OCCUPATIONAL LUNG DISEASES
Occupational lung diseases are a branch of occupational diseases concerned primarily with work related exposures to harmful substances, be they dusts or gases, and the subsequent pulmonary disorders that may occur as a result. Substances known to cause lung disease include coal dust, Asbestos, Silicon (which is usually in the form of quartz) and Barium.
ASBESTOSIS
Introduction
Asbestosis is a chronic (long-term) lung condition caused by prolonged exposure to asbestos. Asbestos is a soft, greyish-white material that does not burn. In the past it was often used in building construction to protect against fire and as a form of insulation.
Breathing in asbestos dust can scar the lungs, which can lead to:
· shortness of breath
· cough
The interval between exposure to asbestos and the onset of symptoms varies, but it can be several decades.
Asbestosis means that the lung tissue has become scarred due to previous asbestos exposure. Pleural plaques or pleural thickening caused by asbestos are not the same as asbestosis. In these conditions, the lining of the lung is damaged by asbestos, but the lungs themselves are unharmed.
Causes
Asbestos fibres
Asbestosis is caused by asbestos fibres. Usually, when you breathe in a foreign body, such as a particle of dust, or metal, small cells, known as macrophages, will break down these particles before they reach your lungs.
However, asbestos fibres are too tough for the macrophages to break down. In an attempt to break down the asbestos fibres, the macrophages release substances that are designed to destroy the fibres. These substances damage the tiny air sacs in your lungs which are known as alveoli.
Alveoli
When you breathe in, the alveoli help transfer oxygen from your lungs into your blood. Also, when you breathe out, the alveoli help to transfer carbon dioxide out of your blood, through your lungs, and out of your mouth.
If you have experienced a prolonged exposure to asbestos fibres lasting for many years, the damage to the alveoli becomes more severe and causes scarring. This scarring is known as fibrosis.
Once the alveoli become scarred, their ability to inhale oxygen, and exhale carbon dioxide, becomes adversely affected, resulting in the symptoms of breathlessness.
Occupational risk factors for asbestosis
The use of asbestos significantly increased after World War Two, peaked during the 1970s and then slowly declined during the 1980s and 1990s. If, during this time, you worked in an industry, or occupation, that used asbestos, you may have been exposed to it.
Occupations that are known to be associated with exposure to asbestos during these times include:
· insulation workers,
· boilermakers,
· plumbers, pipefitters, and steamfitters,
· shipbuilders,
· sheet metal workers,
· plasters,
· chemical technicians, and
· heating, air-conditioning, and refrigeration mechanics.
Industries that are known to have used asbestos during these times include:
· construction,
· shipbuilding and repair,
· chemical manufacturing,
· non-metallic mineral stone production,
· railways,
· yarn, thread, and fabric mills,
· rubber and plastic production, and
· trucking services.
Symptoms
The symptoms of asbestosis usually begin 15-20 years after the initial exposure to the material. Symptoms usually begin gradually before becoming more noticeable and troublesome over the space of many years.
Symptoms of asbestosis include:
· shortness of breath (initially after physical activity, but eventually while resting as well),
· cough, and
· chest pain.
A less common symptom of asbestosis is the ends of the fingers become swollen, misshapen, and red, as a result of a build-up of fluid in the tissue of the fingers. This is known as finger clubbing.
Diagnostics
Before confirming a diagnosis of asbestosis, your GP will ask you about your symptoms and listen to your lungs with a stethoscope. If your lungs have been affected by asbestosis, when you breathe they will make a distinctive crackling noise.
Your GP will require details of your work history, including any times when you may have been exposed to asbestos, the length of any possible exposure, and whether you were issued with any safety equipment, such as a face mask.
If your GP suspects asbestosis, a diagnosis can usually be confirmed by running a series of additional tests. These tests are described below.
Spirometer
A spirometer is a machine that measures how much oxygen you can breathe in, and how much carbon dioxide you can breathe out. These measurements can be used to assess how effective your lungs are.
X-rays
X-rays can detect abnormalities in the structure of your lungs that are caused by asbestosis.
CT scans
CT scans are more detailed than X-rays and can often be used to detect asbestosis in its earliest stage.
Treatment
There are four main components to the treatment of asbestosis:
· quitting smoking (if you are a smoker),
· vaccinations against potentially dangerous lung conditions, such as influenza (flu),
· using medicines to make breathing easier, and, if necessary,
· using equipment, such as oxygen cylinders, to help with breathing.
While none of these components will be able to cure asbestosis, they can help control symptoms and improve your quality of life.
Quitting smoking
If you have been diagnosed with asbestosis, and you smoke, it is very important that you give up as soon as possible.
