Occupational and environmental medicine is perhaps the most wide-ranging of all medical specialties. It is the medical specialty devoted to the prevention and management of occupational and environmental injury, illness and disability, and promotion of health and productivity of workers, their families and communities.
Today, the complexity and pervasiveness of modern industrial processes afford occupational and environmental medicine physicians the opportunity to address work-site and environmental concerns and such community health and policy issues as atmospheric pollution, product safety, health promotion and benefits value management.
The term “environmental medicine” has also recently been used to describe this growing, challenging, modern medical specialty. Environmental medicine addresses the impact of chemical and physical stressors on individuals and groups. Both occupational and environmental medicine use similar skills and focus on the recognition and prevention of hazardous exposures.
Occupational Medicine: Specialty Description
The scope of practice of occupational and environmental medicine has undergone important changes over the last century as a result of changing expectations of society, employers, and workers, as well as evolving federal and state regulations. The role of the OEM physician has expanded to enhancing the productivity of the worker with absence management and increased emphasis on the overall health, wellness, and safety of the worker – not just at the work site, but at home and in the community.The health of the US workforce is central to the nation’s overall prosperity, stability and security. More than 130 million Americans spend most of their waking hours either at the workplace or connected to it. Their health status determines everything from our national productivity on the global stage to the long-term stability of programs such as Medicare and Social Security.
As the workplace has evolved and changed, employers increasingly make the connection between good health and the overall success of their enterprises. The demand for physicians trained in the complex interplay of factors that affect worker health has grown significantly.
As highly trained specialists, occupational and environmental medicine (OEM) physicians enhance the health of workers through preventive medicine, clinical care, disability management, research and education. Careers include academia, corporate, hospital-based and private clinics, federal and local government, and the military.
Most importantly, occupational physicians are at the center of virtually all health-related transactional activities in the workplace. They serve as an important liaison between employer, employee, government and all components of the health care system—understanding the needs and challenges of each of these diverse groups.
In the past, occupational medicine physicians were primarily reactive to the injuries and exposures that occurred in the workplace. Workers who became sick or were injured came to the work-site clinic. Now the role of the OEM physician has changed. As disease prevention and wellness have become a greater part of the health care equation, occupational and environmental medicine has expanded its scope, contributing scientific research, new clinical guidelines for medical care, and public health programming aimed at the workforce and the health of the environment as well as direct patient care.
OEM physicians use the tools of preventive medicine (primary, secondary and tertiary) to improve the health of a defined population of workers and their families, and they are trained in the complex return- to-work process, an advanced system of health monitoring that optimizes the time in which ill or injured workers can safely return to work.
Occupational Lung Diseases
What are occupational lung diseases?
Repeated and long-term exposure to certain irritants on the job can lead to an array of lung diseases that may have lasting effects, even after exposure ceases. Certain occupations, because of the nature of their location, work, and environment, are more at risk for occupational lung diseases than others. Contrary to a popular misconception, coal miners are not the only ones at risk for occupational lung diseases. For instance, working in a car garage or textile factory can expose a person to hazardous chemicals, dusts, and fibers that may lead to a lifetime of lung problems if not properly diagnosed and treated.
Consider these statistics from the American Lung Association:
- Occupational lung diseases are the primary cause of occupation-associated illness in the U.S. based on frequency, severity, and preventability of the illnesses.
- Most occupational lung diseases are caused by repeated, long-term exposure, but even a severe, single exposure to a hazardous agent can damage the lungs.
- Occupational lung diseases are preventable.
- Smoking can increase both the severity of an occupational lung disease and the risk of lung cancer.
What are the symptoms of an occupational lung disease?
The following are the most common symptoms of lung diseases, regardless of the cause. However, each individual may experience symptoms differently. Symptoms may include:
- Coughing
- Shortness of breath
- Chest pain
- Chest tightness
- Abnormal breathing pattern
The symptoms of occupational lung diseases may resemble other medical conditions or problems. Always consult your doctor for a diagnosis.
