Per and poly-fluoroalkyl substances, also known as PFAS, was detected at two sites in Launceston following a national review process conducted by Airservices Australia.

Contamination was found at higher than usual levels at the Launceston Airport in June, while samples found in fish and eel caught in the North Esk River in July prompted Public Health to issue a precautionary health advisory.

Residents were advised to not consume any fish or eel caught in the river between the Tamar Estuary and Corra Linn Gorge.

A Public Health spokesman said this advice was still in place and residents should follow the advice "until further notice."

"This advice will remain in place until further tests indicate PFAS contamination in fish and eels is no longer a concern," the spokesman said.

RELATED STORY: Hazardous PFAS found above safe levels

"Further testing will be discussed at a meeting of all stakeholders this month."

The Airservices Australia review is being conducted at former firefighting and defence sites across the country as firefighting foam containing PFAS was used until 2010.

PFAS has not been proven to cause specific illnesses in humans but it can build up in animals and the environment and does not break down so the federal government has advised minimal exposure as a precaution.

The chemicals have been linked to a cancer cluster in the US after an international investigation last year.

The PFAS investigation in Tasmania is being coordinated by the Environment Protection Authority, jointly with Airservices Australia.

An EPA spokeswoman said a detailed site investigation of the Launceston Airport is due to start in late 2019 and is likely to include investigation of PFAS contamination outside the sites at the airport already tested.

RELATED STORY: Breaking down PFAS contamination: explainer

"These further investigations are required to understand the source of the elevated PFAS levels found in the fish sampled from the lower North Esk River and in order to consider pathways for treatment options," the spokeswoman said.

The EPA will be meeting with Airservices Australia and the Health Department in the coming weeks to discuss proposed investigations and act as a result of the health precautionary advice.