A scientist says further studies are needed to find out if people in the Pacific are being harmed by high levels of mercury.
New research has shown elevated levels of the chemical in a sample of women of child bearing age in the Cook Islands, Marshall Islands, Kiribati and Tuvalu.
A scientist involved in the study, David Evers, said exposure can lead to neurological problems and lower the intelligence quotient (IQ) of children.
He said in the Pacific the mercury levels are likely caused by a diet high in fish.
"And there's indications that people with elevated mercury concentrations can adapt to a certain degree of mercury in their bodies. Now how much they can adapt is unknown and it would be something that would need further study," said Dr Evers.
Dr Evers suggested Pacific islands should promote eating only certain seafood like smaller species of fish.