Gender and snow crab occupational asthma in Newfoundland and Labrador, Canada

A systematic review of the impact of post-harvest aquatic food processing technology on gender equality and social justice

Post-harvest practices and technologies are key to reducing global aquatic harvest loss. The lives of post-harvest fisheries workers, over half of them women, are deeply affected by these technologies, but their equity and equality outcomes are poorly understood. This systematic review synthesizes evidence of post-harvest aquatic food processing technology outcomes, showing that persistent inequalities in social structure and norms disadvantage women across a range of technologies, both traditional and improved, especially regarding control over resources. We found that improved technologies bring enhanced productivity and possibly income for workers, yet contracts are often precarious due to pre-existing social inequities. While power and control of resources is more unequal in factory settings, it is not necessarily equal in traditional contexts either, despite offering greater flexibility. More rigorous comparative research, including voices of diverse actors, is key to understanding the impacts of different technologies on gender equality and social justice and inform policymaking.

Comparison of high- and low-molecular-weight sensitizing agents causing occupational asthma: an evidence-based insight

INTRODUCTION

The many substances used at the workplace that can cause sensitizer-induced occupational asthma are conventionally categorized into high-molecular-weight (HMW) agents and low-molecular-weight (LMW) agents, implying implicitly that these two categories of agents are associated with distinct phenotypic profiles and pathophysiological mechanisms.

AREAS COVERED

The authors conducted an evidence-based review of available data in order to identify the similarities and differences between HMW and LMW sensitizing agents.

EXPERT OPINION

Compared with LMW agents, HMW agents are associated with a few distinct clinical features (i.e. concomitant work-related rhinitis, incidence of immediate asthmatic reactions and increase in fractional exhaled nitric oxide upon exposure) and risk factors (i.e. atopy and smoking). However, some LMW agents may exhibit 'HMW-like' phenotypic characteristics, indicating that LMW agents are a heterogeneous group of agents and that pooling them into a single group may be misleading. Regardless of the presence of detectable specific IgE antibodies, both HMW and LMW agents are associated with a mixed Th1/Th2 immune response and a predominantly eosinophilic pattern of airway inflammation. Large-scale multicenter studies are needed that use objective diagnostic criteria and assessment of airway inflammatory biomarkers to identify the pathobiological pathways involved in OA caused by the various non-protein agents.

Rhino Conjunctivitis and Asthma Among Seafood Processing Workers in Greenland. A Cross-Sectional Study

Introduction: The fishing- and the seafood processing industries are the largest industrial sectors in Greenland. Despite this, only a few cases of occupational diseases in this industry have been reported to the Danish Labor Market Insurance. Occupational asthma and allergy are well-known occupational diseases in the seafood processing industry worldwide and underreporting of occupational diseases in Greenland is suspected.

Objective: The aim of the current study was to examine the associations between job exposures and occupational asthma and rhino conjunctivitis in workers in the Greenlandic seafood processing industry and to compare the prevalence of sensitization by type and degree of exposure to snow crab, shrimp, fish, and the fish parasite, Anisakis simplex.

Methods: Data from 382 Greenlandic seafood processing workers were collected during 2016–2018. Data included questionnaire answers, lung function measurements, skin prick tests, and blood samples with ImmunoCAP. For all analyses, p < 0.05 was considered the level of significance.

Results: 5.5% of the workers had occupational asthma and 4.6% had occupational rhino conjunctivitis. A large proportion of the workers were sensitized to allergens specific to the workplace; 18.1% to snow crab, 13.6% to shrimp, 1.4% to fish, and 32.6% to the fish parasite, A. simplex. We found a dose-response relationship between the risk of being sensitized to snow crab and A. simplex and years of exposure to the allergens in the seafood processing industry.

Conclusion: This study showed that a considerable proportion of workers in the Greenlandic seafood processing industry had occupational asthma and rhino conjunctivitis. Additionally, the study showed high sensitization levels toward snow crab, shrimp, and the fish parasite, A. simplex. This supports the hypothesis of a considerable degree of underreporting of occupational allergic airway disease in the Greenlandic seafood processing industry. Prospectively, it is important to inform workers, leaders, and health care professionals of the health problems and the law on worker's compensation, and to initiate preventive actions at factory and trawler level.

Urinary Metals as a Marker of Exposure in Men and Women in the Welding and Electrical Trades: A Canadian Cohort Study

OBJECTIVES

Men and women working in the welding trades undergo the same apprenticeship training but it is unknown whether, once in the trade, their exposures differ. Comparison of urinary metal concentrations, having adjusted for estimated airborne exposure, may provide an answer.

