Epidemic of asthma in a wood products plant using methylene diphenyl diisocyanate.

Eighteen employees with lower respiratory symptoms later confirmed to be occupational asthma were referred for evaluation. All were employees of a single wood products plant using heated methylene diphenyl diisocyanate (MDI) in the manufacture of a synthetic wood product. Of the 18, 15 had no prior airway symptoms or other known bronchial injury, and 16 had positive methacholine bronchial provocation tests. All cases occurred during a 2.5-year period after exposure to a new manufacturing process using steam-heated MDI resin in a new manufacturing facility. Initially, employees developed symptoms related to the start-up process in the plant, with possible higher MDI exposures and probable higher resin temperatures. Later, most employees who developed new symptoms worked in areas of the plant where they were exposed mostly to heated boards. This suggests MDI sensitization arising at lower temperatures than previously considered likely for this substance.

Cross-sectional epidemiological study of respiratory disease in turkey farmers.

This study was a cross-sectional epidemiological investigation of respiratory disease in farmers involved in the turkey growing industry. Pulmonary function tests and health history questionnaires were administered to a total of 95 turkey farmers throughout Minnesota. Respiratory symptoms were greatest during the winter months when exposure to environmental agents was highest. Prevalence of symptoms was higher for smokers, personnel who worked in hen barns, and for persons who had worked in the turkey growing industry for more than 10 years. Pulmonary function was found to decrease during the work day. Also, pulmonary function was lowest for personnel working in hen bars, and for persons who had been employed in the industry for more than 10 years. These data support the association between respiratory disease and exposure to the environment in confinement farm buildings.