Occupational lung disease

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at June 22, 2016
StartDiseasesOccupational lung disease

Occupational lung disease describes a variety of lung diseases acquired while on the job. These diseases are often caused by the inhalation of dust. They affect workers who, after years of exposure to dust, develop pneumoconiosis, or "dusty lungs.” As work and safety conditions have improved in the United States, fewer workers are developing these dust-related conditions.

Contents

Definition & Facts

Occupational lung disease is a term that covers a broad swath of conditions caused by inhaling chemicals, dust, or proteins. Occupational lung disease describes conditions that have resulted in permanent, irreversible damage to the lungs due to exposure to materials encountered in the occupational context.

Coal workers' pneumoconiosis results from exposure to coal dust. Chronic beryllium disease results from exposure to beryllium. Hard metal disease is caused by cobalt exposure. Silicosis is caused by exposure to silica. Asbestosis is sometimes known as pulmonary fibrosis and results from exposure to asbestos.

The changes in lung tissue found in those who have occupational lung disease can crop up years after exposure. Lung tissue builds up a percentage of silica, for example, without producing symptoms. After years of exposure, however, nodules and lesions may occur, causing silicosis.

Occupational lung diseases often lead to serious, fatal conditions. Patients with silicosis are much more susceptible to bacterial lung disease and tuberculosis, and asbestosis often leads to lung cancer. For those with asbestosis, smoking increases the risk of developing lung cancer, but non-smokers with asbestosis are also at high risk of developing lung cancer.

Symptoms & Complaints

Asbestos-related diseases such as asbestosis cause a range of problems from benign pleural plaques to malignant mesothelioma. Pleural plaque is the most common symptom of asbestos exposure, and results in chest pain, shortness of breath during exertion, and a dry cough. Another symptom is decreased lung capacity.

Patients with silicosis also experience decreased lung volumes and a dry cough. In X-rays, silicosis appears as nodules in the lungs, and if the disease advances, these nodules can accumulate. Debilitating shortness of breath ensues.

Hard metal disease caused by cobalt exposure causes asthma. Cobalt poisoning reduces the elasticity of lung tissue, limiting breath capacity. Beryllium-induced lung disease (berylliosis, chronic beryllium disease) can manifest as temporary lung inflammation and shortness of breath. Over time, lung scarring occurs. In addition, exposure to beryllium can lead to general malaise including weakness, loss of appetite, unexplained weight loss, joint pain, chronic cough, and fever.

Causes

Industrial exposure to asbestos has been greatly reduced due to laws limiting its use and strictly regulating the process of its removal. As a generation of heating and air professionals retire, however, they and their families continue to suffer the aftermath of asbestos exposure. Working in the presence of asbestos and handling garments worn during these labors have led to asbestos-related illness risks for HVAC technicians and their families. While conditions such as asbestosis and malignant mesothelioma are still present, new cases of these illnesses will hopefully continue to decline in the United States.

Silica exposure occurs in mining and stone cutting applications. Hard metal disease is caused by cobalt exposure. Cobalt is used in the manufacture of tungsten carbide cutting blades which are used in industrial applications. Other factories and workplaces where these blades are used, including diamond polishing facilities, dental laboratories, and saw-sharpening facilities, have an increased need for proper personal and ambient ventilation.

Beryllium exposure will continue to be a risk as the manufacture of electronics expands across the globe. The high temperature tolerance of this lightweight metal will keep it in very high demand. It is used in nuclear power, electronics, aerospace, and reclaiming scrap metal.

Diagnosis & Tests

All occupational lung diseases are diagnosed via biopsy wherein a sample of lung tissue is extracted for analysis. Additional tests include review of patient exposure to the industrial toxin, breath volume and pressure tests, X-rays to review nodule development from silica exposure, and blood tests to check oxygen saturation levels.

Beryllium sensitivity can be determined by a blood test called a beryllium lymphocyte proliferation test. This test examines whether the patient has developed immune cells to combat beryllium. If the patient tests positive for beryllium sensitivity, it is likely that he or she will go on to develop chronic beryllium disease. It is recommended that anyone who has worked with beryllium take this test.

Treatment & Therapy

Once occupational lung diseases are diagnosed, treatment will typically focus on symptom reduction and prevention of complications. Any medications offered may alleviate symptoms, but cannot repair the damage done by exposure.

Bronchodilators, antibiotics, and aspirin may be used to treat asbestosis. Cough suppressants may help patients with silicosis to breathe more easily. Lung transplants may be necessary for those with silicosis.

Prevention & Prophylaxis

The risks of asbestos-related disease continue to decline due to bans on the product and more stringent removal requirements. Manufacturing improvements and increased filtration requirements have reduced the risk of silica-related injuries. Tighter regulations on ambient ventilation and filtration, personal ventilation equipment and changes in the mining process are meant to reduce the risk of silica exposure for workers. Diligent care must be taken to protect workers in the industries of coal mining, stone cutting, and foundry work.

Awareness of cobalt exposure and its role in the subsequent development of hard metal disease is growing. Improving personal and ambient filtration in settings where tungsten carbide blades are manufactured or used is critical to preventing this disease. Cobalt exposure can be reduced by isolating and properly ventilating areas in which cobalt is released.

The risk of beryllium exposure can be greatly reduced with proper attention to personal respiratory and skin protection, and by increased ambient filtration of work spaces. Beryllium should be stored in a dry location to prevent oxidation, and any parts processed of beryllium should be stored in a sealed bag with a desiccant packet. Anyone cutting or handling beryllium should be provided a personally fitted respirator and safety suit to reduce the risk of beryllium inhalation. 

Improvements in worker safety need not negatively impact the manufacturing process. Careful attention to working conditions, personal ventilation, ambient filtration systems and the physical health of employees indicates responsible business decisions and must be encouraged and promoted.