DDT could be affecting killer whale hormones - The Wildlife Society

March 28, 2025 by The Wildlife Society

Laboratory tests on cells that mimic killer whale proteins revealed how banned pesticide may still be affecting apex predators

Despite many countries banning DDT pesticide decades ago, the chemical still persists in the environment and is accumulating in the bodies of orcas—possibly at levels high enough to disrupt their hormone balance. In a study published recently in Ecotoxicology and Environmental Safety, researchers used a petri dish to add DDT to cells that mimic killer whale (Orcinus orca) proteins. The team found that the chemical affected the hormonal balance of this protein, which could disrupt estrogen flow. Then, they compared the levels of DDT that caused effects in these lab experiments with the quantities detected in wild killer whales from Canada and Ireland. They found the pesticide levels could be high enough to cause problems in the wild.

Read more at Phys.org.

Header Image: Killer whales in the Lamire Channel in Antarctica. Credit: Pedro Szekely

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