METHODS

Men and women were recruited to a cohort study of workers in the welding and electrical trades (the Workers Health in Apprenticeship Trades-Metal working and Electrical [WHAT-ME study]). They completed a recruitment questionnaire and further questionnaires every 6 months for up to 5 years. At each follow-up, they gave details on employment and, if welding, answered trade-specific questionnaires. Urine samples were collected by mail. Welding exposure matrices were developed to estimate metal exposures from welding process, base metal, and consumables. Urinary metal concentrations, determined by ICP-MS, were compared by trade (welding or electrical). Within welding, the relation of urinary concentrations to estimated airborne exposure was examined, with adjustment for potential confounders including sex, use of respiratory protective equipment (RPE), and time spent outdoors. Natural logarithms were taken of exposure estimates and urinary concentrations, to reduce skew. All regression analyses included creatinine concentration.

RESULTS

Urinary metal concentrations were analysed for 12 metals in 794 samples. Antimony, arsenic, lead, and mercury had a high proportion of samples with no metal detected and were not considered further. The urinary concentrations of aluminum, cadmium, chromium, cobalt, copper, manganese, nickel, and zinc were compared for welders (434 samples) and electrical workers (360). After adjustment for potential confounders, welders had higher urinary concentrations for aluminum (β = 0.13 95%CI 0.03-0.24) and chromium (β = 0.66 95%CI 0.55-0.77). Of 434 welder urines, 334 could be matched securely to detailed information about the most recent day welding. For these, an estimate of airborne exposure was made for aluminum, chromium, manganese, and nickel. Male welders were estimated to have higher airborne exposure to chromium and nickel than women welders. No difference was seen in the estimated exposures for aluminum or manganese (or total dust). Regression analyses of the relation of urinary metals to estimated exposure showed a good concordance for aluminum (β = 0.09 95%CI 0.04-0.15 (P < 0.001) and chromium (β = 0.11 95%CI 0.05-0.17 P < 0.001). The concordance for manganese and nickel was positive, but much weaker. Urinary concentrations of aluminum and nickel were somewhat lower with increasing time wearing RPE and, for chromium and nickel, with time working outdoors. Having adjusted for estimated exposure, creatinine and other confounders, male welders had lower urine concentrations of aluminum (β = -0.35 95%CI -0.51 to -0.19 P < 0.001) chromium (β = -0.38 95%CI -0.57 to -0.19 P < 0.001) and manganese (β = -0.36 95%CI -0.49 to -0.23 P < 0.001) than female welders.

CONCLUSION

Welders had higher urinary concentrations of aluminum and chromium than electrical workers. Exposure estimates of aluminum and chromium for welders were a valid representation of the airborne exposures to these metals. Although male welders were estimated to have higher exposures of chrome and nickel than female welders, the higher urinary metal concentrations in women welders is of concern, particularly for women who may conceive while in the trade.

Chitin induces steroid-resistant airway inflammation and airway hyperresponsiveness in mice

BACKGROUND

Previous reports have shown that pathogen-associated patterns (PAMPs) induce the production of interleukin (IL)-1β in macrophages. Moreover, studies using mouse models also suggest that chitin, which acts as a PAMP, induces adjuvant effects and eosinophilic infiltration in the lung. Thus, we investigated the effects of inhaled chitin in mouse models.

METHODS

We developed mouse models of inhaled chitin particle-induced airway inflammation and steroid-resistant ovalbumin (OVA)-induced airway inflammation. Some experimental groups of mice were treated additionally with dexamethasone (DEX). Murine alveolar macrophages (AMs), which were purified from bronchoalveolar lavage (BAL) fluids, were incubated with chitin, and treated with or without DEX.

RESULTS

The numbers of total cells, AMs, lymphocytes, eosinophils, and neutrophils among BAL-derived cells, as well as the IL-1β levels in BAL fluids and the numbers of IL-1β-positive cells in lung, were significantly increased by chitin stimulation. Airway hyperresponsiveness (AHR) was aggravated in mice of the chitin inflammation model compared to control animals. The production of IL-1β was significantly increased in murine AMs by chitin treatment, but DEX administration did not inhibit this chitin-induced IL-1β production. Furthermore, in mouse models, DEX treatment inhibited the OVA-induced airway inflammation and AHR but not the airway inflammation and AHR induced by chitin or the combination of OVA and chitin.

