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By Dr Dulcy Rakumakoe

Chief Executive Officer

Work environment can bring on occupational asthma

More than 300 substances have been identified as possible causes.

Occupational asthma is asthma that is caused or worsened by breathing in chemical fumes, gases, dust or other substances at work.

Like other types of asthma, occupational asthma can cause chest tightness, wheezing and shortness of breath. It is important to identify it early so that it is reversed and long-term exposure to triggering substances is avoided or minimised.

Treatment is similar to treatment for other types of asthma, and it generally includes taking medications to reduce symptoms.

But the only sure way to eliminate your symptoms and prevent lung damage due to occupational asthma is to avoid whatever is triggering it.

Severe asthma attacks can be life-threatening.


Signs of an asthma attack that needs emergency treatment include:

  • Rapid worsening of shortness of breath or wheezing
  • No improvement even after using short-acting bronchodilators
  • Shortness of breath with minimal activity

Make an appointment to see a doctor if you have breathing problems, such as coughing, wheezing or shortness of breath.

Breathing problems may be a sign of asthma, especially if symptoms seem to be getting worse over time or appear to be aggravated by specific triggers or irritants.

The longer you are exposed to a substance that causes occupational asthma, the worse your symptoms will become, and the longer it will take for them to improve once you end your exposure to the irritant.

In some cases, exposure to airborne asthma triggers can cause permanent lung changes and lifetime asthma symptoms. Occupational asthma symptoms depend on the substance you’re exposed to, how long and how often you’re exposed, and other factors.

Your symptoms may:

  • Get worse as the workweek progresses, go away during weekends and vacations, and recur when you return to work.
  • Occur both at work and away from work.
  • Start as soon as you’re exposed to an asthma-inducing substance at work or only after a period of regular exposure to the substance.
  • Continue after exposure is stopped. The longer you’re exposed to the asthma-causing substance, the more likely you’ll have long-lasting or permanent asthma symptoms.


More than 300 workplace substances have been identified as possible causes of occupational asthma. These substances include: Animal substances like proteins found in dander, hair, scales, fur, saliva and body wastes.

Chemicals like anhydrides, diisocyanates and acids used to make paints, varnishes, adhesives, laminates and soldering resin. Other examples include chemicals used to make insulation, packaging materials, and foam mattresses and upholstery. Enzymes used in detergents and flour conditioners.

Metals, particularly platinum, chromium and nickel sulphate. Plant substances, including proteins found in natural rubber latex, flour, cereals, cotton, flax, hemp, rye, wheat and papain, a digestive enzyme derived from papaya.

Respiratory irritants such as chlorine gas, sulphur dioxide and smoke.

Risk Factors

You’re at increased risk of developing occupational asthma if:

  • You have existing allergies or asthma. Although this can increase your risk, many people who have allergies or asthma do jobs that expose them to lung irritants and never have symptoms.
  • Allergies or asthma runs in your family. Your parents may pass down a genetic predisposition to asthma.
  • You work around known asthma triggers. Some substances are known to be lung irritants and asthma triggers.
  • You smoke. Smoking increases your risk of developing asthma.

High Risk Occupations

It’s possible to develop occupational asthma in almost any workplace. But your risk is higher if you work in certain occupations.

Here are some of the riskiest jobs and the asthma-producing substances associated with them:

  • Adhesive Handlers
  • Animal handlers, veterinarians
  • Bakers, Millers
  • Mine workers
  • Carpet makers
  • Metal workers
  • Forest workers, carpenters
  • Hairdressers
  • Health care workers
  • Pharmaceutical workers
  • Spraypainters
  • Textile workers
  • Users of plastic Symptoms

Occupational asthma symptoms are the same to those caused by other types of asthma.

Signs and symptoms may include:

  • Wheezing, sometimes just at night
  • Coughing
  • Shortness of breath
  • Chest tightness

Other possible accompanying signs and symptoms may include:

  • Runny nose
  • Nasal congestion
  • Eye irritation and tearing


Diagnosing occupational asthma is similar to diagnosing other types of asthma. However, your doctor will also try to identify whether a workplace irritant is causing your symptoms and what it may be.

An asthma diagnosis needs to be confirmed by tests that may include lung (pulmonary) function tests and an allergy skin prick test. He or she may order blood tests, X-rays or other tests to rule out a cause other than occupational asthma. Your doctor may ask you to perform lung function tests.

These include:

  • Spirometry. This noninvasive test, which measures how well you breathe, is the preferred test for diagnosing asthma. During this 10- to 15-minute test, you take deep breaths and forcefully exhale into a hose connected to a machine called a spirometer. If certain key measurements are below normal for a person your age and sex, your airways may be blocked by inflammation which is a key sign of asthma. Your doctor has you inhale a bronchodilator drug used in asthma treatment, then retake the spirometry test. If your measurements improve significantly, it’s likely you have asthma.
  • Peak flow measurement. Your doctor may ask you to carry a peak flow meter, a small hand-held device that measures how fast you can force air out of your lungs. The slower you are able to exhale, the worse your condition. You’ll likely be asked to use your peak flow meter at selected intervals during working and nonworking hours. If your breathing improves significantly when you’re away from work, you may have occupational asthma.
  • Nitric oxide test. This test is used to see how much nitric oxide gas is in your breath.A high level of nitric oxide can be a sign of asthma.


Avoiding the workplace irritant that causes your symptoms is critical. However, once you become sensitive to a substance, tiny amounts may trigger asthma symptoms, even if you wear a mask or respirator.

You may need medications to control your symptoms and prevent asthma attacks. Treating asthma involves both preventing symptoms and treating an asthma attack in progress.

The right medication for you depends on a number of things, including your age, symptoms, asthma triggers and what seems to work best to keep your asthma under control.

Long-term asthma control medications, such as inhaled corticosteroids, are the cornerstone of asthma treatment. But if your long-term control medications are working properly, you shouldn’t need to use your quick-relief inhaler very often. Keep a record of how many puffs you use each week.

If you need to use your quick-relief inhaler more often than your doctor recommends, see your doctor. You probably need to adjust your long-term control medication.


Although you may rely on medications to relieve symptoms and control inflammation associated with occupational asthma, you can do several things on your own to maintain overall health and lessen the possibility of attacks:

  • If you smoke, quit. Being smoke-free may help prevent or lessen symptoms of occupational asthma.
  • Avoid irritating gases. Occupational asthma may be worsened by exposure to industrial pollution, automobile emissions, natural gas stoves and chlorine used in swimming pools.
  • Minimize household allergens. Common household substances like mold, pollen, dust mites and pet dander can aggravate symptoms of occupational asthma. Air conditioners, dehumidifiers and thorough cleaning practices, especially in your bedroom, can minimize your exposure to these substances and help you breathe easier.

If you have a job that exposes you to risk of occupational asthma, your company has legal responsibilities to help protect you from hazardous chemicals.

Under guidelines established by the Occupational Health and Safety Act, your employer is required to:

  • Inform you if you’ll be working with any hazardous chemicals.
  • Train you how to safely handle these chemicals.
  • Train you how to respond to an emergency like a chemical spill. Provide personal protective equipment like masks and respirators.
  • Offer additional training if a new chemical is introduced to your workplace.
  • Keep a material safety data sheet for each hazardous chemical.



Dr Dulcy Rakumakoe. Picture: Refilwe Modise

Dr Dulcy Rakumakoe. Picture: Refilwe Modise



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