Exposure to Bioaerosols During Fish Processing on Board Norwegian Fishing Trawlers.

OBJECTIVES: The main objective was to gain more knowledge on exposure to bioaerosols in the processing area on board fishing trawlers. METHODS: Exposure sampling was carried out during the work shifts when processing fish in the processing area on board five deep-sea fishing trawlers (trawlers 1-5). Exposure samples were collected from 64 fishermen breathing zone and from stationary sampling stations on board five deep-sea fishing trawlers (1-5). Trawlers 2, 3, and 4 were old ships, not originally built for on board processing of the catch. Trawlers 1 and 5 were relatively new and built to accommodate processing machineries. On trawlers 1-4 round fish was produced; the head and entrails were removed before the fishes were frozen in blocks. Trawler 5 had the most extensive processing, producing fish fillets. Samples were analysed for total protein, trypsin activity, parvalbumin, and endotoxin. One side analysis of variance and Kruskal-Wallis H test were used to compare levels of exposure on the different trawlers. RESULTS: Personal exposure to total protein were higher on the three oldest trawlers (2, 3, and 4) compared with the two new trawlers (1 and 5). Highest activity of trypsin was detected on the four trawlers producing round fish (1-4). Parvalbumin was detected in 58% of samples from the fillet-trawler (5) compared with 13% of samples from the four trawlers producing round fish. The highest level of endotoxin was detected when using high-pressure water during cleaning machines and floors in the processing area. CONCLUSIONS: Fishermen in the processing area on board Norwegian trawlers are exposed to airborne bioaerosols as proteins, trypsin, fish allergen parvalbumin, and endotoxin. Levels varied between trawlers and type of production.

Occupational Allergic Sensitization Among Workers Processing King Crab (Paralithodes camtschaticus) and Edible Crab (Cancer pagurus) in Norway and Identification of Novel Putative Allergenic Proteins.

Introduction: Asthma and allergy occur frequently among seafood processing workers, with the highest prevalence seen in the crustacean processing industry. In this study we established for the first time the prevalence of allergic sensitization in the Norwegian king- and edible crab processing industry and characterized the IgE-reactive proteins. Materials and Methods: Two populations of crab processing workers participated; 119 king crab and 65 edible crab workers. The investigation included information on work tasks and health through a detailed questionnaire. Allergic sensitization was investigated by crab-specific IgE quantification and skin prick tests (SPT) to four in-house prepared crab extracts; raw meat, cooked meat, raw intestines and raw shell. Allergen-specific IgE binding patterns were analyzed by IgE immunoblotting to the four allergen extracts using worker serum samples. Total proteins in crab SPT extracts and immunoblot-based IgE binding proteins were identified by mass spectrometric analysis. Results: Positive SPTs were established in 17.5% of king- and 18.1% of edible crab workers, while elevated IgE to crab were demonstrated in 8.9% of king- and 12.2% of edible crab processing workers. There was no significant difference between the king and edible crab workers with respect to self-reported respiratory symptoms, elevated specific IgE to crab or SPT results. Individual workers exhibited differential IgE binding patterns to different crab extracts, with most frequent binding to tropomyosin and arginine kinase and two novel IgE binding proteins, hemocyanin and enolase, identified as king- and edible crab allergens. Conclusions: Occupational exposure to king- and edible crabs may frequently cause IgE mediated allergic sensitization. Future investigations addressing the diagnostic value of crab allergens including tropomyosin and arginine kinase and the less well-known IgE-binding proteins hemocyanin and enolase in a component-resolved diagnostic approach to crab allergy should be encouraged.

Exposures and Health Effects of Bioaerosols in Seafood Processing Workers - a Position Statement.

