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Dust is made of
fine Fine may refer to: Characters * Sylvia Fine (''The Nanny''), Fran's mother on ''The Nanny'' * Officer Fine, a character in ''Tales from the Crypt'', played by Vincent Spano Legal terms * Fine (penalty), money to be paid as punishment for an offe ...
particle In the Outline of physical science, physical sciences, a particle (or corpuscule in older texts) is a small wikt:local, localized physical body, object which can be described by several physical property, physical or chemical property, chemical ...
s of solid
matter In classical physics and general chemistry, matter is any substance that has mass and takes up space by having volume. All everyday objects that can be touched are ultimately composed of atoms, which are made up of interacting subatomic partic ...
. On Earth, it generally consists of particles in the
atmosphere An atmosphere () is a layer of gas or layers of gases that envelop a planet, and is held in place by the gravity of the planetary body. A planet retains an atmosphere when the gravity is great and the temperature of the atmosphere is low. A s ...
that come from various sources such as
soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...
lifted by wind (an
aeolian process Aeolian processes, also spelled eolian, pertain to wind activity in the study of geology and weather and specifically to the wind's ability to shape the surface of the Earth (or other planets). Winds may erode, transport, and deposit materials ...
),
volcanic eruptions Several types of volcanic eruptions—during which lava, tephra (ash, lapilli, volcanic bombs and volcanic blocks), and assorted gases are expelled from a volcanic vent or fissure—have been distinguished by volcanologists. These are often ...
, and
pollution Pollution is the introduction of contaminants into the natural environment that cause adverse change. Pollution can take the form of any substance (solid, liquid, or gas) or energy (such as radioactivity, heat, sound, or light). Pollutants, the ...
. Dust in homes is composed of about 20–50% dead
skin Skin is the layer of usually soft, flexible outer tissue covering the body of a vertebrate animal, with three main functions: protection, regulation, and sensation. Other cuticle, animal coverings, such as the arthropod exoskeleton, have diffe ...
cells Cell most often refers to: * Cell (biology), the functional basic unit of life Cell may also refer to: Locations * Monastic cell, a small room, hut, or cave in which a religious recluse lives, alternatively the small precursor of a monastery w ...
. The rest, and in offices, and other human environments is composed of small amounts of plant
pollen Pollen is a powdery substance produced by seed plants. It consists of pollen grains (highly reduced microgametophytes), which produce male gametes (sperm cells). Pollen grains have a hard coat made of sporopollenin that protects the gametophyt ...
, human
hair Hair is a protein filament that grows from follicles found in the dermis. Hair is one of the defining characteristics of mammals. The human body, apart from areas of glabrous skin, is covered in follicles which produce thick terminal and f ...
s, animal
fur Fur is a thick growth of hair that covers the skin of mammals. It consists of a combination of oily guard hair on top and thick underfur beneath. The guard hair keeps moisture from reaching the skin; the underfur acts as an insulating blanket t ...
,
textile Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, different fabric types, etc. At first, the word "textiles" only referred to woven fabrics. However, weaving is not the ...
fibers,
paper Paper is a thin sheet material produced by mechanically or chemically processing cellulose fibres derived from wood, rags, grasses or other vegetable sources in water, draining the water through fine mesh leaving the fibre evenly distributed ...
fibers,
mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid chemical compound with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. ( ...
s from outdoor soil, burnt
meteorite A meteorite is a solid piece of debris from an object, such as a comet, asteroid, or meteoroid, that originates in outer space and survives its passage through the atmosphere to reach the surface of a planet or Natural satellite, moon. When the ...
particles, and many other
material Material is a substance or mixture of substances that constitutes an object. Materials can be pure or impure, living or non-living matter. Materials can be classified on the basis of their physical and chemical properties, or on their geologi ...
s which may be found in the local environment.