CONCLUSIONS

These results suggest that inhaled chitin induces airway inflammation, AHR, and the production of IL-1β. Furthermore, our findings demonstrate for the first time that inhaled chitin induces steroid-resistant airway inflammation and AHR. Inhaled chitin may contribute to features of steroid-resistant asthma.

Interventions for the prevention of musculoskeletal disorders in a seasonal work context: A scoping review

Seasonal work is characterized by difficult working conditions further influenced by organizational, physical, and time constraints which expose seasonal workers to high risks of MSDs. Our aim was to provide an overview of the recommendations and interventions carried out in a seasonal work context to prevent MSDs. To do this, we conducted a scoping review through a systematic electronic search of seven scientific databases and the websites of ergonomics and occupational health and safety organizations. After screening by independent reviewers according to specific criteria sets, we performed qualitative analyses on the 16 studies retained. Findings revealed six categories of transformation targets sought by the interventions/recommendations with the technical devices/physical work environment category being the most reported. We also found it was quite rare for studies to consider the seasonal work context in and of itself when developing and implementing interventions. Our review thus highlights the need to pay attention to intervention processes in order to better understand the influence of seasonality on the measures taken to prevent MSDs in working environments.

Gender and occupational allergy: Report from the task force of the EAACI Environmental and Occupational Allergy Interest Group

Women's work has traditionally been considered less hazardous to health in comparison with men's work. The increased women's participation in the workforce has led to an increased attention to women's working conditions. Women and men are unequally represented in individual professions or sectors (horizontal segregation), with women also under-represented in leadership positions (vertical segregation). The selection of specific occupations can result in differences between types and levels of occupational exposures among women and men and can affect prevalence of occupational allergy. Gender distribution of work-related asthma appears to vary across countries without clear global difference. Occupational rhinitis tends to be higher in women, although is not clear if this is related to a sex/gender effect or to differences in work exposure. Women are more likely to have occupational contact dermatitis, mainly due to wet work. No clear effects of gender on rates of hypersensitivity pneumonitis have been shown. Besides variation in exposures, physical and physiological characteristics, different behaviours and health consciousness have an impact on the occupational health hazards of women and men. Occupational allergy health promotion strategies need to consider approaches for women and men adjusted by gender, and legislative actions similarly could be implemented in a more gender-sensitive way.

Health and Work in Women and Men in the Welding and Electrical Trades: How Do They Differ?

Objectives

There is little information on how work tasks, demands, and exposures differ between women and men in nominally the same job. This is critical in setting workplace standards that will protect the health of both men and those women moving into less traditional work roles. Information used in setting standards is currently based almost entirely on male workers. This paper describes differences in work and health, and the relation between them, in women and men who have undergone the same trade training for the welding or electrical trades.

Method

Four cohorts were established. Two were women across Canada in the welding and electrical trades who had been in an apprenticeship since 2005. Cohorts of men in the same trades during the same period were established in the province of Alberta, Canada. Participants completed a baseline questionnaire at recruitment and were followed up every 6 months to collect detailed information on work carried out and on their health and habits. At the end of the study (up to 5 years for women and up to 3 years for men), the cohort members completed a final questionnaire including questions on mental health, harassment, and gender.

Results

The four cohorts comprised 1001 welders (447 female; 554 male) and 885 in the electrical trades (438 female; 447 male). Follow-up information was available for 89%. Women were more likely than men to have had some post-secondary education before starting their trade and were less likely to be living as married or to have a child. More welders smoked, and more men were heavy drinkers. At recruitment, more welders than those in the electrical trades reported rhinitis (sneezing and runny nose), depression, and anxiety. Female welders reported more depression (38%) than male welders (30%), compared to 24% in the electrical trades. At first follow-up, new-onset shoulder pain was more frequent in men and new-onset asthma or wheezing in welders. Within each trade, women reported less variety in tasks. Women welders were less likely to be employed in construction than men, and women were less likely to become industrial electricians. Overall, 54% of women and 46% of men reported never using respiratory protection when welding. In the end-of-study questionnaires received to date, 49% reported bullying or harassment during the apprenticeship, with higher proportions in welding than electrical trades and in women compared with men. Such harassment was reflected in higher anxiety and depression scores.

Conclusions

This is the first report on these four cohorts and demonstrates the capacity for detailed analysis of the differences in exposure and new-onset occupationally related ill-health. While women and men in the same trades appear to be doing broadly similar work, and to have similar patterns on health at the first follow-up, there are some significant differences in the types of employment and variety of tasks. The very detailed information collected will allow more precise estimates of exposures to be correlated with health outcomes at the end of the follow-up period.

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.

