Mercury exposure in dental offices, even during routine checkups, is far more of a health hazard than one might suspect, …
//www.newstarget.com/2016-02-10-drilling-out-a-mercury-filling-at-the-dentist-exposes-you-to-30-times-the-osha-limit-for-mercury-as-an-airborne-toxic-heavy-metal-but-the-ada-doesnt-want-you-to-know.html