Whales are particularly vulnerable to environmental contaminants, including organochlorines—such as polychlorinated biphenyl (PCBs), dichlorodiphenyltrichloroethane (DDT) and dioxin—and heavy metals, such as methylmercury.
Each of these environmental contaminants tends to accumulate in the bodies of top predators, including sperm whales, orcas, pilot whales, and false killer whales. The most contaminated whale meat has come from those species that are fish or mammal eaters such as dolphins, porpoises, sperm whales, and beaked whales.
Baleen whales, such as minkes, feed lower on the food chain, and their tissues generally contain lower levels of contaminants. Nonetheless, tests of the blubber of minke whales from the north Pacific have shown unsafe levels of pesticides and PCBs.
Effects on humans
Whale meat or blubber is consumed in Norway, Japan, some Caribbean nations, Russia, Canada, and the state of Alaska—either for subsistence, cultural, or commercial reasons.
In Japanese markets, generic whale meat or “kujira” is said to come from the minke whales killed as part of the so-called scientific whaling program. However, tests have shown that not all kujira is minke whale meat. Some of it is dolphin, porpoise, or beaked whale meat. People who eat kujira, thinking they are avoiding unsafe levels of contaminants, may in fact be eating meat that contains very high levels of toxic substances.
PCBs can cause nerve damage, reproductive and developmental disorders, immune system suppression, liver damage, skin irritation, and endocrine disruption. DDT exposure is associated with certain cancer risks and neurological and reproductive disorders. Dioxins can cause cancer, metabolic dysfunction, and immune system disorders. Methylmercury consumption can cause neurological and developmental problems. The contaminants are often highly concentrated in blubber because they are lipophilic, meaning they bond easily and even preferentially to fat.
One study of Faroe Islanders detected developmental disorders in children whose mothers consumed pilot whale meat and blubber regularly during pregnancy. In addition, some Inuit communities in the Canadian and Alaskan Arctic—where mothers regularly consume beluga whale meat and blubber (as well as meat from bowhead whales, seals, and polar bears)—have detected health problems in children who were exposed to contaminants in utero and through breast milk.
Whales no longer live in a pristine environment; we have polluted their habitat with poisons that concentrate in their tissues. Regardless of the amount, the consumption of whale meat can expose humans to dangerous contaminants.