Island nations are pushing to crack down on industrial emissions in a bid to reduce levels of mercury found in fish.
A recent study found Pacific Islanders in the Cook Island, Kiribati, Tuvalu and the Marshall Islands have particularly high levels of mercury mainly because of their rich fish diet.
Of those tested, 97 percent had three times what the body can safely deal with.
Mercury can harm the brain, heart, kidneys, lungs and immune system, particularly those of unborn children and infants.
Researchers say it's about giving people guidance on which fish are less likely to be damaging.
"It's not very practical to tell people on small pacific islands not to eat fish more than once a month," Pacific study researcher Imogen Ingram said
"My next task is to sort out which fish are safer to eat, perhaps skipjack, not to eat swordfish and marlon.
The issue is being raised at the first UN Convention of mercury held in Geneva this week.