Occupational asthma in New South Wales (NSW): a population-based study

BACKGROUND: The proportion of asthma in adults that is due to occupational exposures is not known. AIM: To examine the contribution of workplace exposures to the development of asthma in adults in New South Wales (NSW) in a cross sectional, population-based study. METHODS: A randomly selected population of 5,331 18- to 49-year olds completed and returned a mailed questionnaire (response rate 37%). In adult-onset asthmatics we examined the association of asthma with reported exposure, within 1 year of asthma onset, to a list of occupations and exposures known to be at risk for occupational asthma (high-risk jobs and exposures). RESULTS: Among 910 subjects (18%) with asthma, 383 (7%) subjects reported adult-onset disease. After adjusting for sex, age and smoking, working in any high-risk job or exposure at the time of asthma onset was significantly associated with adult-onset asthma (OR 1.51, 95% CI 1.19-1.92). The population attributable risk (PAR) of adult-onset asthma for either a high-risk job or an exposure was 9.5%. Sudden onset, irritant or reactive airways dysfunction syndrome type exposures were associated with adult-onset asthma (OR 4.65, 95% CI 1.64-13.2). The PAR of adult-onset asthma for these exposures was 0.2%. CONCLUSION: Reported adult onset of asthma is common and occupational exposures may be associated with 9.5% of prevalent cases of adult-onset asthma in NSW.     

Glutaraldehyde-induced occupational asthma: BALF components and BALF and serum Clara cell protein (CC16) changes due to specific inhalatory provocation test

OBJECTIVES: The purpose of this study was to evaluate bronchoalveolar lavage fluid (BALF) components and Clara cell protein (CC16) concentration in serum and BALF in patients with glutaraldehyde (GA)-induced asthma, before and after a specific inhalatory provocation test (SIPT) with GA, in comparison to atopic asthmatics and healthy individuals. METHODS: Spirometry and bronchoalveolar lavage were performed before and after SIPT. The serum and BALF concentrations of CC16 and cytogram content in BALF were evaluated. RESULTS: In GA-sensitized asthmatics, the level of CC16 in BALF and serum was significantly lower at 24 h after SIPT in comparison with the values recorded prior to the experiment. There was a significant increase in the proportion of eosinophils, basophils and lymphocytes in BALF of GA-sensitized asthmatics obtained after SIPT. CONCLUSIONS: The determination of CC16 either in serum or in BALF is a non-invasive test to detect Clara cell damage.     

Health effects of exposure to active pharmaceutical ingredients (APIs)

BACKGROUND: Workers involved in the manufacture of pharmaceutical products are exposed in the course of their work to the active pharmaceutical ingredient (API) in the products. Such APIs are designed to produce biological change in the human body, which is an unacceptable outcome in the pharmaceutical worker. AIM: To review the evidence for the presence of the health effects of APIs in the pharmaceutical industry. METHOD: The study employed a literature review based on a systematic search of the MEDLINE database. RESULTS: Studies have shown that such biological effects can be produced, particularly in personnel working with potent compounds such as steroids, compounds with capacity to cause cumulative damage such as cytotoxic anti-cancer drugs and antibiotics, unless careful risk assessment and appropriate control measures are implemented. CONCLUSION: There is limited epidemiological evidence for increased mortality and morbidity in this population, but adverse effects on health from exposure to potent agents, such as corticosteroids, sex hormones and antibiotics, can occur. The protection of workers from the potential harmful effects of APIs poses a significant challenge for the pharmaceutical industry.     

Concomitant alveolitis and asthma following exposure to triphenylmethane triisocyanate

A 36-year-old man was admitted to hospital with increasing breathlessness.He had been exposed to triphenylmethane triisocyanate. Pulmonaryfunction tests demonstrated physiological abnormalities consistentwith both asthma and alveolitis. Exposure to less common isocyanatesmay not be immediately apparent. Asthma developing after isocyanateexposure is well recognized. Pneumonitis is a relatively rarecomplication. Measurement of gas transfer may be helpful inthe investigation of isocyanate toxicity.     