Occupational hazards exist in the processing of seafood both in land-based facilities as well as on board vessels. Recent findings on occupational injury and respiratory health risks among seafood processing workers were presented and discussed at the IFISH5 conference. Particular emphasis was put on the challenges that im/migrant workers encounter, the greater risks onboard factory vessels, especially where processing machinery are retrofitted to older vessels not primarily designed for this purpose, and the difficulties in assessing and preventing bioaerosol exposures and associated respiratory health risks despite recent advances in characterising agents responsible for allergic and non-allergic reactions. Based on appraisal of existing knowledge in the published literature and new findings presented at the conference, recommendations for immediate actions as well as for future research have been proposed. Among these include the importance of improving extraction ventilation systems, optimising machinery performance, enclosure of bioaerosol sources, improved work organization, and making special efforts to identify and support the needs of im/migrant workers to ensure they also benefit from such improvements. There is a need for studies that incorporate longitudinal study designs, have improved exposure and diagnostic methods, and that address seafood processing in countries with high seafood processing activities such as Asia and those that involve im/migrant workers worldwide. The medical and scientific community has an important role to play in prevention but cannot do this in isolation and should cooperate closely with hygienists, engineers, and national and international agencies to obtain better health outcomes for workers in the seafood industry.

Musculoskeletal symptoms among workers in the commercial fishing fleet of Norway.

BACKGROUND: Fishers exposed to unfavourable environmental conditions may suffer negative health ef- fects. This study aimed to identify musculoskeletal symptoms in professional fishers in Norway using data from several sources; register data, telephone survey and questionnaire. MATERIALS AND METHODS: Professional fishers (n = 25,971) registered in the period 2008-2013 were selected by Statistics Norway (SSB). An age- and gender-matched control population (n = 77,913) was also selected. Outpatient consultation and hospitalisation data were received from the Norwegian Patient Registry (NPR). To obtain information about self-reported symptoms, 832 registered fishers on board Norwegian fishing vessels were interviewed by telephone, and a questionnaire was distributed to the crews of 5 trawlers (n = 153). RESULTS: Data from NPR showed that fishers, compared to the control population, suffered significantly more acute incidents related to musculoskeletal disorders (5.4% vs. 4.8%, respectively), injuries to arms (11.3% vs. 9.8%), feet (8.4% vs. 8%), and back (0.9% vs. 0.7%). In the telephone survey, 61% and 43% reported that they performed monotonous work operations and heavy lifting often or very often, respec- tively. Thirty-three per cent had experienced pain in neck/shoulders/arms often or very often during the previous 12 months, and 93% believed this was fully or partly due to their work situation. The questionnaire among trawler crew members showed that 57% and 60% had experienced stiffness and/or pain in neck/ /shoulders and lower back/small of the back respectively during the previous 12 months. CONCLUSIONS: Data from the register study, telephone survey and questionnaire all confirmed that musculo- skeletal problems are common among fishers and related to their work situation. However, 77% of the fishers in all vessel groups and on board the 5 trawlers reported their own health as being very good or good.

A Sensitive Assay for Proteases in Bioaerosol Samples: Characterization and Quantification of Airborne Proteases in Salmon Industry Work Environments.

Proteases are probably underestimated exposure agents in bioaerosols. Their roles as barrier disrupters in allergic sensitization and activators of innate inflammation call for more attention in exposure-response studies. The main objectives of this study was (i) to establish a suitable method for detection of small quantities of proteases in filtered air samples and (ii) to utilize the method to characterize exposure to proteases in a salmon industry work environment. Analysis of proteases in filtered air samples was based on zymography, using sodium dodecyl sulfate-polyacrylamide gel electrophoresis with 0.1% gelatin as substrate added in the polyacrylamide gel. Gelatinase activity was evident as cleared (unstained) regions. The area of these regions was quantified using image analysis (UVP Vision Works®). Standard curves with known amounts of active porcine trypsin were added to each gel. Validation of 11 non-linear standard curves showed R2 (range) = 0.8989-0.9882, limit of detection = 0.056 nM, lower limit of quantification = 0.161 nM, and coefficients of variations (range) = 20-28%. Sampling of bioaerosols in salmon industry was performed using polytetrafluoretylene filters with an airflow of 3 l min-1. All samples contained visible bands close to the size of porcine trypsin (23.3 kDa). The bands did not disappear in the presence of EDTA but abolished by Pefabloc, demonstrating that the enzyme is a serine protease, most likely salmon trypsin. Airborne levels of active protease were below the statistical detection limit in the filleting department but quantifiable in extract samples from the slaughter department. Three filtered air samples from the slaughter department showed air concentrations of 6.2, 16.5, and 27.0 ng m-3 air. We conclude that zymography is a sensitive and reliable method for exposure assessment of active proteases in indoor environmental samples. We recommend this assay for use in occupational studies to characterize and quantify exposure to active proteases in bioaerosols.