Atmospheric

Atmospheric or wind-borne
fugitive dust Fugitive dust is an environmental air quality term for very small particles suspended in the air, primarily mineral dust that is sourced from the soil of Earth's pedosphere. A significant volume of fugitive dust that is visible from a distance i ...
, also known as ''aeolian dust'', comes from arid and dry regions where high velocity winds are able to remove mostly silt-sized material, deflating susceptible surfaces. This includes areas where
grazing In agriculture, grazing is a method of animal husbandry whereby domestic livestock are allowed outdoors to roam around and consume wild vegetations in order to convert the otherwise indigestible (by human gut) cellulose within grass and other ...
,
plough A plough or plow ( US; both ) is a farm tool for loosening or turning the soil before sowing seed or planting. Ploughs were traditionally drawn by oxen and horses, but in modern farms are drawn by tractors. A plough may have a wooden, iron or ...
ing,
vehicle A vehicle (from la, vehiculum) is a machine that transports people or cargo. Vehicles include wagons, bicycles, motor vehicles (motorcycles, cars, trucks, buses, mobility scooters for disabled people), railed vehicles (trains, trams), wa ...
use, and other
human behavior Human behavior is the potential and expressed capacity ( mentally, physically, and socially) of human individuals or groups to respond to internal and external stimuli throughout their life. Kagan, Jerome, Marc H. Bornstein, and Richard M. L ...
s have further destabilized the
land Land, also known as dry land, ground, or earth, is the solid terrestrial surface of the planet Earth that is not submerged by the ocean or other bodies of water. It makes up 29% of Earth's surface and includes the continents and various islan ...
, though not all source areas have been largely affected by anthropogenic impacts. One-third of the global land area is covered by dust-producing surfaces, made up of hyper-arid regions like the
Sahara , photo = Sahara real color.jpg , photo_caption = The Sahara taken by Apollo 17 astronauts, 1972 , map = , map_image = , location = , country = , country1 = , ...
which covers 0.9 billion hectares, and
drylands Drylands are defined by a scarcity of water. Drylands are zones where precipitation is balanced by evaporation from surfaces and by transpiration by plants (evapotranspiration). The United Nations Environment Program defines drylands as tropical ...
which occupy 5.2 billion hectares. Dust in the atmosphere is produced by saltation and abrasive sandblasting of sand-sized grains, and it is transported through the
troposphere The troposphere is the first and lowest layer of the atmosphere of the Earth, and contains 75% of the total mass of the planetary atmosphere, 99% of the total mass of water vapour and aerosols, and is where most weather phenomena occur. From ...
. This airborne dust is considered an
aerosol An aerosol is a suspension (chemistry), suspension of fine solid particles or liquid Drop (liquid), droplets in air or another gas. Aerosols can be natural or Human impact on the environment, anthropogenic. Examples of natural aerosols are fog o ...
and once in the atmosphere, it can produce strong local
radiative forcing Radiative forcing (or climate forcing) is the change in energy flux in the atmosphere caused by natural or anthropogenic factors of climate change as measured by watts / metre2. It is a scientific concept used to quantify and compare the external ...
. Saharan dust, in particular, can be transported and deposited as far as the
Caribbean The Caribbean (, ) ( es, El Caribe; french: la Caraïbe; ht, Karayib; nl, De Caraïben) is a region of the Americas that consists of the Caribbean Sea, its islands (some surrounded by the Caribbean Sea and some bordering both the Caribbean Se ...
and the
Amazon basin The Amazon basin is the part of South America drained by the Amazon River and its tributaries. The Amazon drainage basin covers an area of about , or about 35.5 percent of the South American continent. It is located in the countries of Bolivi ...
, and may affect air
temperature Temperature is a physical quantity that expresses quantitatively the perceptions of hotness and coldness. Temperature is measured with a thermometer. Thermometers are calibrated in various temperature scales that historically have relied o ...
s, cause ocean cooling, and alter rainfall amounts.


Middle East

Dust in the Middle East has been a historic phenomenon. Recently, because of
climate change In common usage, climate change describes global warming—the ongoing increase in global average temperature—and its effects on Earth's climate system. Climate change in a broader sense also includes previous long-term changes to E ...
and the escalating process of
desertification Desertification is a type of land degradation in drylands in which biological productivity is lost due to natural processes or induced by human activities whereby fertile areas become increasingly arid. It is the spread of arid areas caused by ...
, the problem has worsened dramatically. As a multi-factor phenomenon, there is not yet a clear consensus on the sources or potential solutions to the problem. In Iran, the dust is already affecting more than 5 million people directly, and has emerged as a serious government issue in recent years. In the
Khuzestan Province Khuzestan Province (also spelled Xuzestan; fa, استان خوزستان ''Ostān-e Xūzestān'') is one of the 31 provinces of Iran. It is in the southwest of the country, bordering Iraq and the Persian Gulf. Its capital is Ahvaz and it covers ...
, it has led to the severe increase of
air pollution Air pollution is the contamination of air due to the presence of substances in the atmosphere that are harmful to the health of humans and other living beings, or cause damage to the climate or to materials. There are many different types ...
. The amount of
pollutant A pollutant or novel entity is a substance or energy introduced into the environment that has undesired effects, or adversely affects the usefulness of a resource. These can be both naturally forming (i.e. minerals or extracted compounds like oi ...
s in the air has surpassed more than 50 times the normal level several times in a year. Recently, initiatives such as Project-Dust have been established to directly study dust in the Middle East.


