Morris, Hg is a liquid at room temperature. It evaporates into gaseous Hg. It "disappears" from all these little reservoirs. So there is no chance of long term Hg build up on floors in medical facilities. Here's an experiment we did as children. Apply a small amount of Hg to a silver coin. The coin becomes very silvery and very slick with little friction. This is only temporary though. The Hg evaporates over night and the coin is back to it's dull color the next day. As a disclaimer, I don't advise doing this experiment today. Stork ------------------------------ Message: 3 Date: Sun, 31 Jan 2010 13:56:20 +1100 From: "Morris Odell" Subject: Re: [time-nuts] Conducting Bench Top Material To: Message-ID: <000001caa220$f73836b0$e5a8a410$@net.au> Content-Type: text/plain; charset="us-ascii" Just about every doctor's surgery or emergency room more than about 15 years old will have had more than one thermometer broken in it. I'm sure there are lots of little balls of mercury lurking in carpet fibres or between tiles in those environments. It doesn't seem to have surfaced as an occupation health hazard. You're more likely to encounter "lead or sharp steel poisoning" in inner city ERs :-( Morris > Date: Sat, 30 Jan 2010 17:22:30 -0500 > From: Chuck Harris > Subject: Re: [time-nuts] Conducting Bench Top Material > > Yes, and no. When mercury hits the ground, it splatters into hundreds > of > miniballs of mercury. When you walk on them, they further fracture, > and > by the time you are done, you have increased the surface area of the > mini > drop of mercury greatly... probably thousands of times. That increases > the mercury vapor emitted into the room. > > Is it harmful? Maybe. Maybe not. > ***