Characterization of Exposure to Cleaning Agents Among Health Workers in Two Southern African Tertiary Hospitals.

BACKGROUND: Whilst cleaning agents are commonly used in workplaces and homes, health workers (HWs) are at increased risk of exposure to significantly higher concentrations used to prevent healthcare-associated infections. Exposure assessment has been challenging partly because many are used simultaneously resulting in complex airborne exposures with various chemicals requiring different sampling techniques. The main objective of this study was to characterize exposures of HWs to various cleaning agents in two tertiary academic hospitals in Southern Africa. METHODS: A cross-sectional study of HWs was conducted in two tertiary hospitals in South Africa (SAH) and Tanzania (TAH). Exposure assessment involved systematic workplace observations, interviews with key personnel, passive personal environmental sampling for aldehydes (ortho-phthalaldehyde-OPA, glutaraldehyde and formaldehyde), and biomonitoring for chlorhexidine. RESULTS: Overall, 269 samples were collected from SAH, with 62 (23%) collected from HWs that used OPA on the day of monitoring. OPA was detectable in 6 (2%) of all samples analysed, all of which were collected in the gastrointestinal unit of the SAH. Overall, department, job title, individual HW use of OPA and duration of OPA use were the important predictors of OPA exposure. Formaldehyde was detectable in 103 (38%) samples (GM = 0.0025 ppm; range: <0.0030 to 0.0270). Formaldehyde levels were below the ACGIH TLV-TWA (0.1 ppm). While individual HW use and duration of formaldehyde use were not associated with formaldehyde exposure, working in an ear, nose, and throat ward was positively associated with detectable exposures (P-value = 0.002). Glutaraldehyde was not detected in samples from the SAH. In the preliminary sampling conducted in the TAH, glutaraldehyde was detectable in 8 (73%) of the 11 samples collected (GM = 0.003 ppm; range: <0.002 to 0.028). Glutaraldehyde levels were lower than the ACGIH's TLV-Ceiling Limit of 0.05 ppm. p-chloroaniline was detectable in 13 (4%) of the 336 urine samples (GM = 0.02 ng/ml range: <1.00 to 25.80). CONCLUSION: The study concluded that detectable exposures to OPA were isolated to certain departments and were dependent on the dedicated use of OPA by the HW being monitored. In contrast, low-level formaldehyde exposures were present throughout the hospital. There is a need for more sensitive exposure assessment techniques for chlorhexidine given its widespread use in the health sector.

Occupational anaphylaxis--an EAACI task force consensus statement.

Anaphylaxis is a systemic allergic reaction, potentially life-threatening that can be due to nonoccupational or, less commonly, to occupational triggers. Occupational anaphylaxis (OcAn) could be defined as anaphylaxis arising out of triggers and conditions attributable to a particular work environment. Hymenoptera stings and natural rubber latex are the commonest triggers of OcAn. Other triggers include food, medications, insect/mammal/snake bites, and chemicals. The underlying mechanisms of anaphylactic reactions due to occupational exposure are usually IgE-mediated and less frequently non-IgE-mediated allergy or nonallergic. Some aspects of work-related allergen exposure, such as route and frequency of exposure, type of allergens, and cofactors may explain the variability of symptoms in contrast to the nonoccupational setting. When assessing OcAn, both confirmation of the diagnosis of anaphylactic reaction and identification of the trigger are required. Prevention of further episodes is important and is based on removal from further exposure. Workers with a history of OcAn should immediately be provided with a written emergency management plan and an adrenaline auto-injector and educated to its use. Immunotherapy is recommended only for OcAn due to Hymenoptera stings.

Exposure-response relationships for inhalant wheat allergen exposure and asthma.

BACKGROUND: A few studies have investigated exposure-response relationships for sensitisation to wheat, work-related symptoms and wheat allergen exposure. IgG4 is suggested to protect against the development of allergic sensitisation. The main aim of this current study was to explore the nature of exposure-response relationships for a range of clinically relevant endpoints among bakery workers, and to investigate the role of IgG4 in these relationships. METHODS: A cross-sectional study of 517 supermarket bakery workers in 31 bakeries used a questionnaire, serum-specific IgE and IgG4 to wheat, and methacholine challenge testing. Exposure models were developed previously using job, bakery size, tasks and specific ingredients used. These models were used to predict average personal exposure to wheat allergens. RESULTS: The exposure-response relationships for average exposure followed a linear relationship for sensitisation, but a bell-shaped curve for allergic symptoms and probable occupational asthma, increasing up to 10-15 µg/m(3) wheat allergen concentration after which they plateau off and decrease at higher exposure concentrations. This relationship was modified by atopic status. IgG4 levels were strongly exposure related: a clear increase in prevalence of higher IgG4 with increase in wheat allergen exposure was observed among those sensitised and non-sensitised to wheat, with IgG4 even more strongly associated with exposure than IgE to wheat. CONCLUSIONS: The bell-shaped exposure-response relationship in the current study is consistent with the findings of previous studies. IgG4 showed no protective effect for sensitisation, confirming the findings of previous studies, suggesting that the pattern is probably related to a healthy worker effect.

