Respiratory symptoms, lung function, and occupational exposure among seafood industry workers.
A study among employees at Norwegian salmon factories and Russian North-West trawl fleet (Arkhangelsk)

Shiryaeva, Olga

dc.contributor.advisor	Bang, Berit Elisabeth
dc.contributor.author	Shiryaeva, Olga
dc.date.accessioned	2013-04-03T08:45:14Z
dc.date.available	2013-04-03T08:45:14Z
dc.date.issued	2013-01-24
dc.description.doctoraltype	ph.d.	en
dc.description.popularabstract	In our cross-sectional study we compared respiratory health status by means of a general questionnaire, lung function tests and measurements of FENO levels between workers engaged in fish processing and control subjects without occupational exposure to fish. In the Norwegian part of the study exposed workers were represented by 139 salmon processing workers and nonexposed by 214 workers from municipal workplaces. In the Russian part of the study, the exposed study population comprised 127 trawler workers engaged in on-board fish processing, while 118 merchant seafarers composed a reference group. In the Norwegian part we also analysed blood samples for measurements of IgE (total, specific to ten common inhalant allergens, and specific to salmon). The Norwegian part of the study was extended by one week of repeated measurements of exposure and respiratory variables. We also described the bioaerosol exposure pattern in the salmon industry by measuring personal exposure levels by means of portable air samplings pumps connected to filters in the breathing zones of the workers. Exposure-response relationships in the salmon-processing workers were explored by analyzing airborne levels of total protein (TP), salmon parvalbumin and endotoxin measured during four 8-hours work shifts and health outcomes (acute respiratory symptoms after each of four shifts, multiple lung function measurements performed on Mondays and Thursdays). In Paper IV we compared respiratory health statuses between onshore salmon workers and offshore trawler fish processing workers. Workers engaged in fish processing either onshore or offshore exhibit impaired respiratory health status more often compared to workers free of specific occupational exposure. The results from the Norwegian part of the study allow us to suggest that salmon processing workers are more likely to be sensitized to salmon. Asthma among salmon workers was not attributable to atopy compared to controls. Synergistic effect of exposure and smoking on some respiratory symptoms among salmon workers is implied. We found significant exposure-response associations only on Monday shifts, as well as gradual decrease of acute respiratory symptoms and cross-shift decline of lung function during a workweek, which is probably due to development of tolerance effect among the salmon workers in the response to continued exposure. The findings from the Russian part of the study allow us to conclude that trawler workers are more likely to have asthma compared to merchant seafarers. The environment of the onboard factories is suggested as a risk factor for work-related respiratory symptoms. We found filleting of fish at onboard processing facilities as specific work task associated with higher prevalence of work-related respiratory symptoms among trawler workers, which implies that exposure between the work tasks is not uniform. Dissimilarities in the exposure levels to cold work environment and to different bioaerosol constituents among the Norwegian salmon-processing workers and Russian trawler fish-processing fishermen could be possible explanatory factors for different respiratory symptoms pattern among these two groups of workers. Respiratory symptoms commonly associated with obstructive airway diseases were more prevalent in salmon workers, while running nose and dry cough, commonly associated with asthma and short-term effects of cold air exposure, were more prevalent in trawler workers. Results of blood test and FeNO levels point to non-allergic mechanisms of respiratory outcomes and less allergic type of asthma in salmon workers, whereas FeNO test results among trawler workers point to more pronounced non-allergic mechanisms of seen respiratory outcomes. Combining all the findings together we suggest that occupational exposure to airborne fish-derived and biological agents is the most likely candidate for the respiratory impairment among fish-processing workers but we cannot exclude a possible contribution of other types of specific or combined physical and chemical exposures as well as individual factors.	en
dc.description.sponsorship	Helse Nord/ISM UiT	en
dc.description	The papers of this thesis are not available in Munin: <br/>1. Shiryaeva O, Aasmoe L, Straume B & Bang BE.: 'Respiratory impairment in Norwegian salmon industry workers: a cross-sectional study', Journal of Occupational and Environmental Medicine (2010), vol. 52(12):1167–1172. Available at <a href=http://dx.doi.org/10.1097/JOM.0b013e3181fc5e35>http://dx.doi.org/10.1097/JOM.0b013e3181fc5e35</a> <br/>2. Shiryaeva O, Lisbeth Aasmoe, Bjørn Straume, Ann-Helen Olsen, Arild Øvrum, Eva Kramvik, Merethe Larsen, Anne Renstrøm, Anne-Sophie Merritt, Kari Kulvik Heldal & Berit Elisabeth Bang: 'Respiratory effects of bioaerosols: exposure-response study among salmon-processing workers' (submitted manucsript). <br/>3. Shiryaeva O, Aasmoe L, Straume B & Bang BE.: 'An analysis of the respiratory health status among seafarers in the Russian trawler and merchant fleets', American Journal of Industrial Medicine (2011), vol. 54(12):971–979. Available at <a href=http://dx.doi.org/10.1002/ajim.20978>http://dx.doi.org/10.1002/ajim.20978</a> <br/>4. Shiryaeva O, Aasmoe L, Straume B & Bang BE.: 'Respiratory symptoms, lung functions and exhaled nitric oxide (FENO) in two types of fish processing workers: Russian trawler fishermen and Norwegian salmon industry workers' (submitted manuscript).	en
dc.identifier.uri	https://hdl.handle.net/10037/5063
dc.identifier.urn	URN:NBN:no-uit_munin_4776
dc.language.iso	eng	en
dc.publisher	University of Tromsø	en
dc.publisher	Universitetet i Tromsø	en
dc.relation.ispartofseries	ISM skriftserie, nr 133
dc.rights.accessRights	openAccess
dc.rights.holder	Copyright 2013 The Author(s)
dc.rights.uri	https://creativecommons.org/licenses/by-nc-sa/3.0	en_US
dc.rights	Attribution-NonCommercial-ShareAlike 3.0 Unported (CC BY-NC-SA 3.0)	en_US
dc.subject	VDP::Medical disciplines: 700::Health sciences: 800::Occupational health: 809	en
dc.subject	VDP::Medisinske Fag: 700::Helsefag: 800::Yrkesmedisin: 809	en
dc.subject	VDP::Medical disciplines: 700::Health sciences: 800::Preventive medicine: 804	en
dc.subject	VDP::Medisinske Fag: 700::Helsefag: 800::Forebyggende medisin: 804	en
dc.title	Respiratory symptoms, lung function, and occupational exposure among seafood industry workers. A study among employees at Norwegian salmon factories and Russian North-West trawl fleet (Arkhangelsk)	en
dc.type	Doctoral thesis	en
dc.type	Doktorgradsavhandling	en