And yet here we are with popsci near the top of HN. I blame Jeff Atwood.
The scariness of the article seems to reside mostly in the comments here and choice of headline. (although the picture of the dissolving I-beam isn't particularly reassuring...)
Both of these comments (in the same thread) do debunk it:
http://www.reddit.com/r/science/comments/85clw/why_mercury_i...
http://www.reddit.com/r/science/comments/85clw/why_mercury_i...
Dear HN - I love youse guys.
Am I in time for today's Two Minute Hate?
It's important to clean it properly (good ventilation, don't spread it around, don't vacuum clean), but unless you do something really stupid (that would get significant amount vaporized and inhaled), it should be ok.
Perhaps the most important thing to remember if you break a household thermometer is do not panic. The amount of mercury contained in an oral thermometer is small and does not present an immediate threat to human health.
http://www.atsdr.cdc.gov/toxprofiles/phs46.html (CDC Public Health Statement for Mercury)
IIRC I used a paper towel (whilst wearing rubber gloves, with the windows all open) to absorb the mercury and slid it into a plastic bottle and bagged it like 10 times before I went outside to make sure I wasn't exposed too long.
From my understanding they recommend all the precautions, not because like one drop will kill you, but because "it's better safe than sorry". You have an entire lifetime, just like you shouldn't be exposed to a huge dose of radiation, you shouldn't expose yourself to a huge dose of mercury, because fish contain mercury (and my lack of eating fish has likely balanced out any mercury I was actually ever exposed to) and if you eat tons of fish, sucking on broken thermometers and breaking florescent bulbs might just get enough mercury into you to make you nuts... although if you're purposefully exposing yourself to raw mercury to begin with I believe it's probably a moot point.
Mercury by itself is very toxic. There was a custodian who broke a thermometer in our office building once. That would have been ok - had she not spread it everwhere by playing with it. And, speaking from experience, as someone who broke a thermometer as a kid in his room and was mesmerized by the liquid, I can't blame them. Whole building had to be detox'd - almost spaceman suit E.T. style.