The trachea, also known as the windpipe, is a cartilaginous tube that connects the larynx to the bronchi of the lungs, allowing the passage of air, and so is present in almost all animals with lungs. The trachea extends from the larynx and branches into the two primary bronchi. At the top of the trachea the cricoid cartilage attaches it to the larynx. The trachea is formed by a number of horseshoe-shaped rings, joined together vertically by overlying ligaments, and by the trachealis muscle at their ends. The epiglottis closes the opening to the larynx during swallowing.
Berylliosis, or chronic beryllium disease (CBD), is a chronic allergic-type lung response and chronic lung disease caused by exposure to beryllium and its compounds, a form of beryllium poisoning. It is distinct from acute beryllium poisoning, which became rare following occupational exposure limits established around 1950. Berylliosis is an occupational lung disease.
The respiratory tract is the subdivision of the respiratory system involved with the process of respiration in mammals. The respiratory tract is lined with respiratory epithelium as respiratory mucosa.
Pulmonary aspiration is the entry of material such as pharyngeal secretions, food or drink, or stomach contents from the oropharynx or gastrointestinal tract, into the larynx and lower respiratory tract, the portions of the respiratory system from the trachea (windpipe) to the lungs. A person may inhale the material, or it may be delivered into the tracheobronchial tree during positive pressure ventilation. When pulmonary aspiration occurs during eating and drinking, the aspirated material is often colloquially referred to as "going down the wrong pipe".
The epiglottis is a leaf-shaped flap in the throat that prevents food and water from entering the trachea and the lungs. It stays open during breathing, allowing air into the larynx. During swallowing, it closes to prevent aspiration of food into the lungs, forcing the swallowed liquids or food to go along the esophagus toward the stomach instead. It is thus the valve that diverts passage to either the trachea or the esophagus.
Nanomaterials describe, in principle, materials of which a single unit is sized between 1 and 100 nm.
Pneumonitis describes general inflammation of lung tissue. Possible causative agents include radiation therapy of the chest, exposure to medications used during chemo-therapy, the inhalation of debris, aspiration, herbicides or fluorocarbons and some systemic diseases. If unresolved, continued inflammation can result in irreparable damage such as pulmonary fibrosis.
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, 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.
Nanotoxicology is the study of the toxicity of nanomaterials. Because of quantum size effects and large surface area to volume ratio, nanomaterials have unique properties compared with their larger counterparts that affect their toxicity. Of the possible hazards, inhalation exposure appears to present the most concern, with animal studies showing pulmonary effects such as inflammation, fibrosis, and carcinogenicity for some nanomaterials. Skin contact and ingestion exposure are also a concern.
Ultrafine particles (UFPs) are particulate matter of nanoscale size (less than 0.1 μm or 100 nm in diameter). Regulations do not exist for this size class of ambient air pollution particles, which are far smaller than the regulated PM10 and PM2.5 particle classes and are believed to have several more aggressive health implications than those classes of larger particulates. In the EU UFP's in ambient air are empirically defined by a technical specification. The important detail is the definition of size, stated: "The lower and upper sizes considered within this document are 7 nm and a few micrometres, respectively". Although the most common referral to UFP is "less than 0.1μm", this is incorrect for ambient air in the EU.
The Institute of Occupational Medicine (IOM) was founded in 1969 by the National Coal Board (NCB) as an independent charity in Edinburgh, UK and retains its charitable purpose and status today. The "Institute" has a subsidiary, IOM Consulting Limited, which became fully independent in 1990 and now celebrates its 25th year within the IOM Group as an independent consultancy and also the commercial part of the IOM organization. It specializes in asbestos surveys and services, occupational hygiene services, nanotechnology safety, laboratory analysis and expert witness consulting services. IOM is therefore one of the UK's major independent "not for profit" centres of scientific excellence in the fields of environmental health, occupational hygiene and occupational safety. Its mission is to benefit those at work and in the community by providing quality research, consultancy, surveys, analysis and training and by maintaining an independent, impartial position as an international centre of excellence.
Inhalation is a major route of exposure that occurs when an individual breathes in polluted air which enters the respiratory tract. Identification of the pollutant uptake by the respiratory system can determine how the resulting exposure contributes to the dose. In this way, the mechanism of pollutant uptake by the respiratory system can be used to predict potential health impacts within the human population.
Acute inhalation injury may result from frequent and widespread use of household cleaning agents and industrial gases. The airways and lungs receive continuous first-pass exposure to non-toxic and irritant or toxic gases via inhalation. Irritant gases are those that, on inhalation, dissolve in the water of the respiratory tract mucosa and provoke an inflammatory response, usually from the release of acidic or alkaline radicals. Smoke, chlorine, phosgene, sulfur dioxide, hydrogen chloride, hydrogen sulfide, nitrogen dioxide, ozone, and ammonia are common irritants.
Chlorine gas poisoning is an illness resulting from the effects of exposure to chlorine beyond the threshold limit value.
Occupational toxicology is the application of toxicology to chemical hazards in the workplace. It focuses on substances and conditions that occur in workplaces, where inhalation exposure and dermal exposure are most important, there is often exposure to mixtures of chemicals whose interactions are complex, health effects are influenced or confounded by other environmental and individual factors, and there is a focus on identifying early adverse affects that are more subtle than those presented in clinical medicine.
Toxicology of carbon nanomaterials is the study of toxicity in carbon nanomaterials like fullerenes and carbon nanotubes.
Intratracheal instillation is the introduction of a substance directly into the trachea. It is widely used to test the respiratory toxicity of a substance as an alternative to inhalation in animal testing. Intratracheal instillation was reported as early as 1923 in studies of the carcinogenicity of coal tar. Modern methodology was developed by several research groups in the 1970s. By contrast, tracheal administration of pharmaceutical drugs in humans is called endotracheal administration.
The health and safety hazards of nanomaterials include the potential toxicity of various types of nanomaterials, as well as fire and dust explosion hazards. Because nanotechnology is a recent development, the health and safety effects of exposures to nanomaterials, and what levels of exposure may be acceptable, are subjects of ongoing research. Of the possible hazards, inhalation exposure appears to present the most concern, with animal studies showing pulmonary effects such as inflammation, fibrosis, and carcinogenicity for some nanomaterials. Skin contact and ingestion exposure, and dust explosion hazards, are also a concern.
A radioactive nanoparticle is a nanoparticle that contains radioactive materials. Radioactive nanoparticles have applications in medical diagnostics, medical imaging, toxicokinetics, and environmental health, and are being investigated for applications in nuclear nanomedicine. Radioactive nanoparticles present special challenges in operational health physics and internal dosimetry that are not present for other substances, although existing radiation protection measures and hazard controls for nanoparticles generally apply.
Titanium dioxide nanoparticles, also called ultrafine titanium dioxide or nanocrystalline titanium dioxide or microcrystalline titanium dioxide, are particles of titanium dioxide with diameters less than 100 nm. Ultrafine TiO2 is used in sunscreens due to its ability to block ultraviolet radiation while remaining transparent on the skin. It is in rutile crystal structure and coated with silica or/and alumina to prevent photocatalytic phenomena. The health risks of ultrafine TiO2 from dermal exposure on intact skin are considered extremely low, and it is considered safer than other substances used for ultraviolet protection.