Smoking will make your symptoms of breathlessness worse, and it will also significantly increase your chances of developing lung cancer.
It is thought that smoking and asbestosis have a synergistic effect on the risk of developing lung cancer. This means that the combined risk associated with smoking and asbestosis is far higher than the sums of their individual risks.
For example, a non-smoker who has asbestosis is approximately three times more likely to develop lung cancer than a non-smoker who does not have asbestosis.
A smoker who does not have asbestosis is five-and-a-half times more likely to develop lung cancer than a non-smoker without asbestosis. However, a smoker who also has asbestosis is 14 times more likely to develop lung cancer than a non-smoker without asbestosis.
Speak to your GP to get help with giving up smoking. They will be able to advise you about nicotine replacement therapies and prescription medicines, such as bupropion, which can greatly increase your chances of quitting successfully. They can also put you in touch with local support groups and one-to-one counsellors.
Vaccinations
If you have asbestosis, your lungs will be more vulnerable to the effects of infection. Therefore, it is recommended that you receive vaccinations against influenza and the pneumococcus bacteria, which can cause serious chest infections. Your GP will be able to arrange these vaccinations for you.
You will require a dose of the influenza vaccine every year. Most people only require one dose of the pneumococcus vaccine, although additional booster shots may be recommended if your general health is poor.
Medicines
Medicines known as bronchodilators are widely used to treat asbestosis. Bronchodilators are usually taken using an inhaler. Bronchodilator inhalers deliver a small dose of medicine directly into your lungs, causing the muscles of your airways to relax and open up, making breathing easier. Theophyllines are another type of medicine that is used in the treat asbestosis. This oral medication helps to widen your airways by relaxing the muscles around them.
In some people, theophyllines have been known to cause a number of side effects including:
· headaches,
· nausea,
· insomnia,
· vomiting,
· irritability, and
· stomach upsets.
Oxygen therapy
If your shortness of breath is particularly bad, your body may not be getting all the oxygen that it needs. If this is the case, oxygen therapy will be required using a machine called an oxygen concentrator. The air that we breathe has quite a low amount of oxygen in it. In fact, oxygen only makes up about 21% of the atmosphere. An oxygen concentrator is plugged into a mains socket and purifies oxygen from the air in the room, producing a more oxygen-rich supply of air. You can then breathe the oxygen-rich air though a mask. The tube connecting the mask is very long, so you will be able to move around your home freely. Do not smoke when you are using an oxygen concentrator. The increased level of oxygen that is produced is highly flammable, and a lit cigarette could trigger a fire, or an explosion. In addition to the oxygen concentrator, you may also be given a small, portable oxygen tank and mask that you can use when you leave your house. This is known as ambulatory oxygen.
BERYLLIOSIS
Berylliosis is a form of metal poisoning caused by inhalation of beryllium dusts, vapors, or its compounds or implantation of the substance in the skin. The toxic effects of beryllium most commonly occur due to occupational exposure. Beryllium is a metallic element used in many industries, including electronics, high-technology ceramics, metals extraction, and dental alloy preparation.
There are two forms of beryllium-induced lung disease: acute and chronic. Acute berylliosis has a sudden, rapid onset and is characterized by severe inflammation of the lungs (pneumonitis), coughing, increasing breathlessness (dyspnea), and other associated symptoms and findings. In addition, in some individuals, the skin or the eyes may be affected. The more common, chronic form of the disease develops more slowly and, in some cases, may not become apparent for many years after initial beryllium exposure. Chronic berylliosis is characterized by the abnormal formation of inflammatory masses or nodules (granulomas) within certain tissues and organs and widespread scarring and thickening of deep lung tissues (interstitial pulmonary fibrosis). Although granuloma development primarily affects the lungs, it may also occur within other bodily tissues and organs, such as the skin and underlying (subcutaneous) tissues or the liver. In individuals with chronic berylliosis, associated symptoms and findings often include dry coughing, fatigue, weight loss, chest pain, and increasing shortness of breath.
Diagnostics
The patient's symptoms and job background provide important clues in diagnosing an occupational lung disease. The doctor will want detailed descriptions of the workplace, the types of substances used, and safety precautions followed. Because occupational lung diseases often take 10 or more years to develop, it is necessary to find out about jobs even in the distant past.
Nonoccupational pursuits such as hobbies that involve exposure to toxic substances should also be investigated. Family members may also have been exposed to toxic materials brought home on work clothes, skin, and hair. Chest X-rays, lung function tests, and biopsies are the mainstays of diagnosis. The X-ray will reveal characteristic opaque areas in the lungs. A biopsy often confirms the type of disease and may also detect the presence, of cancer, a common complication of many occupational lung disorders. Phlegm and sputum samples might be studied for the presence of infection.
