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Asthma in the WorkPlace PDF Print E-mail
Written by Leong Oon Keong   
Monday, 27 August 2012 12:55

Asthma can be triggered by many things both at work and away from work. 

Look for the following clues of asthma in the workplace:  asthma gets worse soon after starting a new job, asthma gets worse while doing a particular part of the job or asthma improves when one is not at work, e.g. on holiday or at the weekend.

Sometimes people who have had asthma before can develop asthma through an allergic reaction to a substance in the workplace. This may happen even after years of working safely with the substance. Sometimes the allergic reaction (and therefore symptoms) doesn’t develop until some hours after the exposure. It is therefore often difficult to identify the workplace as the cause.

Other people develop asthma for the first time in the workplace after heavy exposure to irritants of the breathing tubes ("irritant induced asthma"), such as welding fumes or gaseous vapours like sulphur dioxide.

Occupational asthma is defined as asthma caused by exposure to an agent encountered in the work environment.  It is estimated that 1 in 10 cases of asthma in adults of working age is caused by occupational sensitisers.  Most occupational asthma is immunologically mediated and has a latency period of months to years after the onset of exposure.

Examples of work place triggers (occupational sensitisers) are:

  • Isocyanate paints
  • Foams and plastics, and the fumes given off during their manufacture
  • Animal fur and protein from laboratories and veterinary clinics
  • Flour and grain dusts from farms, granaries and bakeries
  • Wood dusts
  • Epoxy resins and other plastics from boat builders, mould manufacturers and plastic manufacturing processors

If symptoms arise closely after exposure, the person will often be very aware of the substance or area of the worksite which makes their problem worse. Symptoms may improve when the person isn’t at work.

Common exposures include:

  • Working with chemicals such as those used in some paints and glues, foam manufacture etc, or epoxy resins. Common industries include spray painting and boat building.
  • Working with wood dusts (building and joinery industries).
  • Being exposed to metal fumes or dusts (aluminium smelting, welding, etc)
  • Being exposed to dusts from organic sources such as flour, animals, insects, etc.

The prevalence of occupational asthma is higher in smokers.

Do the following if you suspect something at work is causing you to develop asthma or is making your asthma worse?

Talk about the problem with your doctor or the occupational health nurse. The doctor will ask you to:

  • note what substances or processes you are exposed to in your work
  • note if your symptoms worsen during each shift or over a roster period
  • note if there is any improvement away from work
  • measure and record peak flow measurements. It is best done four times a day for a two-week period. This period should include time at work and time away from work.

If a workplace process or substance is causing or making your asthma worse, there are several steps that you can explore.

Elimination

Can the substance or process be changed for something less harmful? For example, one electronics firm eliminated soldering by riveting components to circuit boards.

Isolation

Can the substance or process be isolated to a special place in the worksite or time of day when most people will not be exposed? A manufacturer restricts its production of playground rubber mats to a period at the end of the day when most of the staff are off work. By the time the staff return the next day the fumes have gone.

Minimisation

Can the equipment be improved to reduce the exposure? A joinery factory improved its ventilation and extraction equipment to reduce dust levels. This is always a better method than relying on masks for protection.

Last Updated on Sunday, 16 September 2012 04:39