Seafood processing in South Africa: a study of working practices, occupational health services and allergic health problems in the industry

The work practices, occupational health services and allergic health problems among workplaces which process seafood in Western Cape province of South Africa were examined. A cross-sectional study was conducted among 68 workplaces that were sent a self-administered postal survey questionnaire. Workplaces reporting a high prevalence of work-related symptoms associated with seafood exposure were also inspected. Forty-one (60%) workplaces responded to the questionnaire. The workforce consisted mainly of women (62%) and 31% were seasonal workers. Common seafoods processed were bony fish (76%) and rock lobster (34%). Major work processes involved freezing (71%), cutting (63%) and degutting (58%). Only 45% of workplaces provided an on-site occupational health service and 58% of workplaces conducted medical surveillance. Positive trends were observed between workplace size and activities such as occupational health service provision (P = 0.002), medical surveillance programmes (P = 0.055) and reporting work-related symptoms (P = 0.016). None of the workplaces had industrial hygiene surveillance programmes to evaluate the effects of exposure to seafood. Common work-related symptoms included skin rashes (78%), asthma (7%) and other non-specific allergies (15%). The annual prevalence of work-related skin symptoms reported per workplace was substantially higher for skin (0-100%) than for asthmatic (0-5%) symptoms. The relatively low prevalence of employer-reported asthmatic symptoms, when compared to epidemiological studies using direct investigator assessment of individual health status, suggests likely under-detection. This can be attributed to under-provision and under-development of occupational health surveillance programmes in workplaces with less than 200 workers. This is compounded further by the lack of specific statutory guidelines for the evaluation and control of bio-aerosols in South African workplaces

Occupational allergies in the seafood industry: a comparative study of Australian and South African workplaces

Although seafood allergy due to ingestion is commonly observed in clinical practice, the incidence of seafood allergies in general and more specifically in the occupational setting in Australia is largely unknown. The work practices, occupational health services and allergic health problems in 140 seafood processing workplaces in Australia were examined and compared to previous studies in South Africa. A cross-sectional employer-based survey design was used to conduct the study in both countries. In the South African study a response rate of 60% (n = 41) was obtained, compared to a response rate of 18% (n = 140) in Australia. The most common seafood processed by workplaces in South Africa was finfish (76%) and rock lobster (34%). Similarly in Australia, finfish (34%) was the most frequently handled seafood. However, processing of prawns (24%) and oysters (21%) was more common in Australia. Common work processes in South Africa involved freezing (71%), cutting/filleting (63%) and degutting (58%) procedures. Similar processes were followed in Australian industries with the exception of shucking of oysters, particularly common in the aquaculture industries. About half of the workplaces in both countries provided an occupational health service and medical surveillance of workers. However, none of the workplaces in South Africa and only 9% of the workplaces in Australia had industrial hygiene programs for seafood aerosols in place. In both countries positive trends were observed between the size of the workforce and the provision of occupational health services (p<0.005). Similarly, skin rash accounted for highest of all reported health problems (78-81%) followed by asthmatic symptoms (7-10%) and other non-specific allergic symptoms (9-15%) in both countries. Most workplaces reported the annual prevalence of work-related symptoms to be less than 5%. In Australia 7% of respondents in workplaces reported workers having left their workplace due to work-related allergic problems. Despite a low response rate of contacted companies in Australia, there were great similarities between the two countries suggesting that there is a significantly elevated prevalence of work related allergic symptoms in both countries. Unexpectedly, mollusc processing was more common in Australia although the occupational health related effects among exposed workers has previously not been investigated in detail and merits further study. It is recommended that further epidemiological studies focus on seafood exposure in Australia and identify specific risk factors for sensitisation

Chronic airflow obstruction and respiratory symptoms following tuberculosis: a review of South African studies

BACKGROUND: There is renewed interest in the chronic respiratory sequelae of pulmonary tuberculosis (PTB), particularly chronic airflow limitation. A number of South African epidemiological studies have been published, which, although not specifically designed to examine this association, provide useful data on the nature of the relationship. OBJECTIVE: To review population-based and occupational studies conducted in South Africa that provide estimates of the association between PTB, chronic symptoms and lung function loss. RESULTS: Two general population and a number of occupational studies were included. Most were able to control for likely confounders. Chronic chest symptoms and lung function loss were consistently associated with PTB, whether measured by self-report or prospectively in cohort studies. Odds ratios (ORs) were higher for chronic bronchitis (range 1.5–7.2) than for asthma (range 0.7–2.2). For spirometrically defined chronic obstructive pulmonary disease, the OR range was 2.6–8.9, depending on definition. Combined obstructive/restrictive lung function loss was the most common functional outcome, with a net obstructive effect. The association of past TB with non-specific bronchial hyperresponsiveness was equivocal. CONCLUSION: These studies add to the evidence of a strong association between PTB, even if treated, and subsequent airflow obstruction as well as restrictive loss. Unanswered questions include extent of recovery over time, effect modification by smoking and other cofactors, and degree of reversibility by treatmen