If berylliosis is suspected, broncho0alveolar exam will be performed. In this procedure, a bronchoscope, a viewing tube with magnifying devices is inserted through the mouth and into the lungs. A fluid is then injected through the tube to wash up cells from the bronchial lining. Berylliosis is diagnosed if the cells are found to contain elevated levels of beryllium.
Treatment
For the most part, these diseases are incurable and treatment usually is directed to alleviating symptoms. As lung failure advances, supplementary oxygen may be needed. Preventive antibiotics may be prescribed at the first sign of a cold or flu to head off a secondary lung infection.
Berylliosis is sometimes treated with steroid drugs. Hospitalization may be necessary during an acute episode in which the lungs are inflamed. Patients with severely swollen or bleeding lungs may need assistance with a ventilator.
Alternative Therapies
No alternative therapy can cure serious lung diseases, but some alleviate symptoms and make breathing easier.
Aromatherapy. Inhaling steam to which eucalyptus oil has been added helps to loosen lung secretions and improve breathing.
Herbal Medicine. Drinking a hot tea made from elecampane root thins phlegm and mucus.
Horehound, taken as a decoction, syrup, or a tincture, may also help to clear sputum.
Hydrotherapy. A hot, steamy bath or shower helps to open up the airways. Conversely, a cold pack placed on the chest sometimes relieves lung congestion and makes breathing easier.
Physical Therapy. A respiratory therapist teaches special breathing methods and exercises, as well as a postural drainage technique to help clear secretions from the lungs.
An occupational therapist may be consulted for ways to conserve energy when performing tasks.
CAPLAN’S SYNDROME
Caplan syndrome is swelling (inflammation) and scarring of the lungs in people with rheumatoid arthritis who have been exposed to mining dust, such as coal, silica, or asbestos.
Causes
Caplan syndrome is caused by breathing in mining dust, which causes inflammation and can lead to the development of many small lung bumps (nodules) and mild asthma-like airway disease.
Some people who have been exposed to the dust have severe lung scarring that makes it difficult for their lungs to carry oxygen to the bloodstream (called progressive massive fibrosis). People with rheumatoid arthritis do not seem more likely to have this complication of scarring. Caplan syndrome is very rare in the United States.
Symptoms
Exams and Tests
Your health care provider will take a detailed medical history that will include questions about your jobs (past and present) and other possible sources of exposure to mining dust. The health care provider will also do a physical exam, paying special attention to the presence of joint and skin disease.
Other tests can include:
Treatment
There is no specific treatment for Caplan syndrome.
COAL WORKERS’ PNEUMOCONIOSIS
Coal workers' pneumoconiosis (black lung) is a lung disease caused by deposits of coal dust in the lungs.
· People generally have no symptoms, but people who have severe disease cough and become short of breath.
· Chest x-rays and computed tomography are used to make the diagnosis.
· Prevention by minimizing exposure is important.
· People may need to take drugs to keep the airways open and free of mucus.
Coal workers' pneumoconiosis results from inhaling coal dust or graphite over a long time. Although coal dust is relatively inert and does not provoke much reaction, it spreads throughout the lungs and shows up as tiny spots on an x-ray. Coal dust may block the airways. In simple coal workers' pneumoconiosis, coal dust collects around the small airways (bronchioles) of the lungs. Every year, 1 to 2% of people with simple coal workers' pneumoconiosis develop a more serious form of the disease called progressive massive fibrosis, in which large scars (at least ½ inch [about 1.3 centimeters] in diameter) develop in the lungs as a reaction to the dust. Progressive massive fibrosis may worsen even after exposure to coal dust stops. Lung tissue and the blood vessels in the lungs can be destroyed by the scarring.
In Caplan's syndrome, a rare disorder that can affect coal miners who also have rheumatoid arthritis, large round nodules of scarring develop quickly in the lung. Such nodules may form in people who have had significant exposure to coal dust, even if they do not have coal workers' pneumoconiosis.
Symptoms and Diagnosis
Simple coal workers' pneumoconiosis usually does not cause symptoms. However, many people with this disease cough and easily become short of breath because they also have an airway disease, such as bronchitis or emphysema. These disorders are more likely to occur in smokers, so smokers with coal workers' pneumoconiosis are more likely to have symptoms. The severe stages of progressive massive fibrosis, on the other hand, cause coughing and often disabling shortness of breath.
Doctors make the diagnosis after noting characteristic spots on a chest x-ray or computed tomography (CT) scan of a person who has been exposed to coal dust for a long time—usually someone who has worked in a coal mine for at least 10 years.
