is a general name for minute solid particles
with diameters less than 20 thou
). Particles in the atmosphere
arise from various sources
such as soil dust lifted up by wind, volcanic eruptions
, and pollution. Dust
in homes, offices, and other human environments contains human
, small amounts of plant pollen
, human and animal hairs, textile fibers
, paper fibers
minerals from outdoor soil, and many other materials which may be
found in the local environment.
Composition and types
The precise composition of domestic dust may vary widely:
According to the German Environmental Survey
approximately 6 mg/m²/day of house dust is formed in private
households, depending primarily on the amount of time spent at
home. Nearly 1000 dust particles per square centimeter
settle on domestic
surfaces every hour. Some dust consists of human skin. Scientists
estimate that humans shed the entire outer layer of skin every day
or two, at a rate of 7 million skin flakes per minute, which
corresponds to a mass emission rate of about 20 mg/minute.
" are small clumps of fluff
that form when sufficient dust accumulates.
Domestic dust and humans
Insects and other small fauna found in houses subtly interact with
dust and may have adverse impact on the health of humans
Dust may worsen hay fever
outdoor air through a house by keeping doors and windows open, or
at least slightly ajar, may reduce the risk of hay fever-causing
dust. In colder climates, occupants seal even the smallest air
gaps, and eliminate outside fresh air circulating inside the house.
So it is essential to manage dust and airflow.
House dust mites
exist on all indoor
surfaces and even suspended in the air. They feed on minute
particles of organic matter, the main constituent of house dust.
Dust mites flourish in the fibers of bedding, furniture, and
carpets. They excrete enzymes to digest the organic particles, and
excrete feces, that together become part of the house dust, and may
irritate allergies in humans.
Alternately, the hygiene
posits that the modern obsession with cleanliness
is as much a problem as house dust
mites. The hygiene hypothesis argues that our lack of prior
pathogenic exposure may in fact encourage
of ailments including hay fever
Airborne dust is considered an aerosol
and can have a strong local radiative
on the atmosphere and significant effects on climate.
In addition, if enough minute particles are dispersed within the
air in a given area (such as flour or coal dust), under certain
circumstances can cause an explosion
is responsible for the lung
disease known as Pneumoconiosis
including black lung
disease, that occurs
among coal miners. The danger of coal dust resulted in
environmental legislation regulating work place air quality in some
Dust kicked up by vehicles traveling on roads
may make up 33% of air pollution
dust consists of deposition of vehicle exhausts and industrial
exhausts, tire and brake wears, dust from paved roads or potholes
, and dust from construction sites. Road
dust represents a significant source contributing to the generation
and release of particulate matter
the atmosphere. Control of road dust is a significant challenge in
urban areas, and also in other spheres with high levels of
vehicular traffic upon unsealed roads such as mines and garbage
dumps. Road dust may be suppressed by mechanical methods like
sweeping vehicles, with vegetable oils, or with water
Dust control is the suppression
of solid particles with
diameters less than 500 micrometers. Dust in the airstream poses a
serious health threat to children, older people, and those with
Control of domestic dust
House dust can become airborne easily. Care should be exercised
when removing dust to avoid causing the dust to become airborne.
Some dust removing devices trap some dust, but broadcast some dust
into the air, which may settle in the cleaner's lungs, and make the
activity hazardous . One way to repel dust is with an electrical
charge . Water-trap vacuums
eliminate the risk of broadcasting dust by drowning the dust
particles in water. Dust can't escape the container to fly back
into the air.
Control of atmospheric dust
The U. S. Environmental
(EPA) mandates facilities that generate 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
United States Federal law requires that construction sites obtain
permits to conduct earth moving, and include plans to control dust
. Control measures include
such simple practices as spraying construction and demolition
sites with water, and preventing the
tracking of dust onto adjacent roads. US federal laws require dust
control on sources such as vacant lots, unpaved parking lots, and
unpaved roads. Dust in such places may be suppressed by mechanical
methods , including paving or laying down gravel, or stabilizing
the surface with water, vegetable oils or other dust suppressants,
or by using water misters to suppress dust that is already airborne
Dust in other contexts
Snowmelt in the San Juan
Image:Dust Reduces Snow Cover in the San Juans - 2005.jpg|2005
(Less dust)Image:Dust Reduces Snow Cover in the San Juans -
2006.jpg|2006 (More dust)Image:Dust Accelerates Snow Melt in San
Juan Mountains - May 31, 2008.jpg|2008 (Less dust)Image:Dust
Accelerates Snow Melt in San Juan Mountains - May 18, 2009.jpg|2009
Dust in outer space
is widely present in space,
where gas and dust clouds are primary precursors for planetary systems
. The zodiacal light
seen in the dark night sky, is
produced by sunlight reflected from particles of dust in orbit
around the Sun. The tails of comets
produced by emissions of dust and ionized gas from the body of the
comet. Dust also covers solid planetary bodies, and vast dust storms
occur on Mars that cover almost the
entire planet. Interstellar dust
is found between the stars, and high concentrations produce
and reflection nebulae
Dust is widely present in the galaxy. Ambient radiation heats dust
and re-emits dust into the microwave band, which may distort the
power spectrum. Dust in this regime has a
complicated emission spectrum, and includes both thermal dust
emission and spinning dust emission.
Dust samples returned from outer space may provide information
about conditions in the early solar system. Several spacecraft have
sought to gather samples of dust and other materials. Among these
craft was Stardust
, which flew
past Comet Wild 2
in 2004, and returned
a capsule of the comet's remains to Earth in January 2006.
Japanese Hayabusa spacecraft is on a
mission to collect samples of dust from the surface of an asteroid.
- Kathleen Hess-Kosa, (2002), Indoor Air Quality: sampling
methodologies, page 216. CRC Press.
- George W. Ware, (2002), Reviews of Environmental
Contamination and Toxicology, page 4. Springer.
- Heinsohn, R., Cimbala, J., (2003) Indoor Air Quality
Engineering: Environmental Health and Control of Indoor
Pollutants. page 146. CRC Press.
- "Dust mites in the humid atmosphere of Bangalore trigger around
60% of asthma" 
- Holmes, Hannah; (2001)The Secret Life of Dust. Wiley.
- Steedman, Carolyn; (2002) Dust. Manchester University Press.