The Organization of Working Time: Developing an Understanding and Action Plan to Promote Workers' Health in a Seasonal Work Context: L'organisation temporelle du travail: la comprendre pour développer des actions favorisant la santé des travailleuses en contexte de travail saisonnier

Despite the health problems associated with irregular schedules and long working hours, few studies have focused on the temporal dimension of work in seasonal working contexts. Through the monitoring of sixteen seasonal workers in the crab-processing industry over a two-year period, this study aimed to better understand their working reality and to provide a detailed picture of the temporal dimension of seasonal work as experienced by these workers. Observations of the work activity, interviews, and analysis of official documents were carried out. The findings reveal that the organization of working time and working conditions are very restrictive. These constraints are linked not only to the work environment and management but also to various public policies and ministerial directives. Methodological elements essential for the study of the organization of working time have been identified and could contribute to a better understanding of temporal constraints experienced by seasonal workers. Résumé Malgré les problèmes de santé associés aux horaires non standards et aux longues heures de travail, peu d'études se sont attardées à dégager un portrait de la dimension temporelle du travail en contexte de travail saisonnier. Par le suivi de 16 travailleuses saisonnières de l'industrie de la transformation du crabe pendant deux années, cette étude visait à mieux comprendre leur réalité de travail et à dresser un portrait détaillé de la dimension temporelle du travail saisonnier tel que vécu par ces travailleuses. Des observations du travail, des entretiens et l'analyse de documents ont été réalisés. Les résultats révèlent une organisation temporelle et des conditions de travail fort contraignantes pour ces travailleuses liées, entre autres, à l'environnement et à la gestion du travail, mais également à diverses politiques publiques et consignes ministérielles. Des éléments méthodologiques essentiels pour l'étude des temps de travail ont également été identifiés et contribueront à mieux cerner les contraintes temporelles des situations de travail vécues par les travailleuses saisonnières.

Prevalence of asthma and wheezes among snow crab workers in western Japan: a cross-sectional study

OBJECTIVES

Few reports are available concerning the prevalence of asthma among snow crab workers in Japan. The object of this study was to estimate the prevalence of asthma and wheezes among Japanese snow crab workers and their associations with exhaled nitric oxide (FeNO) and YKL-40.

METHODS

Forty-nine snow crab workers enrolled in this study, which was cross-sectional by design and was conducted using a translated version of the European Community Respiratory Health Survey questionnaire. The levels of FeNO and serum YKL-40 were measured between September and October 2014.

RESULTS

The prevalences of current asthma and wheezes were 10.2% (95% CI, 3.4 to 22.2) and 12.2% (95% CI, 4.6 to 24.8), respectively. There was no association between these prevalences and the duration of snow crab employment. Six subjects' FeNO levels exceeded 50 ppb, and nine subjects' levels exceeded 25 ppb. Twelve subjects' (25.5%) serum YKL-40 levels exceeded 77.2 ng/mL, which was 2 standard deviations above the mean for healthy subjects. However, there were no significant relationships among the prevalences for asthma and wheezes, FeNO, and serum YKL-40.

CONCLUSIONS

This study provides information concerning the prevalences of asthma and wheezes among Japanese snow crab processing workers.

Monitoring of occupational and environmental aeroallergens-- EAACI Position Paper. Concerted action of the EAACI IG Occupational Allergy and Aerobiology & Air Pollution

Exposure to high molecular weight sensitizers of biological origin is an important risk factor for the development of asthma and rhinitis. Most of the causal allergens have been defined based on their reactivity with IgE antibodies, and in many cases, the molecular structure and function of the allergens have been established. Significant information on allergen levels that cause sensitization and allergic symptoms for several major environmental and occupational allergens has been reported. Monitoring of high molecular weight allergens and allergen carrier particles is an important part of the management of allergic respiratory diseases and requires standardized allergen assessment methods for occupational and environmental (indoor and outdoor) allergen exposure. The aim of this EAACI task force was to review the essential points for monitoring environmental and occupational allergen exposure including sampling strategies and methods, processing of dust samples, allergen analysis, and quantification. The paper includes a summary of different methods for sampling and allergen quantification, as well as their pros and cons for various exposure settings. Recommendations are being made for different exposure scenarios.

Gender differences in work-related asthma: surveillance data from California, Massachusetts, Michigan, and New Jersey, 1993-2008

OBJECTIVE

To characterize work-related asthma by gender.

METHODS

We analyzed state-based sentinel surveillance data on confirmed work-related asthma cases collected from California, Massachusetts, Michigan, and New Jersey during 1993-2008. We used Chi-square and Fisher's Exact Test statistics to compare select characteristics between females and males.

