"To make a global statement that high levels of mercury are safe based upon this study would be unfair," he said. "Some people are affected at lower levels."
"Lots of people are walking around with high levels of mercury," he added. "People tolerate different levels."
But even those who tolerate higher levels would be better off without it, Perlmutter contends.
"Where could they be in terms of functioning if they didn't have the mercury?" he says.
But so far, the children of the Seychelles appear to be functioning just fine. And Davidson said that he didn't believe the entire group he studied could be immune to effects of mercury because they are a diverse population.
"It's not likely," he said. "People have immigrated from all over -- it's a fairly young country."
"At this time, EPA and FDA have no current plans to revise the advisory," said Jim Pendergast of the EPA's Office of Water. "However, as science continues to advance, there is always a possibility to revisit the advisory."