How are occupational lung diseases diagnosed?
Occupational lung diseases, like other lung diseases, usually require an initial chest X-ray or CT scan for a clinical diagnosis. In addition, various tests may be performed to determine the type and severity of the lung disease, including:
- Pulmonary function tests. Diagnostic tests that help to measure the lungs’ ability to move air into and out of the lungs effectively. The tests are usually performed with special machines into which the person must breathe.
- Microscopic examination from biopsy or autopsy of tissue, cells, and fluids from the lungs
- Biochemical and cellular studies of lung fluids
- Measurement of respiratory or gas exchange functions
- Examination of airway or bronchial activity
What is the difference between inorganic and organic dust?
Particles in the air may cause lung problems. Often called particulate matter (PM), particles can consist of a combination of dust, pollens, molds, dirt, soil, ashes, and soot. Particulate matter in the air comes from many sources, such as factories, smokestacks, exhaust, fires, mining, construction, and agriculture. The finer the particles are, the more damage they can do to the lungs, because they are easily inhaled deep into the lungs, where they are absorbed into the body.
Inorganic refers to any substances that do not contain carbon, excluding certain simple carbon oxides, such as carbon monoxide and carbon dioxide. Organic refers to any substances that do contain carbon, excluding simple carbon oxides, sulfides, and metal carbonates.
Examples of inorganic dust diseases
- Asbestosis. Asbestosis is caused by the inhalation of microscopic fibers of asbestos. The disease is progressive, resulting in scarring of the lungs with fibrous tissue, according to the American Lung Association. An estimated 1.3 million construction and industry workers are currently exposed to asbestos on the job.
Asbestos is a mineral fiber that was added in the past to certain products for strengthening, heat insulation, and fire resistance. Most products today are not made with asbestos. Normally safe when combined with other materials, asbestos is hazardous to the lungs when the fibers become airborne (such as when a product deteriorates and crumbles).
The risk of asbestos exposure is not just limited to the workplace. Many homes were built with asbestos products (especially those homes built before the 1970s). Examples of products that may have previously contained asbestos include:- Insulation blankets or tape around steam pipes, boilers, and furnace ducts
- Resilient floor tiles
- Vinyl sheet flooring backing
- Adhesives used to install floor tiles
- Insulation made of cement sheet, millboard, and paper used around furnaces and wood-burning stoves
- Door gaskets in furnaces, wood stoves, and coal stoves
- Sprayed soundproofing or decorative material on walls and ceilings
- Patching and joint compounds for walls and ceilings
- Cement roofing, shingles, and siding
- Coal worker’s pneumoconiosis. Coal worker’s pneumoconiosis is caused by inhaling coal dust. Also known as black lung disease, the condition, in severe cases, is characterized by scarring on the lungs (which often permanently damages the lungs and may lead to shortness of breath). About 2.8 percent of coal miners have coal worker’s pneumoconiosis.
- Silicosis. Silicosis is a lung disease caused by inhaling free crystalline silica, a dust found in the air of mines, foundries, blasting operations, and stone, clay, and glass manufacturing facilities. Characterized by scarring of the lungs, silicosis itself can increase the risk for other lung diseases, including tuberculosis (a chronic, bacterial infection that usually infects the lungs). Over one million workers per year are exposed to silica.
Examples of organic dust diseases
- Byssinosis. Byssinosis is caused by dust from hemp, flax, and cotton processing. Also known as brown lung disease, the condition is chronic and characterized by chest tightness and shortness of breath. Byssinosis affects textile workers–both former and current–and almost exclusively those who work with unprocessed cotton.
- Hypersensitivity pneumonitis. Hypersensitivity pneumonitis is a lung disease caused by the inhalation of fungus spores from moldy hay, bird droppings, and other organic dusts. The disease is characterized by inflamed air sacs in the lungs, leading to fibrous scar tissue in the lungs and abnormal breathing. There are variations of hypersensitivity pneumonitis depending on the occupation, including cork worker’s lung, farmer’s lung, and mushroom worker’s lung.
