asbestos is (was) mined in many countries. It kind of grows in the ground in veins under certain conditions. It is mined, ground up and then made into many products. They (the government) did know of the dangers BEFORE 1920 but they made a load of money from it, so didn’t worry too much.
Carcinogenic…two types…Mesothelioma or Lung cancer. Both bad. both affect slightly different areas of the lung.
I thought it was where the body tries to destroy the fibre that clumping occurs, and lung cancer is the other.

Source:

Asbestos is a group of minerals with long, thin fibrous crystals. The word “asbestos” is derived from a Greek adjective meaning inextinguishable. The Greeks termed asbestos the “miracle mineral” because of its soft and pliant properties, as well as its ability to withstand heat.

Asbestos became increasingly popular among manufacturers and builders in the late 19th century due to its resistance to heat, electricity and chemical damage, sound absorption and tensile strength. When asbestos is used for its resistance to fire or heat, the fibers are often mixed with cement or woven into fabric or mats. Asbestos is used in brake shoes and gaskets for its heat resistance, and in the past was used on electric oven and hotplate wiring for its electrical insulation at elevated temperature, and in buildings for its flame-retardant and insulating properties, tensile strength, flexibility, and resistance to chemicals.

The inhalation of asbestos fibers can cause serious illnesses, including mesothelioma and asbestosis. Since the mid 1980s, many uses of asbestos are banned in many countries.

Asbestos from the 1960s, 70s and 80s was left in place in millions of public buildings and private homes. Some of this is still in place today, but strict regulations require the use of safety equipment to handle and dispose of it when and if it is ever removed.

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Asbestos fibers under a microscope look like long spears. When you breath them in they actually stab lung cells. When a cell gets stabbed it either dies or splits abnormally. An abnormal split can result in cells that mutate into a cancer cell and then multiply resulting in Mesothelioma.

Asbestos shingle siding is okay as long as you keep it painted. If it is cut or scraped so it exposes the inside, the fibers can go airborne. It’s less hazardous to keep painted than to try to tear it all out.

The effects were not known back in the 1920’s. In the 1970’s it was supposed to be banned but the EPA was paid off by industry and it’s still legal to use. Bad deal.

Asbestos is a group of minerals with long, thin fibrous crystals. The word “asbestos” is derived from a Greek adjective meaning inextinguishable. The Greeks termed asbestos the “miracle mineral” because of its soft and pliant properties, as well as its ability to withstand heat.

It has hooks on the fiber and when the stuff lodges in your lungs they don’t let go all that well, especially if there is tar or sticky substance in the lungs to help it stay there and then it limits the breathing to a point that you don’t get air. It is like asthma and or emphasema.

ehh.. it can cause this cancer of the lungs called Mesothelioma thats how it is carcinogenic but idk how it was formed