Airway responsiveness, respiratory symptoms, and exposures to soluble oil mist in mechanical workers.
OBJECTIVE
To assess the relation between measured levels of exposure to soluble oil mists in a plant manufacturing ball bearings, and both respiratory symptoms and airway responsiveness in the workforce.


METHODS
114 male workers exposed to oil mist and 55 unexposed male controls from nearby factories were studied. Soluble oil mist concentrations were measured with area samplers. Respiratory symptoms were assessed by questionnaire and measurement of airway responsiveness to methacholine with an abbreviated method. Subjects were labelled positive to methacholine airway challenge (MAC+) if forced expiratory volume in one second (FEV1) fell by > or = 20%. The linear dose-response slope was calculated as the percentage fall in FEV1 at the last dose divided by the total dose given.


RESULTS
Geometric mean concentrations of oil mists ranged from 0.65 mg/m3 (GSD 1.29) to 2.20 mg/m3 (GSD 1.55) based on 92 measurements obtained from 1979-93. The prevalence of chronic cough or phlegm, bouts of bronchitis, and dyspnoea was greater among exposed workers than among controls (odds ratio (OR) 4.64, P = 0.002 for chronic cough and phlegm). After adjustment for smoking and age, dyspnoea was significantly related to an index of cumulative exposure to oil mist (OR 1.44, P = 0.006/10 y.mg/m3). The proportion of MAC+ subjects was similar in the two groups. However, after adjustment for baseline FEV1 and age, the dose-response slope was significantly steeper among exposed workers than among controls (P = 0.01), a finding indicating airway hyperresponsiveness in the exposed workers. Furthermore, the dose-response slope was significantly related to baseline FEV1, age, and, after adjustment for FEV1, the index of cumulative exposure to oil (P = 0.004).


CONCLUSIONS
Subjects with exposure to soluble oil mist in the metal industry are at risk of developing both respiratory symptoms and airway hyperresponsiveness.
Massin
N
N
Institut National de Recherche et de Sécurité, INRS, Vandoeuvre-lès-Nancy, France.
Bohadana
A B
AB
Wild
P
P
Goutet
P
P
Kirstetter
H
H
Toamain
J P
JP
D000336:Aerosols / Q000009:adverse effects / Q000032:analysis; D000395:Air Pollutants, Occupational / Q000009:adverse effects* / Q000032:analysis*; D016022:Case-Control Studies; D003430:Cross-Sectional Studies; D004781:Environmental Exposure / Q000032:analysis*; D006801:Humans; D007219:Industrial Oils / Q000009:adverse effects* / Q000032:analysis*; D007221:Industry; D008171:Lung Diseases / Q000139:chemically induced* / Q000453:epidemiology*; D008297:Male; D016210:Methacholine Chloride; D008899:Mineral Oil / Q000009:adverse effects / Q000032:analysis; D016017:Odds Ratio; D015995:Prevalence; D012120:Respiration Disorders / Q000139:chemically induced* / Q000453:epidemiology*; D012129:Respiratory Function Tests
D000336:Aerosols; D000395:Air Pollutants, Occupational; D016210:Methacholine Chloride; D008899:Mineral Oil