Medical Foundations of Workers’ Compensation Chemical Exposure Objective: This section will introduce the student to the topic of chemical exposure; related conditions will also be covered. Chemical Exposure Methods of Entry Typical Diagnoses Airway Diseases (Asthma vs Reactive Airway Disease Syndrome) Heavy Metal Poisoning Skin Diseases Interstititial Lung Diseases Other Chronic Diseases Tests Treatments/Prescriptions/Medication Outcomes 1 Medical Foundations of Workers’ Compensation Chemical Exposure Chemical Exposure Chemical exposure can occur in the workplace in a variety of settings, ranging from the use of cleaning solvents, the inhalation of smoke, “sick building syndrome” or from exposure to manufacturing materials. There are literally thousands of chemical exposure scenarios in the workplace. Methods of Entry Inhalation - The exposure to potentially harmful chemical, physical, or biological agents by inhaling them. Dermal Absorption: Absorption through the skin surface or through breaks in the skin such as in burns, atopic dermatitis, rashes, fresh cuts, abrasions, etc. Needlesticks – Infectious diseases: A substance gains entry into the body when a sharp needle breaks the skin. The substance can vary greatly and depending upon the circumstances and could transmit an infectious disease if previously used on an infected individual. Ingestion – Material taken into the body by swallowing and proceeding through the digestive tract. The ingested material may cause immediate burns to the mouth, esophagus or stomach, or, following the process of metabolism, could be converted into carcinogens or other types of harmful substances. Eyes – By vapor, gas, smoke, liquid or blunt trauma Typical Diagnoses Can include airway diseases, skin disorders, digestive conditions, renal problems and neurological damage. Airway Diseases Asthma, Irritant Induced (“RADS” Reactive Airways Dysfunction Syndrome) Asthma Asthma can be either an acute or chronic lung disease. With asthma, the airflow in and out of the lungs may be blocked by bronchial muscle squeezing and swelling and excess mucus. Asthma is characterized by episodes of obstructed breathing, which occur due to narrowing of the breathing passages, making it difficult to inhale but even more difficult to exhale. With mild asthma, the airways are relatively normal between attacks. In more severe asthma, there is some degree of constant airway constriction, with additional narrowing that occurs during an acute attack. 2 Individuals with asthma may react to certain factors (triggers) in the environment, which do not affect non-asthmatics. In response to a trigger, an asthmatic's airways become narrowed and inflamed, resulting in wheezing and/or coughing. Bronchitis Acute bronchitis is an inflammation of the mucous membranes lining the air passages of the lungs (bronchi). Both large and small airways can be involved, with swelling and fluid leakage. The condition is acute and limited in duration. The most common risk factor for developing acute bronchitis is a recent viral upper respiratory infection such as the common cold. The viral infection produces bronchial inflammation, which in turn can cause bronchitis and secondary bacterial infection. Environmental factors such as gases, fumes, chemicals, dust, and smoke may also contribute to the development of acute bronchitis. These irritants may cause or prolong an episode of acute bronchitis. Lung Cancer Lung cancer is also called carcinoma of the lung and refers to an abnormal growth within the lung tissue and the airways of the lungs (trachea and bronchi or tracheobronchial tree). Most lung cancers arise from the bronchial tree and are referred to as bronchogenic carcinoma. Lung cancer is classified into two major types according to the type of cell present in the tumor. These are small cell lung carcinoma (SCLC) and non small cell lung carcinoma (NSCLC). It is important to note that these are different types of cancer and have key differences in incidence, potential to spread, treatment options, and outcome. Heavy Metal Poisoning Manganese Manganese is often concentrated in cell mitochondria, mostly in the pituitary gland, liver, pancreas, kidney, and bone and is necessary to sustain life. However, there are limits to the amount of Manganese the body requires. In spite of our need for Manganese, certain levels or compounds containing Manganese are harmful. Mercury Mercury is used in many industrial applications and its salts have been employed therapeutically as purgatives, disinfectants, and astringents. It can be absorbed through the skin and mucous membranes which leads to mercury poisoning. Because of its toxicity, the clinical use of mercury and mercury-containing products is diminishing. Chromium A trace element that