U.S. scientists who took tissue samples from nearly 1,000 sperm whales discovered high levels of toxic and heavy metals that they say could affect the health of millions of people who eat seafood.
A report last week noted high levels of cadmium, aluminum, chromium, lead, silver, mercury and titanium in the mammals, according to samples taken over five years.
Analysis of cells from the sperm whales showed that pollution is reaching the farthest corners of the oceans, said biologist Roger Payne, founder and president of Ocean Alliance. Whales travel on voyages up to 87,000 miles.
"The entire ocean life is just loaded with a series of contaminants, most of which have been released by human beings," Payne said. "These contaminants, I think, are threatening the human food supply. They certainly are threatening the whales and the other animals that live in the ocean."
Ultimately, he said, the metals could contaminate fish, which are a primary source of animal protein for 1 billion people -- one in seven of the Earth's population.
"You could make a fairly tight argument to say that it is the single greatest health threat that has ever faced the human species. I suspect this will shorten lives, if it turns out that this is what's going on," he said.
U.S. Whaling Commissioner Monica Medina told the 88 member nations of the International Whaling Commission about the report and urged the commission to conduct further research.