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Trial Lecture – time and place
See Trial Lecture.
Adjudication committee
- First opponent: Professor Mohamed Fareed Jeebhay, University of Cape Town, South Africa
- Second opponent: Associate Professor Hanna Karlsson, Karolinska Institutet, Sweden
- Third member and chair of the evaluation committee: Professor Lars Eide, University of Oslo
Chair of the Defence
Professor Bjørn Steen Skålhegg, University of Oslo
Principal Supervisor
Senior Researcher Johanna Samulin Erdem, STAMI
Summary
Respiratory ailments, such as cough, breathlessness, asthma and allergy, are prevalent among workers in the seafood industry. These health problems have largely been attributed to exposure to allergenic proteins, yet the contributions of other components in the work environment remain insufficiently understood. The aim of this thesis was to investigate the relationship between occupational exposure to allergenic proteins and microbial agents in shrimp processing environments and respiratory health outcomes, including symptoms, allergic sensitisation, and inflammatory responses.
Respiratory symptoms as well as allergy and asthma-related biomarkers were assessed among Norwegian shrimp processing workers using questionnaires and blood analyses. Occupational exposure was characterised through work-environment air sampling, protein measurements, microbial identification, and proteomic analyses.
Shrimp processing workers reported a higher prevalence of upper and chronic lower respiratory symptoms than controls and exhibited elevated levels of inflammatory, allergy and asthma-related biomarkers. Multiple known and potential shrimp allergens were identified in workplace air, with particularly high levels of tropomyosin detected during shrimp cooking.
Airborne microbial exposure was further characterised across different shrimp processing tasks using full-shift personal air sampling and molecular analyses. Higher bacterial load, species richness, and immune activation potential were observed during work processes involving raw shrimp, while cooking substantially reduced bacterial exposure.
Experimental studies using human alveolar co-culture cell models demonstrated that combined exposure to shrimp allergens and microbial components can enhance inflammatory responses relative to individual exposures.
Overall, the findings demonstrate that complex occupational bioaerosol exposure contributes to respiratory health risks among shrimp-processing workers, with task-specific exposure differences underscoring the need for targeted preventive measures.
Additional information
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