New contaminant study finds Brisbane River estuary contamination levels higher than Melbourne and Sydney

By A/Prof Ian Tibbetts

Emerging contaminants are compounds that can enter the environment and potentially affect public health. A recent study measured pharmaceuticals and pesticides in three Australian estuaries.

Pesticides that are used to improve crop yields, and medicines that protect human and animal health are entering our estuaries. Pesticides can enter either from surface run-off or via wastewater treatment plants, and diuron, the main herbicide found in Great Barrier Reef waters, is also an antifouling agent used on boats that frequent our estuaries. Medicines can leach from landfill sites; however, their main pathway is from sewage, which carries medicines that have not been completely metabolized and are not removed by wastewater treatment plants.

In a preliminary study of the three Australian estuaries, Brisbane, Melbourne and Sydney, the concentrations of 25 medicines and 53 pesticides were measured. Carbamazepine, a medicine used to treat epilepsy and neuropathic pain was detected in all water samples in all three estuaries. Other dominant pharmaceuticals measured were gabapentin, iopromide, venlafaxine and tramadol. Similarly, the current-use pesticides; atrazine, diuron, metolachlor and simazine were prevalent in all three estuaries. Generally, contamination was higher in the Brisbane River estuary than Sydney and Melbourne.

The Brisbane River is the major freshwater system that enters Moreton Bay. The river flows through agricultural, commercial and industrial areas before emptying into the Bay, so it is important to monitor pollutants that are entering the Bay. Unfortunately, the concentrations of emerging contaminants entering Moreton Bay is likely to rise due to the rapidly increasing human population and the accompanying demand for medicines and farm produce. Thus, the ongoing research on these contaminants will be important as we search for ways to reduce the amount that enters the Bay, and understand their impacts on Bay ecosystems.

Dr Alfred Kwablah Anim (PhD), Queensland University of Technology Prof Jochen Muller, Queensland Alliance for Environmental Health Sciences, Faculty of Health and Behavioural Sciences, The University of Queensland

Anim AK, Thompson K, Duodu GO, Tscharke B, Birch G, Goonetilleke A, Ayoko GA, Mueller JF. (2020) Pharmaceuticals, personal care products, food additive and pesticides in surface waters from three Australian east coast estuaries (Sydney, Yarra and Brisbane), Marine Pollution Bulletin, 153. https://doi.org/10.1016/j.marpolbul.2020.111014.