Preventing Occupational Lung Disease

May 13, 2014

Occupational lung disease results from the inhalation of harmful mists, vapours, particles or gases. Appropriate preventative measures should be in place to control the risk of occupational lung disease. Monitoring should be in place to ensure prompt diagnosis and treatment of individual cases. Diagnosis and treatment of lung disease should be carried out by occupational physicians.

Assessment and Prevention of Risk

To control the risk of occupational lung disease, a number of steps are required.

A risk assessment must be carried out to clarify the nature of the hazards, identify who is impacted, and to highlight what processes need to be in place to eliminate, control and manage the risk.

All exposure to hazardous substances should be prevented or avoided. This means the:

• Removal of toxic materials, where possible.
• Substitution with less toxic materials, where possible.
• Elimination of processes that might cause exposure.
• Enclosure of harmful processes with automatic operation, if possible.

Where exposure cannot be avoided or prevented, the following options should be considered.

• Isolation of harmful processes from the remainder of the plant and appropriate personal protection for designated workers.
• Local exhaust ventilation (fume hoods/cupboards).
• General extraction ventilation.
• Control of dusts by wetting or precipitation.
• Limiting exposure hours by shorter working periods or rotation of jobs.
• Planned maintenance to ensure machinery and dust control systems are working to specification.
• Personal protective equipment (respirators, suits, etc) and ensuring any equipment is used appropriately.
• Warning signs and notices.

The risk assessment should be reviewed in confirmed cases of occupational lung disease.

Guidance Documents

There are numerous publications that deal with the hazards and control of individual substances capable of causing occupational lung disease. These are available on the Health and Safety Executive’s website or from trade associations and professional bodies. Also available are guidance documents dealing with personal protective equipment, including respiratory protection.

Monitoring the Environment

To maintain a safe working environment it is necessary to regularly monitor levels of hazardous substances. The level of monitoring will depend on the level of risk.

Sampling and monitoring of the workplace should be undertaken on a periodic basis. Surveys will also be required to investigate confirmed cases of occupational lung disease.

Such sampling should be undertaken only by qualified safety personnel or occupational hygienists, who will be able to ensure proper sampling procedures and subsequent analysis.

Employee Screening

Medical monitoring of groups or individuals can be undertaken as part of the organisation’s health-screening process or in an emergency.

To reduce the likelihood of employees developing occupational lung disease, the following measures should be adopted.

• The selection of fit personnel for employment in areas where there may be a significant risk of occupational lung disorders.
• Regular screening of employees, particularly in the first two years of employment.
• The removal of employees for medical assessment when they develop potential respiratory symptoms.

In the event that employees develop disordered respiratory function, redeployment and ill-health retirement may have to be considered.

Symptoms of Respiratory Disease

The lungs have a number of responses to inhaled harmful substances and a careful history must be noted to enable an accurate assessment of the symptoms.

• Cough — the character (e.g. dry or productive with sputum), frequency and relationship to work of any cough should be determined.
• Wheezing — close attention should be paid to any history of wheezing. Of particular interest is whether the wheeze is worse in expiration, which is a feature of asthma in general, or if it occurs in both expiration and inhalation. The relationship to work must be established and it is important to note any improvement in symptoms when away from the workplace.
• Dyspnoea (breathlessness) — any breathlessness should be assessed in terms of whether it is related to effort and whether it is associated with any other respiratory symptoms. Heart disease is a common cause of dyspnoea and the different diagnosis between respiratory and cardiac causes for breathlessness may not be easy to establish.
• Sputum — in individuals with a productive cough, the amount and character of the sputum produced, as well as a relationship to work, should be established.
• Chest pain — chest pain is quite rare in occupational respiratory disorders and is usually due to cardiac or musculoskeletal disorders. However, it may occur with pneumothorax and pleurisy — both possible outcomes of occupational respiratory disease.

Tests for lung disease

Chest X-rays and lung function tests should be considered as part of pre-employment screening where there is any risk of occupational lung disease. They will establish any existing lung disease, assess fitness for employment and provide a baseline for future screening.

The following clinical investigations may be used to monitor individuals who have been or are currently exposed to a potential hazard.

• Chest X-rays — large posteroanterior and lateral views are essential. These tests may be augmented by other scans to demonstrate changes in lung structure.
• Pulmonary function tests — these tests attempt to quantify the efficiency of the lungs in terms of flow rates and lung volumes. They are particularly useful in identifying conditions such as obstructive airways disease, Chronic Obstructive Pulmonary Disease (COPD) or emphysema. Pre-employment lung function testing should always be carried out where there is any assessed risk of lung disease.
• Sputum (the mucus material from the lungs that a person coughs up) — this may be examined for evidence of harmful dusts and cultured for pathogenic bacteria.
• Blood tests — testing may identify hyper-allergic individuals.

Diagnosis of Occupational Respiratory Disease

The diagnosis of respiratory disease in general relies on the nature of the symptoms described by the patient and the results of clinical tests.

A diagnosis of occupationally-linked lung disease will rely on symptoms that are clearly related to work and a history of exposure to potentially harmful substances. It is important to remember that, although a number of workers may be affected, certain individuals may have more severe problems.

Managing Employees with Occupational Lung Disease

Immediate Action — Acute Symptoms

Occupational lung disease rarely requires emergency treatment but inhalation of toxic fumes and vapours may result in such a need. It is also possible that individuals may become sensitised over a period of time with the result that even minimal exposure to the sensitising agent may provoke an acute allergic reaction.

The initial treatment must be based on the first-aid principles of removing the victim from the source of the problem, providing such life support as is necessary and the administration of oxygen if breathing is in any way affected. Urgent transfer to a medical facility should then be undertaken.

Chronic Occupational Lung Disease

In non-acute cases, any action taken should result from consultation between management, the employee and occupational health professionals.

Occupational lung disease should be managed on the following principles.

• Can the employee’s exposure to the causative agent be modified to allow continuing employment without further progression of the condition? This will involve detailed consideration of work practices, use of personal protective equipment and the need for monitoring. Alternative employment may need to be considered.
• Can the symptoms be controlled by medical treatment to allow the same employment to continue without progression of the condition?
• If disability is, or becomes, severe enough to warrant retirement on health grounds, it is important that this decision is taken only on the recommendation of a qualified occupational health physician.