Roads

Dust kicked up by vehicles traveling on
road A road is a linear way for the conveyance of traffic that mostly has an improved surface for use by vehicles (motorized and non-motorized) and pedestrians. Unlike streets, the main function of roads is transportation. There are many types of ...
s may make up 33% of air pollution. Road dust consists of deposits of vehicle and industrial
exhaust gas Exhaust gas or flue gas is emitted as a result of the combustion of fuels such as natural gas, gasoline (petrol), diesel fuel, fuel oil, biodiesel blends, or coal. According to the type of engine, it is discharged into the atmosphere through an ...
, particles from
tire A tire (American English) or tyre (British English) is a ring-shaped component that surrounds a Rim (wheel), wheel's rim to transfer a vehicle's load from the axle through the wheel to the ground and to provide Traction (engineering), t ...
and
brake A brake is a mechanical device that inhibits motion by absorbing energy from a moving system. It is used for slowing or stopping a moving vehicle, wheel, axle, or to prevent its motion, most often accomplished by means of friction. Background ...
wear, dust from paved roads or
pothole A pothole is a depression in a road surface, usually asphalt pavement, where traffic has removed broken pieces of the pavement. It is usually the result of water in the underlying soil structure and traffic passing over the affected area. Water ...
s, and dust from
construction Construction is a general term meaning the art and science to form objects, systems, or organizations,"Construction" def. 1.a. 1.b. and 1.c. ''Oxford English Dictionary'' Second Edition on CD-ROM (v. 4.0) Oxford University Press 2009 and com ...
sites. Road dust is a significant contributor to the generation and release of
particulates Particulates – also known as atmospheric aerosol particles, atmospheric particulate matter, particulate matter (PM) or suspended particulate matter (SPM) – are microscopic particles of solid or liquid matter suspended in the air. The ter ...
into the atmosphere. Control of road dust is a significant challenge in
urban area An urban area, built-up area or urban agglomeration is a human settlement with a high population density and infrastructure of built environment. Urban areas are created through urbanization and are categorized by urban morphology as cities, t ...
s, and also in other locations with high levels of vehicular traffic upon unsealed roads, such as mines and
landfill A landfill site, also known as a tip, dump, rubbish dump, garbage dump, or dumping ground, is a site for the disposal of waste materials. Landfill is the oldest and most common form of waste disposal, although the systematic burial of the waste ...
s. Road dust may be suppressed by mechanical methods like
street sweeper A street sweeper or street cleaner may refer to a person's occupation or to a machine that cleans streets. Street sweepers have been employed in cities as "sanitation workers" since sanitation and waste removal became a priority. A stre ...
, vehicles equipped with
vacuum cleaner A vacuum cleaner, also known simply as a vacuum or a hoover, is a device that causes suction in order to remove dirt from floors, upholstery, draperies, and other surfaces. It is generally electrically driven. The dirt is collected by either a ...
s,
vegetable oil Vegetable oils, or vegetable fats, are oils extracted from seeds or from other parts of fruits. Like animal fats, vegetable fats are ''mixtures'' of triglycerides. Soybean oil, grape seed oil, and cocoa butter are examples of seed oils, or fat ...
sprays, or with water sprayers.
Calcium chloride Calcium chloride is an inorganic compound, a salt with the chemical formula . It is a white crystalline solid at room temperature, and it is highly soluble in water. It can be created by neutralising hydrochloric acid with calcium hydroxide. Ca ...
can be used. Improvements in
automotive engineering Automotive engineering, along with aerospace engineering and naval architecture, is a branch of vehicle engineering, incorporating elements of mechanical, electrical, electronic, software, and safety engineering as applied to the design, manufactu ...
have reduced the amount of PM10s produced by road traffic; the proportion representing re-suspension of existing particulates has increased as a result.


