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Biomedical subjects

R M Niven

Publications and source records attributed to R M Niven.

28 records · Page 2Linked to original sources
PubMed1994

Domiciliary air filtration units, symptoms and lung function in atopic asthmatics.

Air infiltration units (AFUs) incorporating a high efficiency particulate air filter are theoretically able to remove almost all potential airborne allergens. This may have implications for subjects with allergic lower respiratory disease. AFUs were placed in the living room of 12 atopic asthmatics, and the internal filters were inserted and removed in a double-blind fashion. No difference in subjective symptom scoring, spirometry or bronchial reactivity was demonstrated. Peak expiratory flow rate (PEFR) variability was significantly improved from baseline readings, and there was a trend towards higher mean PEFRs when the filters were present in the AFU. Trends towards lower levels of airborne micro-organisms were also demonstrated when the filters were present, however no effect upon total airborne dust and airborne Der pI could be demonstrated.

Air Conditioning↗
PubMed1994

Ocular and nasal irritation in operatives in Lancashire cotton and synthetic fibre mills.

OBJECTIVES: To document the prevalence of work related ocular (eyeWRI) and nasal (noseWRI) irritation in workers in spinning mills of cotton and synthetic textile fibres and to relate the prevalence of symptoms to atopy, byssinotic symptoms, work history, and measured dust concentrations in the personal breathing zone and work area. METHODS: A cross sectional study of 1048 cotton workers and 404 synthetic fibre workers was performed. A respiratory questionnaire was given to 1452 workers (95% of the total available population). Atopy was judged by skin prick tests to three common allergens. Work area cotton dust sampling (WAdust) was carried out according to EH25 guidelines in nine of the 11 spinning mills included in the study. Personal breathing zone dust concentrations were assessed with the IOM sampler to derive total dust exposure (PTdust) and a concentration calculated after the removal of fly (Pless). RESULTS: 3.7% of all operatives complained of symptoms of byssinosis, 253 (17.5%) complained of eyeWRI and 165 (11%) of noseWRI. These symptoms did not relate to atopy or byssinosis, or correlate univariately with any measure of cotton dust exposure (noseWRI v WAdust r = 0.153, PTdust r = 0.118, eyeWRI v WAdust r = 0.029, PTdust r = 0.052). Both of these symptoms on logistic regression analysis were related to being of white origin (P < 0.001), female sex (P < 0.001), and younger age (P < 0.001). With regression analysis, there was a negative relation between dust concentration and prevalence of symptoms. CONCLUSION: Work related ocular and nasal irritation are the most common symptoms complained of by cotton textile workers. There was no relation between these symptoms and atopy, byssinosis, or dust concentration. It is likely that they relate to as yet unidentified agents unrelated to concentration of cotton dust.

Adult↗
PubMed1994

Respiratory symptoms and dust exposure in Lancashire cotton and man-made fiber mill operatives.

A cross-sectional study of work-related symptoms and cotton dust exposure was made in 404 man-made fiber and 1,048 cotton operatives in Lancashire spinning mills; 39 cotton-exposed operatives (3.7%) had symptoms of byssinosis. This was associated on regression analysis with cumulative lifetime cotton dust exposure (p < 0.001), total years spent carding (p < 0.001), and currently working in the carding area (p = 0.0041). Smoking habit did not differ significantly between byssinotic and nonbyssinotic workers. Other work-related symptoms were common: chronic bronchitis (CB) and persistent cough. The prevalence of CB correlated positively with dust exposure (r = 0.59). Cotton dust sampling was performed in the work area (SDPRES) and personal breathing zone (PD1). A retrospective estimate of lifetime cotton dust exposure based on SDPRES correlated best with the prevalence of byssinosis (r = 0.797), although correlations with PD1 (r = 0.709) and SDPRES (r = 0.594) were also significant.

Adult↗
PubMed1992

A study of the performance and comparability of the sampling response to cotton dust of work area and personal sampling techniques.

In order to compare and contrast the sampling response to cotton dust of two forms of dust sampling 85 work areas were identified over a 2-year period for investigation in eight Lancashire spinning mills. Three hundred and five work area dust samples were undertaken and 252 personal dust samples were performed. Operatives who spent a minimum of 80% of their working shift in the area in which work area sampling was also performed were selected for personal sampling. Work area dust exposures have recently shown an upward trend, with highest concentrations occurring in the ring spinning room (median 1.15 mg m-3, range 0.82-2.06). Personal dust samples showed a reduction in dust exposures as cotton processing progressed, from a high in the opening room (median value of 6.24 mg m-3, range 1.0-41.5) to a minimum of 1.02 mg m-3 (range 0.30-0.93) in the winding room. The ratio of measured personal sampling dust exposure to work area sampling exposure was used to compare the relative performance of the two techniques. This ratio was highest in the early processes. There was a 7.8-fold difference in measurement between the two techniques in the opening processes, falling to 4.9 in carding and 4.2 in the other card-room processes. However in ring spinning the ratio was only 1.4, suggesting a degree of comparability in the methods at this stage of processing. The value rose to 2.5 for the last stage (winding). Respiratory disease is known to occur predominantly in the early stages of processing (opening and carding) where high dust concentrations are found using the personal technique. These data support the use of personal sampling for setting exposure limits to cotton dust in preference to the current recommended method using work area sampling techniques, which may significantly underestimate dust exposure in the high risk work areas and is outdated.

Dust↗
PubMed1992

Lung function, bronchial reactivity, atopic status, and dust exposure in Lancashire cotton mill operatives.

A total of 645 cotton mill operatives were administered a respiratory questionnaire. Of these, 85 (13.2%) complained of one or more work-related respiratory symptoms: 23 (3.6%) had byssinosis and the remaining 62 had symptoms not conforming to byssinosis (nonbyssinotic symptomatics, NBS). All byssinotic, 56 NBS, and 84 matched asymptomatic operatives underwent pulmonary function testing (FEV1 and FVC), skin testing to common allergens, and histamine bronchial challenge. Work area and personal breathing zone cotton dust concentrations were assessed, and a cumulative cotton dust exposure index was calculated for each individual. Byssinotic, NBS, and asymptomatic operatives all had reduced FEV1; observed mean liters (95% CI); predicted mean: byssinosis, 2.36 (2.09 to 2.63), 3.02; NBS, 2.94 (2.71 to 3.17), 3.29; and asymptomatic, 3.12 (2.95 to 3.29), 3.31. Only byssinotic subjects had evidence of impaired FVC: 3.31 (2.97 to 3.65), 3.69. The majority of byssinotic operatives (18 of 23) had bronchial hyperreactivity (BHR) in comparison with 21 of 56 NBS and 14 of 84 asymptomatic operatives. Mean log PD20 (95% CI) values were significantly lower in the byssinotic group -0.72 (-1.42, -0.02) than in NBS 0.57 (0.08, 1.06) and asymptomatic subjects 0.57 (-0.26, 1.39). The distribution of atopy did not differ significantly between groups, and lung function did not differ significantly between atopic and nonatopic subjects. The cumulative cotton dust exposure index was the only dust parameter to be significantly greater in those with BHR (mean mg-yr/m3 [95% CI] 14.13 [13.1 to 15.1]) than those with normal reactivity [5.35 (3.9 to 6.8)].

Adult↗