Occupational asthma

Determinants of Task-Based Exposures to Alpha-Diketones in Coffee Roasting and Packaging Facilities Using a Bayesian Model Averaging Approach

Coffee production workers can be exposed to inhalational hazards including alpha-diketones such as diacetyl and 2,3-pentanedione. Exposure to diacetyl is associated with the development of occupational lung disease, including obliterative bronchiolitis, a rare and irreversible lung disease. We aimed to identify determinants contributing to task-based exposures to diacetyl and 2,3-pentanedione at 17 U.S. coffee production facilities. We collected 606 personal short-term task-based samples including roasting (n = 189), grinding (n = 74), packaging (n = 203), quality control (QC, n = 44), flavoring (n = 15), and miscellaneous production/café tasks (n = 81), and analyzed for diacetyl and 2,3-pentanedione in accordance with the modified OSHA Method 1013/1016. We also collected instantaneous activity-based (n = 296) and source (n = 312) samples using evacuated canisters. Information on sample-level and process-level determinants relating to production scale, sources of alpha-diketones, and engineering controls was collected. Bayesian mixed-effect regression models accounting for censored data were fit for overall data (all tasks) and specific tasks. Notable determinants identified in univariate analyses were used to fit all plausible models in multiple regression analysis which were summarized using a Bayesian model averaging method. Grinding, flavoring, packaging, and production tasks with ground coffee were associated with the highest short-term and instantaneous-activity exposures for both analytes. Highest instantaneous-sources of diacetyl and 2,3-pentanedione included ground coffee, flavored coffee, liquid flavorings, and off-gassing coffee bins or packages. Determinants contributing to higher exposures to both analytes in all task models included sum of all open storage sources and average percent of coffee production as ground coffee. Additionally, flavoring ground coffee and flavoring during survey contributed to notably higher exposures for both analytes in most, but not all task groups. Alternatively, general exhaust ventilation contributed to lower exposures in all but two models. Additionally, among facilities that flavored, local exhaust ventilation during flavoring processes contributed to lower 2,3-pentanedione exposures during grinding and packaging tasks. Coffee production facilities can consider implementing additional exposure controls for processes, sources, and task-based determinants associated with higher exposures to diacetyl and 2,3-pentanedione, such as isolating, enclosing, and directly exhausting grinders, flavoring mixers, and open storage of off-gassing whole bean and ground coffee, to reduce exposures and minimize risks for lung disease among workers.

The Burden of Respiratory Abnormalities Among Workers at Coffee Roasting and Packaging Facilities

Introduction: Respiratory hazards in the coffee roasting and packaging industry can include asthmagens such as green coffee bean and other dust and alpha-diketones such as diacetyl and 2,3-pentanedione that can occur naturally from roasting coffee or artificially from addition of flavoring to coffee. We sought to describe the burden of respiratory abnormalities among workers at 17 coffee roasting and packaging facilities. Methods: We completed medical surveys at 17 coffee roasting and packaging facilities that included interviewer-administered questionnaires and pulmonary function testing. We summarized work-related symptoms, diagnoses, and spirometry testing results among all participants. We compared health outcomes between participants who worked near flavoring and who did not. Results: Participants most commonly reported nose and eye symptoms, and wheeze, with a work-related pattern for some. Symptoms and pulmonary function tests were consistent with work-related asthma in some participants. About 5% of workers had abnormal spirometry and most improved after bronchodilator. Health outcomes were similar between employees who worked near flavoring and who did not, except employees who worked near flavoring reported more chronic bronchitis and ever receiving a diagnosis of asthma than those who did not work near flavoring. Conclusion: The symptoms and patterns likely represent overlapping health effects of different respiratory hazards, including green coffee bean and other dust that can contribute to work-related asthma, and diacetyl and 2,3-pentanedione that can contribute to obliterative bronchiolitis. Healthcare providers and occupational health and safety practitioners should be aware that workers at coffee roasting and packaging facilities are potentially at risk for occupational lung diseases.

Non-malignant respiratory disease among workers in the rubber manufacturing industry: A systematic review and meta-analysis

BACKGROUND

Non-malignant respiratory disease (NMRD) cases have occurred among rubber manufacturing workers. We examined exposure to rubber manufacturing emissions as a risk factor for NMRD.

METHODS

From a systematic literature review, we identified case reports and assessed cross-sectional and mortality studies for strength of evidence of positive association (strong, intermediate, non-significant positive association, none) between exposure to rubber manufacturing emissions and NMRD-related morbidity and mortality, and conducted two meta-analyses.