- Occupational asthma. Occupational asthma is caused by inhaling certain irritants in the workplace, such as dusts, gases, fumes, and vapors. It is the most common form of occupational lung disease and can worsen pre-existing asthma. Characterized by common asthma symptoms (such as a chronic cough and wheezing), occupational asthma is a reversible condition when diagnosed at an early stage. People at higher risk for occupational asthma often work in manufacturing and processing operations, farming, animal care, food processing, cotton and textile industries, and refining operations.
How can occupational lung diseases be prevented?
The best prevention for occupational lung diseases is avoidance of the inhaled substances that cause lung diseases. The National Heart, Lung, and Blood Institute recommends taking other preventive measures, as well, including:
- Do not smoke. Smoking can actually increase the risk for occupational lung disease.
- Wear proper protective devices, such as facial masks, when around airborne irritants and dusts.
- Evaluate lung function with spirometry (an evaluation of lung function performed in the doctor’s office) as often as recommended by your doctor to familiarize yourself with your lung function.
- Educate your workers concerning the risks of lung disease.
- Hire a specially-trained occupational health expert to investigate your work environment for risks for occupational lung diseases.
Treatment of occupational lung diseases
Treatment will be determined by your doctor based on:
- Your age, overall health, and medical history
- Extent and type of lung disease
- Your tolerance for specific medications, procedures, or therapies
- Expectations for the course of the disease
- Your opinion or preference
Consult your doctor for more information regarding the treatment of occupational lung diseases.
Occupational Dermatitis
Occupational skin exposure is the second most common cause of occupational disorders, with a rate of 2.3 injuries per 10,000 workers.2 More than 13 million U.S. workers annually are potentially exposed to chemicals absorbed through the skin.29 Most recently, a decrease in the incidence of occupational dermatitis has been reported in 10 European countries.30 The following discussion focuses on occupational contact dermatitis because it accounts for 90% to 95% of occupational skin disorders.6,7,29,31,32 Table 3 lists occupational skin disorders and associated occupations.6–8,29,31–33
Occupational Skin Disorders and Associated Occupations
| Disorder | Associated occupations/industries |
|---|---|
| Acne | Artisans, factory workers, asphalt workers, carpenters, construction workers, paint manufacturing workers |
| Allergic contact dermatitis | Agricultural workers, cement workers, forestry workers, health care workers, laboratory workers |
| Burns | Asphalt workers, carbonated drink production, construction workers, farmers, food service industry, pesticide application workers |
| Folliculitis | Engineering industry workers, mechanics, oil field/refinery workers, roadway workers, sheep shearers |
| Irritant contact dermatitis | Auto workers, hairdressers, health care workers, paint industry workers, printers |
| Mechanical injury | Auto workers, construction workers, metal industry, wood industry |
| Skin cancer | Carbonated drink production, chimney sweeps, coal/tar workers, farmers, metal industry, mining, outdoor occupations, printing industry, roadway workers, roofing |
| Skin infections | Agricultural workers, food service industry, health care workers, livestock industry, meat workers |
Information from references 6 through 8, 29, and 31 through 33.
DIAGNOSIS
Occupational contact dermatitis can be divided into irritant and allergic types. Irritant contact dermatitis is inflammation due to phototoxic reactions or skin contact with a chemical agent such as acids, bases, oxidizing or reducing agents, water, detergents, and cleaning agents. Exposure to wet work accounts for 68% of occupational contact dermatitis cases.29 Allergic contact dermatitis is caused by an allergic skin reaction. Common causes include metals, epoxy, acrylic resins, rubber additives, agrochemicals, and commercial chemicals. Nickel exposure occurs in many occupations with the use of stainless steel, magnets, metal plating, coinage, and certain alloys. Some substances can produce both irritant and allergic contact dermatitis.
