively associated with current exposure to wool mill dust, or duration of exposure. In general, statistically significant relations between exposure and lung function indices were not found, with the exception of an inverse relation between the forced expiratory volume/forced vital capacity ratio and dust concentration in European women. A suggestive but not statistically significant inverse relation between FVC and current dust concentration was seen in Asian men. Substantial differences were found between mills in mean values of lung function variables after adjustment for other factors but these were not apparently related to the differences in dust concentrations between these mills. Dyeworkers and wool scourers (mostly European men in relatively dust free jobs) on average experienced an FEV1 251 ml lower than other workers when age, height, smoking habits, and occupational factors had been taken into account. Twenty four per cent of the workforce responded to intracutaneous application of one or more common allergens (weal diameter at least 4 mm), only 12 (7.9%) of these responding to wool extracts. Atopic subjects did not appear to have an increased susceptibility to the effects of inspirable wool dust on lung function. These studies suggest that exposure to wool mill dust may cause functional impairment in some workers but there is little indication from these data of frequent or severe dust related functional deficits. More detailed estimates of cumulative dust exposure by reconstruction of exposure histories might clarify associations between exposure to dust and lung function. These chest radiographic findings provide no evidence that exposure to wool mill dust is related to lung fibrosis.

Adult↗
PubMed1990

Inflammation in the lungs of rats after deposition of dust collected from the air of wool mills: the role of epithelial injury and complement activation.

In a previous study assessing respiratory symptoms in individuals employed in wool textile mills in the north of England relations between symptoms of chronic bronchitis, breathlessness and wheeze, and rhinitis and current exposure to airborne mass concentration of dust were shown. As preliminary steps in defining the potential hazard associated with dust from the air of wool mills the ability of inspirable dust, collected from the air of wool textile mills, to cause inflammation when injected into the lungs of rats was determined. Dusts were collected from the beginning of wool processing (opening) in one factory and from the middle (combing) and late (backwinding) stages of the process in two other factories. Ability of the dusts to cause inflammation was assessed by instillation into the lungs of rats followed by bronchoalveolar lavage. All the dusts caused some inflammation which peaked on day 1 and did not persist beyond one week. A distinctive aggregation response of mononuclear cells in the lavage, however, had a different time course, peaking at day 7. An attempt was made to determine how the wool mill dusts caused inflammation and experiments showed that the dusts themselves had no inherent chemotactic activity but that they did have a pronounced ability to generate chemotaxins in serum and so could activate complement in lung fluid. In addition, dust collected from ledges in the mills had the ability to injure epithelial cells in vitro which could also contribute to inflammation. A role for endotoxin in the inflammatory activity of the dusts was not discounted and a leachate of the dust had the ability to cause inflammation when injected into the lungs of rats. Wool mill dust is likely to be a complex mixture of materials and these experiments represent a preliminary approach to understanding the biological activity of the whole unfractionated dust and further studies are in progress to define more accurately the toxic material(s) in the dust.

Animals↗
PubMed1988

Respiratory and allergic symptoms in wool textile workers.

An epidemiological study of 2153 workers in 15 West Yorkshire wool textile mills was conducted to determine relations between respiratory symptoms and exposure to inspirable wool mill dust. A questionnaire designed to elicit all the common respiratory symptoms was developed and tested, and administered to all workers willing to participate (85%). It was translated and administered in Urdu for the 385 workers from Pakistan whose English was not fluent. Symptoms investigated included cough and phlegm, wheezing and chest tightness, breathlessness and its variability, rhinitis, conjunctivitis, chills, nosebleeds, and chest illnesses. Additional questions were asked, where appropriate, about the times of day, days of the week, seasons, and places that the symptoms were worse or better than normal. An environmental survey was carried out at each mill, which included 629 measurements of inspirable dust, enabling estimates to be made of the airborne concentrations of inspirable dust usually experienced by each member of the workforce under current conditions. Overall symptom prevalences were: persistent cough and phlegm, 9%; wheeze, 31%; breathlessness on walking with others on level ground, 10%; persistent rhinitis, 18%; persistent conjunctivitis, 10%; persistent chills, 2%; ten or more nosebleeds a year, 2%; and three or more chest illnesses in past three years, 5%. After allowing for the effects of age, sex, smoking habit, and ethnic group, cough and phlegm, wheeze, breathlessness, rhinitis, conjunctivitis, and nosebleeds were found to be more frequent in those exposed to higher than to lower concentrations of dust. In some experiencing high concentrations (blenders and carpet yarn backwinders) cough and phlegm, wheeze, rhinitis, and conjunctivitis were related to the years worked in such jobs. Relative risks of each symptom in relation to inspirable dust concentrations were calculated by means of a logistic regression analysis. At concentrations of 10 mg/m3, the current United Kingdom standard for nuisance dusts, the risk of cough and phlegm relative to that of an unexposed worker was 1.37, that of wheeze 1.40, breathlessness 1.48, rhinitis 1.24, and conjunctivitis 1.70. Since some of these symptoms may be associated with functional impairment of the lungs, further studies of selected workers are being carried out to estimate the functional effects of exposure to dust in wool textile mills.

Adolescent↗
PubMed1977

Acceptable levels for the breathing resistance of respiratory apparatus: results for men over the age of 45.

Tolerance of additional external resistance to inspiration has been investigated in a group of coalworkers older than 45 years. Peak inspiratory pressure, external respiratory work rate, ventilation, and gas exchange were measured, during periods with and without one of four inspiratory resistances, on 41 subjects walking on a treadmill. Minute volume was reduced, breathing frequency was unchanged and oxygen uptake and carbon dioxide elimination were reduced by the presence of resistance. It was established that, at the workload studied, older men were able to tolerate inspiratory resistance to at least the same extent as younger men, when the respiratory work was expressed in terms of unit ventilation. It is suggested that the acceptable level of breathing resistance established for younger men can also be applied to older workers.

Age Factors↗
PubMed1976

Aerosol deposition and airway obstruction.

Intrapulmonary deposition of 1-mum-diameter particles of dioctyl sebacate was studied in 58 working coalminers. Total deposition was found to be significantly correlated with lung function measurements characterizing airway obstruction. The closest relationship was between deposition and the mean maximal flow rate in the third quarter of a forced expiration. The shape of the exhaled aerosol recovery curve was also found to be related to the degree of airway obstruction; 3 basic types are described. The concave type was more common in smokers, in whom deposition was significantly greater. The presence of simple pneumoconiosis was not associated with the degree of aerosol deposition. The significance of the findings of aerosol deposition and its recovery pattern are discussed in relation to the pathogenesis of lung disease.

Adult↗