Something to think about, then: a good friend of mine, probably the best old school "tosher" (decorator) I ever knew who could do all the specialist stuff like graining, marbling, etc died from mesothelioma a few years back after more than 40 years in the trade. The medics reckoned his problems stemmed from all the hand dusting of Artexed walls and ceilings (without a mask, obviously) that he'd done over his working life. Towards the end it was a slow, horrible death. Maybe people wouldn't have such a cavalier attitude towards asbestos if they had watched someone die from exposure to it. Overboarding is OK providing the asbestos is damped down and not disturbed (i.e. broken, sawn, drilled, etc). Disturbing it by "knocking off the high spots" isn't the cleverest thing to do - even if you have worn protective overclothes, shoes and gloves (because otherwise the fibres can still cling onto your clothes and hair) and disposed of them correctly before decontaminating yourself properly (you did take those precautions, didn't you?). With asbestos-related illness killing some 1 in 17 joiners born in the 1940s (Source: HSE) maybe a bit more thought about how to approach potential asbestos-bearing substances is required
100% agree, it is something that is not to be taken lightly and I do feel for your friend. However that is after 40 years of fairly frequent exposure, not from doing the odd ceiling or two. I have seen quite a few people that have died from it, being stuck in a chair on oxygen is not the best life... I have taken precautions but I feel H&S has gone a bit overboard with ceiling asbestos. At the end of the day, plasters, plumbers and electricians still have to run cables through the ceilings, or fit lights or skim ceilings (which you do generally need to knock the high spots off before skimming)