Evidence-based decision making in an endoscopy nurse with respiratory symptoms exposed to the new ortho-phthalaldehyde (OPA) disinfectant

BACKGROUND: ortho-Phthalaldehyde (OPA) can cause mucous irritation, respiratory symptoms and IgE-mediated hypersensitivity reactions. Very little information is available about OPA-related effects in health personnel. AIM: To report the decision-making process for the case of an endoscopy nurse complaining of cough and burning of the nose and throat during OPA exposure at work. METHODS: The problem focused on the relationship between OPA exposure and the respiratory symptoms and was investigated using an evidence-based (EB) medicine paradigm. RESULTS: A literature search was performed using the database Medline and the search engine Google. Papers and guidelines were assessed for their suitability in the EB case identification of suspected occupational asthma (OA). A multistep approach suggested by a guideline was considered most appropriate for practical use. The nurse shared the decision-making process and underwent evaluation of the clinical suspicion index and interventions for diagnosis of OA. Despite the high clinical suspicion index, the diagnosis of OA was excluded and any work restriction was avoided. Health surveillance follow-up showed a good clinical outcome and prompt recovery from respiratory symptoms after improvement of environmental control measures. CONCLUSION: The case study shows that the implementation of EB guidelines provides the occupational physician with an appropriate decision-making process for the identification and management of workers with suspected OA. Screening out of OA is highly relevant because diagnosis of disease requires removal from exposure and frequently impacts negatively on worker employment.     

Occupational asthma (OA) with sensitization to diphenylmethane diisocyanate (MDI) presenting at the onset like a reactive airways dysfunction syndrome (RADS)

BACKGROUND: Two types of OA are distinguished: immunological (OA with sensitization) and non-immunological, i.e., irritant induced asthma or reactive airways dysfunction syndrome (RADS). METHODS: We describe the case of a worker who developed respiratory symptoms after a spill of diphenylmethane diisocyanate (MDI) at the workplace. RADS was initially diagnosed and the worker resumed working. The progressive worsening of symptoms and the appearance of symptoms-work relationship one year later, when concentrations of isocyanates were no longer "irritant," suggested immunological OA. RESULTS: The diagnosis was confirmed by specific inhalation challenge test, followed by removal from exposure and complete recovery. CONCLUSIONS: In the case of RADS due to an agent with both irritant and sensitizing properties, history should be repeatedly assessed for a possible symptom-work relationship. If this is found, further investigations should be carried out, including specific inhalation challenges, to confirm the possibility of immunological OA.     

Prevention of laboratory animal allergy

Background Laboratory animal allergy (or LAA) is an importantthreat to the occupational health of those who work with rats,mice and other species. Aim This review examines the risk factorsfor LAA and the effectiveness of control measures. Methods A literature review was performed. Results An extensive literature was identified regarding LAAand the use of control measures. The contribution that thesemeasures can make to the overall effectiveness of an occupationalhealth and safety programme is discussed in the context of theliterature currently available. Conclusion The incidence of this disease can be reduced by effective,integrated health risk management, with the conscientious useof engineering, procedural and personal control measures.     

Occupational dermatitis and allergic respiratory diseases in Finnish metalworking machinists

AIM: To investigate the incidences and trends of occupational skin diseases (OSDs) and allergic respiratory diseases (ARDs) in machinists working in the fabrication of metal products. METHODS: Data from the Finnish Register of Occupational Diseases during 1992-2001 were analysed. Incidence rates for skin and respiratory diseases of machinists were calculated and compared to the total working population. The patients investigated at the Finnish Institute of Occupational Health in the same period were described in detail. RESULTS: A total of 279 dermatoses and 34 ARDs were reported. Skin diseases accounted for 27% of all occupational diseases. The incidences of the skin and respiratory diseases were 1.6 and 0.2 cases per 1000 person-years, respectively. This represents a 3-fold risk for getting an OSD compared to the total working population. The number of allergic contact dermatitis (ACD) increased 3-fold during the study period. The most common causes of ACD were metalworking fluids (MWFs) and their ingredients such as formaldehyde, ethanolamines and colophony. Eighty-five per cent of ARDs were asthmas. The commonest causes of asthma were metal dusts and fumes, epoxy resins and hardeners and MWFs and their components. CONCLUSIONS: Contact dermatitis is a common occupational health problem in metalworking machinists, whereas occupational respiratory disease is rare. Only a few specific chemicals in the metalworking have thus far been identified as respiratory allergens. Specific skin tests and inhalation challenge tests with MWFs and their ingredients are recommended if an OSD or a respiratory disease is suspected.     

