I was exposed to mercury at 34 weeks via CFL bulb breaking.
From what I've read:
- consumption of mercury via food has a much smaller absorbtion rate than breathing in vapours (like I did). So not all of the mc of mercury in the shark stayed your body. Most passed through your system without bonding to anything.
- mercury is in your blood stream at first but then settles into tissue - mostly your kidneys, brain, etc...... The body then slowly breaks it down - faster in the kidneys than the brain, I believe. But from what I understand, there isn't much in your blood after a period of time.
If there was some in your blood when your placenta started to grow - mercury can get stored in the placenta and then to the baby. The placenta is thought to have some protection mechanisms and will store more mercury in itself than it will pass on to the baby. There isn't a lot of research on this, but it was found in animal studies. So that is another place where it would get trapped before entering baby. Once in baby some goes to kidneys, brain and other organs. The worry would be what is stored in the brain - BUT you can see that before it gets there, there are alot of road blocks and other places to store mercury on the way. The amount gets diffused.
So - if it was 3 months ago - and you are newly pregnant, I would assume that your risk is very low. You may want to look at absorbtion rate with eating mercury (and get a better idea of how much woud have been in your body) and re-do your math. Then look up how it distributes in your body to see how much might have been in your blood once your baby implanted. I was focused on mercury vapour when I was reading - so do encourage you to look into this stuff yourself.
It is scary - I was freaked out. I did call motherisk and poison control and got some good information there too. They were very reassuring about the low risk level of my exposure. Let me know what you learn :) Best to you and your LO!