title: Incidence of airflow limitation among employees in Norwegian smelters.
abstract: We have investigated the association between the incidence of airflow limitation and occupational exposure. The employees (n = 3,924) were investigated annually during five years (n = 16,570) using spirometry. Exposure was classified using job category and a job exposure matrix. Airflow limitation was expressed using two indices: (i) as forced expiratory volume in one second/force vital capacity (FEV(1) /FVC) <0.7 and (ii) lower limit of normal (LLN). The incidence of airflow limitation was 21.2/1000 years(-1) and 15.1/1000 years(-1) using the fixed limit (0.7) and the LLN criterion, respectively. We found a dose-response relationship between the incidence of airflow limitation and tobacco consumption and with job-category in non-smokers. The associations between airflow limitation and covariates were independent of how airflow limitation was defined. The incidence of airflow limitation defined as FEV(l) /FVC <0.7 yielded higher incidence rates of airflow limitation than LLN. We found a significant association between the incidence of airflow limitation and occupational exposure in non-smokers.
authors.affiliation: Department of Medicine, Faculty Division Akershus University Hospital, University of Oslo, Lørenskog, Norway. vidar.soyseth@medisin.uio.no
authors.forename: Vidar
authors.initials: V
authors.lastname: Søyseth
authors.forename: Helle Laier
authors.initials: HL
authors.lastname: Johnsen
authors.forename: Merete Drevvatne
authors.initials: MD
authors.lastname: Bugge
authors.forename: Siri Merete
authors.initials: SM
authors.lastname: Hetland
authors.forename: Johny
authors.initials: J
authors.lastname: Kongerud
mesh_terms: D000328:Adult; D019652:Extraction and Processing Industry; D005260:Female; D005541:Forced Expiratory Volume; D006801:Humans; D015994:Incidence; D008171:Lung Diseases / Q000453:epidemiology* / Q000503:physiopathology; D008297:Male; D008875:Middle Aged; D009664:Norway / Q000453:epidemiology; D009784:Occupational Diseases / Q000453:epidemiology* / Q000503:physiopathology; D016273:Occupational Exposure; D012907:Smoking / Q000453:epidemiology