Work-related asthma is a serious condition indeed. Asthma affects your life and well-being more than many other afflictions. It is a condition which may be very difficult to live with and impossible to come to terms with.

In serious cases, asthma is a killer disease and every year people die from it.

What is asthma? In short, it may be explained as a reduction in the diameter of the bronchi. By muscular contraction, this reduction hinders the passage of air, and sometimes closes it off entirely.

The bronchial "tightening" is caused by various agents that are triggered by allergic reactions, physical irritation, neurogenic phenomena, or pharmacodynamic agents.

In addition to the blocking of the bronchi, there is also hypersensitivity and inflammation of the mucous membranes. The hypersensitivity can render the asthmatic person extremely susceptible to the particular substance and even minute amounts may cause a severe attack.

Occupational asthma is often connected with other allergic reactions, such as hay fever, rhinitis, coughs, etc What makes it a work-related illness is that it is brought about by single or repeated exposure to substances present in the working environment.

SYMPTOMS
An asthma attack often starts after work, sometimes in the evening, often at night, most commonly in the early hours of the morning. The asthmatic usually wakes up with an initial sense of anxiety — even panic — coupled with pressure about the chest, coughing and a runny nose. The impaired breathing is further compounded by phlegm and secretion. Acute asthma attacks may require urgent resuscitation and emergency medical assistance.

Treatment is difficult. Antihistamine and other preparations (such as the common inhalation spray tubes) may be used to milden the attack and relieve the breathing impairment — but these are only used for symptomatic treatment, In order to treat the asthma itself, immunological desensitising treatment is necessary. However, this may prove very difficult and, in some situations, downright dangerous. Many people are left to live with their condition for the rest of their lives.

PREVENTION
The main effective means of prevention is to examine which airborne particles are present in the workplace and then to determine whether these particles are capable of causing asthma. If so, radical steps should be taken to a) replace the substance with a non-allergenic one b) engineer out the problem through mechanical exhaust, improved ventilation, etc., and c) determine the type of respirator needed, and make sure that all workers wear one.

WHEN IS ASTHMA OCCUPATIONAL?
This question is often a "hot potato", because it is not always possible to clearly define the cause of the illness. The presence of the allergen may not be clear-cut, for instance, if the asthma is triggered by a substance that occurs in high concentrations at work, but also is generally dispersed elsewhere.

To our knowledge conclusive guidelines have yet to be determined. However, here is a short list of normally accepted criteria as to what is — and what isn’t — occupational asthma:

ASTHMA IS OCCUPATIONAL:

• When there is only one trigger substance and that substance occurs at work, and the asthma disappears when work is stopped.
• When an irritant substance causes the asthma, and the asthma disappears when the occupation is terminated or changed.
• When the person is sensitive to a substance that occurs both at work and at home but does not experience asthmatic attacks after finishing work. In this case the asthma is still regarded as occupational, because the work environment creates the additional exposure that results in an attack.
• When the person is sensitive to a substance not present at work, but whose attacks are created by an irritant found at work. This is still treated as occupational asthma, because the patient recovers after leaving work.

...BUT NOT OCCUPATIONAL:

• When the asthma attacks do not disappear after work is relinquished.

The list of asthma-producing substances is already very long, and growing rapidly. Here are just a few well-known agents of occupational asthma:

Sources: Encyclopaedia of Occupational Health and Safety, International Labour Office, Geneva 1985, Black's Medical Dictionary, 35th ed., London 1987; Chemical Hazards at the Workplace, Proctor and Hughes, Philadelphia 1978