An assessment of occupational exposure to inhalable aerosols and airborne proteins in food manufacturing plants.

Abstract

As the range of allergens continues to expand and the food industry evolves, there is a growing need for more efficient, affordable, and comprehensive methods to monitor protein exposures. This study aimed to assess the concentrations of inhalable aerosols and soluble proteins (SP) in food manufacturing environments. Additionally, the study sought to optimize the extraction methods for determining SP across diverse food matrices. One hundred forty-six participants from 12 different dry food production facilities were included in the study. The mass of inhalable aerosols was determined using gravimetric analysis, and the concentration of SP was determined using a bicinchoninic acid (BCA) protein assay kit. A mixed-effects Tobit regression model was employed to assess the relationship between aerosol and SP concentrations across different production environments and work tasks. The optimized SP extraction method proved effective across a wide range of powder food matrices, although variability in relative extraction efficiency across matrices highlighted the importance of using multiple extraction rounds for accurate protein quantification. Significant differences in SP concentrations were found across production environments. Confectionery and chocolate production (p < 0.001) and snacks, nuts, and chips production (p = 0.007) were associated with significantly lower SP concentrations compared to bakery production. Tasks such as grinding and milling (p = 0.037) and weighing and mixing (p = 0.019) showed significantly higher SP concentrations. The positive association between inhalable aerosol and SP concentrations suggests that higher aerosol concentrations generally correspond to higher protein exposure, but the strength of this relationship varied across productions and tasks. This study demonstrates the feasibility and potential value of measuring SP concentrations as an addition to aerosol measurements in food manufacturing environments. Given the health risks associated with inhaled proteins, particularly in provoking allergic reactions and respiratory problems, measuring total SP concentrations may serve as a more reliable indicator of occupational exposures, especially during tasks and in production types where the relationship between inhalable aerosols and proteins is weak.