Fate of Outstanding COIDA Occupational Disease Claims Following Closure of the Western Cape Provincial Medical Advisory Panel in 2008 : An audit

Background and objectives: The Western Cape Provincial Medical Advisory Panel (PMAP) was established in 2004 in terms of Section 70(1) of COIDA. A primary function was to improve the efficiency of medical assessment of occupational disease claims. The PMAP was closed by the Compensation Commissioner in 2008. This audit aimed to determine the fate of claims outstanding at the time of closure. Methods: A total of 68 claims outstanding in April 2008 were followed up by telephone; email and/or internet to determine what proportion had progressed or; if accepted; had resulted in a permanent disablement compensation payment. Results: Of the 68 claims; 31 (44) were confirmed as having progressed. Of these; payment of permanent disablement awards could be confirmed in only 15 claims (22). The remaining 56 either showed no progress or no longer had a record in the COIDA system. Those stages of the claims process that had previously been aided by PMAP functioning had deteriorated in efficiency. Conclusions: Overall; the low proportion of outstanding claims finalised and awarded is consistent with inefficiency in claims handling of occupational disease; a finding echoed by recent complaints about general Compensation Fund performance from both healthcare providers and parliamentary investigation

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.

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 treatment.

Determinants of asthma phenotypes in supermarket bakery workers.

While baker's asthma has been well described, various asthma phenotypes in bakery workers have yet to be characterised. Our study aims to describe the asthma phenotypes in supermarket bakery workers in relation to host risk factors and self-reported exposure to flour dust. A cross-sectional study of 517 supermarket bakery workers in 31 bakeries used a questionnaire, skin prick tests, and specific immunoglobulin E to wheat, rye and fungal alpha-amylase and methacholine challenge testing. The prevalence of probable occupational asthma (OA, 13%) was higher than atopic (6%), nonatopic (6%) and work-aggravated asthma (WAA, 3%) phenotypes. Previous episodes of high exposure to dusts, fumes and vapours causing asthma symptoms were more strongly associated with WAA (OR 5.8, 95% CI 1.7-19.2) than OA (2.8, 1.4-5.5). Work-related ocular-nasal symptoms were significantly associated with WAA (4.3, 1.3-13.8) and OA (3.1, 1.8-5.5). Bakers with OA had an increased odds ratio of reporting adverse reactions to ingested grain products (6.4, 2.0-19.8). OA is the most common phenotype among supermarket bakery workers. Analysis of risk factors contributes to defining clinical phenotypes, which will guide ongoing medical surveillance and clinical management of bakery workers.

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 (<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.

Occupational asthma in the developing and industrialised world: a review.

Occupational asthma is the most common occupational lung disease in industrialised countries, and the second most common occupational lung disease reported after pneumoconioses in developing countries. The median proportion of adult cases of asthma attributable to occupational exposure is between 10% and 15%. The population attributable fraction appears to be similar in industrialised and developing countries characterised by rapid industrialisation (13-15%), but lower in less industrialised developing countries (6%). The high-risk occupations and industries associated with the development of occupational asthma vary depending on the dominant industrial sectors in a particular country. High-risk exposure to cleaning agents and pesticide exposure in developing countries appear to be as important as exposure to isocyanates, cereal flour/grain dust, welding fumes, wood dust and, more recently, hairdressing chemicals, commonly reported in industrialised countries. The reported mean annual incidence of occupational asthma in developing countries is less than 2 per 100 000 population, compared to very high rates of up to 18/100 000 in Scandinavian countries. While occupational asthma remains under-recognised, especially in developing countries, it remains poorly diagnosed and managed and inadequately compensated worldwide. Primary and secondary preventive strategies should be directed at controlling workplace exposures, accompanied by intense educational and managerial improvements. Appropriate treatment remains early removal from exposure to ensure that the worker has no further exposure to the causal agent, with preservation of income. However, up to one third of workers with occupational asthma continue to remain exposed to the causative agent or suffer prolonged work disruption, discrimination and risk of unemployment.

Environmental exposure characterization of fish processing workers.

