The first test of a project backed to spray millions of tonnes of chalk into the stratosphere, in an attempt to 'dim the sun' and cool the Earth, could happen in June.
Harvard University experts will test the system by sending a large balloon 12 miles above the Swedish town of Kiruna and have it drop 2kg of chalk dust into the stratosphere.
The aim of the estimated $3 million mission, backed by billionaire Bill Gates, is to have the chalk deflect a portion of the sun's radiation, stop it from hitting the surface, and cool the planet.
https://www.dailymail.co.uk/sciencetech/article-9392641/Bill-Gates-wants-spray-millions-tonnes-CHALK-stratosphere.html, archived: https://archive.is/mcdo4
Aside from the fact that we're in Solar Cycle 25, which means the sun is quite inactive right now with very few sun spots, what kind of damage can chalk dust do?
A small amount of inhaled dust is not considered harmful. Those with healthy respiratory systems can expel it through coughing, and the remaining material should be absorbed safely into the body. For those with chronic breathing issues such as asthma, however, exposure can trigger a reaction. In fact, many school systems strongly urge teachers to move students with respiratory problems away from the chalkboard area. Chalkboards, trays and erasers filled with dust should also be cleaned regularly.
Teachers who used traditional chalk for a number of years developed some respiratory problems.
Chalk dust is considered an irritant and an occupational hazard by a number of occupational safety organizations around the world. People who must work around it for extended periods of time may want to use a filtered mask over the mouth and nose and taking a number of breaks in a fresh air environment.
Beyond the human health aspects of chalk dust exposure, there are also potential electronic hazards. Devices such as computers and digital versatile disc (DVD) players stored inside classrooms can suffer damage from accumulated dust. As the chalk particles circulate throughout the room, cooling fans may draw them into the computers' inner workings. As it builds up on the motherboard and other heat-sensitive parts, the risk of overheating increases. This dust can also cause severe damage to sensitive electronics, such as the laser reader of a DVD player or the playback heads of a video cassette recorder (VCR).
https://www.infobloom.com/is-chalk-dust-harmful.htm, archive: https://archive.ph/wip/IWpmE
Particles that evade elimination in the nose or throat tend to settle in the sacs or close to the end of the airways. But if the amount of dust is large, the macrophage system may fail. Dust particles and dust-containing macrophages collect in the lung tissues, causing injury to the lungs.
The amount of dust and the kinds of particles involved influence how serious the lung injury will be. For example, after the macrophages swallow silica particles, they die and give off toxic substances. These substances cause fibrous or scar tissue to form. This tissue is the body's normal way of repairing itself. However, in the case of crystalline silica so much fibrous tissue and scarring form that lung function can be impaired. The general name for this condition for fibrous tissue formation and scarring is fibrosis. The particles which cause fibrosis or scarring are called fibrogenic. When fibrosis is caused by crystalline silica, the condition is called silicosis.
Some types of lung diseases caused by the inhalation of dust are called by the general term "pneumoconiosis". This simply means "dusty lung".
Some particles dissolve in the bloodstream. The blood then carries the substance around the body where it may affect the brain, kidneys and other organs.
Use of personal protective equipment may be vital, but it should nevertheless be the last resort of protection. Personal protective equipment should not be a substitute for proper dust control and should be used only where dust control methods are not yet effective or are inadequate. Workers themselves, through education, must understand the need to avoid the risks of dust.
https://www.ccohs.ca/oshanswers/chemicals/lungs_dust.html, archived: https://archive.ph/TNATS
> The first test of a project backed to spray millions of tonnes of chalk into the stratosphere, in an attempt to 'dim the sun' and cool the Earth, could happen in June.
> Harvard University experts will test the system by sending a large balloon 12 miles above the Swedish town of Kiruna and have it drop 2kg of chalk dust into the stratosphere.
> The aim of the estimated $3 million mission, backed by billionaire Bill Gates, is to have the chalk deflect a portion of the sun's radiation, stop it from hitting the surface, and cool the planet.
https://www.dailymail.co.uk/sciencetech/article-9392641/Bill-Gates-wants-spray-millions-tonnes-CHALK-stratosphere.html, archived: https://archive.is/mcdo4
Aside from the fact that we're in Solar Cycle 25, which means the sun is quite inactive right now with very few sun spots, what kind of damage can chalk dust do?
> A small amount of inhaled dust is not considered harmful. Those with healthy respiratory systems can expel it through coughing, and the remaining material should be absorbed safely into the body. For those with chronic breathing issues such as asthma, however, exposure can trigger a reaction. In fact, many school systems strongly urge teachers to move students with respiratory problems away from the chalkboard area. Chalkboards, trays and erasers filled with dust should also be cleaned regularly.
> Teachers who used traditional chalk for a number of years developed some respiratory problems.
> Chalk dust is considered an irritant and an occupational hazard by a number of occupational safety organizations around the world. People who must work around it for extended periods of time may want to use a filtered mask over the mouth and nose and taking a number of breaks in a fresh air environment.
> Beyond the human health aspects of chalk dust exposure, there are also potential electronic hazards. Devices such as computers and digital versatile disc (DVD) players stored inside classrooms can suffer damage from accumulated dust. As the chalk particles circulate throughout the room, cooling fans may draw them into the computers' inner workings. As it builds up on the motherboard and other heat-sensitive parts, the risk of overheating increases. This dust can also cause severe damage to sensitive electronics, such as the laser reader of a DVD player or the playback heads of a video cassette recorder (VCR).
https://www.infobloom.com/is-chalk-dust-harmful.htm, archive: https://archive.ph/wip/IWpmE
> Particles that evade elimination in the nose or throat tend to settle in the sacs or close to the end of the airways. But if the amount of dust is large, the macrophage system may fail. Dust particles and dust-containing macrophages collect in the lung tissues, causing injury to the lungs.
> The amount of dust and the kinds of particles involved influence how serious the lung injury will be. For example, after the macrophages swallow silica particles, they die and give off toxic substances. These substances cause fibrous or scar tissue to form. This tissue is the body's normal way of repairing itself. However, in the case of crystalline silica so much fibrous tissue and scarring form that lung function can be impaired. The general name for this condition for fibrous tissue formation and scarring is fibrosis. The particles which cause fibrosis or scarring are called fibrogenic. When fibrosis is caused by crystalline silica, the condition is called silicosis.
> Some types of lung diseases caused by the inhalation of dust are called by the general term "pneumoconiosis". This simply means "dusty lung".
> Some particles dissolve in the bloodstream. The blood then carries the substance around the body where it may affect the brain, kidneys and other organs.
> Use of personal protective equipment may be vital, but it should nevertheless be the last resort of protection. Personal protective equipment should not be a substitute for proper dust control and should be used only where dust control methods are not yet effective or are inadequate. Workers themselves, through education, must understand the need to avoid the risks of dust.
https://www.ccohs.ca/oshanswers/chemicals/lungs_dust.html, archived: https://archive.ph/TNATS
(post is archived)