we determined bronchial hyperresponsiveness by methacholine inhalation test , administered a standardized respiratory questionnaire , and performed spirometry on 1,392 male workers in various industries : 229 ( 16.5 % ) had pc20 less than 8 mg/ml , 66 ( 4.7 % ) had pc20 less than 2 mg/ml , and 8 ( 0.6 % ) had pc20 less than 0.5 mg/ml .
C0085129
bronchial hyperresponsiveness
C0600370
methacholine