Wednesday, May 6, 2009

High levels of what in whales?

Researchers assisted by the Ocean Alliance have discovered alarmingly high levels of chromium contamination in sperm whales, according to research published this week in the journal Chemosphere. The Ocean Alliance ship the Odyssey collected 361 skin samples from sperm whales all over the world over a period of five years. These samples were then analyzed by scientists at the University of Southern Maine. Virtually all the samples contained chromium, and samples from some regions contained levels typically only seen in humans who have had high occupational exposure.

The high levels of chromium that the researchers found don't bode well for whales or humans. Chromium is a known carcinogen. It has become more prevalent in the environment mostly due to human activities, although there are natural sources. Whales take in chromium either through the air or through fish consumption - activities humans also participate in regularly. Thus chromium contamination in whales could indicate that humans are at risk for chromium contamination as well. It also indicates that chromium pollution is extremely widespread, with high levels found in whales even in the South Pacific.

Sperm whales, like humans, are at the top of the food chain. This study provides sobering but important information about the level of pollution present in the marine environment, and how that pollution might effect large mammals.

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