PT Journal AU Ulvestad, B Melbostad, E Fuglerud, P TI Asthma in tunnel workers exposed to synthetic resins SO Scandinavian Journal of Work, Environment & Health PD 8VL PY 1999 BP 335 EP 341 IS 4 DI 10.5271/sjweh.443 WP https://www.sjweh.fi/show_abstract.php?abstract_id=443 DE isocyanates; methacholine responsiveness SN 0355-3140 AB '

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OBJECTIVES ': 'The prevalence of airway symptoms among tunnel workers exposed to synthetic resins was studied by determining methacholine responsiveness and lung function.

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METHODS ': 'Nineteen injection workers were compared with a group of 104 other tunnel workers with similar exposure, except for that to synthetic resins. A questionnaire on respiratory symptoms, smoking habits, use of respiratory protection, and work tasks was used. Lung function was studied using a bellows spirometer. Bronchial reactivity was tested with methacholine. Allergy screening with Phadiatop and radioallergosorbent tests for toluene-diisocyanate-HSA, diphenylmethane-4.4-diisocyanate-HSA, and formaldehyde-HSA (HSA = human serum albumin) were carried out. Methylene diphenyl diisocyanate (MDI) and MDI prepolymer exposure was estimated by filter sampling, and the filters were analyzed by high-performance liquid chromatography. The most common work situations were simulated for an estimation of exposure to isocyanates.

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RESULTS ': 'The injection workers reported more respiratory symptoms than the reference group, and they had higher prevalences of bronchial hyperresponsiveness (37% versus 14%), asthma (26% versus 1%), and airflow limitation (37% versus 4%). Toluene-diisocyanate-HSA-specific immunoglobulin E antibodies were found in 2 of the 19 injection workers, but in none of the other tunnel workers. By simulation at a worksite, the average exposure to polymerized MDI was estimated to be 5.5–300 µg/m3 during injection work and 18–4300 µg/m3 during short-term exposure, the highest exposure occurring when cured polyurethane was ground.

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CONCLUSIONS ': 'Exposure to partly decomposed MDI in tunnel work enhances the risk for respiratory symptoms, methacholine hyperresponsiveness, asthma, and airflow limitation.

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