Exposure to PCB stunts growth in turtles. Turtles are an indicator species and can help gauge the health of an entire ecosystem, providing insight into how PCBs can affect humans.

Researchers exposed turtles to levels of PCB 126 equivalent to what reptiles would experience in an urban aquatic environment. Exposed turtles were smaller, had lower bone density, and slower metabolic rates compared to the control group.

PCBs are absorbed by ingesting exposed animals or contaminated water, and are stored in fat cells. PCBs affect the endocrine system and hormones that control growth.