plays a role in glucose metabolism, however, some of its compounds have been listed as known carcinogens. Lead It is not normal to have lead in your body. However, since lead was widely used in the past, most people have at least small amounts of lead in their bodies. Lead can damage almost every organ system, with the most harm caused to the central nervous system, 3 kidneys, and blood. Arsenic It occurs throughout the universe, mostly in the form of metallic arsenides. Most forms are toxic. According to the Fourth Annual Report on Carcinogens (NTP 85-002, 1985), arsenic and certain arsenic compounds have been listed as known carcinogens. (From Merck Index, 11th ed) Skin Diseases Contact Dermatitis Contact dermatitis is a skin inflammation that comes in two forms, irritant and allergic, and occurs when the skin comes in direct contact with an irritating or allergenic substance, respectively. Irritant contact dermatitis can cause overly dry or moist skin conditions. Common irritants are detergents, nickel (found in jewelry and the fastenings of underclothes), certain chemicals, rubber gloves, certain cosmetics, and medications used on the skin (topical). Contact dermatitis caused by an irritant develops within minutes or hours (not days) after immediate exposure. Irritant contact dermatitis occurs more often in individuals whose work brings them into frequent contact with irritants such as soaps, detergents, chemicals, and abrasives. Individuals in certain outdoor and manufacturing occupations are at higher risk for exposure to allergens and irritants that may cause dermatitis. These substances can either erode the protective oily barriers of the skin or physically injure its surface. The irritant form accounts for 80% of all cases of contact dermatitis. Contact Urticaria Urticaria, commonly known as hives, is a skin reaction pattern characterized by the appearance of itchy, red, raised welts or lumps on the skin. They usually occur in batches. Urticaria that occurs in frequent, recurring episodes over a period of over 6 weeks is called chronic urticaria. Burns A burn is an injury to body tissues from exposure to heat (flames, hot liquids, steam, hot appliances), electricity (including lightning), chemicals (acidic or alkali, deployment of automobile airbags), and radiation (ultraviolet radiation, welding). Burns impair the skin's ability to prevent heat and water loss and protect against infection. Chemical burns account for about 10% of all burn injuries and occur as a result of exposure to acid or alkali chemicals or the deployment of automobile airbags. Interstitial Lung Diseases Pneumoconiosis Interstitial pneumonia is pneumonia located in the space around the alveoli (interstitial tissue). Pneumonia is a general term used for an infection of the lungs. This infection can be caused by a variety of microorganisms and results in an inflammatory reaction within the small air spaces of the lung (alveoli). The alveoli fill with fluid and white blood cells, interfering with the lung's ability to receive oxygen. This process can occur 4 gradually or quickly, depending on the potency of the infecting organism and the ability of the body's immune system to fight off the infection. Pneumonia can be mild enough to be cured with oral antibiotics and a few days rest, or severe enough to require hospitalization in an intensive care unit. Death may occur as a result of respiratory failure. Silicosis Silicosis is a lung disease caused by breathing dust that contains extremely fine particles of crystalline silica. Crystalline silica is a common mineral found in materials such as sand, quartz, concrete, masonry, and rock. As the body tries to eliminate these irritating particles, inflammation causes scarring of the lung tissue (pulmonary fibrosis). The result is less efficient transfer of oxygen and decreased lung capacity. The four different types of silicosis are chronic simple silicosis, chronic complicated silicosis, subacute silicosis, and acute silicosis. Chronic simple silicosis is generally without symptoms (asymptomatic) and is nonprogressive once exposure ends. It usually follows 10 to 12 years of silica dust exposure and is generally limited to small round spots in the lungs that show on x-ray. Chronic complicated silicosis tends to occur after 20 years or more of exposure. It has progressively worsening symptoms and the areas of lung damage continue to enlarge even after exposure ends. Subacute silicosis tends to occur after 3 to 6 years of heavy silica exposure and resembles chronic complicated silicosis. Acute silicosis can occur after less than 2 years of massive exposure and is clinically distinct from the other forms. Asbestosis Asbestosis is a chronic lung condition caused by inhalation of asbestos particles