They do die from mercury poisoning when they have eaten enough of it to kill them but it is also kept in the flesh and organs of the fish before the fish dies, and when creatures further up the food...
about just about 750
Yes, if you absorb enough mercury in the right (or wrong compounds), you can die shortly after absorbing it whatever your age.
No because the sun has helium inside and it is the only star that can die out?
All sorts if you have a big quantity of it. For example it can cause cancer, brain damage, and asthma as just a few