Coal

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 o ...
is responsible for the
respiratory disease Respiratory diseases, or lung diseases, are pathology, pathological conditions affecting the organs and tissues that make gas exchange difficult in Breathing, air-breathing animals. They include conditions of the respiratory tract including the t ...
known as
pneumoconiosis Pneumoconiosis is the general term for a class of interstitial lung disease where inhalation of dust ( for example, ash dust, lead particles, pollen grains etc) has caused interstitial fibrosis. The three most common types are asbestosis, silicos ...
, including
Coalworker's pneumoconiosis Coal workers' pneumoconiosis (CWP), also known as black lung disease or black lung, is an occupational type of pneumoconiosis caused by long-term exposure to coal dust. It is common in coal miners and others who work with coal. It is similar to b ...
disease that occurs among
coal miners People have worked as coal miners for centuries, but they became increasingly important during the Industrial revolution when coal was burnt on a large scale to fuel stationary and locomotive engines and heat buildings. Owing to coal's strategic ro ...
. The danger of coal dust resulted in
environmental law Environmental law is a collective term encompassing aspects of the law that provide protection to the environment. A related but distinct set of regulatory regimes, now strongly influenced by environmental legal principles, focus on the manage ...
regulating workplace air quality in some jurisdictions. In addition, if enough coal dust is dispersed within the air in a given area, in very rare circumstances, it can cause a
dust explosion A dust explosion is the rapid combustion of fine particles suspended in the air within an enclosed location. Dust explosions can occur where any dispersed powdered combustible material is present in high-enough concentrations in the atmosphere or ...
. These circumstances are typically within confined spaces.


Control


Atmospheric

Most governmental Environmental Protection Agencies, including the
United States Environmental Protection Agency The Environmental Protection Agency (EPA) is an independent executive agency of the United States federal government tasked with environmental protection matters. President Richard Nixon proposed the establishment of EPA on July 9, 1970; it be ...
(EPA) mandate that facilities that generate fugitive dust, minimize or mitigate the production of dust in their operation. The most frequent dust control violations occur at new residential housing developments in urban areas. United States federal law requires that construction sites obtain
planning permission Planning permission or developmental approval refers to the approval needed for construction or expansion (including significant renovation), and sometimes for demolition, in some jurisdictions. It is usually given in the form of a building perm ...
s to conduct earth moving and clearing of areas, so that plans to control dust emissions while the work is being carried out are specified. Control measures include such simple practices as spraying construction and
demolition Demolition (also known as razing, cartage, and wrecking) is the science and engineering in safely and efficiently tearing down of buildings and other artificial structures. Demolition contrasts with deconstruction, which involves taking a ...
sites with water, and preventing the tracking of dust onto adjacent roads. Some of the issues include: *Reducing dust related health risks that include
allergic Allergies, also known as allergic diseases, refer a number of conditions caused by the hypersensitivity of the immune system to typically harmless substances in the environment. These diseases include hay fever, food allergies, atopic derma ...
reactions,
pneumonia Pneumonia is an inflammatory condition of the lung primarily affecting the small air sacs known as alveoli. Symptoms typically include some combination of productive or dry cough, chest pain, fever, and difficulty breathing. The severity ...
and
asthma Asthma is a long-term inflammatory disease of the airways of the lungs. It is characterized by variable and recurring symptoms, reversible airflow obstruction, and easily triggered bronchospasms. Symptoms include episodes of wheezing, cou ...
tic attacks. *Improving
visibility The visibility is the measure of the distance at which an object or light can be clearly discerned. In meteorology it depends on the transparency of the surrounding air and as such, it is unchanging no matter the ambient light level or time of ...
and
road traffic safety Road traffic safety refers to the methods and measures used to prevent road users from being killed or seriously injured. Typical road users include pedestrians, cyclists, motorists, vehicle passengers, horse riders, and passengers of on-road ...
. *Providing cleaner air, cleaner vehicles and cleaner homes and promoting better health. *Improving
agricultural productivity Agricultural productivity is measured as the ratio of agricultural outputs to inputs. While individual products are usually measured by weight, which is known as crop yield, varying products make measuring overall agricultural output difficu ...
. *Reducing vehicle maintenance costs by lowering the levels of dust that clog filters, bearings and machinery. *Reducing driver fatigue, maintenance on
car suspension Suspension is the system of tires, tire air, springs, shock absorbers and linkages that connects a vehicle to its wheels and allows relative motion between the two. Suspension systems must support both road holding/ handling and ride ...
systems and improving
fuel economy in automobiles The fuel economy of an automobile relates distance traveled by a vehicle and the amount of fuel consumed. Consumption can be expressed in terms of volume of fuel to travel a distance, or the distance traveled per unit volume of fuel consumed. S ...
. *Increasing cumulative effects—each new application builds on previous progress. US federal laws require dust control on sources such as vacant lots, unpaved
parking lot A parking lot (American English) or car park (British English), also known as a car lot, is a cleared area intended for parking vehicles. The term usually refers to an area dedicated only for parking, with a durable or semi-durable surface ...
s, and
dirt road A dirt road or track is a type of unpaved road not paved with asphalt, concrete, brick, or stone; made from the native material of the land surface through which it passes, known to highway engineers as subgrade material. Dirt roads are suitable ...
s. Dust in such places may be suppressed by mechanical methods, including paving or laying down
gravel Gravel is a loose aggregation of rock fragments. Gravel occurs naturally throughout the world as a result of sedimentary and erosive geologic processes; it is also produced in large quantities commercially as crushed stone. Gravel is classifi ...
, or stabilizing the surface with water, vegetable oils or other dust suppressants, or by using water misters to suppress dust that is already airborne.


