...."IS" mercury
that dangerous? There are numerous videos on YouTube showing modern-day people handling raw mercury with bare hands. Do they die? Yes, eventually. Maybe from the mercury; maybe not. The videos never seem to include that part. However, mercury is not only a carcinogen (think cigarettes), but is also poisonous if it gets in the blood stream. Some amount of mercury may be absorbed by the skin. Here's the thing though - apparently the mercury has to be water-soluable to be dangerous to handle.
from
https://en.wikipedia.org/wiki/Mercury_(element):
Mercury poisoning can result from exposure to water-soluble forms of mercury (such as mercuric chloride or methylmercury), by inhalation of mercury vapor, or by ingesting any form of mercury.
from
What are the dangers of mercury exposure? | HowStuffWorks
In its pure form, mercury is an element -- symbol Hg on the periodic table, metallic, atomic number 80. It's a silvery substance that's liquid at room temperature, and it's naturally occurring. Some estimates put the amount of mercury emissions from natural activities, like volcanic eruptions and the wearing away of rocks, at 2,100 tons annually [source: UDEQ].
While mercury emissions are notoriously difficult to pin down, most sources agree that human activities put more mercury into the atmosphere than natural ones, perhaps 2,900 tons per year [source: UDEQ]. That mercury can come from mining and processing for use in products (like those thermometers) and manufacturing, or from energy-related sources like coal-fired power plants.
Mercury is a neurotoxin, meaning it has detrimental effects on the nervous system. It can damage the brain and lead to physical and emotional disorders. So whether its presence is natural or anthropogenic, it's a potential problem for humans. How big a problem depends on the form of the mercury, how much is present, and which humans are being exposed to it.
While exposure to mercury and its compounds can be devastating, it's not a particularly common occurrence.
And finally, this website is devoted to mercury - both the dangers and the selling of (they sell it):
Liquid MercuryLiquid Mercury -
TONS of good reading here.