Some of the highest mercury levels in the country are found in Georgia streams.

That’s according to a federal study of mercury contamination that found the toxic substance in every fish tested at nearly 300 streams across the country.

The finding released Wednesday underscores how widespread mercury pollution has become.

The U.S. Geological Survey tested thousands of fish from 291 streams nationwide from 1998 to 2005.

Some of the highest levels in fish were detected in the remote blackwater streams along the coasts of the Carolinas, Georgia, Florida and Louisiana.

Mercury can damage the nervous system and cause learning disabilities in developing fetuses and young children.

Tags: Georgia, mercury, fish, streams, toxic, substance, U.S. Geological Survey