BACKGROUND: Aerosolization of seafood and subsequent inhalation, during processing is a potential high-risk activity for allergic respiratory disease. OBJECTIVES: To quantify total thoracic particulate, protein concentration and specific fish (pilchard, anchovy) antigen concentrations in fish processing plants; to determine the correlation between these exposure metrics; and to identify the major determinants of variability and the optimal grouping strategies for establishing dose-response relationships for fish antigen exposures. METHODS: Exposure assessments were conducted on randomly selected individuals within each of the identified 'exposure groups' (EGs) in two fish processing factories. Personal time-integrated sampling was conducted with a thoracic fraction sampler and analysed for particulate mass, total protein and specific fish antigens. Exposure metrics were developed on the basis of individually measured exposures and average levels of these personal samples within EGs. The main components of the exposure variability were determined using ANOVA techniques. RESULTS: A total of 198 full-shift personal aerosol samples were collected and analysed. Twenty-two percent of the samples were below the limit of detection (LOD) for pilchard and 23% for anchovy assays. Personal sampling revealed wide variations across EGs in arithmetic mean concentrations of thoracic particulate 0.61 mg m(-3) (range: LOD-11.3), total protein 0.89 microg m(-3) (LOD-11.5), pilchard antigen 150 ng m(-3) (LOD-15 973) and anchovy antigen 552 ng m(-3) (LOD-75 748) levels. The fishmeal loading and bagging sections of both plants showed consistently high thoracic particulate mass (0.811-2.714 mg m(-3)), total protein (0.185-1.855 microg m(-3)), pilchard antigen (538-3288 ng m(-3)) and anchovy antigen (1708-15 431 ng m(-3)). The a priori strategy that grouped workers according to EGs produced reasonably satisfactory summary exposure metric statistics. An alternative grouping strategy based on department revealed comparable elasticity (exposure contrast). While the correlation between the log-transformed thoracic particulate mass and fish antigen concentrations were generally modest (Pearson's r = 0.32-0.35, P < 0.001), a high correlation was found between pilchard and anchovy antigen concentrations (Pearson's r = 0.71, P < 0.001). Models using factory and department grouping strategies accounted for a significant portion of the variability (adjusted r(2) = 0.18, P = 0.043) in pilchard antigen levels. Grouping strategies using a combination of factory and department yielded the highest degree of elasticity for thoracic particulate (0.38) and pilchard antigen (0.42) levels. CONCLUSIONS: Workers involved in bony fish processing are at risk of inhaling aerosols containing pilchard and anchovy fish antigens. Antigen exposures are highest during fishmeal production and bagging. Grouping strategies based on department and factory may provide a more efficient approach than a priori classification of EGs for evaluating fish antigen exposures.

Occupational allergy in laboratory workers caused by the African migratory grasshopper Locusta migratoria.

BACKGROUND: Recent reports of fatal asthma cases associated with swarms of locusts affecting African countries have highlighted the importance of this insect in causing asthma morbidity and mortality. However, only limited information is available about the allergic health outcomes such as asthma and its determinants in exposed individuals. In this study, workers exposed to the African migratory locust Locusta migratoria were evaluated for allergic health outcomes as well as the nature of the offending allergens. METHODS: Ten scientists and technicians exposed to locusts in a laboratory were investigated for locust-related allergy using questionnaires and immunological tests. The presence of allergy was determined by quantification of specific IgE and IgG to L. migratoria using the UniCAP system and via skin-prick testing (SPT). The allergens were characterized by Western blot and ImmunoCAP inhibition assays. RESULTS: Six of the 10 workers experienced symptoms ranging from urticaria and rhinoconjuctivitis to asthma. Seven individuals demonstrated sensitivity on SPT and five had specific IgE antibodies to L. migratoria. Significant cross-reactivity was demonstrated for allergens in the locust faeces, body and wings but not to cockroach allergens. Novel allergens with molecular weights of approximately 70 kDa were identified in locust wings, which are distinctly different from other known allergen sources from locusts. CONCLUSION: Exposure to L. migratoria allergens is a potential sensitizer in exposed individuals. Raised levels of locust-specific IgE can be readily quantified. The wings of this insect species have been identified as a novel allergen source.

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.

Occupational seafood allergy: a review.

BACKGROUND: Recent years have seen increased levels of production and consumption of seafood, leading to more frequent reporting of allergic reactions in occupational and domestic settings. This review focuses on occupational allergy in the fishing and seafood processing industry. REVIEW: Workers involved in either manual or automated processing of crabs, prawns, mussels, fish, and fishmeal production are commonly exposed to various constituents of seafood. Aerosolisation of seafood and cooking fluid during processing are potential occupational situations that could result in sensitisation through inhalation. There is great variability of aerosol exposure within and among various jobs with reported allergen concentrations ranging from 0.001 to 5.061(microg/m(3)). Occupational dermal exposure occurs as a result of unprotected handling of seafood and its byproducts. Occupational allergies have been reported in workers exposed to arthropods (crustaceans), molluscs, pisces (bony fish) and other agents derived from seafood. The prevalence of occupational asthma ranges from 7% to 36%, and for occupational protein contact dermatitis, from 3% to 11%. These health outcomes are mainly due to high molecular weight proteins in seafood causing an IgE mediated response. Cross reactivity between various species within a major seafood grouping also occurs. Limited evidence from dose-response relations indicate that development of symptoms is related to duration or intensity of exposure. The evidence for atopy as a risk factor for occupational sensitisation and asthma is supportive, whereas evidence for cigarette smoking is limited. Disruption of the intact skin barrier seems to be an important added risk factor for occupational protein contact dermatitis. CONCLUSION: The range of allergic disease associated with occupational exposure to crab is well characterised, whereas for other seafood agents the evidence is somewhat limited. There is a need for further epidemiological studies to better characterise this risk. More detailed characterisation of specific protein antigens in aerosols and associated establishment of dose-response relations for acute and chronic exposure to seafood; the respective roles of skin contact and inhalational exposure in allergic sensitisation and cross reactivity; and the contribution of host associated factors in the development of occupational seafood allergies are important areas for future research.

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.