RESULTS

Of the 8239 confirmed work-related asthma cases, 60% were female. When compared to males with work-related asthma, females with work-related asthma were more likely to be identified through workers' compensation (14.8% versus 10.6%) and less likely to be identified through hospital data (14.2% versus 16.9%). Moreover, when compared to males, females were more likely to have work-aggravated asthma (24.4% versus 13.5%) and less likely to have new-onset asthma (48.0% versus 56.5%). Females were also more likely than males with work-related asthma to work in healthcare and social assistance (28.7% versus 5.2%), educational services (11.8% versus 4.2%), and retail trade (5.0% versus 3.9%) industries and in office and administrative support (20.0% versus 4.0%), healthcare practitioners and technical (13.4% versus 1.6%), and education training and library (6.2% versus 1.3%) occupations. Agent groups most frequently associated with work-related asthma were miscellaneous chemicals (20.3%), cleaning materials (15.3%), and indoor air pollutants (14.9%) in females and miscellaneous chemicals (15.7%), mineral and inorganic dusts (13.2%), and pyrolysis products (12.7%) in males.

CONCLUSIONS

Among adults with work-related asthma, males and females differ in terms of workplace exposures, occupations, and industries. Physicians should consider these gender differences when diagnosing and treating asthma in working adults.

Differences in PAR-2 activating potential by king crab (Paralithodes camtschaticus), salmon (Salmo salar), and bovine (Bos taurus) trypsin

BACKGROUND

Salmon trypsin is shown to increase secretion of the pro-inflammatory cytokine interleukin (IL)-8 from human airway epithelial cells through activation of PAR-2. Secretion of IL-8 induced by king crab trypsin is observed in a different concentration range compared to salmon trypsin, and seems to be only partially related to PAR-2 activation. This report aim to identify differences in the molecular structure of king crab trypsin (Paralithodes camtschaticus) compared to salmon (Salmo salar) and bovine trypsin (Bos taurus) that might influence the ability to activate protease-activated receptor-2 (PAR-2).

RESULTS

During purification king crab trypsin displayed stronger binding capacity to the anionic column used in fast protein liquid chromatography compared to fish trypsins, and was identified as a slightly bigger molecule. Measurements of enzymatic activity yielded no obvious differences between the trypsins tested. Molecular modelling showed that king crab trypsin has a large area with strong negative electrostatic potential compared to the smaller negative areas in bovine and salmon trypsins. Bovine and salmon trypsins also displayed areas with strong positive electrostatic potential, a feature lacking in the king crab trypsin. Furthermore we have identified 3 divergent positions (Asp196, Arg244, and Tyr247) located near the substrate binding pocket of king crab trypsin that might affect the binding and cleavage of PAR-2.

CONCLUSION

These preliminary results indicate that electrostatic interactions could be of importance in binding, cleavage and subsequent activation of PAR-2.

Airborne seafood allergens as a cause of occupational allergy and asthma

Occupational allergy and asthma is a serious adverse health outcome affecting seafood-processing workers. Allergic reactions are directed to two major seafood groups: fish and shellfish, with the latter group comprising crustaceans and molluscs. Several allergenic proteins have been identified in these different groups, but few have been characterised on a molecular level. Parvalbumin appears to be the major fish allergen, while tropomyosin the major crustacean allergen. Other IgE-binding proteins have also been identified in molluscs and other seafood-associated agents (e.g. Anisakis sp), although their molecular nature has not been characterised. Aerosolised allergens can be identified and quantified using immunological and chemical approaches, detecting levels as low as 10 ng/m(3). This contemporary review discusses interesting and recent findings in the area of occupational seafood allergy including high-risk occupations, environmental risk factors for airborne exposures, major and minor allergens implicated and innovative approaches in diagnosing and managing occupational allergy and asthma associated with seafood processing.

Occupational allergies in seafood-processing workers

Global increased demand for seafood and its products has been associated with a concomitant rise in fishing, aquaculture, and processing activities. This increased harvesting of seafood is associated with more frequent reporting of allergic health problems among seafood processors. This review outlines the high-risk working populations, work processes, as well as host and environmental exposure risk factors for occupational respiratory and skin allergies. It also provides insights into the major and minor allergens as well as the pathophysiological mechanisms implicated. Diagnostic and preventive approaches are outlined in managing work-related allergy associated with seafood processing.

