Experts say man-made contaminants pose serious threats to dolphins across southern Australia.

The Environment Protection Authority (EPA) in South Australia has found that bottlenose dolphins living in waterways including Adelaide's Port River and Perth's Swan River face some of the most intense contamination risks in the world.

Samples taken from the livers of more than 40 deceased dolphins revealed high levels of perfluorinated chemicals – which are used in firefighting foams, non-stick cookware and in carpets and couches to make them stain-proof.

They are from a class of chemicals called per- and polyfluoroalkyl substances (PFAS).

The compounds are absorbed by marine life through general environmental exposure or their consumption of other contaminated fish.

The levels of the PFAS contaminants were high compared to international research findings.

Those levels were much higher in the Port River, near the city of Adelaide, and much higher in the Swan River near industrial areas of Perth, than they are in non-industrial areas.

The EPA study says more work is needed to understand how the environment can cope with emerging PFAS chemicals and how they can be managed for the future.

The impact of the chemical compounds on both dolphins and on humans who eat contaminated fish needs more investigation too.

There is no definitive link between PFAS and human illnesses, but a growing body of evidence suggests it is better to be cautious.

The chemicals are not manufactured in Australia, so the body of research about local worker exposure is lacking.

The experts say more research is needed.