Do houses built from asbestos shingles, pose a health-threat to humans?

only if you scrape or wire brush the siding and create asbestos dust as in paint prep. If scraping can’t be avoided use an approved face mask. Legaly an apron is supposed to laid out on the ground to catch ALL the paint chips so they don’t get ground up under foot and cause soil contamination. Long story short; painting the outside of such homes is a BIG hassle.

Materials containing asbestos aren’t dangerous unless and until they start to deteriorate, or you start tearing them out and up, to the point that the asbestos becomes friable. Asbestos is only a hazard when inhaled. It needs to be “friable,” to be easily broken down into a state where the fibers become respirable. Here’s another link. If the asbestos is bound up in some other material that prevents the fibers from being respirable then it’s not hazardous; but if that “stuff,” whatever it is that contains or is binding the asbestos fibers, deteriorates enough or gets compromised when it’s being removed to the point that the asbestos fibers can be inhaled, then yes, it can be dangerous.

Asbestos is a serious health consideration in housing, and any time you consider purchasing a home, you must insist that it pass an asbestos safety inspection. In California, it is the responsibility of the seller to remove any asbestos hazard (siding, ceiling) before a sale is final. We lost thousands of dollars on our last sale because we had to hire the asbestos hazardous material company to remove the asbestos from our home. If only we would have known when we bought the house.

what many do is put on a vinyl siding over lay and be done with it. There’s no cheap way to deal with that stuff. If it is encapsulated where nothing will be exposed to it, there it will sit probably through many owners.

Not unless you start hatcheting the shingles. The problem comes when they are broken.