the widespread usage of something does not say anything about its safety. It's fallacious to assume just because something is widespread, that it has been shown to be safe. This illogical mindset is how we ended up with lead paint and asbestos in most homes in the US at one point. Studies showed the dangers as early as 1904 yet congress didn't ban lead paint until 1971. One number I'm seeing is that 87% of homes built before 1940 have lead based paint.