RT Journal Article SR Electronic T1 Airway obstruction related to diacetyl exposure at microwave popcorn production facilities JF European Respiratory Journal JO Eur Respir J FD European Respiratory Society SP 63 OP 71 DO 10.1183/09031936.00050808 VO 34 IS 1 A1 J. E. Lockey A1 T. J. Hilbert A1 L. P. Levin A1 P. H. Ryan A1 K. L. White A1 E. K. Borton A1 C. H. Rice A1 R. T. McKay A1 G. K. LeMasters YR 2009 UL http://erj.ersjournals.com/content/34/1/63.abstract AB Obstructive lung diseases including bronchiolitis obliterans have been reported among microwave popcorn production employees. Butter flavourings including diacetyl have been associated with these findings. The present study was initiated at four microwave popcorn production plants to determine if exposure to diacetyl was associated with decrements in pulmonary function. Comprehensive diacetyl exposure assessment was undertaken for all job tasks. Spirometry was conducted for 765 full-time employees between 2005 and 2006. Outcomes included decrement in forced expiratory volume in one second (FEV1) % predicted, airway obstruction and persistent decline in FEV1. Inclusion in the high-exposure group (mixers) prior to respirator use was associated with a significantly decreased FEV1 % pred in non-Asian and Asian males at -6.1 and -11.8% pred, respectively, and an eight-fold increased risk for airway obstruction. Cumulative diacetyl exposure ≥0.8 ppm-yr caused similar results. No significant impact was seen in nonmixers or between current diacetyl exposure and persistent decline in FEV1. Unprotected exposure as a mixer to butter flavouring including diacetyl resulted in decrements in FEV1 (% pred) and increased airway obstruction. Control of employee exposure to butter flavouring additives is warranted in regard to both short-term peak and 8-h workday exposure.