Lisbeth Aasmoe

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.

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.

Sex-dependent induction of alcohol dehydrogenase activity in rats

The glycolethers 2-methoxyethanol (2-ME), 2-ethoxyethanol (2-EE), and 2-butoxyethanol are widely used organic solvents with teratogenic, spermatotoxic, and hematotoxic effects due to the respective alkoxyacetic acid metabolites formed via alcohol dehydrogenase (ADH). ADH displays sexually dimorphic activities in adult rats, and is probably at least in part under the control of testosterone. The aim of this study was to investigate whether induction of ADH is also sex-dependent. Ethanol, 2-ME, and 2-EE were tested as inducers of hepatic and gastric ADH in female, male, and castrated male rats. The activity of hepatic ADH was higher in female than in male rats, while the activity of gastric ADH was higher in male than in female rats. The activities of ADH increased with increasing chain length of the glycolethers and alcohols. Castration of male rats led to a female pattern of ADH activity, i.e. increased activity of hepatic ADH and decreased activity of gastric ADH. Ethanol had no inducing effect on hepatic ADH in either male or female rats. 2-ME and 2-EE caused an increase in the activity of hepatic ADH in male and castrated male rats only. The present data demonstrate a different expression of ADH isoenzymes in male and female rats, and a sex-dependent induction of ADH isoenzymes. The different possible regulatory mechanisms for the different ADH isoenzymes require further investigation.

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.

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 β: -5.28, 95%CI: -9.28 to -1.27), FVC % of predicted values (adjusted β: -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.