Future advances in work-related asthma and the impact on occupational health

Work-related asthma (WRA) and WRA-like conditions refer to all situations in which asthma or asthma-like syndromes occur or worsen in the workplace. This occurs in approximately 10% of all adult-onset asthma subjects. Occupational asthma (OA) is a specific type of WRA that is 'caused' by the workplace, being mediated either by an allergic process with a latency period or by a non-allergic irritant-induced mechanism. Personal asthma can also 'worsen' at work (work-aggravated or exacerbated asthma), the reasons, mechanisms, extent and consequences of this situation being unknown. The author reviews various aspects of WRA with an emphasis on OA (about which more is known) and proposes key issues that need to be further studied, proposed and applied in at-risk workplaces in order to improve recognition, diagnosis and management of this condition. OA represents a unique situation that, unfortunately, is only very rarely provided to health-care providers: affected workers can be cured with minimal impact on quality of life. All efforts should be made to achieve this goal at an affordable socio-economic cost.     

Occupational asthma prevention and management in industry--an example of a global programme

Isocyanates are widely used in the manufacture of polyurethane foams, plastics, coatings and adhesives, and are known to cause occupational asthma in a proportion of exposed workers. Substitution as a prevention strategy is not currently a feasible option. For this reason, health and safety professionals working together in an automotive coatings business created a proactive global programme to address the known potential effects of isocyanates on its workers. The goals of the programme are prevention, early detection and mitigation of effect of key endpoints, especially asthma and to a lesser degree dermatitis, in people who are occupationally exposed, or potentially exposed, to isocyanates and products containing isocyanates. The surveillance programme for isocyanates has several important components, which include assessment of exposure, pre-placement questionnaire and spirometry, training and education of employees, regularly administered periodic questionnaires, medical assessment for abnormal questionnaire responses, process for early reporting and investigation of symptomatic employees and incidents, group data review and management reporting. Although regional differences exist regarding availability of specialized services, we have successfully implemented this programme in parts of North America, Europe and Latin America, and are currently implementing elsewhere. These simple control measures are relatively inexpensive and can be applied in even small business settings. It is recommended that all employers who manufacture, handle or use isocyanate-containing products consider such a strategy.     

SWORD '98: surveillance of work-related and occupational respiratory disease in the UK

The SWORD surveillance scheme, now 10 years old, uses systematic reporting from physicians to provide a picture of the incidence of occupational respiratory disease in the United Kingdom. An estimated total of 2966 incident cases was derived from reports by chest and occupational physicians during the 1998 calendar year. Occupational asthma continues to be the most-reported respiratory condition, with an estimated 822 cases (27% of total cases). The proportion of cases of mesothelioma (23%), benign pleural disease (21%) pneumoconiosis (7%) and inhalation injuries (6%) remain similar to those estimated in past years, although fewer cases overall were reported. The most commonly identified agents causing asthma in 1998 were enzymes, isocyanates, laboratory animals and insects, colophony and fluxes, flour, latex, and glutaraldehyde. An increased incidence of respiratory diseases of short latency was seen in mining, whilst cases in chemical, mineral products and motor vehicle manufacture remained high; lower rates were noted in wood products and textile manufacture when compared with 1997 figures. Inhalation accidents over the past 3 years were reviewed; gaseous agents and combustion products accounted for nearly half of cases. High rates for inhalation injuries were seen in coal miners, fuel production, motor vehicle manufacturing, water purification, and chemical manufacturing.     

Occupational toxicology and the control of exposure to pharmaceutical agents at work

BACKGROUND: The pharmaceutical industry employs >350 000 people worldwide in operations including research and development (R&D), manufacturing, sales and marketing. Workers employed in R&D and manufacturing sectors are potentially exposed to drug substances in the workplace that are designed to modify physiology and also to chemical precursors that are potentially hazardous to health. Pharmaceutical workers are at risk from adverse health effects, including occupational asthma, pharmacological effects, adverse reproductive outcomes and dermatitis. AIM: This study aimed to describe the approaches taken by pharmaceutical companies for identifying and communicating potential adverse health effects that may result from workplace exposures and in setting 'in-house' exposure control limits and to highlight the challenges in controlling workplace exposures to increasingly potent compounds. METHOD: The literature was reviewed by searching the Medline and HSELine databases. RESULTS: The findings are presented in five sections, covering: test methods and approaches to occupational toxicology; hazard communication; approaches to setting health-based occupational exposure limits for pharmaceutically active agents; recent approaches to risk control; and occupational hygiene and exposure controls. CONCLUSION: Significant efforts have been directed at predicting and evaluating potential occupational health hazards in the pharmaceutical industry. The pharmaceutical industry has provided leadership in controlling exposure to hazardous substances. Much of this work has been driven by a real need to control occupational exposures to substances that can have profound adverse health effects in exposed employees and that are becoming increasingly more potent.     