Domestic

Dust control is the suppression of solid particles with diameters less than 500micrometers (''i.e.'' half a millimeter). Dust poses a health risk to children, older people, and those with respiratory diseases. House dust can become airborne easily. Care is required when removing dust to avoid causing the dust to become airborne. A
feather duster A feather duster is a cleaning tool that is typically made from a wooden dowel handle onto which ostrich feathers are wound with a wire. The feathers are most often long. Some dusters have a retractable casing instead of a dowel handle and thes ...
tends to agitate the dust so it lands elsewhere. Certified
HEPA HEPA (, high-efficiency particulate air) filter, also known as high-efficiency particulate absorbing filter and high-efficiency particulate arrestance filter, is an efficiency standard of air filters. Filters meeting the HEPA standard must sa ...
(tested to MIL STD 282) can effectively trap 99.97% of dust at 0.3 micrometers. Not all HEPA filters can effectively stop dust; while vacuum cleaners with HEPA filters, water, or cyclones may filter more effectively than without, they may still exhaust millions of particles per cubic foot of air circulated.
Central vacuum cleaner A central vacuum cleaner (also known as built-in or ducted) is a type of vacuum cleaner appliance, installed into a building as a semi-permanent fixture. Central vacuum systems are designed to remove dirt and debris from homes and buildings, sen ...
s can be effective in removing dust, especially if they are exhausted directly to the outdoors.
Air filter A particulate air filter is a device composed of fibrous, or porous materials which removes solid particulates such as dust, pollen, mold, and bacteria from the air. Filters containing an adsorbent or catalyst such as charcoal (carbon) may als ...
s differ greatly in their
effectiveness Effectiveness is the capability of producing a desired result or the ability to produce desired output. When something is deemed effective, it means it has an intended or expected outcome, or produces a deep, vivid impression. Etymology The ori ...
. Laser particle counters are an effective way to measure filter effectiveness, medical grade instruments can test for particles as small as 0.3 micrometers. In order to test for dust in the air, there are several options available. Pre-weighed filter and matched weight filters made from polyvinyl chloride or mixed
cellulose ester Cellulose is an organic compound with the formula , a polysaccharide consisting of a linear chain of several hundred to many thousands of β(1→4) linked D-glucose units. Cellulose is an important structural component of the primary cell wall ...
are suitable for respirable dust (less than 10 micrometers in diameter).


Dust resistant surfaces

A dust resistant surface is a state of prevention against dust contamination or damage, by a design or treatment of materials and items in
manufacturing Manufacturing is the creation or production of goods with the help of equipment, labor, machines, tools, and chemical or biological processing or formulation. It is the essence of secondary sector of the economy. The term may refer to a r ...
or through a repair process . A reduced
tacticity Tacticity (from el, τακτικός, taktikos, "relating to arrangement or order") is the relative stereochemistry of adjacent chiral centers within a macromolecule. The practical significance of tacticity rests on the effects on the physical p ...
of a synthetic layer or covering can protect surfaces and release small molecules that could have remained attached. A panel, container or enclosure with
seams Seam may refer to: Science and technology * Seam (geology), a stratum of coal or mineral that is economically viable; a bed or a distinct layer of vein of rock in other layers of rock * Seam (metallurgy), a metalworking process the joins the ends ...
may feature types of strengthened
structural rigidity In discrete geometry and mechanics, structural rigidity is a combinatorial theory for predicting the flexibility of ensembles formed by rigid bodies connected by flexible linkages or hinges. Definitions Rigidity is the property of a structure ...
or
sealant Sealant is a substance used to block the passage of fluids through openings in materials, a type of mechanical seal. In building construction ''sealant'' is sometimes synonymous with ''caulking'' and also serve the purposes of blocking dust, s ...
to vulnerable
edges Edge or EDGE may refer to: Technology Computing * Edge computing, a network load-balancing system * Edge device, an entry point to a computer network * Adobe Edge, a graphical development application * Microsoft Edge, a web browser developed by ...
and
joins Join may refer to: * Join (law), to include additional counts or additional defendants on an indictment *In mathematics: ** Join (mathematics), a least upper bound of sets orders in lattice theory ** Join (topology), an operation combining two topo ...
.