Lung function and prevalence of respiratory symptoms in Norwegian crab processing workers.

BACKGROUND: Seafood processing workers have an increased risk of developing occupational asthma. This has not been studied among Norwegian crab processing workers, nor has the respiratory health of exposed workers been compared to a control group. OBJECTIVES: Assessing the impact of working in the crab processing industry on workers' respiratory health. DESIGN: A cross-sectional study of the respiratory health in two types of crab processing workers compared to a control group. METHODS: The study included 148 king crab (Paralithodes camtschaticus) workers, 70 edible crab (Cancer pagurus) workers and 215 controls. Workers answered a questionnaire and performed spirometry measurements. χ2 and Fishers exact tests were performed on self-reported respiratory symptoms. Regression analyses and t-tests were used to assess lung function values. RESULTS: Self-reported respiratory symptoms were higher among crab processing workers compared to controls, and higher among king crab workers compared to edible crab workers. There was no significant difference between crab processing workers and controls in lung function measurements. Self-reported doctor-diagnosed asthma prevalence was highest in the control group. CONCLUSIONS: Increased respiratory symptoms reported by crab processing workers were not reflected in impaired lung function values or asthma diagnose. We suggest a healthy worker effect among crab processing workers in Norway.

Thermophysiological responses and work strain in fishermen on deep-sea fishing vessels.

BACKGROUND: Fishermen working on deep-sea vessels in the Barents and Norwegian Sea are exposed to low air temperatures, strong winds, high humidity, rain, snow and work at different intensities. Few studies have investigated the effect of environmental work factors on the physiology of this occupational group. The aim of the study was to investigate work strain and thermophysiological responses of fishermen on the trawl and factory decks of deep-sea vessels. MATERIALS AND METHODS: Twenty-five professional male fishermen (age 39 ± 13 years) were recruited to the study which was performed on three trawlers in the Norwegian Sea in April, June and August 2014. During a six-hour shift, heart rate (HR), core (Tc) and mean skin (Ts) temperatures were recorded, and questions about subjective thermal sensation and comfort were answered. RESULTS: Short periods of hard (above 86% of HRmax) work raised Tc by 0.8°C to 37.8°C and decreased Ts by 2.3°C to 29.8°C during work on the trawl deck, and subjects reported being warm and sweaty. On the factory deck long periods of fairly light (between 52% and 66% HRmax) work, Tc of 37.4°C and Ts of 30.9°C were measured. CONCLUSIONS: Fishermen experience intermittent periods of heavy work on the trawl deck shown with elevated core temperature and HR. Work on the factory deck includes long periods of repetitive work with light to moderate work strain. A better understanding of work strain and environmental challenges during work on Norwegian deep-sea vessels will help identify exposure risks during work in the cold and heat.

Occupational Exposure to Bioaerosols in Norwegian Crab Processing Plants.

INTRODUCTION: Aerosolization of components when processing king crab (Paralithodes camtschaticus) and edible crab (Cancer pagurus) may cause occupational health problems when inhaled by workers. METHODS: A cross-sectional study was carried out in three king crab plants and one edible crab plant. Personal exposure measurements were performed throughout work shifts. Air was collected for measurement of tropomyosin, total protein, endotoxin, trypsin, and N-acetyl-ß-d-glucosaminidase (NAGase). T-tests and ANOVAs were used to compare the levels of exposure in the different plants and areas in the plants. RESULTS: Total protein and tropomyosin levels were highest in the edible crab plant, endotoxin levels were highest in king crab plants. King crab exposure levels were highest during raw processing. Tropomyosin levels were highest during raw king crab processing with geometric mean (GM) 9.6 versus 2.5ng m(-3) during cooked processing. Conversely, edible crab tropomyosin levels were highest during cooked processing with GM 45.4 versus 8.7ng m(-3) during raw processing. Endotoxin levels were higher in king crab plants than in the edible crab plant with GM = 6285.5 endotoxin units (EU) m(-3) versus 72 EU m(-3). In the edible crab plant, NAGase levels were highest during raw processing with GM = 853 pmol4-methylumbelliferone (MU) m(-3) versus 422 pmol4-MU m(-3) during cooked processing. Trypsin activity was found in both king crab and edible crab plants and levels were higher in raw than cooked processing. Differences in exposure levels between plants and worker groups (raw and cooked processing) were identified. CONCLUSIONS: Norwegian crab processing workers are exposed to airborne proteins, tropomyosin, endotoxins, trypsin, and NAGase in their breathing zone. Levels vary between worker groups and factories.

