Pneumoconiosis is a lung condition caused by the inhalation of dust, characterized by formation of nodular fibrotic changes in lungs. The heart in relation to the lungs (from an older edition of Grays Anatomy) This x-ray of the human chest shows the lungs as dark regions The lung is an organ belonging to the respiratory system and interfacing to the circulatory system of air-breathing vertebrates. ... Fibrosis is the formation or development of excess fibrous connective tissue in an organ or tissue as a reparative or reactive process, as opposed to formation of fibrous tissue as a normal constituent of an organ or tissue. ...

Many substances can cause pneumoconiosis including asbestos, silica, talc and metals. Asbestos (Greek a-, not; sbestos, extinguishable) is a group of fibrous metamorphic minerals. ... The chemical compound silicon dioxide, also known as silica, is the oxide of silicon, chemical formula SiO2. ... Talc block Talc is a mineral composed of hydrated magnesium silicate with the chemical formula H2Mg3(SiO3)4 or Mg3Si4O10(OH)2. ... In chemistry, a metal (Greek: Metallon) is an element that readily forms ions (cations) and has metallic bonds, and it is sometimes said that it is similar to a cation in a cloud of electrons. ...

Depending on the type of dust, variants of the disease are considered. For example there are silicosis, also known as grinders' disease; and pneumosilicosis, which is caused by the inhalation of the dust of stone, sand, or flint containing silica. Because many common minerals contain silica, there are different types of silicosis.

The term Pneumonoultramicroscopicsilicovolcanoconiosis and some variants thereof turned out to be a hoax created as a word puzzle. The word pneumonoultramicroscopicsilicovolcanoconiosis is defined as a lung disease caused by the inhalation of very fine silica dust, mostly found in volcanos. Etymology: Pneumono = Related to lungs (Latin) Ultra = Very (Latin) microscopic = Extremely small (Latin/Old English) silico = Silica (Latin) volcano = Volcano (Latin) coni = related to dust (Greek: konis, dust...

Incidents

The Hawk's Nest incident was one of the earliest and most prominent incidents of large-scale silicosis deaths. But while stringent occupational reforms have largely eliminated it in Europe, the US National Institute for Occupational Safety and Health (NIOSH) estimates that a million workers remain at risk to silicosis, 100,000 of whom are at high risk. They estimate 59,000 will develop adverse effects. The Hawks Nest Incident involved injuries and deaths as the result of the construction of the Hawks Nest Tunnel near Gauley Bridge, West Virginia as part of a hydroelectric project. ... The National Institute for Occupational Safety and Health (NIOSH) is the United States federal agency responsible for conducting research and making recommendations for the prevention of work-related injury and illness. ...

But due to pressure from industry groups, its effects are little known and hardly acted upon. A 1992 Houston Chronicle investigation found "silicosis is often misdiagnosed by doctors, disdained by industry officials and unknown to the very workers who stand the greatest chance of getting it. ... Old warnings and medical studies have been ignored, products falsely advertised and government rules flouted--especially with regard to sandblasting, an activity so hazardous that NIOSH recommended its banning in 1974." 1992 is a leap year starting on Wednesday of the Gregorian calendar. ... The Houston Chronicle is a daily newspaper in Houston, Texas. ... Sandblasting is a generic term for the process of smoothing, shaping and cleaning a hard surface by forcing solid particles across that surface at high speeds. ...

Black lung disease

Black lung disease, also known as coal miners' pneumoconiosis, is caused by long exposure to coal dust. Since dust that enters the lungs can neither be destroyed or removed by the body, it remains, causing inflammation and scarring (fibrosis). The most usual symptom is shortness of breath; it can also lead to emphysema and heart failure. Coal is a fossil fuel extracted from the ground either by underground mining, open-pit mining or strip mining. ... The heart and lungs (from an older edition of Grays Anatomy) The heart (Latin cor) is a hollow, muscular organ that pumps blood through the blood vessels by repeated, rhythmic contractions. ...

It is a common affliction of coal miners and others who work with coal, similar to silicosis from inhaling silica dust, and to the long term effects of tobacco smoking. Species N. acuminata N. clevelandii N. forgetiana N. glauca N. knightiana N. langsdorffii N. longiflora N. obtusifolia N. paniculata N. plumbagifolia N. quadrivalvis N. rustica N. × sanderae N. suaveolens N. sylvestris N. tabacum Ref: ITIS 30562 as of 2002-08-28 Tobacco () is a broad-leafed plant of the nightshade...

Pathology

Continuous accumulation of collagen around inhaled silica crystals produces pulmonary fibrotic hyalinized (silicotic) nodules. Microscopically, they present concentric laminated collagen fibers (blue) and tend to become confluent, compressing adjacent alveola. Silica crystals appear as empty cleft-like spaces. With progression, perivascular and peribronchic fibrosis (collagen deposits) will produce pulmonary hypertension and respiratory failure.

External links

Image of Silicotic nodules (http://www.pathologyatlas.ro/Silicosis%20Pneumoconiosis.html)