Outer space

Cosmic dust Cosmic dust, also called extraterrestrial dust, star dust or space dust, is dust which exists in outer space, or has fallen on Earth. Most cosmic dust particles measure between a few molecules and 0.1 mm (100 micrometers). Larger particles are c ...
is widely present in
outer space Outer space, commonly shortened to space, is the expanse that exists beyond Earth and its atmosphere and between celestial bodies. Outer space is not completely empty—it is a near-perfect vacuum containing a low density of particles, pred ...
, where gas and dust clouds are the primary precursors for
planetary system A planetary system is a set of gravitationally In physics, gravity () is a fundamental interaction which causes mutual attraction between all things with mass or energy. Gravity is, by far, the weakest of the four fundamental interacti ...
s. The
zodiacal light The zodiacal light (also called false dawn when seen before sunrise) is a faint glow of diffuse sunlight scattered by interplanetary dust. Brighter around the Sun, it appears in a particularly dark night sky to extend from the Sun's direction in ...
, as seen in a dark night sky, is produced by
sunlight Sunlight is a portion of the electromagnetic radiation given off by the Sun, in particular infrared, visible, and ultraviolet light. On Earth, sunlight is scattered and filtered through Earth's atmosphere, and is obvious as daylight when t ...
reflected from particles of dust in orbit around the
Sun The Sun is the star at the center of the Solar System. It is a nearly perfect ball of hot plasma, heated to incandescence by nuclear fusion reactions in its core. The Sun radiates this energy mainly as light, ultraviolet, and infrared radi ...
. The tails of
comet A comet is an icy, small Solar System body that, when passing close to the Sun, warms and begins to release gases, a process that is called outgassing. This produces a visible atmosphere or coma, and sometimes also a tail. These phenomena ar ...
s are produced by emissions of dust and ionized gas from the body of the comet. Dust also covers solid planetary bodies, and vast
dust storm A dust storm, also called a sandstorm, is a meteorological phenomenon common in arid and semi-arid regions. Dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface. Fine particles are transporte ...
s can occur on
Mars Mars is the fourth planet from the Sun and the second-smallest planet in the Solar System, only being larger than Mercury (planet), Mercury. In the English language, Mars is named for the Mars (mythology), Roman god of war. Mars is a terr ...
which cover almost the entire planet. Interstellar dust is found between the
star A star is an astronomical object comprising a luminous spheroid of plasma (physics), plasma held together by its gravity. The List of nearest stars and brown dwarfs, nearest star to Earth is the Sun. Many other stars are visible to the naked ...
s, and high concentrations produce
diffuse nebulae A nebula ('cloud' or 'fog' in Latin; pl. nebulae, nebulæ or nebulas) is a distinct luminescent part of interstellar medium, which can consist of ionized, neutral or molecular hydrogen and also cosmic dust. Nebulae are often star-forming region ...
and
reflection nebula Reflection or reflexion may refer to: Science and technology * Reflection (physics), a common wave phenomenon ** Specular reflection, reflection from a smooth surface *** Mirror image, a reflection in a mirror or in water ** Signal reflection, in s ...
e. Dust is widely present in the
galaxy A galaxy is a system of stars, stellar remnants, interstellar gas, dust, dark matter, bound together by gravity. The word is derived from the Greek ' (), literally 'milky', a reference to the Milky Way galaxy that contains the Solar System. ...
. Ambient
radiation In physics, radiation is the emission or transmission of energy in the form of waves or particles through space or through a material medium. This includes: * ''electromagnetic radiation'', such as radio waves, microwaves, infrared, visi ...
heats dust and re-emits radiation into the
microwave Microwave is a form of electromagnetic radiation with wavelengths ranging from about one meter to one millimeter corresponding to frequencies between 300 MHz and 300 GHz respectively. Different sources define different frequency ran ...
band, which may distort the
cosmic microwave background In Big Bang cosmology the cosmic microwave background (CMB, CMBR) is electromagnetic radiation that is a remnant from an early stage of the universe, also known as "relic radiation". The CMB is faint cosmic background radiation filling all spac ...
power spectrum. Dust in this regime has a complicated
emission spectrum The emission spectrum of a chemical element or chemical compound is the spectrum of frequencies of electromagnetic radiation emitted due to an electron making a atomic electron transition, transition from a high energy state to a lower energy st ...
and includes both thermal dust emission and
spinning dust In astronomy, spinning dust emission is a mechanism proposed to explain anomalous microwave emission from the Milky Way. The emission could arise from the electric dipole of very rapidly spinning (10–60 GHz) extremely small (nanometer) dus ...
emission. Dust samples returned from outer space have provided information about conditions of the early
solar system The Solar SystemCapitalization of the name varies. The International Astronomical Union, the authoritative body regarding astronomical nomenclature, specifies capitalizing the names of all individual astronomical objects but uses mixed "Solar S ...
. Several
spacecraft A spacecraft is a vehicle or machine designed to fly in outer space. A type of artificial satellite, spacecraft are used for a variety of purposes, including communications, Earth observation, meteorology, navigation, space colonization, p ...
have sought to gather samples of dust and other materials. Among these craft was Stardust, which flew past
81P/Wild Comet 81P/Wild, also known as Wild 2 (pronounced "vilt two") ( ), is a comet named after Swiss astronomer Paul Wild, who discovered it on January 6, 1978, using a 40-cm Schmidt telescope at Zimmerwald, Switzerland. For most of its 4.5 billion- ...
in 2004, and returned a capsule of the comet's remains to Earth. In 2010 the Japanese
Hayabusa was a robotic spacecraft developed by the Japan Aerospace Exploration Agency (JAXA) to return a sample of material from a small near-Earth asteroid named 25143 Itokawa to Earth for further analysis. ''Hayabusa'', formerly known as MUSES-C ...
spacecraft returned samples of dust from the surface of an
asteroid An asteroid is a minor planet of the inner Solar System. Sizes and shapes of asteroids vary significantly, ranging from 1-meter rocks to a dwarf planet almost 1000 km in diameter; they are rocky, metallic or icy bodies with no atmosphere. ...
.


