Association between occupational exposure and chronic obstructive pulmonary disease and respiratory symptoms in the Spanish population Eduardo Loeb; Jan-Paul Zock; Marc Miravitlles; Esther Rodríguez; Juan José Soler-Cataluña; Joan B. Soriano; Francisco García-Río; Pilar de Lucas; Inmaculada Alfageme; Ciro Casanova; José Miguel Rodríguez González-Moro; Julio Ancochea; Borja G. Cosío; Jaume Ferrer Sancho;