Eligibility criteria will differ depending on the type of data gathering volunteers participate in:  Questionnaire Inclusion Criteria: All workers employed in the factory Exclusion Criteria: No restrictions  Exposure assessment study  Inclusion Criteria: Participants (12 workers each day, two repeated measurements = 24 workers) will be collected at random among workers having the following work stations/tasks during the study period:  Monday and Thursday (n=12 workers): Slaughtering department (n=5), filleting department (n=4) and other (n=3).  Tuesday and Wednesday (n=12 workers participating in the questionnaire-based study and): Slaughtering department (n=3), filleting department (n=3), packing department (n=2), laboratory/technical department (n=2) and central control room/administration (n=2).  Exclusion Criteria: Not working in those areas, not able to wear backpack with equipment.  Cross-week follow-up (Monday to Thursday) Inclusion Criteria: Participant in both 1 and 2, i.e. having filled out questionnaire and participated in exposure measurement on mondays.  Exclusion Criteria: Not fulfilling inclusion criteria, not able to wear backpack with equipment.  Health examinations Inclusion criteria: All subjects working in the factories during the field work period of four days will be eligible. However, due to logistic constraints we aim to invite at least 20 subjects each day, primarily those working in the salmon production line. Those invited will be randomly selected according to a distribution between slaughtering, filleting and others (ratio 5:4:3).  Exclusion criteria:  For spirometry measurements: heart attack, operation on eyes, stomach or in the chest region in the course of the last three months, ongoing treatment for tuberculosis or other respiratory infection, pregnancy For skin prick tests: pregnancy