Chitin elicits CCL2 from airway epithelial cells and induces CCR2-dependent innate allergic inflammation in the lung

Chitin exposure in the lung induces eosinophilia and alternative activation of macrophages and is correlated with allergic airway disease. However, the mechanism underlying chitin-induced polarization of macrophages is poorly understood. In this paper, we show that chitin induces alternative activation of macrophages in vivo but does not do so directly in vitro. We further show that airway epithelial cells bind chitin in vitro and produce CCL2 in response to chitin both in vitro and in vivo. Supernatants of chitin-exposed epithelial cells promoted alternative activation of macrophages in vitro, whereas Ab neutralization of CCL2 in the supernate abolished the alternative activation of macrophages. CCL2 acted redundantly in vivo, but mice lacking the CCL2 receptor, CCR2, showed impaired alternative activation of macrophages in response to chitin, as measured by arginase I, CCL17, and CCL22 expression. Furthermore, CCR2 knockout mice exposed to chitin had diminished reactive oxygen species products in the lung, blunted eosinophil and monocyte recruitment, and impaired eosinophil functions as measured by expression of CCL5, IL-13, and CCL11. Thus, airway epithelial cells secrete CCL2 in response to chitin and CCR2 signaling mediates chitin-induced alternative activation of macrophages and allergic inflammation in vivo.

Occupational asthma: etiologies and risk factors

The purpose of this article is to critically review the available evidence pertaining to occupational, environmental, and individual factors that can affect the development of occupational asthma (OA). Increasing evidence suggests that exploration of the intrinsic characteristics of OA-causing agents and associated structure-activity relationships offers promising avenues for quantifying the sensitizing potential of agents that are introduced in the workplace. The intensity of exposure to sensitizing agents has been identified as the most important environmental risk factor for OA and should remain the cornerstone for primary prevention strategies. The role of other environmental co-factors (e.g., non-respiratory routes of exposure and concomitant exposure to cigarette smoke and other pollutants) remains to be further delineated. There is convincing evidence that atopy is an important individual risk factor for OA induced by high-molecular-weight agents. There is some evidence that genetic factors, such as leukocyte antigen class II alleles, are associated with an increased risk of OA; however, the role of genetic susceptibility factors is likely to be obscured by complex gene-environment interactions. OA, as well as asthma in general, is a complex disease that results from multiple interactions between environmental factors and host susceptibilities. Determining these interactions is a crucial step towards implementing optimal prevention policies.

Risk factors, predictors, and markers for work-related asthma and rhinitis

The burden of asthma attributable to occupational exposures is significant. A better evaluation of markers of asthma and rhinitis in occupational settings may help reduce the frequency of occupational asthma (OA) and rhinitis (OR). This publication reviews articles published in 2008 and 2009 to provide an update on aspects related to markers of asthma and rhinitis. Markers derived from occupational exposure assessment, questionnaires, clinical data, and noninvasive tests such as functional tests or measures of serum antibodies are used to develop prediction models for the likelihood of OA and OR development. Findings from prospective studies highlight the course of preclinical signs and markers of airway inflammation in the natural history of OA and OR. Airway inflammation, evaluated by quantification of cells and mediators in induced sputum or nasal lavage and by exhaled nitric oxide, is associated with OA and OR; however, the sensitivity and specificity of these means, especially exhaled nitric oxide, have not been sufficiently assessed.

Seafood workers and respiratory disease: an update

PURPOSE OF REVIEW

This review focuses on seafood workers engaged in harvesting, processing and food preparation. These groups are increasingly at risk of developing occupational allergy and respiratory disease as a result of seafood handling and processing activities. This review provides an update of a previous review conducted a decade ago.

RECENT FINDINGS

Exposure characterization studies have demonstrated that aerosolization of seafood (muscle, visceral organs, skin/mucin) during canning and fishmeal operations result in highly variable levels of airborne particulate (0.001-11.293 mg/m3) and allergens (0.001-75.748 ug/m3). Occupational asthma is more commonly associated with shellfish (4-36%) than with bony fish (2-8%). Other seafood-associated biological (Anisakis) and chemical agents (protease enzymes, toxins and preservatives) have also been implicated. Atopy, smoking and level of exposure to allergens are significant risk factors for sensitization and the development of occupational asthma. Molecular studies of the allergens suggest that aside from tropomyosin and parvalbumin, other as yet uncharacterized allergens are important.

SUMMARY

Future research needs to focus on detailed characterization of allergens in order to standardize exposure assessment techniques, which are key to assessing the impact of interventions. The clinical relevance of agents such as serine proteases and endotoxins in causing asthma through nonallergic mechanisms needs further epidemiological investigation.

