Chemicals called PCBs - or polychlorinated biphenyls - are toxic to people and wildlife. The Environmental Protection Agency says they can cause cancer and other adverse health effects on the immune, reproductive, nervous, and endocrine systems. PCBs were banned in the 1970s, but they’re still in the environment.
Researchers at Cornell University have previously found that PCBs can change the song centers in the brains of songbirds.
Now – a new study suggests that PCBs could be altering the songs some birds sing.