Cancer is extremely rare in wild animals. However, a large number of sea lions are dying off the coast of California from the disease. After twenty years of searching, researchers know why.
Staff at the Marine Mammal Center in San Francisco have seen sea lions wash ashore in excruciating pain for years. Their organs and lymph nodes are filled with tumors. Of the 400 admitted to the center, a quarter of them suffered from cancer.
The cause of cancer appears to be an unknown type of herpes, but the risk of death was much higher in animals with a high concentration of the toxic chemicals DDT and PCBs. “The concentration of toxins in these animals in California is exceptional and can lead to cancer,” said pathologist Badreg Duinan of the Marine Mammal Center. “Harmful material that was dumped here in the past has hardly decomposed in recent years and no one knows if this is the case at all.”
It’s bad news for people, too. “Sea lions live in the same waters that we swim and surf in,” said Francis Golland, a veterinarian with the US Marine Mammal Commission. Los Angeles Times. “They eat the same fish and seafood as we do. So we are also exposed to the risk of harmful substances in the water.”
Bron (nene): HLN