Differentiating occupational from nonoccupational contact dermatitis relies on a careful occupational history. Irritant and allergic contact dermatitis can have similar presentations. A validated scoring tool for the severity of irritant contact dermatitis has been developed using clinical findings of erythema, desquamation, cracked skin, and the amount of skin affected.8 There is some genetic disposition for irritant contact dermatitis in patients with filaggrin mutation (a protein defect associated with diseases of keratinization), a history of adult atopic dermatitis, or nickel sensitivity. Patients with both filaggrin mutation and atopic dermatitis have the highest risk of developing irritant contact dermatitis.6,31,33 Patch testing can help identify allergic contact dermatitis and should be considered when occupational contact dermatitis has not improved after three months of treatment and a contact allergy is suspected.6,7
Occupational contact dermatitis can develop at any point during a person’s career7 and has a variable clinical course: one-third of patients have resolution of skin symptoms, one-third have partial improvement but persistence of symptoms, one-fourth have no change, and a few experience worsening of symptoms.34 However, quality of life and daily function are affected in nearly 50% of workers with occupational contact dermatitis.32,33
CARPAL TUNNEL SYNDROME
Among occupational disorders, carpal tunnel syndrome is the most expensive upper-extremity disorder in terms of days away from work and treatment costs. Although many occupations pose a risk of carpal tunnel syndrome, there are some individual risk factors, such as body mass index (more than 30 kg per m2); age (older than 50 years); female sex (hazard ratio = 1.30; 95% confidence interval, 0.98 to 1.72); being a new employee (less than 3.5 years at the occupation); and comorbidity with rheumatoid arthritis, diabetes mellitus, or thyroid disease.39,40 Additional occupational risk factors include no varied pace over work, lack of variety of work, high job strain, and inability to schedule breaks.39 Social support has a protective factor (hazard ratio = 0.54; 95% confidence interval, 0.31 to 0.95).39
Treatment is mainly conservative with rest, activity modification, splinting at the wrist/elbow, physical therapy, nonsteroidal anti-inflammatory drugs, and steroid injections. Using a differently configured keyboard may be beneficial.41 General recommendations with poor evidence include modifying duties, evaluating the workstation, and decreasing exposure to hand vibration.41 Surgery is reserved for severe, refractory cases.42
Occupational Musculoskeletal Disorders
Occupational musculoskeletal disorders are injuries or disorders of the muscles, tendons, joints, cartilage, and nerves that are caused or exacerbated by sudden exertion or prolonged exposure to physical factors such as repetitive movement, force, vibration, or awkward positions. Common upper-limb disorders include shoulder disorders, lateral epicondylitis, wrist tendinitis, and carpal tunnel syndrome, in addition to nonspecific strains, sprains, muscle tears, back pain, and hernias. Approximately one-half of occupational musculoskeletal disorders occur in those working in the manufacturing and services industries.35 According to 2011 data, musculoskeletal disorders accounted for 33% of all occupational injuries and illnesses.36 The true prevalence of occupational musculoskeletal disorders is difficult to determine because studies use different definitions.37 Risk is measured based on level of hand activity and forceful exertion, awkward positions, and hand-transmitted vibration.
Family physicians should inquire about routine heavy lifting, daily exposure to vibrations, routine overhead work, and repetitive forceful tasks. Workers at risk of occupational musculoskeletal disorders should be encouraged to engage in physical activity and maintain a healthy weight to reduce disease progression. Workplace adaption is critical for prevention and treatment of occupational musculoskeletal disorders. Ideally, the hazard should be removed. Engineering controls should alter factors of applied force, fixed body position, and pace of work. Administrative controls can protect workers through job rotation, forced breaks, and alteration of work pace. A systematic review of workplace-based interventions for the prevention of upper-extremity musculoskeletal disorders showed a positive effect of resistance exercise (dumbbell or kettlebell exercises).38