Shellfish allergy

Seafood plays an important role in human nutrition and health. The growing international trade in seafood species and products has added to the popularity and frequency of consumption of a variety of seafood products across many countries. This increased production and consumption of seafood has been accompanied by more frequent reports of adverse health problems among consumers as well as processors of seafood. Adverse reactions to seafood are often generated by contaminants but can also be mediated by the immune system and cause allergies. These reactions can result from exposure to the seafood itself or various non-seafood components in the product. Non-immunological reactions to seafood can be triggered by contaminants such as parasites, bacteria, viruses, marine toxins and biogenic amines. Ingredients added during processing and canning of seafood can also cause adverse reactions. Importantly all these substances are able to trigger symptoms which are similar to true allergic reactions, which are mediated by antibodies produced by the immune system against specific allergens. Allergic reactions to 'shellfish', which comprises the groups of crustaceans and molluscs, can generate clinical symptoms ranging from mild urticaria and oral allergy syndrome to life-threatening anaphylactic reactions. The prevalence of crustacean allergy seems to vary largely between geographical locations, most probably as a result of the availability of seafood. The major shellfish allergen is tropomyosin, although other allergens may play an important part in allergenicity such as arginine kinase and myosin light chain. Current observations regard tropomyosin to be the major allergen responsible for molecular and clinical cross-reactivity between crustaceans and molluscs, but also to other inhaled invertebrates such as house dust mites and insects. Future research on the molecular structure of tropomyosins with a focus on the immunological and particularly clinical cross-reactivity will improve diagnosis and management of this potentially life-threatening allergy and is essential for future immunotherapy.

Identification of crab proteins that elicit IgE reactivity in snow crab-processing workers

BACKGROUND

The expanding snow crab-processing industry has resulted in increased numbers of workers at risk of occupational allergy.

OBJECTIVE

Our study is to identify relevant allergenic proteins in cooked snow crab meat (CM) and crab water (CW) used for cooking for improved remediation, diagnosis, and treatment.

METHODS

Extracts were prepared from CM extracts, CW extracts, and an air-filter collection near the crab cooker. Of the 207 workers, 24 with the highest IgE antibody reactivity to CM and CW extracts, as determined by using RASTs, were tested for reactivity to nitrocellulose membranes containing CM and CW proteins separated with SDS-PAGE. A 3-serum pool was similarly incubated against nitrocellulose-bound proteins from air samples collected near the crab cooker.

RESULTS

Of the 207 sera tested, 27 and 39 sera exhibited positive IgE antibody reactivity (>or=2%) to CM and CW extracts, respectively. Twenty-two of 24 sera with the highest RAST activity (>or=3.5% binding) demonstrated IgE binding to multiple proteins (13.6-50 kd). A majority of the sera reacted to 4 proteins: 79% and 71% to a 34.0-kd protein, 79% and 42% to a 25-kd protein, 67% and 71% to an 18.5-kd protein, and 75% to a 14.4-kd protein in both CM and CW extracts, respectively. The pool of IgE-positive sera blotted against the air-filter extract reacted to 14.4-, 18.5-, 34.0-, 43.2-, and 50-kd proteins present in both crab extracts.

CONCLUSION

Four major IgE-reactive proteins were identified in CM extracts, CW extracts, and air-filter eluate. Analysis of any potential association of protein reactivity with disease suggested crab proteins at 34.0 and 14.4 kd might be more relevant.

Psychological distress and occupational asthma

PURPOSE OF REVIEW

To summarize recent findings on the psychological impact of occupational asthma, on the basis of a review of medical and psychological literature published between 1998 and 2008. For the purposes of this review, 'psychological impacts' are defined as the experience of psychological stress or distress, which refers to the experience of negative emotions (e.g., anxiety and sadness/depression). When severe and chronic, psychological distress may reach clinical levels and is referred to as a 'psychiatric disorder', which is a clinical diagnosis based on established diagnostic criteria.

RECENT FINDINGS

Only one original article assessing psychological impacts has been published in the past 10 years (in 2007). Levels of psychological distress (i.e., depression, anxiety, and cognitive dysfunction) were all in the clinical range, and rates of anxiety disorders and dysthymia (a chronic form of depression) affected approximately 35 and 23% of patients, respectively.

SUMMARY

The paucity of available literature indicates that the study of psychological factors associated with occupational asthma is still in its infancy. Though preliminary and in need of replication, the only published study to date suggests that patients with occupational asthma may be highly anxious and many are chronically depressed, a finding that is consistent with previous studies with nonoccupational asthmatics. The established link between psychological factors (e.g., depression and anxiety) and nonoccupational asthma suggests that future studies are desperately needed to more comprehensively assess the scope and severity of the psychological burden of this disease.