High concentrations of natural rubber latex allergens in gloves used by laboratory health personnel in South Africa

Introduction. Gloves made of natural rubber latex (NRL) are commonly used by healthcare workers because of their good qualities. However, allergic reactions to latex allergens are still commonly reported.\ud \ud Objective. To measure the concentrations of Hev b 1, Hev b 3, Hev b 5 and Hev b 6.02 allergens in gloves used by a large laboratory service in South Africa.\ud \ud Methods. NRL gloves as well as non-latex gloves supplied by various suppliers that were used by the laboratory personnel during the period June 2009 - May 2010 were obtained from various suppliers on the vendor list. Proteins were extracted from the gloves and Hev b 1, Hev b 3, Hev b 5 and Hev b 6.02 allergens were quantified using the FITkit assay.\ud \ud Results. Twenty NRL gloves from 13 different brands were analysed. Only four (20%) of the 20 NRL gloves analysed had a total allergen content <0.15 μg/g, the suggested threshold limit for low allergenicity for the sum of these four allergens.\ud \ud Conclusion. This study demonstrated that a very low proportion of gloves tested had a total allergen content below the threshold for low allergenicity

Novel way to study the function of native proteins in solution

Introduction: Aerosolisation 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 ng/m3 vs 2.5 ng/m3 during cooked processing. Conversely, edible crab tropomyosin levels were highest during cooked processing with GM 45.4 ng/m3 vs 8.7 ng/m3 during raw processing. Endotoxin levels were higher in king crab plants than in the edible crab plant with GM=6285.5 endotoxin units (EU)/m3 vs 72 EU/m3. In the edible crab plant, NAGase levels were highest during raw processing with GM=853 pmol4- methylumbelliferone (MU)/m3 vs 422 pmol4-MU/m3 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

Monitoring of occupational and environmental aeroallergens - EAACI position paper.

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

Risk Factors for allergy due to the Two-spotted spider mite (Tetranychus urticae) among table grape farm workers

BACKGROUND: Recent studies have reported an increased prevalence of respiratory symptoms among farm workers. The aim of this study was to identify risk factors associated with spider mite allergy among table grape farm workers. METHODS: A cross-sectional study of 207 workers in table grape farms was conducted. Skin prick tests used extracts of 8 common aeroallergens, grape mould (Botrytis cinerea) and Tetranychus urticae. Specific IgE to T. urticae was quantified using ImmunoCAP (Phadia). Erythrocyte cholinesterase levels were determined using the Test-mate ChE Cholinesterase Test System (model 460). Results: The average duration of employment of workers was 10 years and 12% were pesticide crop sprayers. Work-related wheeze (26%), ocular-nasal (24%) and urticaria/skin symptoms (14%) were more prevalent in the orchards. The prevalence of sensitization (skin prick test) was highest to T. urticae (22%) followed by house dust mite (16%), with 25% being atopic. The prevalence of allergy to T. urticae (skin reactivity and work-related symptoms) was 9.5%, with respiratory allergy (6%) more common than skin allergy (3%). Work-related ocular-nasal (OR = 4.9) and skin (OR = 3.7) symptoms were more commonly reported by pesticide crop sprayers. Workers with T. urticae-allergic rhino-conjunctivitis and probable asthma were more likely to be atopic, spray pesticides and have low (&lt;30 U/g hemoglobin) erythrocyte cholinesterase levels. CONCLUSIONS: This study demonstrated that spider mite, T. urticae, is an important outdoor allergen among table grape farm workers. The increased risk of spider mite allergy appears to be related to high pesticide exposure among crop sprayers

Statement in Response to Asbestos Industry Efforts to Prevent a Ban on Asbestos in Pakistan: Chrysotile Asbestos Use is Not Safe and Must Be Banned

Qualified scientists and organizations condemn in the strongest possible terms the dangerous misinformation that the International Chrysotile Association is disseminating in its effort to defeat a proposed ban on asbestos in Pakistan (letter to the Editor)