Exposure to parvalbumin allergen and aerosols among herring processing workers

Abstract

Background:There are increasing reports of allergies and respiratory symptoms among workers in the fish processing industry, coinciding with an increasing use of high-pressure water in the processing plants. However, few studies have measured exposure in these work environments.Objectives:The aim of this study was to characterize the occupational exposure of workers to herring antigen and to screen environmental factors at a herring (Clupea harengus) plant in which new and more encapsulated filleting machines had been installed. To assist in this, a method to assess airborne exposure to herring allergen was needed.Methods:Exposure to airborne herring antigen, mould spores, and endotoxin were measured during work. Antigen exposure was assessed using a newly developed sensitive (detection limit, 0.1 ng ml-1) rabbit polyclonal sandwich enzyme-linked immunosorbent assay against the major herring muscle protein allergen, parvalbumin. Aerosols were measured by mass concentration (DataRAM) and number of particles (Climet I-500).Results:Personal geometric mean herring allergen exposure was 986 ng m-3 at the old filleting workstations and 725 ng m-3 at the new workstations (difference not significant). Outside the production room, the level was ~130 ng m-3. Number of particles and mass concentration were both significantly lower around the new machines than around the old machines (P < 0.001 and P < 0.0001, respectively). The highest particle count was seen for the 0.3-0.5 μm fraction, with more than 400 000 particles per cubic metre air. Endotoxin concentration in the air varied between 3 and 92 EU m-3, with the highest levels when the catch mainly contained herring that had eaten krill or seaweed.Conclusions:We developed a sensitive method to detect herring antigen. High exposure to herring antigen was measured during filleting work. The particles in the air around the fillet machines were mainly <0.5 μm and the newer encapsulated machines generated fewer particles. It is important to reduce occupational exposure of workers to aerosols by improving the ventilation system, machines, and organization of work. © The Author 2013.