Berit Bang

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.

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.

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.

The Human Promyelocytic Leukemia Cell (HL‐60 Cell) β‐Adrenergic Receptor

We have characterized the β‐adrenergic receptor binding site and the β‐adrenergic cAMP response of the HL‐60 cell. The hydrophilic ligand [3H]‐(–)‐CGP‐12177 was specifically and reversibly bound to one single class of binding sites (Kd 220 pM and Bmax 1,970 sites/cell). The adrenergic agonists inhibited the specific radioligand binding. The order of potency was isoproterenol > epinephrine > norepinephrine. The β‐2 selective antagonist ICI 118551 had a binding affinity 3 orders of potency higher than the β‐1 selective antagonist, atenolol. The adrenergic agonists elevated the cAMP accumulation in a concentration‐dependent mode. The order of potency was isoproterenol > epinephrine > norepinephrine. Both the binding and the functional studies revealed stereospecificity and reversibility. The present data show that HL‐60 cells possess β‐2 adrenergic receptors functionally coupled to adenylate cyclase.

Skin symptoms in the seafood-processing industry in north Norway.

A survey of occupational skin problems, based on a questionnaire, was carried out among 883 workers in different types of seafood‐processing industries in northern Norway. The prevalence of dry skin, itching, rash/eczema, chapped skin and chronic sores was significantly higher among production workers (55.6%) in the white fish‐, shrimp‐ and salmon‐processing industries, compared to administrative workers in the same industries (27.5%). Among production workers, there was a significantly higher prevalence of skin symptoms among females (60.2%) compared to males (50.1%). A strong sex division of work tasks rather than sex itself may explain this. There was no sex difference among administrative workers. Several risk factors for skin symptoms to occur are indicated. The workers are exposed to raw materials and a mixture of water and juice from the fish or shrimp, salt, detergents and disinfectants. Gloves may also cause skin problems. Major risk factors believed to cause skin symptoms were contact with raw materials, fish juice, water and gloves. The results also indicate that skin symptoms are of moderate severity and seldom interfere with working capacity.

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.

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.

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-β-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.

Salmon and king crab trypsin stimulate interleukin-8 and matrix metalloproteinases via protease-activated receptor-2 in the skin keratinocytic HaCaT cell line.

Occupational skin symptoms are prevalent among the workers of the seafood processing industry. In this study we investigate the role of salmon (Salmo salar) and king crab trypsin (Paralithodes camtschaticus) as inducers of inflammation in skin via secretion of inflammatory mediators. Human skin keratinocytes (HaCaT cells) were exposed to purified salmon and king crab trypsin. We observed that salmon trypsin enhanced the secretion of IL-8 and MMP-2 and crab trypsin enhanced the secretion of IL-8, MMP-2 and MMP-9 in a dose dependent manner. As protease activated receptors (PAR)-2 in skin are known to play an important role in physiology and pathology, we explored the involvement of these receptors in mediating the release of interleukin (IL)-8 and matrix metalloproteinase (MMP)-2 and -9 subsequent to exposure of skin keratinocytes to salmon and crab trypsin. In addition we observed that salmon and crab trypsin exhibit individual differences in stimulating the release of these inflammatory mediators. Finally, using specific small interfering RNA (siRNA) against PAR-2, we confirmed that the increase in secretion of IL-8, MMP-2 and MMP-9 in skin keratinocytes following exposure to salmon and crab trypsin was mediated via activation of PAR-2. These results suggest that exposure to proteases from the seafood may lead to inflammatory reactions in skin.