Occupational allergy and asthma among salt water fish processing workers

BACKGROUND

Fish processing is a common economic activity in Southern Africa. The aim of this study was to determine the prevalence and host determinants of allergic symptoms, allergic sensitization, bronchial hyper-responsiveness and asthma among workers processing saltwater fish.

METHODS

A cross-sectional study was conducted on 594 currently employed workers in two processing plants involved in pilchard canning and fishmeal processing. A modified European Community Respiratory Health Survey (ECRHS) questionnaire was used. Skin prick tests (SPT) used extracts of common airborne allergens, fresh fish (pilchard, anchovy, maasbanker, mackerel, red eye) and fishmeal. Spirometry and methacholine challenge tests (MCTs; tidal breathing method) used ATS guidelines.

RESULTS

Work-related ocular-nasal symptoms (26%) were more common than asthma symptoms (16%). The prevalence of atopy was 36%, while 7% were sensitized to fish species and 26% had NSBH (PC(20) < or = 8 mg/ml or > or =12% increase in FEV(1) post-bronchodilator). The prevalence of probable occupational asthma was 1.8% and fish allergic rhino-conjunctivitis 2.6%. Women were more likely to report work-related asthma symptoms (OR = 1.94) and have NSBH (OR = 3.09), while men were more likely to be sensitized to fish (OR = 2.06) and have airway obstruction (OR = 4.17). Atopy (OR = 3.16) and current smoking (OR = 2.37), but not habitual seafood consumption were associated with sensitization to fish.

CONCLUSIONS

Based on comparison with previous published studies, the prevalence of occupational asthma to salt water fish is lower than due to shellfish. The gendered distribution of work and exposures in fish processing operations together with atopy and cigarette smoking are important determinants of occupational allergy and asthma.

Agents causing occupational asthma

The workplace is a significant contributor to the burden of asthma. Although the majority of cases probably represent what is labeled work-exacerbated asthma, in a significant number of subjects, asthma is actually caused by 1 or more agents present in the workplace; this is occupational asthma. Two types of occupational asthma are distinguished, according to whether the asthma appears after a latency period. This article discusses (1) two types of agents causing asthma with a latency period and acting through an apparently immunologic mechanism (high-molecular-weight agents and low-molecular-weight agents) and (2) agents causing asthma without a latency period.

Occupational exposures and adult asthma

Occupational exposures can cause a new onset of asthma in a subset of susceptible workers on the basis of sensitization to a specific work agent or a high-level irritant exposure. Epidemiologic studies give insight into the natural history of occupational asthma, including host factors and environmental factors leading to the development of occupational asthma, the progression, and the potential role of preventive measures. Work-exacerbated asthma has been a focus of studies only recently but is recognized as common among asthmatic workers and is a potential cause of significant morbidity and socioeconomic impact.

The use of raw or boiled crustacean extracts for the diagnosis of seafood allergic individuals

BACKGROUND

Seafood plays an important role in human nutrition and is responsible for severe hypersensitivity reactions.

OBJECTIVE

To evaluate how the cooking process may alter the in vivo and in vitro allergenicity of these extracts.

METHODS

Raw and boiled extracts of shrimps and 2 types of lobsters were manufactured. Boiled extracts were prepared after the raw material was boiled for 15 minutes in phosphate-buffered saline. Raw and boiled extracts were homogenized and extracted for 4 hours. Afterward, the extracts were centrifuged, dialyzed, filtered, and freeze-dried. Seventy-eight patients were skin prick tested with these raw and boiled extracts. Specific IgE against the 6 extracts was measured by enzyme-linked immunosorbent assay (ELISA). Immunoblots and ELISA inhibition studies were performed with a pool of sera.

RESULTS

In vivo results showed that boiled extracts induced statistically significant larger wheals than raw extracts. More patients with positive results were also detected with boiled extracts. In vitro experiments by direct ELISA confirmed the in vivo results. The protein content in the boiled extracts decreased, and important differences were detected by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Cross-reactivity experiments showed that both types of extracts retained similar allergenic characteristics, even if the immunoblots revealed some differences in IgE binding.

CONCLUSIONS

More patients were identified using boiled extracts of shrimp and American and spiny lobsters than with raw extracts. The wheal sizes of the skin test reactions and specific IgE levels were also significantly greater using boiled extracts. The use of boiled extracts seems to be more effective in diagnosing seafood allergy.