Respiratory symptoms, lung functions, and exhaled nitric oxide (FENO) in two types of fish processing workers: Russian trawler fishermen and Norwegian salmon industry workers.

OBJECTIVE: Respiratory outcomes and work-related factors were studied in two seafood worker populations representing different occupational environments. METHODS: Levels of fractional exhaled nitric oxide (FENO), spirometric values, prevalence of respiratory symptoms, and self-evaluated exposures were compared between 139 Norwegian salmon workers and 127 Russian trawler workers. RESULTS: Increased odds ratios (ORs) of shortness of breath with wheezing and prolonged cough as general respiratory symptoms were found in salmon workers, while increased ORs of work-related dry cough and running nose were found in trawler fishermen. Both worker groups ranked "cold work environment," "use of disinfectants," and "contaminated indoor air" as the first, second, and third most important causes of work-related respiratory symptoms, respectively. Fractional exhaled nitric oxide levels were higher in asthmatic trawler workers compared to asthmatic salmon workers. CONCLUSIONS: Respiratory symptoms commonly associated with obstructive airway diseases were more prevalent in salmon workers, while symptoms commonly associated with asthma and short-term effects of cold air exposure were more prevalent in trawler workers.

Molecular and immunological approaches in quantifying the air-borne food allergen tropomyosin in crab processing facilities.

Tropomyosin is a cross-reactive allergenic protein present in ingested shellfish species. Exposure and sensitization to this protein via inhalation is particularly important in the crustacean processing industry where workers are continuously exposed to the aerosolized form of this allergen. The aim of this study was to develop an antibody-based immunoassay to enable the specific and sensitive quantification of aerosolized tropomyosin present in the environment of two crab processing facilities. Anti-tropomyosin antibody was generated in rabbits against tropomyosins from four different crustacean species. These antibodies were purified using recombinant tropomyosin using an immuno-affinity column. The recombinant tropomyosin was also used as an allergen standard for the sandwich ELISA. In order to quantify aerosolized tropomyosin, air collection was performed in the personal breathing zone of 80 workers during two crab processing activities, edible crab (Cancer pagurus) and king crab (Paralithodes camtschaticus) using polytetrafluoroethylene filters. The purified antibody was able to detect tropomyosin selectively from different crustaceans but not from vertebrate sources. The limit of detection (LOD) for the developed sandwich ELISA was 60 picogram/m(3) and limit of quantitation (LOQ) 100 picogram/m(3). Immunoassay validation was based on linearity (R(2) 0.999), matrix interference test (78.8±6.5%), intra-assay CV (9.8%) and inter-assay CV (11%). The novel immunoassay was able to successfully identify working activities, which generated low, medium or high concentrations of the aerosolized food allergen. We describe an IgG antibody-based immunoassay for quantification of the major food allergen tropomyosin, with high sensitivity and specificity. This modified immunological approach can be adapted for the detection of other aerosolized food allergens, assisting in the identification of high-risk allergen exposure areas in the food industry.

Respiratory effects of bioaerosols: exposure-response study among salmon-processing workers.

OBJECTIVES: The aim of the study was to determine exposure-response relationships in salmon-processing workers. METHODS: Cross-shift FEV1, acute respiratory symptoms, and exposure to total protein, parvalbumin and endotoxin were main variables measured during one workweek. Exposure-response relationships were analyzed by Generalized Estimation Equations of cross-week data and by multiple regressions of day-to-day data. RESULTS: Exposure levels were higher in those workers who reported use of water hose. GEE showed negative coefficients for interaction between TP exposure and time (days) on cross-week change of FEV1. Multiple regressions showed significant associations between TP levels and cross-shift change of FEV1 and symptoms (cough, chest tightness) only for Monday shifts. CONCLUSIONS: A tolerance effect during the course of a workweek is suggested. Use of water hose is a risk process with regard to the liberation of measured components of bioaerosols.

