Queensland health is advising people to not eat fish caught in some waterways in the state's southeast as they may be contaminated with firefighting chemicals.

Fish caught in some southeast Queensland waterways shouldn't be eaten due to health concerns raised after some were found to be contaminated with firefighting chemicals.

Department of Defence testing has revealed perch, mullet and eel caught in Warrill Creek and the Bremer River, near Amberley, had high levels of PFAS chemicals in their systems.

They have notified Queensland Health, who advise there are ""possible elevated health risks for people who eat the fish over a long period of time".

"As an interim precaution, until Department of Defence can carry out further testing, people should not eat fish caught within this locality," a spokeswoman said on Friday.

Those who have infrequently eaten fish caught in the area of concern shouldn't worry about PFAS risks.

Authorities are also looking for traces of the chemicals at the towns of Ayr and Bundaberg, and also around airports, military sites and emergency services sites across the state.