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Occupational Lung Disease
Occupational lung diseases are work-related, lung conditions that have been caused or made worse by the materials a person is exposed to within the workplace. It includes a broad group of diseases, including occupational asthma, industrial bronchitis, chronic obstructive pulmonary disease (COPD), bronchiolitis obliterans, inhalation injury, interstitial lung diseases (such as pneumoconiosis, hypersensitivity pneumonitis, lung fibrosis), infections, lung cancer and mesothelioma. These diseases can be caused directly or due to immunological response to an exposure to a variety of dusts, chemicals, proteins or organisms. Occupational cases of interstitial lung disease may be misdiagnosed as COPD, idiopathic pulmonary fibrosis, or a myriad of other diseases; leading to a delay in identification of the causative agent. Types of occupational lung diseases Asthma Asthma is a respiratory disease that can begin or worsen due to exposure at work and is characterized by episodic narrowi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Occupational Asthma
Occupational asthma is new onset asthma or the recurrence of previously quiescent asthma directly caused by exposure to an agent at workplace. It is an occupational lung disease and a type of work-related asthma. Agents that can induce occupational asthma can be grouped into sensitizers and irritants. ''Sensitizer-induced'' occupational asthma is an immunologic form of asthma which occurs due to inhalation of specific substances (i.e., high-molecular-weight proteins from plants and animal origins, or low-molecular-weight agents that include chemicals, metals and wood dusts) and occurs after a latency period of several weeks to years. ''Irritant-induced'' (occupational) asthma is a non-immunologic form of asthma that results from a single or multiple high dose exposure to irritant products. It is usually develops early after exposure; however can also develop insidiously over a few months after a massive exposure to a complex mixture of alkaline dust and combustion products, as sho ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bronchiolitis Obliterans
Bronchiolitis obliterans (BO), also known as obliterative bronchiolitis, constrictive bronchiolitis and popcorn lung, is a disease that results in obstruction of the smallest airways of the lungs (bronchioles) due to inflammation. Symptoms include a dry cough, shortness of breath, wheezing and feeling tired. These symptoms generally get worse over weeks to months. It is not related to cryptogenic organizing pneumonia, previously known as bronchiolitis obliterans organizing pneumonia. Causes include breathing in toxic fumes, respiratory infections, connective tissue disorder or complications following a bone marrow or heart-lung transplant. Symptoms may not occur until two to eight weeks following toxic exposure or infection. The underlying mechanism involves inflammation that results in scar tissue formation. Diagnosis is by CT scan, pulmonary function tests or lung biopsy. A chest X-ray is often normal. While the disease is not reversible, treatments can slow further wors ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pleura
The pulmonary pleurae (''sing.'' pleura) are the two opposing layers of serous membrane overlying the lungs and the inside of the surrounding chest walls. The inner pleura, called the visceral pleura, covers the surface of each lung and dips between the lobes of the lung as ''fissures'', and is formed by the invagination of lung buds into each thoracic sac during embryonic development. The outer layer, called the parietal pleura, lines the inner surfaces of the thoracic cavity on each side of the mediastinum, and can be subdivided into ''mediastinal'' (covering the side surfaces of the fibrous pericardium, oesophagus and thoracic aorta), ''diaphragmatic'' (covering the upper surface of the diaphragm), ''costal'' (covering the inside of rib cage) and cervical (covering the underside of the suprapleural membrane) pleurae. The visceral and the mediastinal parietal pleurae are connected at the root of the lung ("hilum") through a smooth fold known as ''pleural reflections'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesothelium
The mesothelium is a membrane composed of simple squamous epithelial cells of mesodermal origin, which forms the lining of several body cavities: the pleura ( pleural cavity around the lungs), peritoneum ( abdominopelvic cavity including the mesentery, omenta, falciform ligament and the perimetrium) and pericardium (around the heart). Mesothelial tissue also surrounds the male testis (as the tunica vaginalis) and occasionally the spermatic cord (in a patent processus vaginalis). Mesothelium that covers the internal organs is called visceral mesothelium, while one that covers the surrounding body walls is called the parietal mesothelium. The mesothelium that secretes serous fluid as a main function is also known as a serosa. Origin Mesothelium derives from the embryonic mesoderm cell layer, that lines the coelom (body cavity) in the embryo. It develops into the layer of cells that covers and protects most of the internal organs of the body. Structure The mesotheli ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mesothelioma
Mesothelioma is a type of cancer that develops from the thin layer of tissue that covers many of the internal organs (known as the mesothelium). The most common area affected is the lining of the lungs and chest wall. Less commonly the lining of the abdomen and rarely the sac surrounding the heart, or the sac surrounding the testis may be affected. Signs and symptoms of mesothelioma may include shortness of breath due to fluid around the lung, a swollen abdomen, chest wall pain, cough, feeling tired, and weight loss. These symptoms typically come on slowly. More than 80% of mesothelioma cases are caused by exposure to asbestos. The greater the exposure the greater the risk. As of 2013, about 125 million people worldwide have been exposed to asbestos at work. High rates of disease occur in people who mine asbestos, produce products from asbestos, work with asbestos products, live with asbestos workers, or work in buildings containing asbestos. Asbestos exposure and the ons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypersensitivity
Hypersensitivity (also called hypersensitivity reaction or intolerance) refers to undesirable reactions produced by the normal immune system, including allergies and autoimmunity. They are usually referred to as an over-reaction of the immune system and these reactions may be damaging and uncomfortable. This is an immunologic term and is not to be confused with the psychiatric term of being hypersensitive which implies to an individual who may be overly sensitive to physical (i.e. sound, touch, light, etc.) and/or emotional stimuli. Although there is a relation between the two – studies have shown that those individuals that have ADHD (a psychiatric disorder) are more likely to have hypersensitivity reactions such as allergies, asthma, eczema than those who do not have ADHD. Hypersensitivity reactions can be classified into four types. Type I: IgE mediated immediate reaction Type II: Antibody-mediated reaction (IgG or IgM antibodies) Type III: Immune complex-mediated r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lung
The lungs are the primary organs of the respiratory system in humans and most other animals, including some snails and a small number of fish. In mammals and most other vertebrates, two lungs are located near the backbone on either side of the heart. Their function in the respiratory system is to extract oxygen from the air and transfer it into the bloodstream, and to release carbon dioxide from the bloodstream into the atmosphere, in a process of gas exchange. Respiration is driven by different muscular systems in different species. Mammals, reptiles and birds use their different muscles to support and foster breathing. In earlier tetrapods, air was driven into the lungs by the pharyngeal muscles via buccal pumping, a mechanism still seen in amphibians. In humans, the main muscle of respiration that drives breathing is the diaphragm. The lungs also provide airflow that makes vocal sounds including human speech possible. Humans have two lungs, one on the left an ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pulmonary Alveolus
A pulmonary alveolus (plural: alveoli, from Latin ''alveolus'', "little cavity"), also known as an air sac or air space, is one of millions of hollow, distensible cup-shaped cavities in the lungs where oxygen is exchanged for carbon dioxide. Alveoli make up the functional tissue of the mammalian lungs known as the lung parenchyma, which takes up 90 percent of the total lung volume. Alveoli are first located in the respiratory bronchioles that mark the beginning of the respiratory zone. They are located sparsely in these bronchioles, line the walls of the alveolar ducts, and are more numerous in the blind-ended alveolar sacs. The acini are the basic units of respiration, with gas exchange taking place in all the alveoli present. The alveolar membrane is the gas exchange surface, surrounded by a network of capillaries. Across the membrane oxygen is diffused into the capillaries and carbon dioxide released from the capillaries into the alveoli to be breathed out. Alveoli are ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inflammation
Inflammation (from la, inflammatio) is part of the complex biological response of body tissues to harmful stimuli, such as pathogens, damaged cells, or irritants, and is a protective response involving immune cells, blood vessels, and molecular mediators. The function of inflammation is to eliminate the initial cause of cell injury, clear out necrotic cells and tissues damaged from the original insult and the inflammatory process, and initiate tissue repair. The five cardinal signs are heat, pain, redness, swelling, and loss of function (Latin ''calor'', ''dolor'', ''rubor'', ''tumor'', and ''functio laesa''). Inflammation is a generic response, and therefore it is considered as a mechanism of innate immunity, as compared to adaptive immunity, which is specific for each pathogen. Too little inflammation could lead to progressive tissue destruction by the harmful stimulus (e.g. bacteria) and compromise the survival of the organism. In contrast, too much inflammation, in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hypersensitivity Pneumonitis
Hypersensitivity pneumonitis (HP) or extrinsic allergic alveolitis (EAA) is a syndrome caused by the repetitive inhalation of antigens from the environment in susceptible or sensitized people. Common antigens include molds, bacteria, bird droppings, bird feathers, agricultural dusts, bioaerosols and chemicals from paints or plastics. People affected by this type of lung inflammation ( pneumonitis) are commonly exposed to the antigens by their occupations, hobbies, the environment and animals. The inhaled antigens produce a hypersensitivity immune reaction causing inflammation of the airspaces (alveoli) and small airways ( bronchioles) within the lung. Hypersensitivity pneumonitis may eventually lead to interstitial lung disease. Signs and symptoms Hypersensitivity pneumonitis (HP) can be categorized as acute, subacute, and chronic based on the duration of the illness. Acute In the acute form of HP dose of antigen exposure tends to be very high but only for a short duration. Sympt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Coal Dust
Coal dust is a fine powdered form of which is created by the crushing, grinding, or pulverizing of coal. Because of the brittle nature of coal, coal dust can be created during mining, transportation, or by mechanically handling coal. It is a form of fugitive dust. Grinding coal to dust before combusting it improves the speed and efficiency of burning and makes the coal easier to handle. However, coal dust is hazardous to workers if it is suspended in air outside the controlled environment of grinding and combustion equipment. It poses the acute hazard of forming an explosive mixture in air and the chronic hazard of causing pulmonary illness in people who inhale excessive quantities of it. The distribution of the particle-size of coal dust is frequently measured in mesh. The British slang term for cheap fuel consisting of coal dust (slack) containing small lumps of coal (nuts) is nutty slack. Risks The Occupational Safety and Health Administration (OSHA) has set the legal limi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Silica
Silicon dioxide, also known as silica, is an oxide of silicon with the chemical formula , most commonly found in nature as quartz and in various living organisms. In many parts of the world, silica is the major constituent of sand. Silica is one of the most complex and most abundant families of materials, existing as a compound of several minerals and as a synthetic product. Notable examples include fused quartz, fumed silica, silica gel, opal and aerogels. It is used in structural materials, microelectronics (as an electrical insulator), and as components in the food and pharmaceutical industries. Structure In the majority of silicates, the silicon atom shows tetrahedral coordination, with four oxygen atoms surrounding a central Si atomsee 3-D Unit Cell. Thus, SiO2 forms 3-dimensional network solids in which each silicon atom is covalently bonded in a tetrahedral manner to 4 oxygen atoms. In contrast, CO2 is a linear molecule. The starkly different structures of th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
