Introduction:
Occupational lung diseases refer to serious lung disorders that occur due to repeated exposure to certain irritants or substances that can have lasting effects even after the cessation of exposure. The irritants in the air from various sources result in these lung disorders. The sources such as fires, mining, exhaust, smokestacks, factories, agriculture, and construction are responsible for causing lung problems. These are small tiny particles that get easily inhaled deep into the lungs and absorbed into the body. In addition to the development, it also worsens respiratory diseases such as asthma, chronic obstructive lung disease, and lung cancer. Reports suggest that these occupational disorders are more seen in older people who are no longer at work but occurred due to their previous job.
What Are the Acute Inhalation Injuries in the Working Environment?
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Exposure to high organic dust or metal fumes associated with bacterial endotoxins may result in metal fume fever and organic dust toxic syndrome, respectively.
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The occurrence of fever is a manifestation of severe pulmonary inflammation. These acute febrile attacks are common in agricultural work environments resulting from organic dust exposure.
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The inhalation of toxic gasses, vapors, fires, leaks or spills from industrial installations, compounds released from explosions, and terrorist operations result in more severe injury to the tracheobronchial tree and destruction of lung parenchyma resulting in long-term structural and functional damage to the lungs.
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Firefighters are at increased risk as their working areas are confined to exposure.
Specific Occupational Lung Disorders -
Various work-related exposures resulting in occupational lung diseases are as follows:
Work-Related Asthma -
Work-related asthma involves both occupational-induced asthma (sensitizer-induced occupational asthma) which is caused due to work, and asthma, which is not caused by work but occurs due to exacerbation of irritants in the work environment (work-exacerbated asthma).
What Are the Common Causes of Occupational Asthma Induced by Allergens?
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In Bakers - The allergens such as wheat, rye, and fungal amylase in flour.
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In Farmers - Grains, mites, and plant and animal allergens are responsible for inducing asthma.
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In Medical - Instrument cleaning, pharmaceutical or laboratory workers, and detergent-making industry workers - enzymes such as pancreatic enzymes and enzymes produced by bacteria Bacillus subtilis contribute to developing asthma.
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Greenhouse Workers - Pollen, fungi, and mites cause asthma in greenhouse workers and florists.
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In Food Workers - Food allergens such as milk, eggs, or vegetables can induce asthma.
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In Health Care Workers - Latex allergens, ortho-phthalaldehyde, glutaraldehyde, and aerosolized medications.
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In Factories and Other Industrial Workers- Chemicals in spray paints, polyurethane, spray insulation, and adhesives cause asthma.
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In Electronic Workers - Soldering flux with colophony stimulates the development of asthma.
Clinical Manifestations of Sensitizer-Induced Occupational Asthma -
This type of occupational asthma is caused due to specific immune response to exposure to the sensitizing agent in the work environment. The higher the level of exposure is associated with a higher rate of sensitization.
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The patient may develop symptoms within the first year of exposure. However, once a patient becomes sensitized, even fewer triggers can develop asthma. Based on the molecular weight of sensitizers, high-molecular-weight sensitizer agents can cause an immediate response within minutes after exposure. In contrast, exposure to low-molecular-weight sensitizers can start responding four to six hours after exposure.
Diagnosis -
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In these patients, allergic rhinitis or conjunctivitis associated with work frequently appears before the development of asthma.
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Allergy skin-prick tests, and blood samples, are taken to evaluate specific immunoglobulins E to relevant sensitizer agents.
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Monitoring peak expiratory flow rates, symptom diary records, and use of rescue inhalers give supportive information.
Treatment -
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The primary goal in treating sensitizer-induced occupational asthma involves the complete removal of exposure to sensitizers, and in addition to this, drug therapy is provided.
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The primary preventive measures are undertaken by reducing exposure to occupational sensitizers and removing unnecessary agents recommended for the workers.
What Is Reactive Airways Dysfunction Syndrome?
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Irritant-induced asthma manifests as reactive airway dysfunction syndrome.
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The asthmatic symptoms manifest within 24 hours of exposure and persist for about three months.
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The symptoms may subside after weeks or months.
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The management is similar as followed for other types of asthma.
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Affected patients may need a modified work environment to prevent future asthma exacerbations.
What Is Occupational Chronic Obstructive Pulmonary Disease?
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Chronic exposure to dust, gasses, and fumes may cause occupationally induced chronic obstructive pulmonary disease with changes similar to smoking-related chronic obstructive pulmonary diseases.
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It is one of the leading causes of morbidity and mortality in industrialized and developing countries.
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It is characterized by symptoms of chronic bronchitis, including chronic cough, sputum production, and changes in pulmonary function testing.
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It is mainly caused due to mineral dust such as silica, organic dust exposures of farmers and woodworkers, diesel exhaust fumes, ozone, and fine particles in welding fumes.
Diagnosis -
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An occupational history is essential, and it should be the initial step in evaluating the patient.
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No specific diagnostic test is carried out to distinguish it from nonoccupational chronic obstructive lung disease.
Prevention -
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Reduce exposure to the workplace and should follow other hygiene measures.
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Monitor occupational data and dissemination of knowledge to industrializing countries.
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Assessing individual occupational risk factors is vital for preventing disease and reducing the progression of the disease.
What Is Beryllium Disease?
Chronic beryllium disease is a hypersensitivity disorder with genetic association to HLA-dpb1 genes (which belong to the family of genes called the human leukocyte antigen-HLA complex).
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Clinically, the manifestations are similar to sarcoidosis, which results in severe granulomatous restrictive lung disease.
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The onset of this disease varies up to 20 years or more after exposure to beryllium.
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The incidence of beryllium disease decreased after eliminating beryllium from fluorescent bulbs in the 1950s but later increased due to beryllium in electronics, dental ceramics, metal alloys, aerospace recycling of metals, and bicycle products.
Diagnosis -
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Lymphocyte Proliferation Test: This provides early diagnosis, demonstrating sensitized lymphocytes in the blood.
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Chest X-ray: The enlarged hilar or mediastinal lymph nodes, multiple lung nodules, or both are seen in chest radiographs.
What Is Occupational Lung Cancer?
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Long-term exposure to recognized carcinogens such as asbestos (bronchogenic carcinoma), chromium, polycyclic aromatic hydrocarbons, arsenic, and silica may increase the risk of lung cancer.
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The exposure to specific types of agents and the exposure conditions determines the degree of carcinogenicity.
What Are the Precautions that Can Be Taken?
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A detailed history determines the easy diagnosis and helps in providing the appropriate treatment.
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Reducing or eliminating patients’ exposure to carcinogens is preferable to treating existing cases.
What Are the Other Related Occupational Diseases?
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Asbestosis: This refers to the chronic inhalation of tiny asbestos fibers in the workplace. Long-term inhalation of these fibers leads to scarring or fibrosis and stiffness of the lung tissue. It is often associated with construction workers.
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Silicosis: The inhalation of crystalline silica causes silicosis. It can also be found in the clay, stone, and glass manufacturing industries. It causes lung fibrosis and other lung complications.
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Byssinosis: It is caused due to inhalation of dust from flax, hemp, and cotton processing. It is also known as brown lung disease and is most commonly seen in textile workers, particularly those with unprocessed cotton. This condition causes chest tightness and shortness of breath.
Conclusion:
Occupational exposure is an important cause of almost all respiratory diseases. Work-related exposure to chemicals, dust, and gasses should be considered and supported as good evidence in diagnosing pulmonary diseases. The prognosis for treating lung scarring or fibrosis is poor. The role of the work environment in the development and aggravation of infection is often under-recognized and undoubtedly under-reported.
