As far as flooring, the asbestos is encapsulated in the vinyl or glue, the problems come from dry scraping or sanding. The fibers are shaped like a corkscrew, and if they bury themselves in your lungs, after awhile it will cause cancer.
Smokers and children are most at risk, and mostly people who worked in the factories are the ones who died, but I would never recommend asbestos removal a DIY project.
Better safe than sorry.