An analysis of the respiratory health status among seafarers in the Russian trawler and merchant fleets.

OBJECTIVES: Trawler fishermen and merchant seafarers have tough working conditions. While workers in both occupations are exposed to a challenging environment, trawler fishermen are also engaged in onboard fish processing, which is considered to be additional exposure. The aim of the present study was to characterize respiratory health status in both groups of seamen. METHODS: In total 127 trawler fishermen and 118 merchant seafarers were enrolled during their regular medical health examinations. The study protocol comprised a standardized questionnaire, lung function test and measurements of fractional nitric oxide concentrations (FE(NO) ) in exhaled air. RESULTS: Doctor-diagnosed asthma was reported only by trawler fishermen (3.9%, P < 0.05, Pearson Chi-square test). Adjusted odds ratios (OR) of respiratory symptoms were more often elevated in trawler fishermen compared to merchant seafarers. Trawler fishermen had reduced spirometric parameters: FEV(1) % of predicted values (adjusted ß: -5.28, 95%CI: -9.28 to -1.27), FVC % of predicted values (adjusted ß: -5.21, 95%CI: -9.25 to -1.17). Increased OR of the work-related cough with phlegm (OR: 6.6, 95% CI: 1.8-21.9), running nose (OR: 3.0, 95%CI: 1.2-7.7), and frequent sneezing (OR: 3.4, 95%CI: 1.0-12.7) were found among those trawler workers whose work tasks included filleting of fish. FE(NO) levels were not significantly different between trawler and merchant seamen. CONCLUSIONS: The present study indicated that trawler fishermen exhibited impaired lung function and were more likely to have asthma. The environment of the onboard factories where fishermen fillet fish is suggested as a risk factor for work-related respiratory symptoms.

Respiratory impairment in Norwegian salmon industry workers: a cross-sectional study.

OBJECTIVES: The aim of this study was to assess the respiratory status in salmon-processing workers. METHODS: The study population was composed of 139 salmon workers and 214 controls. A study protocol comprised a questionnaire, spirometry, measurements of fractional exhaled nitric oxide concentration, and total and specific immunoglobulin E analyses. RESULTS: Adjusted odds ratio of general respiratory symptoms ranged from 2.2 for wheezing to 3.6 for daily morning cough. Salmon workers were found to have an excess of work-related respiratory symptoms (2.9 ≤ adjusted odds ratio ≤ 13.6) and reduced lung function. Positive interaction of smoking and exposure was found for work-related upper respiratory symptoms and shortness of breath. Fractional exhaled nitric oxide concentration levels were higher in controls. None from the controls had salmon-specific immunoglobulin E, compared with 2.2% of salmon workers. CONCLUSIONS: Salmon-processing workers exhibit impaired respiratory status and are more likely to be sensitized to salmon.

Proteases from salmon stimulate IL-8 in airway epithelial cells.

In this study the ability of salmon tissue extracts to stimulate interleukin 8 (IL-8) production in airway epithelial cells (A549) was investigated; in particular, the role of serine protease enzymes and endotoxin was examined with respect to IL-8-stimulating ability. A549 cells were stimulated by various concentrations of fish tissue extracts for 6 h. Parallel samples were incubated with a protease inhibitor cocktail, a serine protease inhibitor, or an endotoxin inhibitor. The amount of secreted IL-8 in the supernatant was determined by an enzyme-linked immunosorbent assay. A549 cells showed a concentration-dependent increase in IL-8 secretion after stimulation with extracts of salmon tissues. The IL-8-stimulating effect was inhibited by serine protease inhibitors but not by endotoxin inhibitors.

Salmon trypsin stimulates the expression of interleukin-8 via protease-activated receptor-2.

