Do you remember your science lessons where you all sat around while the teacher heated something over a bunsen burner? They material being heated sat on top of a tripod with a little metal mesh mat that had a circle of white stuff. That white stuff until recently was asbestos. In many countries other than Australia it probably still is asbestos.
These asbestos gauze mats are very high in asbestos fibre content and with the repetitive heating and cooling involved with their use begin to deteriorate and flake rapidly. There is also the actual abrasion from the tripod and whatever is being placed upon it. If they are in a school or tertiary institution they also have to suffer at the hands of students who like to bend and twist the wire mesh releasing more asbestos.