SWORD '99: surveillance of work-related and occupational respiratory disease in the UK

Systematic reports from chest and occupational physicians under the SWORD and OPRA (Occupational Physicians Reporting Activity) surveillance schemes continue to provide a picture of the incidence of occupational respiratory disease in the UK. An estimated total of 4393 incident cases (comprising 4530 diagnoses) were reported during the 1999 calendar year, an increase of 1427 cases over the previous year. Benign pleural disease was the single most frequently reported condition (28% of all diagnoses reported). Occupational asthma cases (1168; 26%) remained high, as did mesothelioma (1032; 23%). Analysis of trends over the past 8 years shows an increase in mesothelioma cases, but little change in asthma. The annual incidence per 100,000 employed people, 1996-1999, for mesothelioma, lung cancer and pneumoconiosis was high amongst construction workers (28.7), miners and quarrymen (26.5), woodworkers (18.9) and gas, coal and chemical workers (15.2). Trends in mesothelioma incidence by birth cohort continue to show an increase in construction workers and a continuing decline in shipyard and insulation workers. The relative proportion of pneumoconiosis cases attributed to coal mining has fallen steadily in workers born since approximately 1920 and most cases are now in men who have been employed in quarrying and rock drilling.     

SWORD '96: surveillance of work-related and occupational respiratory disease in the UK

Chest and occupational physicians who report to the SWORD surveillancescheme are estimated to have seen some 3,300 new cases of work-relatedrespiratory disease in 1996. This total has regained the levelrecorded prior to a low in 1995, probably because of improvedchest physician participation and the introduction of a samplingsystem for occupational physicians. Trends in disease incidencehave remained fairly constant with some changes only in pneumoconiosisand inhalation accidents. It is of concern that there has beenno evidence of a decrease in frequency of occupational asthmaor in any of the incriminated agents since the scheme beganin 1989. Comparison with other sources of data shows that, forasthma, SWORD records a relatively high frequency in women,a substantial proportion of whom do not appear to receive compensation.For mesothelioma, rates based on death certificates continuefor understandable reasons to run at about twice the level reportedto SWORD or as reflected by successful claims to the DSS forindustrial injuries benefit. The SWORD programme is now oneof six clinically-based reporting schemes which, by the endof 1997, are planned to cover all types of occupational diseasein the UK.     

Occupational asthma after exposure to plaster casts containing methylene diphenyl diisocyanate

BACKGROUND: The case of a 34-year-old female nurse is presented. She worked in an accident and emergency department in a district general hospital, with methylene diphenyl diisocyanate (MDI)-containing synthetic plaster casts. She worked with MDI on a daily basis for 4 years. She was out of the department for 1 year and on her return developed cough, wheeze and dyspnoea within 5 min of exposure to MDI- containing synthetic casts. METHOD: A bronchial provocation test was performed and confirmed an early asthmatic response. RESULTS: There was a 39% decrease in the forced expiratory volume in 1 s 15 min after exposure, which required the administration of a bronchodilator on two occasions. The patient has subsequently avoided MDI-containing synthetic plaster casts and has experienced no further respiratory symptoms. CONCLUSION: This case illustrates that respiratory sensitization can occur as a result of exposure to MDI-containing synthetic casts and highlights the need for vigilance when health care workers are using isocyanate-containing synthetic casts.     

Nasal challenge test in the diagnosis of allergic respiratory diseases in subjects occupationally exposed to a high molecular allergen (flour)

The objective of this study was the evaluation of the usefulnessof the nasal challenge test in the diagnosis of allergic respiratorydiseases in subjects occupationally exposed to flour. A single-blind,placebo controlled study was conducted in 100 subjects withoccupational atopic asthma with rhinitis. The control groupsconsisted of 20 atopic subjects not sensitized to investigatedallergens and 20 healthy subjects. A ‘nasal pool’technique was used to evaluate the changes of the cellular responseand protein level in nasal washings after topical provocationwith allergen or placebo. The concentrations of eosinophil cationicprotein and mast cell-derived tryptase in nasal fluid were evaluatedin 60 cases. There were significant increases in eosinophiland basophils number, albumin/total protein ratio, eosinophilcationic protein and tryptase levels in occupationally sensitizedpatients challenged with specific allergens. There were neithersevere bronchial reactions or an increase of bronchial hyperreactivityin occupationally sensitized patients after the nasal provocationwith flour. The nasal challenge test appears to be a very usefuland safe tool for diagnosing occupational allergy.     

