| Work-Related Asthma (WRA) FAQ |
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| What is asthma? |
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Asthma is a lung disease characteracterized by recurrent episodes of chest tightness, wheezing, cough and shortness of breath. It is associated with environment, genetics, and other factors. In the illustration, the structure on the left side is a normal, healthy airway. In an asthma attack, the muscles around the airways tighten, causing less air to circulate. Swelling also narrows the airway, which can cause mucus to clog it, leading to the diseased airway pictured on the right.1
1 National Heart Lung and Blood Institue. 2006. What is asthma? Available at URL: http://www.nhlbi.nih.gov/health/dci/Diseases/Asthma/Asthma_WhatIs.html.
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| Who is at greatest risk for WRA? |
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Anyone can be at risk for WRA. The greatest risk factor is exposure to the substance causing the asthma. Studies in high-risk industries have found that the higher the risk for exposure, the higher the WRA prevalence. However, even when multiple workers experience the same level of exposure, only a small proportion develop WRA, suggesting that latent factors in the worker may play a role.2 A genetic predisposition to develop IgE antibodies to allergens (atopy) is the main factor that predisposes a person to develop asthma (especially WRA that is triggered by the immune system). In addition, the incidence of WRA varies within individual industries and in relation to the chemicals used in those industries.
2 Chan-Yeung M. 1994. Asthma. Chapter 11.1 in Rosenstock L, Cullen MR, editors. Textbook of clinical occupational and environmental medicine. Philadelphia, PA: W.B. Saunders Company, p 197-209.
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| What are different types of WRA? |
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Work-related asthma falls into three general categories:
- Immunologically mediated asthma resulting from exposure to sensitizers in the workplace (sensitizer induced);
- Asthma that results from acute exposure to irritants in the workplace (called reactive airways dysfunction syndrome or RADS);
- Pre-existing asthma exacerbated by workplace exposures (work-aggravated asthma).
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| How is WRA diagnosed? |
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Asthma is diagnosed by excluding other conditions and by procuring a history of recurrent symptoms such as coughing, wheezing, chest tightness and shortness of breath as well as reversible airflow obstruction revealed through a spirometry lung function test.
WRA is challenging to diagnose because it is hard to differentiate environmental from occupational exposures, and because WRA looks and acts like other forms of asthma. However, diagnosis is vital since WRA is expensive to treat, preventable, and can be partially or completely reversed if early diagnosis coincides with adequate exposure control.
A physician can help identify WRA by asking about asthma symptoms and workplace activities. The diagnosis is supported by evidence of an association between airway obstruction and workplace exposure(s). A WRA diagnosis should be considered in all cases of new-onset or substantially deteriorating asthma symptoms in working adults.
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| How can I prevent WRA? |
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Work-related asthma is avoidable with primary, secondary and tertiary prevention. Primary prevention activities seek to eliminate the risk of WRA before it actually occurs. Secondary prevention activities include screenings to detect WRA so that prompt interventions to control disease and minimize its impact can occur. Finally, tertiary prevention activities help lessen the impact of WRA.3
Type of Prevention
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Activity
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Example
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Primary
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Eliminate exposure
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- Replace sensitizing substances with safer alternatives
- Conduct pre-employment screening to reduce susceptible worker population
- Limit number of exposed workers
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Reduce exposure
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- Wear personal protective equipment (PPE) such as respirators
- Provide engineering controls
- Monitor workplace
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Secondary
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Detect disease
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- Supply routine medical screenings
- Conduct skin testing for specific IgE antibodies
- Monitor workplace
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Shorten disease duration
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- Detect early through screenings + remove workers from exposure = good outcome
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Tertiary
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Prevent permanent damage
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- Use pharmaceutical interventions, including inhaled corticosteroids and bronchodilators
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3 National Institute for Occupational Safety and Health. 2005. Prevention of occupational asthma: primer. Available at URL: http://www.cdc.gov/niosh/topics/asthma/OccAsthmaPrevention-primer.html.
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