RESULTS

We analyzed 62 articles. We identified 11 cases of NMRD. Nine (30%) of 30 cross-sectional studies and one (4%) of 26 mortality studies had strong evidence. The summary odds ratio and SMR for the cross-sectional and mortality meta-analyses were 3.83 (95% confidence interval [CI], 2.28-6.51) and 0.90 (95%CI, 0.82-0.99), respectively.

CONCLUSION

Available evidence supports rubber manufacturing emissions as a potential risk factor for NMRD-related morbidity. Further investigations with longer follow-up periods and inclusion of short-tenured workers could further define risks for NMRD and identify prevention strategies.

Respiratory morbidity in a coffee processing workplace with sentinel obliterative bronchiolitis cases

RATIONALE

Obliterative bronchiolitis in former coffee workers prompted a cross-sectional study of current workers. Diacetyl and 2,3-pentanedione levels were highest in areas for flavoring and grinding/packaging unflavored coffee.

METHODS

We interviewed 75 (88%) workers, measured lung function, and created exposure groups based on work history. We calculated standardized morbidity ratios (SMRs) for symptoms and spirometric abnormalities. We examined health outcomes by exposure groups.

RESULTS

SMRs were elevated 1.6-fold for dyspnea and 2.7-fold for obstruction. The exposure group working in both coffee flavoring and grinding/packaging of unflavored coffee areas had significantly lower mean ratio of forced expiratory volume in 1 s to forced vital capacity and percent predicted mid-expiratory flow than workers without such exposure.

CONCLUSION

Current workers have occupational lung morbidity associated with high diacetyl and 2,3-pentanedione exposures, which were not limited to flavoring areas.

A new risk of occupational disease: allergic asthma and rhinoconjunctivitis in persons working with beneficial arthropods

Allergic asthma and rhinoconjunctivitis have been reported in workers who are constantly in close contact with arthropods during the course of breeding and research. We investigated a group of ten people working with beneficial arthropods in a "bio-factory." The following tests were carried out: skin prick test with allergens present in the workplace, baseline pulmonary function test, aspecific bronchial provocation test with ultrasonically nebulized distilled water, and pulmonary function test after workplace exposure in two subjects. The results demonstrated a good correlation between skin prick test, previous RAST positive reactions, clinical symptoms, and exposure. Pulmonary function test after workplace exposure proved positive in one asthmatic subject and in one subject with rhinoconjunctivitis. It is concluded that the evidence supports the occupational nature of these allergic diseases and that there is a need for careful surveillance and environmental monitoring within the workplace.

Eicosanoid release from human bronchial epithelial cells upon exposure to toluene diisocyanate in vitro

Epithelial injury and inflammation are involved in airway hyperresponsiveness and asthma induced by toluene diisocyanate. In that isocyanates are insoluble and highly reactive compounds, bronchial epithelial cells may represent the most important target cells of their toxic effect. We hypothesized that damage to airway epithelium by toluene diisocyanate may result in the release of metabolites of arachidonic acid, which are known to promote inflammation and to alter epithelial cell function and airway smooth muscle responsiveness. To test this hypothesis we examined eicosanoid products in the culture media of bronchial epithelial cells exposed in vitro to 8 and 18 ppb toluene diisocyanate. Epithelial cells derived from human bronchi obtained at surgery were cultured to confluency on collagen-coated microporous membranes. Those cells, which expressed differentiated characteristics of epithelial cells (they showed keratin-containing filaments and had a cobblestone appearance), were alternatively exposed to toluene diisocyanate or air for 30 min in a specially designed in vitro chamber. The production of metabolites of arachidonic acid was assessed by measuring the release of immunoreactive products into the cell medium at the end of the exposure and during a 2 hr period after exposure. This method revealed a predominant isocyanate-induced release of immunoreactive 15-hydroxyeicosatetraenoic acid. Release rate of this compound tended to be dose-related and was associated with cell damage as assessed by the release of lactate dehydrogenase in the medium.

