Tuesday, 28 May 2013

Marine environment monitored to the nanogram: trace elements of PAH detectable

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FishschoolPAHs are a carcinogen and in high levels they can be toxic to all levels of marine ecosystems.They can also have negative impacts on public health and industries, like fisheries. Image: Vancity Allie NEW polycyclic aromatic hydrocarbon (PAH) testing developed by scientists at ChemCentre could help protect marine health and improve marine industry environmental impacts.

The testing techniques have enabled scientists to detect smaller amounts and different types of PAHs in seawater, sediments and marine life than ever before.

PAHs occur naturally in the environment and from bush fires but the majority occur through oil spills and general offshore oil and gas drilling.

PAHs are a carcinogen and in high levels they can be toxic to all levels of marine ecosystems.

They can also have negative impacts on industries, public health and ecology.

ChemCentre senior chemist Leif Cooper says there are two main benefits from the new techniques.

They will enable chemists to understand what PAHs are entering the marine environment, and in much more detailed levels.

“One way is to improve the concentration factor during the extraction and treatment of the samples,” he says.

“They’re one hundred to a thousand times lower than what you would see normally, for example in waters normally you’d see one microgram per litre whereas what we’re doing now, we can see down to one nanogram per litre.”

“Knowing the baseline levels means you can quickly respond to any changes and in doing so reduce or avoid detrimental effects.”

Mr Cooper says the second benefit of the techniques is to improve the instrument detection limits.

“Because PAH’s can also be formed during combustion you might find them in the marine environment if you’ve had bush fires in the area,” he says.

“By looking for the alkylated PAHs we can tell not just whether there’s been an impact on the environment but also whether that impact has been caused by oil or something else.

“Because we can see the difference between what we call petrogenic PAHs [oils] and pyrogenic PAHs [bushfires] you can also tell which is causing the problem.”

The new techniques will enable more accurate environmental management plans of marine industry operations.

ChemCentre is the only Australian laboratory able to provide accurate testing for very low levels of PAHs in marine sediments.

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