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Catherine,
I found this article on Google...
Despite the ban on many household mercury items like thermometers and barometers in many European countries, these items are not generally a cause for concern, at least in terms of human health. The greater concern for these items is environmental, since mercury-containing items should never be simply thrown in the trash. The true hazard from thermometers and barometers is the accumulation of mercury from millions of these things being thrown into landfills, which eventually contaminates drinking water, soil, and fish. Nevertheless, this source of mercury has always been quite small compared to industrial sources, these days particularly coal-fired power plants. (Most coal contains mercury, which evaporates into the atmosphere as the coal is burned.)
"But wait," you say, "I thought a broken mercury thermometer was a real health hazard."
Well, in most circumstances, no.
Elemental mercury is only dangerous in vapor form. Exposure to a little liquid is unlikely to cause any harm, let alone major health effects. Many older people remember playing around with mercury from broken thermometers when they were kids; they haven't all died.
In fact, it's quite unlikely to get mercury poisoning from playing around with mercury in your hands or even eating it. As mentioned above, 99.99% of ingested elemental liquid mercury will be excreted right away. Studies on other animals have shown that it takes a relatively large amount of ingested mercury to cause any harm. A normal adult would have to eat about a quarter pound of mercury to approach a minimum level for lethal exposure! (I don't encourage you to try this, but it's important to note that small doses of mercury have been ingested for health benefits for centuries; few would have continued the practice if a small dose was likely to kill you.)
Similarly, elemental mercury is absorbed very slowly through skin; mercury vapor is absorbed about 50 times as fast through vapor in the lungs than through the skin, so unless you're breathing through a sealed mask while bathing in pure mercury (which would be difficult, because you'd float), skin exposure is very unlikely to be significant.
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