In this study, we focus on salmon trypsin as an activator of inflammatory responses in airway cells in vitro. The rationale behind the investigation is that salmon industry workers are exposed to aerosols containing enzymes, which are generated during industrial processing of the fish. Knowing that serine proteases such as trypsin are highly active mediators with diverse biological activities, the stimulation of nuclear factor-kappa B (NF-kappaB) and interleukin (IL)-8 and the role of protease-activated receptors (PAR) in inflammatory signal mediation were investigated. Protease-activated receptors are considered important under pathological situations in the human airways, and a thorough understanding of PAR-induced cellular events and their consequences in airway inflammation is necessary. Human airway epithelial cells (A549) were exposed to trypsin isolated from fish (Salmo salar), and we observed that purified salmon trypsin could generate secretion of IL-8 in a concentration-dependent manner. Furthermore, we demonstrate that PAR-2 activation by salmon trypsin is coupled to an induction of NF-kappaB-mediated transcription using a PAR-2 transfected HeLa cell model. Finally, we show that the release of IL-8 from A549 following stimulation with purified salmon trypsin is mediated through activation of PAR-2 using specific small interfering RNAs (siRNAs). The results presented suggest that salmon trypsin, via activation of PAR-2, might influence inflammation processes in the airways if inhaled in sufficient amounts.

Musculoskeletal symptoms among seafood production workers in North Norway.

AIMS: To investigate the prevalence of musculoskeletal complaints among male and female production workers in different types of seafood industries in North Norway and to analyse associations between musculoskeletal symptoms and some possible risk factors in the seafood industry. METHODS: A self-administered anonymous questionnaire, covering several aspects concerning occupational environment and health issues, was mailed to employees in seafood-processing plants in North Norway. RESULTS: A total of 1767 employees in 118 seafood-processing plants participated giving a 50% response rate. This included 744 production workers in whitefish, shrimp and salmon industries, and 129 administrative workers in all types of seafood industries. The prevalence of musculoskeletal symptoms was high among seafood production workers. The odds ratio for symptoms from upper limbs was significantly higher for females compared to men. Production workers had the highest relative risk for symptoms from wrist/hands (OR = 4.1-9.4) and elbows (OR = 3.5-5.2) when compared to administrative workers. The main difference between types of seafood industries was the high prevalence of symptoms from wrist/hands among female (82%) and male (64%) production workers in the salmon industry compared to whitefish (62 and 47%, respectively) and shrimp industry (66 and 37%, respectively). CONCLUSIONS: Musculoskeletal symptoms were found among the majority of production workers in the whitefish, shrimp and salmon industry, the highest prevalence being among female workers. The main difference between types of seafood industries was the high prevalence of symptoms from wrist/hands among workers in the salmon industry. Cold work was an important risk factor for musculoskeletal symptoms.

Exposure and airway effects of seafood industry workers in northern Norway.

OBJECTIVE: In this study, we explored airway symptoms and exposure to bioaerosols and exhaust gases in seafood industry plants. METHODS: The study details the results from personal and environmental exposure measurements (17 plants), a questionnaire (n = 984), and clinical examinations (n = 225). RESULTS: The workers were exposed to allergens, endotoxins, molds, and exhaust. The 1-year prevalence of work-related airway symptoms was 42.8% for production workers and 25.9% for administrative workers. Mean levels of forced expiratory volume in 1 second and forced vital capacity were less than the predicted values in all exposed nonsmoker groups. A total of 20.5% had increased levels of total IgE (>/=100 kU/L). Specific IgE-mediated reactions seemed to be relevant only in the shrimp industry. CONCLUSIONS: Seafood industry workers showed a high prevalence of work-related airway symptoms. Further research on the relationship between exposure and effects is necessary.

Feeling cold at work increases the risk of symptoms from muscles, skin, and airways in seafood industry workers.

BACKGROUND: Norwegian workers in seafood industry plants are exposed to a cold and often wet environment. METHODS: 1,767 seafood industry workers participated in a questionnaire study. Seventeen plants were visited for thermal measurements. RESULTS: 15.9% of industrial workers and 1.7% of administrative workers reported that they often felt cold at work. Mean finger temperatures after 1 hr work varied between 16 and 22 degrees C. Foot temperature dropped from morning measurement until lunch time in 85% of the measurements. Industrial workers who reported that they often felt cold, had significantly increased prevalence of symptoms from muscles, skin, and airways while working, compared to workers who reported that they never felt cold at work. CONCLUSIONS: Moderate cooling, caused by a cold indoor working environment, may increase muscle-, airway-, and skin symptoms. The prevalence of feeling cold may be a useful exposure estimate in moderate cold exposure situations.