Atmospheric gallery

Image:Dust over Southeast Australia.jpg, Dry, windy weather sends clouds of dust across south-eastern
Australia Australia, officially the Commonwealth of Australia, is a Sovereign state, sovereign country comprising the mainland of the Australia (continent), Australian continent, the island of Tasmania, and numerous List of islands of Australia, sma ...
. Image:Spring Bloom and Dust off Argentina.jpg, A pale brown plume of dust sweeps out of
Argentina Argentina (), officially the Argentine Republic ( es, link=no, República Argentina), is a country in the southern half of South America. Argentina covers an area of , making it the second-largest country in South America after Brazil, th ...
’s
Pampa The Pampas (from the qu, pampa, meaning "plain") are fertile South American low grasslands that cover more than and include the Argentine provinces of Buenos Aires, La Pampa, Santa Fe, Entre Ríos, and Córdoba; all of Uruguay; and Brazil ...
s. Image:Dust Extends from Saudi Arabia to Iran.jpg, A thick dust plume over
Kuwait Kuwait (; ar, الكويت ', or ), officially the State of Kuwait ( ar, دولة الكويت '), is a country in Western Asia. It is situated in the northern edge of Eastern Arabia at the tip of the Persian Gulf, bordering Iraq to the nort ...
and the north-western tip of the
Persian Gulf The Persian Gulf ( fa, خلیج فارس, translit=xalij-e fârs, lit=Gulf of Persis, Fars, ), sometimes called the ( ar, اَلْخَلِيْجُ ٱلْعَرَبِيُّ, Al-Khalīj al-ˁArabī), is a Mediterranean sea (oceanography), me ...


