Sperm whales feeding even in the most remote reaches of Earth's oceans have built up stunningly high levels of toxic and heavy metals, according to American scientists who say the findings spell danger not only for marine life but for the millions of humans who depend on seafood. A report released Thursday noted high levels of cadmium, aluminum, chromium, lead, silver, mercury and titanium in tissue samples taken by dart gun from nearly 1,000 whales over five years. From polar areas to equatorial waters, the whales ingested pollutants that may have been produced by humans thousands of miles away, the researchers 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,” said biologist Roger Payne, founder and president of Ocean Alliance, the research and conservation group that produced the report. The researchers found mercury as high as 16 parts per million in the whales. The whales studied averaged 2.4 parts of mercury per million, but the report's authors said their internal organs probably had much higher levels than the skin samples contained. “The entire ocean life is just loaded with a series of contaminants, most of which have been released by human beings,” Payne said in an interview on the sidelines of the International Whaling Commission's annual meeting. Payne said sperm whales, which occupy the top of the food chain, absorb the contaminants and pass them on to the next generation when a female nurses her calf. Ultimately, he said, the contaminants could jeopardize seafood, a primary source of animal protein for 1 billion people. After more than five years and 87,000 miles, samples had been taken from 955 whales. The researchers were stunned with the results. Payne said the contamination was embedded in the blubber of males formed in the frigid polar regions, indicating that the animals had ingested the metals far from where they were emitted. Chromium, an industrial pollutant that causes cancer in humans, was found in all but two of the 361 sperm whale samples that were tested for it. “The biggest surprise was chromium,” Payne said. “That's an absolute shocker. Nobody was even looking for it.” The corrosion-resistant metal is used in stainless steel, paints, dyes and the tanning of leather. It can cause lung cancer in people who work in industries where it is commonly used. It was impossible to say from the samples whether any of the whales suffered diseases, but Wise found that the concentration of chromium found in whales was several times higher than the level required to kill healthy cells in a Petri dish, Payne said.
