Occupational asthma is asthma that is caused or made worse by types of working practices or because a person is exposed to irritants, fumes, allergens, or gasses at work.
With early diagnosis, treatment for occupational asthma can be effective. But long-term exposure to the irritant or allergen may cause the asthma to become chronic or long term, and irreversible.
Treatment for occupational asthma is similar to that of asthma that is not work related, but a person with occupational asthma may have the option of avoiding the irritant or allergen, by either changing jobs or working with an employer that provides better working conditions.
Between 10–25% of adult-onset asthma is believed to be work related.
Asthma linked to the workplace may be described as:
- work-aggravated, which becomes worse because of the work environment
- allergic, when the immune system becomes sensitized to a substance at work, and after some time, a person develops symptoms
- irritant, when a person’s airway reacts to an irritant soon after exposure
In all cases, exposure to a substance in the workplace causes swelling or inflammation that may result in wheezing, chest tightness, and other signs and symptoms of asthma.
Some people’s airways become constricted after exposure to certain triggers or irritants. The muscles around the airways tighten, the airways swell up or become inflamed, and the production of mucus increases significantly. Breathing becomes more difficult.
As with other types of asthma, occupational asthma can involve wheezing, coughing, difficulty breathing, and chest tightness.
A person may find that their symptoms get worse as the working week progresses. During vacations, the asthma may go away, but it comes back soon after they return to work.
In some cases, asthma symptoms may continue even after there is no exposure to the irritant, especially if there has been long-term exposure.
The United States Department of Labor estimates that 11 million workers in various types of employment in the U.S. experience exposure to at least one agent linked to occupational asthma.
Some occupations associated with asthma include:
- detergent and drug manufacturers
- people who work with laboratory animals
- healthcare workers exposed to natural rubber latex
- people who work with cereals, such as farmers and agricultural workers, dockers, millers, and agricultural maintenance engineers
- workers in metal or plastic, and solderers, including employees in the electronics and assembly industries
- woodworkers, especially those who carry out machining and sanding tasks
- vehicle spray painters
A person with a family history of asthma has a higher risk of developing occupational asthma, particularly if they work in one of the occupations mentioned above.
People who already have asthma or an allergy, and who work in places where known irritants exist, are at risk of developing worsening and chronic symptoms.
Other factors that may increase the likelihood of developing occupational asthma include the person’s age and the type of irritant they experience exposure to.
Occupational asthma may be caused by animal products, such as fur, scales, urine, feces, or saliva. Certain chemicals, plants, fumes, wood dust, grain dust, fungi, and some enzymes are also common triggers.
Substances that can trigger asthma in the workplace include:
- amylase, found in starch
- carmine, an insect-derived coloring for drugs, cosmetics, and food
- chloramine-T, a disinfectant
- cockroach material
- coffee bean dust
- isocyanates, used in plastics
- some antibiotics
As in the home, air conditioning systems that are not maintained regularly can develop mold, and this can provoke symptoms of asthma.
It remains unclear why some people develop asthma when exposed to a known irritant, while others do not. It is probably due to a combination of genetic and environmental factors. The intensity of exposure may also impact the degree to which a person experiences symptoms.
Diagnosis of occupational asthma is similar to that of other types of asthma, but if the symptoms appear to be work related, the doctor may try to find out what the irritant or allergen might be.
If the asthma stems from exposure to a workplace irritant, avoiding the environment in which the irritant occurs is the best option, if possible. If the person has developed a sensitivity to the substance, they will have symptoms even after being exposed to extremely small amounts.
It may be difficult to avoid substances used in the workplace, and changing jobs may be the only option for some people.
Complications are more likely if the person receives no treatment for their condition and does not do anything to minimize their exposure to the substance that is causing the problem.
If exposure continues for a long time, the individual has a higher chance of developing long-term symptoms.
Adults who work in certain occupations and experience exposure to certain substances may have occupational asthma. The symptoms are typically similar to other types of asthma and will often have the same treatment.
A person who is experiencing asthma symptoms from their occupation should visit a doctor, if possible, to discuss treatment options. Treatment may involve finding a new occupation.