Sensitization to green coffee bean (GCB) and castor bean (CB) allergens among dock workers

Dock workers (n = 218) occupationally exposed to green coffee beans (GCB) were studied, using a specific questionnaire for allergic symptoms and skin tests for common and occupational allergens. Thirty-one workers (14.3%) complained of allergic symptoms of the eye, nose and bronchial system at the workplace. The prick tests, using both commercial allergens and specific extracts prepared from the most common types of coffee and their corresponding sacks, confirmed a sensitization in 21 workers (9.6%). A positive skin reaction to castor beans (CB) was found in nearly all these cases; in ten workers there was also a positive reaction to GCB allergens and in 14 cases prick tests were positive to extracts of sacks. There was a good concordance between prick tests and specific IgE for CB (95.0%) and also, but to a lesser extent, for GCB. The authors concluded that there is a significant risk of sensitization to CB and GCB allergens in dock workers occupied in handling green coffee bean, despite the fact that the exposure is not continuous. CB emerged as a common contaminant of GCB from various countries. For effective prevention, a modification of the methods of transport is required to avoid CB contamination to other products. Eliminating environmental dust during shipping operations is the most important preventive measure and it can be achieved by the use of containers, as some exporting countries are already doing.

Prolonged fever associated with inhalation of multiple pyrolysis products

A case of smoke inhalation with a self-limited but prolonged febrile course, including headaches and chills, is reported. A final diagnosis of polymer fume fever was made, although the duration of fever was longer than generally has been reported with this syndrome. Pyrolysis products involved included those of polyurethane, methylene chloride, and polytetrafluoroethylene ("Teflon"). The results of toxicological testing are reported and discussed.

Respiratory impairment in coffee factory workers in the Asaro Valley of Papua New Guinea

In a coffee growing area of Papua New Guinea, a developing country in the western Pacific region, coffee factory workers were found to have more chronic symptomatic respiratory impairment than a carefully matched group of neighbouring villagers. This impairment was not related to their duration of employment. Coffee factory workers were found also to have a greater prevalence of reversible but asymptomatic airways obstruction on entering their factories after two days off duty than a group of soft drink factory workers. These findings are thought to be related to exposure to the dust produced in large quantities during coffee processing.

Diagnostic tests in allergy to green coffee

Twenty-two coffee roastery workers with work-related symptoms of various degree from the eyes, nose or bronchi were tested with partly purified water-soluble extract from dust of green coffee beans (GCB). Eighteen persons had a positive prick test, eight a positive bronchial provocation test and seven a positive nasal provocation test. Fourteen had a positive methacholine test, indicating unspecific bronchial hyperreactivity. Specific IgE antibodies to GCB extract were found in sera of 11 workers and to castor bean (CB) extract in 16. The workers measured their lung function with an air flow meter, three times a day for 1 week, and the values were lower in the second half of the week for the workers with IgE antibodies to GCB, but not for the others. It is concluded that the case history, prick test, RAST, and simple lung function tests for one or a few weeks are the best tools when investigating occupational allergy. When the allergen is unknown, but the occurrence of an IgE-mediated allergy is suspected, serial lung function measurements and determinations of total serum IgE, in addition to taking a careful case history, are valuable methods with which to start the investigation.

Coffee worker's allergy

Workers in the coffee industry were investigated. Study I comprised 50 selected cases of whom 25 had work-related symptoms and 25 had not. Prick tests and RAST investigations with different factory dust extracts were performed. Study II was a cross-sectional study comprising 129 workers who were prick-tested with one factory dust extract and with castor bean (CB). More than 40% described occupationally related asthma, rhinitis, conjunctivitis or pruritus, and in about half of these cases sensitization with one or two allergens was found. One allergen comes from coffee beans and is found in the factory dust, mainly where the raw coffee is handled. This allergen is destroyed in the roasting process. The other allergen is identical with the allergen from castor bean and its presumed to enter the plant via the sacks. Predisposing factors to developing sensitization were atopic status, degree and length of exposure, and smoking habits.

Radioallergosorbent testing of toluene diisocyanate-reactive individuals using p-tolyl isocyanate antigen

Serum from 26 persons shown to react to provocative inhalation challenge with low concentration of toluene diisocyanate (TDI) was tested by radioallergosorbent test (RAST) using a p-tolyl isocyanate-human serum albumin (TMI-HSA) conjugate. Results were evaluated by the RAST ratio and by the mean +3 standard deviation methods. Positive results were obtained in 15% to 19% of TDI reactors, depending on the method of evaluation. These findings suggest that TDI asthma may be a complex syndrome with several types of reaction possible, including an IgE mechanism in some individuals, but they do not support the theory that TDI asthma is based solely on an immune mechanism. However, they do not disagree with the hypothesis that TDI reactivity may be mediated by a pharmacologic mechanism.

Asthma in adults III: occupational asthma

Recognition of the disease may be difficult, since symptoms may be atypical and a temporal association with exposure is often obscure. Attention is given to the ways of differentiating the truly allergic in origin from other types of occupational asthma.