Children who had any type of neurological,intellectual or emotional problems were excluded from this study. These are the children who are genetically predisposed to be most effected by mercury.The children who were excluded likely had mercury exposure from their mothers fillings, breast milk vaccines or other sources. Also,mercury kills brain cells. That is an established fact.Mercuury has numerous effects on the brain causeing tremors,problems with memory,neurotransmitter diruptions leading to depression.It also causes the neurofibrillary tangles in the brain characteristic of Alzheimer's disease.As far as I.Q. the study did'nt span enough years for any conclusions to be drawn. There are however numerous studies showing cognitive deficet in people occupationally exposed to mercury.I think Harleygirl has posted some of these.
Even if mercury does not cause I.Q. reduction in children in a few years,there is almost no biochemical pathway or organ it does'nt disrupt.Just open Principles of
Internal Medicine(not that you would understand it). Just about every process in there is disrupted by mercury.Mercury is also the most potent mutagen on the planet.It's actually worse than x rays since hg prevents repair of DNA breaks.