Clin Pulm Med 2012 Jul; 19(4):165-173
Fixed airways obstruction was found in workers producing microwave popcorn in relation to inhaling synthetic butter flavoring volatiles in 2000. Since then, an industry-wide hazard of clinical bronchiolitis obliterans was found in other microwave-popcorn plants, in flavoring manufacture, and in diacetyl (2,3-butanedione) manufacture. Recently, workers in 1 food production and 1 flavoring manufacturing facility have had excesses of spirometric restrictive abnormalities. Evidence of flavoring-related excessive declines in forced expiratory volume in 1 second (FEV1) suggests that restriction in the latter flavoring plant is work-related. However, the pathologic and physiological correlates of restriction in flavoring-exposed workers remain uninvestigated. Diacetyl vapor causes respiratory epithelial necrosis in rodents, compatible with the pathologic mechanism for constrictive bronchiolitis, but exposures in flavoring manufacturing are more diverse than diacetyl. The diacetyl substitute, 2,3-pentanedione, has comparable toxicity to diacetyl, and other members of the [alpha]-diketone family have not been evaluated for respiratory toxicity. With the increasing spectrum of flavoring-related lung diseases and chemical exposures, pulmonologists caring for flavoring-exposed workers have novel challenges. These include examining excessive FEV1 declines in serial spirometry and improving surveillance spirometry quality so that excessive declines can be detected at an earlier stage. The best means of preventing permanent impairment from irreversible occupational lung disease is to intervene for workers with excessive FEV1 decline within the normal range and before diagnostic criteria for occupational lung disease can be met. Regulation of diacetyl and 2,3-pentanedione, which does not yet exist, may not prevent all occupational lung disease in flavoring-exposed workers.
Airway-obstruction; Respiratory-system-disorders; Respiratory-irritants; Pulmonary-function; Pulmonary-system; Pulmonary-system-disorders; Pulmonary-disorders; Hazards; Inhalants; Workers; Food-additives; Food-processing-workers; Food-processing; Food-processing-industry; Spirometry; Vapors; Exposure-levels; Toxic-effects; Toxic-vapors; Lung-disease; Lung; Lung-function; Lung-irritants; Lung-disorders;
Author Keywords: flavorings; bronchiolitis obliterans; 2,3-butanedione; spirometry surveillance
Kathleen Kreiss, MD, Division of Respiratory Disease Studies, National Institute for Occupational Safety and Health, Centers for Disease Control, Mail Stop H-2800. NIOSH, 1095 Willowdale Road, Morgantown, WV 26505
Clinical Pulmonary Medicine