Ferrell Duncan Clinic Allergy and Immunology

Asthma
Occupational Asthma

Occupational asthma is a lung disorder caused by inhaling or coming into contact with fumes, gasses, dust, or other substances in the workplace.

It can occur for the first time in a worker with no history of asthma, or it may be due to pre-existing asthma being reactivated by exposure to irritants in the workplace.

Symptoms of Occupational Asthma

As with other forms of asthma, the symptoms of occupational asthma include wheezing, chest tightness, shortness of breath, coughing, and trouble breathing. Most of the time, occupational asthma is chronic as long as the person works around on-the-job triggers, but sometimes the symptoms may come and go or be triggered by a workplace accident involving high exposure to certain fumes or dust.

Causes of Occupational Asthma

Occupational asthma is usually triggered in one of three ways:

  • Direct irritant effects. These are substances that trigger asthma symptoms immediately. Substances that can result in direct irritant effects include hydrochloric acid, sulfur dioxide, and ammonia. These are usually found in the petroleum or chemical industries. These substances provoke an irritant reaction, not an allergic one, because it doesn't involve the immune system. Workers with preexisting asthma or those with other respiratory illnesses are especially reactive to the effects of these irritants.
  • Allergic reaction from ongoing exposure. Occupational asthma related to allergies usually develops after months or years of exposure to workplace irritants, because the immune system often takes that long to develop a response. The immune system responds with allergic antibodies or histamine release. Workers in food-processing industries or who work with plastic, rubber, resin, or latex are the most at-risk for this kind of occupational asthma.
  • Inhalation--Aerosol inhalants can trigger occupational asthma over time, as these substances cause histamines, acetylcholine or other allergic chemicals to build up in the body. Examples of such irritants include insecticides.

Occupational Risk Factors

Workers who are regularly exposed to on-the-job irritants are most at risk for developing occupational asthma. This includes employees in many different industries, such as manufacturing, health care, and food processing.

Other people at risk are workers with other respiratory disorders, such as bronchitis or chronic sinusitis.

Prevention of Occupational Asthma

After identifying the cause of occupational asthma, the next step is to reduce the person's exposure to the irritating substance. This may mean moving the worker to a different job or providing masks or air-filtering devices.

Employers can also consider these measures:

  • Prescreening new employees with lung function tests that can provide baseline readings to be compared with future test results--such monitoring can keep potential cases of occupational asthma from going unnoticed and untreated
  • Monitoring the work environment to check for (and minimize) the presence of potential asthma-triggering irritants.

Treatment of Occupational Asthma

People with occupational asthma should seek medical attention for help with medications or other treatments that can provide symptom relief and prevention. If such treatments don't work, the employee may need to completely avoid workplace irritants.