Dust
Dust is a general name for minute solid particles with diameters less than 500 micrometers (otherwise, please see sand or granulates and, more generally, finely divided matter). On Earth, dust occurs in the atmosphere from various sources; soil dust lifted up by wind, volcanic eruptions, and pollution are some examples. Airborne dust is considered an aerosol and can have a strong local radiative forcing on the atmosphere and significant effects on climate. In addition, if composed of a flammable substance (such as flour or coal dust), under some circumstances it can be an explosion hazard.
Dust is responsible for the lung disease known as Pneumoconiosis, including black lung disease, which occurs among coal miners. This danger has resulted in a number of laws regulating environmental standards for working conditions.
House dust
Dust in homes, offices, and other human environments is mainly generated by the inhabitants (especially domesticated pets such as dogs, cats and birds), and mainly from their skin cells that slough off. [citation needed] Some atmospheric dust from the outdoors is also present. On average, approximately 6 mg/m2/day[1] of house dust is formed in private households, depending primarily on the amount of time spent at home. "Dust bunnies" are little clumps of fluff that form when sufficient dust accumulates.
Insects and other small fauna found in houses have their own subtle interactions with dust that may have adverse impact on the health of its regular occupants. Thus, in many climates it is wise to keep a modicum of airflow going through a house, by keeping doors and windows open or at least slightly ajar. In colder climates, it is essential to manage dust and airflow, since the climate encourages occupants to seal even the smallest air gaps, and thus eliminate any possibility of fresh air entering.
House dust mites are on all surfaces and even suspended in air. Dust mites feed on minute particles of organic matter, the main constituent of house dust. They excrete enzymes to digest dust particles; these enzymes and their feces, in turn, become part of house dust and can provoke allergic reactions in humans. Dust mites flourish in the fibers of bedding, furniture, and carpets.
The particles that make up house dust can easily become airborne, so care must be exercised when removing dust, as the activity intended to sanitize or remove dust may make it airborne. One way to repel dust is with some kind of electrical charge, but house dust can be removed by as many as 10 methods, such as: wiping, swiping, or sweeping by hand, or with a dust cloth, sponge, duster, or broom, or by suction by a vacuum cleaner or air filter. The device being used traps the dust; however, some may become airborne and come to settle in the cleaner's lungs, thus making the activity somewhat hazardous.
Allergen's Investigated.
Airborne Dust
Dust, above all “fine dust” was moved more into the public and political interest during 2005. The fact that dust can damage our health but is something that we have to contend with living as we do, has been well documented for hundreds of years, only recently has it been brought to the fore.
Dust measuring techniques have vastly improved over the years following the requirements of testing in the mining industry, with the event of progressive industrialisation which increased the levels of pollutants and dust loading in outside air, around the middle of the last century scientific realisation ventured towards avoidance strategies regarding these forms of air pollutants from 1973 it was recognised through the limitation values of in-breathable dust and alveole-fine dust under the MAK (=Maximum Job concentration level) measurement.
From the view of the German Asthma & Allergy Federation.(DAAB) and the Society for the Environment and Interior Analytics (GUI) with regard to the interior where we spend some 90% of our all to brief life time. Findings from naturally ventilated buildings which were subject to window/outdoor air ventilation, which allows contamination from dust, loaded outdoor air being carried into the interior. But what happens to the contaminated air? Is it inhaled directly by the inhabitants? Do the airs content materials attach themselves to the equipment , furnishings and contents of the dwelling? When are they released again, into the air? What causes this release? As the fine dust loading is in the interior, possibly in the form of smoke from open fires and particles from domestic animals. How best can we live in these conditions, taking health and hygienic advice into account?
Fine dust is a major problem for the allergy sufferer, regardless of the kind of inhaled dust particles, the particles themselves are attractive to the respiratory system due to there mechanical effect on the human body.
These dust particles will effect far more strongly those who already have a damaged bronchial system, these particles and pollutants can effect all genes and can penetrate deep into the respiratory tract and lung systems causing the appropriate and sometime severe reaction. Cat hair can hold various forms of pollutants both on the fine hair matter and between the hair and the cats skin, such as sweat etc. this type of pollutant can easily be transmitted and carried as a fine particulate matter in a state of suspension in the air.
Also the excrement from the house dust mite disintegrates and its particulate matter is suspended in a similar if not identical process, which again means it is carried in the air we breathe.
There are many types of fine dust some of which are responsible for carrying diseases.
Coal dust for example attaches itself to the connective tissue of the lung and destroys the Alveolus. Pure floating dust can mix with the blood, and will make it more viscous thereby increasing the risk of cardiac infarction. Some types of dust such as asbestos, or booking wood dust are known to cause cancer.
An independent European study means that the life expectancy of humans was reduced by 9 months due to the inhalation of fine dust matter. The World Health Organisation has recognised similar findings.
Outside air quality is improving, only due to scientific realization and the implementation of new laws and regulations for the protection of humans, these are pursuant to the core of the current discussions with specific regard to fine dust matter.
