Work-related airway diseases

Airway diseases is a large group of diseases that affect millions worldwide. It is well documented that vapours, dust, gas, and fumes can affect respiratory health, and that tobacco smoking is a major cause of lung diseases. Still, 10-15 % of diagnosed lung diseases can be related to different exposures at the workplace. A work-related respiratory disease can be defined as an upper or lower airway disease that has been induced or aggravated by a particular exposure in the workplace.

Particle size matters. Exposure to coarse dust is associated with upper airway health effects whereas exposure to finer dust even gives lower airway health effects. ^{© Colourbox/G. Tjalvin}

Before we talk more about work-related respiratory diseases we will show you a video that illustrates the difference between restrictive and obstructive lung function impairment.

Pneumoconioses

Pneumoconioses refers to a range of diseases that are caused by the inhalation and deposition of mainly inorganic particles and mineral dust in the lungs. For some of the pneumoconioses, the dust exposure leads to a subsequent inflammation and fibrotic reaction of the lung. The result is “stiff” lungs, as we illustrated in the video about the cup of smoothie. The overall outcome is lungs with limited gas exchange capacity.

Pneumoconioses are the most common occupational lung diseases in developing countries. They are named after the dust that leads to the disease, for example: asbestosis, silicosis and coal worker’s pneumoconiosis, also known as “black lung”.

Typically, the exposure levels have to be quite high over a long period of time, often 10-30 years, for a worker to develop pneumoconiosis. It is also typical that there is a long latency period between the first time a person was exposed to the dust to the onset of the actual pneumoconiosis. Therefore, cases of the disease that are emerging today could be a consequence of the patient’s work conditions many years ago. Some very aggressive forms of silicosis can, however, develop very rapidly.

Workers in asbestos quarries are at high risk of developing both pneumoconiosis and cancer. ^{© Colourbox}

Obstructive lung diseases

Asthma and chronic obstructive pulmonary disease (COPD) are obstructive lung diseases. As the name implies, such diseases are characterized by obstruction of the airway. The problem is that the airway is too narrow, – as we illustrated in the video about the cup of smoothie.

Asthma

Asthma is characterized by airway hyper-responsiveness, which can lead to recurrent episodes of widespread, but variable, airflow obstruction. The main symptoms are wheezing, breathlessness, chest tightness, and coughing. The obstruction is reversible either spontaneously or with treatment. An asthma diagnosis is mainly based on symptoms, but different tests can help to confirm the diagnosis.

Work-related asthma

Work-related asthma typically worsens at work and improves on days away from work. Work-related asthma is further divided into occupational asthma and work-aggravated asthma.

Work-related asthma can be divided into occupational asthma and work-aggravated asthma. ^{© University of Bergen/Arjun Ahluwalia}

Occupational asthma develops during adulthood and is induced by immunologic or irritant exposures at the workplace. Occupational asthma often develops during the first two years of employment.

Work-aggravated asthma is a condition where a pre-existing asthma, such as childhood asthma, is aggravated by workplace exposures. The aggravation is typically due to an occupational irritant.

Occupational asthma is the second most common occupational lung disease in developing countries, while it is the most common in industrialized countries. Around 5-20 % of new cases of adult asthma can be attributed to work exposure. There is an urgent need for intensified preventive efforts because these numbers represent many thousands of people who are suffering from a preventable disease.

All types of artificial nails contain sensitizing compounds such as acrylates that can cause allergic eczema in the beauticians who apply them. Many beauticians also experience asthma symptoms, conjunctivitis and rhinitis while creating artificial nails.
^{© Colourbox}

Medical surveillance programs including questionnaires and spirometry are important to identify workers at risk of developing occupational or work-aggravated asthma.

Chronic obstructive pulmonary disease (COPD)

While asthma has recurrent episodes of airway obstruction, each of which is reversible, chronic obstructive pulmonary disease (COPD) is characterized by an airflow limitation that is not fully reversible.

The obstruction level is usually progressive and associated with an abnormal chronic inflammatory response in the airways and the lungs to vapours, gases, dust and fumes. COPD symptoms include shortness of breath, chest tightness, daily cough and sputum production, wheezing and frequent respiratory infections. The symptoms often do not appear until significant lung damage has occurred, and usually worsen over time, particularly if exposure continues.

Workers in most occupations associated with high exposure to vapours, dust, gas and fumes are at risk of developing COPD.

Quarry workers, miners, tunnel construction workers, and other workers who drill, blast, remove, or crush rock, are at high risk of developing work-related COPD due to high levels of dust in their working environment. During blasting processes, large amounts of dust and gases, such as nitrogen oxides are liberated. Depending on the geology at the work site, high exposures to crystalline silica may even occur. ^{© Colourbox}

Workers in the cement manufacturing industry are also highly exposed to dust. ^{© Alexander Mtemi Tungu}

Welders are exposed to welding gas and fumes, a complex mixture of metallic oxides, silicates and fluorides, nitrous oxides, carbon dioxide, carbon monoxide, shielding gas (e.g. argon or helium), and ozone, and can be at risk of work-related COPD. ^{© Colourbox}

About 15% of all cases of COPD are work-related. The induction time from exposure to the detection of early COPD is usually long, – often 10 years or more. Thus, the cases of the disease that are emerging today can be a consequence of the patient’s work conditions many years ago.

The lung function can be measured by a spirometer.
^{© G. Tjalvin}

COPD can be diagnosed by spirometry. This test can detect reduced lung volumes even before the patient has developed any symptoms. Therefore, medical surveillance programs including short questionnaires that ask about common COPD symptoms and spirometry are important tools for identifying workers at risk of developing COPD.