Prevention and Treatment
Prevention is crucial because there is no cure for coal workers' pneumoconiosis. The disorder can be prevented by adequately suppressing coal dust at a work site. Ventilation systems may help. Face pieces (masks) that filter and purify the air may provide some additional benefit, but the protection is limited.
Doctors usually recommend that coal workers have chest x-rays every year, so that the disease can be detected at a relatively early stage. If the disease is detected, the worker should be transferred to an area where coal dust levels are low to help prevent progressive massive fibrosis. Coal workers who smoke are encouraged to stop. Workers may be given the pneumococcal vaccine and an annual influenza vaccination to help protect against infections to which workers may be more vulnerable.
SILICOSIS
Silicosis is an occupational lung disease that develops over time when dust that contains silica is inhaled into the lungs. Other examples of occupational lung disease include coalworker's pneumoconiosis and asbestosis.
Causes and risk factors
Silica in crystalline form is toxic to the lining of the lungs. When the two come into contact, a strong inflammatory reaction occurs. Over time this inflammation causes the lung tissue to become irreversibly thickened and scarred - a condition known as fibrosis.
Common sources of crystalline silica dust include:
· Sandstone
· Granite
· Slate
· Coal
· Pure silica sand
People who work with these materials, as well as foundry workers, potters and sandblasters, are most at risk. Other forms of silica, such as glass, are less of a health risk as they aren't as toxic to the lungs.
Men tend to be affected more often than women, as they are more likely to have been exposed to silica.
Silicosis is most commonly diagnosed in people over 40, as it usually takes years of exposure before the gradually progressive lung damage becomes apparent.
There are now fewer than 100 new cases of silicosis diagnosed each year in the UK. This is mostly the result of better working practices, such as wet drilling, appropriate ventilation, dust-control facilities, showers and the use of face masks. Many foundries are also replacing silica sand with synthetic materials.
With these measures and an increased awareness of the risks of silica exposure, the number of cases should fall even further in the future.
When silicosis is suspected, a chest x-ray will look for any damaged areas of the lungs to confirm the diagnosis. Lung function tests are often performed to assess the amount of damage the lungs have suffered and to guide treatment.
Symptoms
Damage to the lung tissue means the lungs can't perform their function of supplying oxygen to the blood as well as they should. The symptoms resulting from this include:
· a cough, with or without sputum
· shortness of breath, particularly on exertion
· chest tightness
In the most common form of the disease, chronic silicosis, these symptoms develop over many years of exposure. The lung tissue becomes irreversibly damaged by fibrosis and is replaced with solid nodules of scar tissue.
In the rarer form, acute silicosis, the symptoms develop quickly after only a short period of exposure to high levels of silica dust. People with this acute form usually die within a year.
The damage suffered by the lungs leaves a person susceptible to lung infections, in particular TB. Smoking not only aggravates the symptoms of silicosis but also speeds up the progress of the disease. For this reason, it's essential that those diagnosed with silicosis are helped to stop smoking.
Treatment and recovery
There's no cure for silicosis. It's essential, however, that the person affected removes any risk of further silica exposure and stops smoking. Prevention of any other lung disease which would further damage the remaining health lung tissue is important, so, immunisation against winter flu is recommended. People with silicosis should also be vaccinated against pneumococcal infection, a common cause of pneumonia.
Treatment to reduce inflammation and improve lung function may help and home oxygen therapy can be provided to help with breathing difficulties.
FARMER’S LUNG
Farmer's Lung is an allergic disease usually caused by breathing in the dust from moldy hay. However, dust from any moldy crop--straw, corn, silage, grain, or even tobacco--can also cause Farmer's Lung.
Causes and those at risk
People can get Farmer's Lung by breathing in dust containing the spores of special, heat-tolerating bacteria or moulds often found on moldy crops. Spores from two types of bacteria, "Micropolyspora faeni" and "Thermoactinomyces vulgaris", and certain types of moulds called "Aspergillus" are the major causes of Farmer's Lung.
In areas where crops are harvested in wet or rainy weather, crops usually undergo self-heating while in storage. When this happens, heat-tolerating bacteria and moulds grow rapidly and cause spoilage. As spoiled hay dries, it darkens, crumbles easily, and is extremely dusty. This dust that contains bacteria and mould spores is extremely fine. People can breathe these spores into the innermost regions of the lungs (alveoli) where the problem begins.
Farmer's Lung is a risk for adults who breathe dust from moldy hay or other moldy crops. For reasons not completely understood, children rarely develop Farmer's Lung.
