mikeman7918 wrote:
Yes, there is Formaldehyde which is a molecule that contains Mercury atoms but being in a molecule like that completely changes it's properties.
Formaldehyde does not contain mercury atoms. It has a chemical formula of CH2O, as it is the simplest aldehyde. I think you were commenting upon the molecule thimerosal (chemical formula of NaHgC8H9O2S), not formaldehyde in the above statement. Thimerosal was/is used in certain medical shot solutions as a stabilizer.
But, you are right in that chelated (bonded) metal cations in compounds act differently than their non-ionized metallic forms. The main thing to think about with respect to the effect of mercury on human bodies is the blood-brain barrier. Atomic mercury can exist in the blood stream of exposed people. However, since the metal is not ionized, it cannot cross the blood-brain barrier to cause damage there. Unfortunately, certain bacterial can oxidize metallic mercury into mercury(I) which can cross the blood-brain barrier and then short circuit the nerve synapses. Too much of that at one time can lead to a progression of damage collectively known as Mad Hatter's disease. Mercury damage to young brains has been known to cause many potential health issues, including neurological problems.
I have first hand experience handling organomercury compounds in an experimental laboratory setting. I also worked with organocadmium and organolead compounds in the same research study. The first thing you learn is to never reuse any gloves while handling said materials. That is an easy route to personal contamination by those toxic materials.
Dimethylmercury has a special problem in handling. It can penetrate latex gloves and skin readily, on top of absorption by vapor. If I remember right, it is #2 or 3 on the most toxic compound list for humans. Better to use a nitrile-based glove when handling it or better yet, use a glovebox with negative pressure and multiple layers of thick rubber gloves.