The DAAB study paid special attention to indoor air quality and the effect of soft furnishings in the form of carpeting against the presence of resilient/hard smooth flooring its contribution to the overall issue .
The investigation was based in and around the Rhine/Westphalia area of Germany and randomly selected 100 private homes during the survey. The rooms tested were Bedrooms, living rooms and a children's room( Play room) if available. The split between hard and soft/carpeted flooring was 64% hard floor and 36% soft flooring/carpet which is in direct proportion to that found across the country.
To ascertain the dust level a scientifically proven method using a 16 channel laser particle analyser was used, which captured and tested all fine dust broken into 10µm particle diameter in air. In particular it was determined that the measuring groups were 0.3µm, 0.5µm, 0.7µm, 1.0µm,1.5µm, 2.0µm, 2.5µm, 3µm, 4µm, 5µm, 6, 7, 8, 9, and 10µm(1µm is equal to 1 thousandth of a meter) during the exercise dust was gravimetrically seized/captures by means of a vacuum pump which captured the particulate matter through a filter medium at a level of below 10µm, by purging the filter before and after the test and measuring the dust mixes it was possible to set these in relationship to the volume of air captured. The same process could be used to determine the dust matter present in the outside air. The graphs attached show the levels of fine dust present in both carpeted and non carpeted environments, produced by Dr Dipl-Ing Adreas Winkens VDI Gesellschaft Umwelt and Innenraumananalytik GUI Mönchengladbach.
The graphs show conclusively that the fine dust matter present in a non carpeted environment was at a far higher level, 62µm as to the carpeted areas which showed a level of 36µm far above the European safe recognised level of 50µm
The results were produced for the DAAB and are not related to any flooring or carpet manufacturer, a clear indication that the current information available to the public which states that removal of carpets is the really safe option, is WRONG!!!
The above was reproduced with the permission of Solution UK Ltd ( http://www.solution-uk.com )
Dust in outer space
Cosmic dust is widely present in space, where gas and dust clouds are primary precursors for planetary systems. The zodiacal light, seen in the sky on a dark night, is produced by sunlight reflected from particles of dust in orbit around the Sun. The tails of comets are produced by emissions of dust and ionized gas from the body of the comet. Dust also covers solid planetary bodies, and vast dust storms can occur on Mars that can cover almost the entire planet. Interstellar dust is found between the stars, and high concentrations can produce diffuse nebulae and reflection nebulae.
Dust samples returned from outer space could provide information about conditions in the early solar system. Several spacecraft have been launched in an attempt to gather samples of dust and other materials. Among these was Stardust, which flew past Comet Wild 2 in 2004 and returned a capsule of the remains of the comet to the U.S. in January 2006. The Japanese Hayabusa spacecraft is currently on a mission to collect samples of dust from the surface of an asteroid.
Dust in fiction
- In JM Barrie's children's novel Peter Pan (1911), "pixie dust" is a substance used to help create magical effects.
- In Clark Ashton Smith's short horror story "The Treader In The Dust" (1935) [1], a scholar unwittingly calls forth a demon that personifies dustiness.
- In the Peanuts comic strip, the character Pig-Pen (1954) is constantly surrounded by a cloud of dust.
- In Arthur C. Clarke's A Fall of Moondust (1961), 21st century tourists "cruise" across the Moon's "Seas" that have filled over eons with very fine dust, which is so fine that it almost behaves like water.
- In Hal Clement's short science fiction story "Dust Rag" (1965), two astronauts struggle with dust that stuck to their helmets, blinding them.
- In Philip Pullman's best-selling series His Dark Materials (1995), dust (or "Dust", as it is spelled in the books) plays an important part by creating a connection between different worlds.
- In the TV comedy Little Britain (2003), Fat Fighters group leader Marjorie Dawes distinctively instructs the dieters to eat dust as it is "low in fat."
- In "The Dust Has Landed", an episode Graham Duff's science-fiction radio comedy Nebulous, sentient dust declares war against humanity, forcing the reinvention of the vacuum cleaner.
Dust in religion
In ancient Sumerian mythology:
- The afterlife consists of the dreary "House of Dust and Darkness".
In the Bible:
- In Genesis 3:19, God — following The Fall, Adam and Eve's transgression — states to the couple (representing humanity):
- By the sweat of your brow you will eat your food until you return to the ground, since from it you were taken; for dust you are and to dust you will return. [Emphasis added]
This latter clause is used in the Ash Wednesday service in some churches for the administering of ashes.
- I will make your offspring like the dust of the earth, so that if anyone could count the dust, then your offspring could be counted.
Note however that in both of these Biblical passages, the Hebrew word is עפר (`âfâr), which can also mean earth or dirt.
See also
Sources
- ^ House dust formation rate (in German)
Reference
- Holmes, Hannah; (2001)The Secret Life of Dust. Wiley. ISBN 0-471-37743-0