Symptoms and signs
Acute Farmer's Lung
Acute Farmer's Lung is easy to notice and occurs in about one in three cases. It starts as an intense attack about 4 to 8 hours after the person breathes in a large amount of dust from moldy crops. These are some of the signs and symptoms:
· shortness of breath,
· a dry irritating cough,
· a sudden general feeling of sickness,
· fever and chills,
· a rapid heart rate, and
· rapid breathing.
If the person avoids further exposure to moldy dust, the signs and symptoms usually decrease after l2 hours, but they can last up to two weeks. Serious attacks can last as long as 12 weeks. The symptoms are sometimes confused with pneumonia.
Sub-Acute Farmer's Lung
Sub-acute Farmer's Lung is more common than acute Farmer's Lung but it is less intense and more difficult to notice. It develops slowly, responding to continual exposure to small amounts of moldy dust. The signs and symptoms include:
· coughing,
· shortness of breath,
· a mild fever and occasional chills,
· a general feeling of sickness,
· aches and pains in the muscles and joints, and
· a loss of appetite and loss of weight.
People who are sensitive to dust from moldy crops continue to exhibit these signs and symptoms as long as they are exposed to the dust. This condition sometimes resembles a "chest cold" that lingers throughout the winter. Some people lose weight over several weeks.
Chronic Farmer's Lung
Chronic Farmer's Lung develops after several acute attacks over a period of years. It afflicts people who have been continually exposed to large amounts of moldy dust. Sometimes, the illness lasts several months and is marked by increasing shortness of breath, an occasional mild fever, and often, a significant loss in weight and a general lack of energy. The symptoms are accompanied by permanent lung damage and gradually worsen as exposure to moldy dust continues.
Diagnostics
There is no single, simple test to distinguish between Farmer's Lung and other types of lung diseases. The most important evidence for Farmer's Lung is the history of exposure to dust from moldy hay or other moldy crops and the development of signs and symptoms 4 to 8 hours later. This is why it is so important for a doctor to know if a patient with shortness of breath has been exposed to moldy crops.
A physician may request a number of tests including:
a) a lung x-ray,
b) a blood test for antibodies,
c) a pulmonary lavage test to examine the contents in a small area of the lungs,
d) lung function tests to examine air flowing into the lungs and gas exchange from the lungs to the blood,
e) a lung allergy challenge test to identify the specific cause of the allergic reaction, and
f) a lung biopsy to examine lung tissue in more serious cases.
Treatment
For people suffering from acute attacks of Farmer's Lung, the first step in treatment is to avoid further contact with moldy dust. For serious cases, bed rest is recommended and oxygen therapy may be needed to relieve shortness of breath.
Certain medications provide relief from an allergic response during acute attacks and make breathing easier. The long-term use of these drugs is not advisable since they can hide the symptoms of Farmer's Lung without preventing lung damage from re-exposure to moldy dust.
No cure exists for people who become hypersensitive to moldy dust. Once people become hypersensitive, they remain hypersensitive for years, perhaps for life.
Prevention
There is no simple method to prevent conditions that lead to Farmer's Lung. Steps must be taken to avoid crop spoilage and production of bacterial or mould spores that cause the allergic reaction. Workers must also take precautions to avoid breathing in spores from moldy crops. The following measures are recommended:
· Wet hay, grain, or other crops can be dried at harvest. This is often an effective solution but it is seldom easy and usually expensive.
· If possible, hay with a high risk of spoilage should be stored in silage instead of bales.
· Buildings with large amounts of dusty material should be properly ventilated.
· Farm chores that involve handling hay or feed should be mechanized as much as possible to reduce exposure to moldy dust.
· During cleaning of barns or stables, dust from moldy crops should be wetted down before being swept to prevent it from becoming airborne.
SOURCES
http://en.wikipedia.org/wiki/Occupational_lung_disease
http://www.nhs.uk/Conditions/Asbestosis/
http://www.webmd.com/lung/berylliosis
http://www.healthlessonsonline.com/occupational-lung-disorders/
http://www.nlm.nih.gov/medlineplus/ency/article/000137.htm
http://www.merckmanuals.com/home/sec04/ch049/ch049f.html
http://www.bbc.co.uk/health/physical_health/conditions/silicosis1.shtml
MINISTRY OF EDUCATION AND SCIENCE OF UKRAINE
SUMY STATE UNIVERSITY
MEDICAL INSTITUTE
DEPARTMENT OF OCCUPATIONAL DISEASES
PULMONARY DISEASES IN OCCUPATIONAL DISEASES
Charles N. Macharia
Group 615
5th Course
Lecturer: Vladimir Stanislavovich
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