Asthma at Work

Occupational Asthma

Occupational Asthma can be a serious problem. More than 200 substances have been reported as triggers for occupational asthma. In the western world, it is thought than 200,000 people suffer from occupational asthma, and a further 500,000 have asthma that may be made worse by their job. Occupational asthma is a common cause of work-related illness.

Allergy or Sensitivity?

The potential for a true allergic reaction is present after your body has been exposed to an allergen and has produced IgE antibodies. These have contact with the mast cells in your body. When the allergen re-enters your body, your mast cells respond by releasing histamine, which triggers an attack.

If you experience symptoms because of exposure to triggers in your occupation, it is not necessarily true that you are allergic to those substances. Your reaction may instead be the result of sensitivity to an irritant, which is not an IgE-related or allergic response. Many strong odors can irritate the twitchy airways of an asthmatic and provoke symptoms. Whether an allergy or irritation causes your reactions, you can try to identify and avoid the offending substance.

The fact that you have developed asthma while at a particular occupation does not necessarily mean that these triggers have actually caused your asthma; it may simply mean that these irritants provoke asthma symptoms. However, it is also possible that airborne substances inhaled while working can actually start asthma in someone who previously did not have it. These substances are known as respiratory sensitisers. If you have been exposed to respiratory sensitisers during the course of your job, your airways may have become sensitised. As a result you have become prone to asthma symptoms.

Respiratory Sensitisers

Isocyanates - used for making plastics, foam, synthetic inks, paints and adhesives.

Platinum salts - used in platinum refining workshops and some laboratories

Crustaceans, fish or their products - involved in food processing

Reactive Dies - used in the textile industry

Fumes - from stainless steel welding

Soya bean - involved in food processing

Tea and coffee dust - food processing

Epoxy Resin curing and hardening agents. These include phytalic anhydride, tetrachlorophtalic anhydride, trimellitic anhydride or triethylenetretramine which are all used in paint manufacturing

Colophony fumes arising from the use of rosin as a soldering flux used in the electronics industry

Proteolytic enzymes used in the detergent industry, as well as the baking, brewing, fish, silk and leather industries

Dust from barley, oats, rye, wheat or maizes, or flour made from such grains - may be found in the baking or flour milling industries. Farmers may also be exposed to these dusts.

Wood dust such as cedar and mahogany. Carpenters, joiners, paper mill and sawmill workers would be exposed to it.

Isphagula dust - This is a component of bulk laxatives and workers employed in the manufacture and administration may be exposed to it.

Castor bean dust - seaman, laboratory workers and felt makers

Ipecacuanha - used in the the preparation of Ipecacuanha tablets

Persulphate salts and henna - used in hairdressing

Animals, insects, larvae etc may affect laboratory workers, pest controllers.

Glutaraldehyde used as a disinfectant in hospitals, leather tanning and cooling towers

Antibiotics and cimetidine implicated in drug manufacture

Source: UK Department of Social Security

High Risk Jobs

Being an asthmatic will also affect your own choice of employment. For example, you are unlikely to want to work in a flour mill if dust is one of your triggers.

Asthma usually manifests itself within a few months of starting the job, but may take longer. Bakers, spray painters, welders, solders, metal treaters, plastics workers, chemical processors, factory workers and laboratory workers are considered the most hazardous jobs in terms of asthma.

Some types of employment such as the police force, armed services, flying and commercial scuba diving will not usually hire asthmatics.

Is my job causing my Asthma?

The following circumstances usually indicate whether your asthma is job-related or not:

1. Asthma starts within weeks or months of starting a new job
2. Asthma regularly and predictably comes on while you are at work or within a few hours after you have finished work
3. You work with common triggers
4.  You work with others, who also develop similar problems
5. Your asthma seems to improve when you are away from work, on weekends or holidays. It returns almost immediately when you resume the same job

Once you suspect that your asthma symptoms are job related, you should discuss it with your doctor.

Keep an asthma diary, noting symptoms and severity. Do this over a period of several weeks to see if your symptoms are generally worse during the work week, and improve on weekends, and almost clear completely the longer you are away from work.

Once a pattern between your work and asthma severity has been established, find out what substances may actually trigger your asthma. Try the list of respiratory sensitisers or contact the appropriate government agency (Ministry of Health, Department of Labour, Community services etc).

An asthma specialist may perform an inhalation challenge test which confirms whether you developed asthma while you were working at that particular occupation or as a result of working at that job.

Managing Occupational Asthma

If you have been exposed to a respiratory sensitiser over a long period of time, asthma symptoms are likely to become increasingly severe. Even if you change jobs and are no longer exposed to the sensitiser, it is likely asthma will continue. If you have occupational asthma, it might be possible to transfer you to a job that does not contain the substance to which you are sensitive.

It may be possible to claim compensation if your asthma has been caused by exposure to certain substances in your workplace. However, this varies from country to country.

Your working conditions can have a marked bearing on your asthma. It may be possible to replace substances, which are known to cause asthma with safer ones. The next best step is to protect the employee by reducing exposure to hazards. For example, fitting extractor fans may be helpful, as good ventilation is important in dispersing triggers. A non-smoking workplace may help to reduce smoke, which is a known irritant for asthmatics.

If you are having problems with your working environment and employers seem uncooperative to help, then notify the Health and Safety Officer of your union or a similar government department.

Good working conditions and well managed asthma will mean fewer days off work. This will mean a happier employer, and workmates. Watch for warning signs that your asthma is slowly getting worse and take the necessary steps to prevent it.