Small bakeries--a cross-sectional study of respiratory symptoms, sensitization and dust exposure.

This cross-sectional study investigated the prevalence of respiratory symptoms and sensitization to dust components in 224 individuals in 18 small bakeries in Scotland. Each work practice in the bakeries was characterized by an assessment of dust exposure and assigned to a category with either a direct exposure to flour dust of an indirect exposure to flour dust. We found that work-related respiratory symptoms were significantly associated with specific IgE to wheat flour and amylase but not to exposure category (except for nasal/eye symptoms). However, specific IgE to wheat flour was significantly associated with exposure category. There was a higher prevalence of immunological sensitization, reporting of work-related respiratory symptoms and exposure to dust than in other studies and of the 144 personal dust sample results taken, 21 (14.6%) of the total exceeded 10 mg/m3, the substantial dust concentration as outlined by the COSHH Regulations. Follow-up of those with work-related asthma symptoms (questionnaire response) was inconclusive of the work-relatedness of their symptoms, although it did confirm respiratory morbidity.     

甲苯二异氰酸甲酯所致支气管哮喘患者的支气管激发试验及免疫学研究

对18例临床上诊断为支气管哮喘的TDI作业者进行变应原BPT,并与其它免疫学指标对比观察。发现BPT阳性14例(占77.8％),其中速发反应7例,迟缓反应6例,双相反应1例。BPT阳性者的肺功能指标FVC、FEV_1、MMF、PF、V_(75)、V_(50)、V_(25)等均有明显降低。免疫指标中以IgA、特异性IgE的增高为著,各占7例及9例,并与BPT阳性反应相一致。以上证明了TDI哮喘的变态反应机理,特别是与IgE介导的速发型反应有关。此外,BPT作为一种病因诊断手段,有明显的特异性及实用性。     

Absence of platinum salt sensitivity in autocatalyst workers exposed to tetraamine platinum dichloride

Background Platinum salt sensitivity (PSS) is well recognizedfollowing occupational exposure to platinum salts, though specificplatinum compounds have been suggested to be non-allergenic.We report on a cohort of autocatalyst workers exposed to tetraamineplatinum dichloride (TPC) and other platinum-group elements. Methods All subjects employed at an autocatalyst productionplant undertook medical surveillance with symptoms, examinationfindings and results of skin prick testing and spirometry prospectivelyrecorded. Environmental testing of the workplace was also performedto determine the level of exposure. Results Twenty-six subjects had a mean duration of employmentof 46 (±30) months and undertook a mean 6.8 (±4.3)examinations. No subjects described the development of new respiratoryor dermatological symptoms. No patients developed positive skinreactivity to platinum salts. FEV₁ remained unchanged for allsubjects over the course of the study period. Conclusions TPC and platinum-group elements are not associatedwith the development of PSS or occupational asthma. Identificationof chemical compounds is important when advising on occupationalhealth screening. TPC and/or platinum-group elements shouldbe used in preference to chloroplatinic acid in catalyst productionto minimize the impact of occupational illness due to PSS.     

Underreporting of fatal occupational injuries in Catalonia (Spain)

BACKGROUND: Thoroughness in a given health information system is one of its most important quality indicators. In Spain, in approximately 30% of serious occupational injuries, there is no information on the final outcome. AIM: To assess underreporting of fatal occupational injuries in Catalonia. METHODS: All serious occupational injuries (excluding commuting injuries) reported in Catalonia (Spain) between 1994 and 1998 (n = 7330) were linked with data from the Catalonian Mortality Register, 117 deaths being identified during the year following the injury date. In order to assess whether death could or could not have been related to the prior occupational injury, two experts examined these cases independently. RESULTS: The experts concluded (kappa = 0.98) that 69 (59%) of these deaths were probably related to occupational injuries; the vast majority (n = 65) occurred within 3 months of the injury. This represents an accumulated risk of dying of approximately 1% for the total of serious injuries, not varying with economic activity or job category. However, this risk varied depending on the form of accident, and the site and nature of the injury. CONCLUSIONS: Occupational injury cases, especially serious ones, should be followed up over at least 3 months. These results suggest the importance of carrying out active case-finding and of incorporating the death certificate as one of the documents to be systematically reviewed in order to complete the statistics.