Dust mites

House dust mite House dust mites (HDM, or simply dust mites) are various species of acariform mites belonging to the family Pyroglyphidae that are found in association with dust in dwellings. They are known for causing allergies. Biology Species The current ...
s are present indoors wherever humans live. Positive tests for dust mite allergies are extremely common among people with asthma. Dust mites are microscopic
arachnid Arachnida () is a class of joint-legged invertebrate animals (arthropods), in the subphylum Chelicerata. Arachnida includes, among others, spiders, scorpions, ticks, mites, pseudoscorpions, harvestmen, camel spiders, whip spiders and vinegaroon ...
s whose primary food is dead human skin cells, but they do not live on living people. They and their feces and other
allergen An allergen is a type of antigen that produces an abnormally vigorous immune response in which the immune system fights off a perceived threat that would otherwise be harmless to the body. Such reactions are called allergies. In technical terms ...
s that they produce are major constituents of house dust, but because they are so heavy they are not suspended for long in the air. They are generally found on the floor and other surfaces, until disturbed (by walking, for example). It could take somewhere between twenty minutes and two hours for dust mites to settle back down out of the air. Dust mites are a nesting species that prefer a dark, warm, and humid
climate Climate is the long-term weather pattern in an area, typically averaged over 30 years. More rigorously, it is the mean and variability of meteorological variables over a time spanning from months to millions of years. Some of the meteorologic ...
. They flourish in
mattress A mattress is a large, usually rectangular pad for supporting a lying person. It is designed to be used as a bed, or on a bed frame as part of a bed. Mattresses may consist of a quilted or similarly fastened case, usually of heavy cloth, conta ...
es,
bedding Bedding, also known as bedclothes or bed linen, is the materials laid above the mattress of a bed for hygiene, warmth, protection of the mattress, and decorative effect. Bedding is the removable and washable portion of a human sleeping environm ...
,
upholstered Upholstery is the work of providing furniture, especially seats, with padding, springs, webbing, and fabric or leather covers. The word also refers to the materials used to upholster something. ''Upholstery'' comes from the Middle English word ...
furniture, and
carpet A carpet is a textile floor covering typically consisting of an upper layer of pile attached to a backing. The pile was traditionally made from wool, but since the 20th century synthetic fibers such as polypropylene, nylon, or polyester hav ...
s. Their feces include
enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products. A ...
s that are released upon contact with a moist surface, which can happen when a person inhales, and these enzymes can kill cells within the
human body The human body is the structure of a Human, human being. It is composed of many different types of Cell (biology), cells that together create Tissue (biology), tissues and subsequently organ systems. They ensure homeostasis and the life, viabi ...
. House dust mites did not become a problem until humans began to use textiles, such as western style
blanket A blanket is a swath of soft cloth large enough either to cover or to enfold most of the user's body and thick enough to keep the body warm by trapping radiant body heat that otherwise would be lost through convection. Etymology The term ...
s and
clothing Clothing (also known as clothes, apparel, and attire) are items worn on the body. Typically, clothing is made of fabrics or textiles, but over time it has included garments made from animal skin and other thin sheets of materials and natural ...
.


See also

*
Contamination control Contamination control is the generic term for all activities aiming to control the existence, growth and proliferation of contamination in certain areas. Contamination control may refer to the atmosphere as well as to surfaces, to particulate matte ...
*
Dust bunny Dust bunnies (or dustbunnies) are small clumps of dust that form under furniture and in corners that are not cleaned regularly. They are made of hair, lint, flakes of dead skin, spider webs, dust, and sometimes light rubbish and debris and a ...
*
Dust explosion A dust explosion is the rapid combustion of fine particles suspended in the air within an enclosed location. Dust explosions can occur where any dispersed powdered combustible material is present in high-enough concentrations in the atmosphere or ...
* Hanānā *
Lint (material) Lint is the common name for visible accumulations of textile fibers and other materials, usually found on and around clothing. Certain materials used in the manufacture of clothing, such as cotton, linen, and wool, contain numerous, very shor ...
*
Medical geology Medical geology is an emerging interdisciplinary scientific field studying the relationship between natural geology, geological factors and their effects on human and animal health. The Commission on Geological Sciences for Environmental Planning d ...
*
Mineral dust Mineral dust is atmospheric aerosol originated from the suspension of minerals constituting the soil, composed of various oxides and carbonates. Human activities lead to 30% of the airborne dust load in the atmosphere. The Sahara Desert is th ...
*
Nephelometer A nephelometer or aerosol photometer is an instrument for measuring the concentration of suspended particulates in a liquid or gas colloid. A nephelometer measures suspended particulates by employing a light beam (source beam) and a light detec ...
*
Occupational dust exposure Occupational dust exposure can occur in various settings, including agriculture, forestry, and mining. Dust hazards include those that arise from handling grain and cotton, as well as from mining coal. Wood dust, commonly referred to as "sawdust", ...
*
Sawdust Sawdust (or wood dust) is a by-product or waste product of woodworking operations such as sawing, sanding, milling, planing, and routing. It is composed of small chippings of wood. These operations can be performed by woodworking machinery, ...


References


Further reading

* Holmes, Hannah; (2001)''The Secret Life of Dust''. Wiley. * Steedman, Carolyn; (2002) ''Dust''.
Manchester University Press Manchester University Press is the university press of the University of Manchester, England and a publisher of academic books and journals. Manchester University Press has developed into an international publisher. It maintains its links with th ...
.


External links


Global map of atmospheric dust
{{Authority control Articles containing video clips