Animal Cancer: Human Pollutants Threaten Animal Species

Scientists are finding that cancer is threatening more and more animals, and a new study by the Wildlife Conservation Society suggests that there is a strong link between animal cancers and man-made pollutants.

"Cancer is one of the leading health concerns for humans, accounting for more than ten percent of human deaths," said Dr. Denise McAloose, lead author and chief pathologist for WCS-Global Health. "But we now understand that cancer kills some wild animals at similar rates."

The Tasmanian devil, the world's largest carnivorous marsupial, faces extinction as a result of a cancer called devil facial tumor disease (picture right), while the second leading cause of death in St. Lawrence River Beluga whales is intestinal cancer, which is thought to come from a pollutant in the waters called polycyclic aromatic hydrocarbons, and is known to cause cancer in humans.

Dolphins and sea lions are showing high rates of genital tumors, and turtles are showing elevated cancer rates as well. Bottom-dwelling fish like brown bullhead catfish and English sole in the world's industrialized waterways also show high levels of cancer. Common effects of cancer in animals include changes to eyesight, reduced ability to feed, tumors, and drastically shortened life spans.

"Examining the impact of cancer in wildlife, in particular those instances when human activities are identified as the cause, can contribute to more effective conservation and fits within WCS's One World-One Health approach of reducing threats to both human and animal health," said Dr. William Karesh, Vice President and Director of WCS- Global Health.

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