Meet Dayanthi Nugegoda: pollution detective

Nugegoda has worked with Australian state and federal governments to examine the environmental effects of toxic pollution for many years.

Most recently, she was appointed to the Victorian Scientific Reference Group for Onshore Conventional Gas where she will provide advice on the risks, benefits and impacts of onshore conventional gas developments.

We spoke to her to find out more about her passion for this critical area of research.

What is environmental toxicology?

Environmental toxicology is the study of how toxic chemicals and other pollutants affect ecosystems and non-human biota.

Mercury, for example, is a toxic trace metal resulting from prior gold-mining. It affects brain function and is detectable in the blood and feathers of little Penguins in Port Phillip Bay.

Another example is the industrial chemical nonylphenol and oestrogens in sewage from contraceptive pills, which can cause feminisation of male fish.

Why is research in this area important?

Research in this area is vital to ensuring non-human animals and plants are not adversely affected or their survival threatened by pollution and other related human activities.

In addition to these environmental impacts, our food and our recreational and drinking water can be contaminated causing serious health issues.

For example, nutrient pollution in our waterways can result in blooms of cyanobacteria and other microorganisms which produce toxins.

These toxins are accumulated by fish and shellfish and may cause serious gastro-intestinal harm and conditions such as Paralytic Shellfish Poisoning.

This type of problem has led to fisheries bans in the Gippsland Lakes on several occasions.

Industry and agriculture can also be negatively impacted, being penalised by law and becoming unsustainable unless the release of environmental pollutants is minimised.

What is your current research focus?

My current research examines endocrine disrupting chemicals (EDCs), which are contaminants of emerging concern.

These EDCs can affect vertebrate hormones (including humans), impacting on growth, reproduction and health.

I am also studying the toxicity of human-produced nanoparticles and evaluating the effects of pollutants including mercury on hormones in shearwaters.

What drew you to this field and what continues to excite you about it?

I grew up in Sri Lanka where I was passionate about protecting the native wildlife. Since then I have been committed to conservation and environmental protection.

I researched the effects of pollution on invertebrates for my PhD in London and understood that they were far more sensitive than large mammals to pollutants.

If the animals at the bottom of the food chain die out, we will eventually follow.

When I moved to Australia 23 years ago there were very few studies on Australian native species and this became a research focus for me.

There is always a new pollutant to research as new chemicals are produced and used indiscriminately, so an environmental toxicologist can never rest!

What are the biggest challenges for  environmental toxicology?

Environmental chemicals are always released as mixtures, not as individual pollutants, making it difficult to determine which one causes a particular effect.

Evaluating the effects of mixtures of chemicals is a significant challenge for scientists working in this field.

Another major challenge is that environmental stressors such as global warming can affect how chemicals act in the environment. 

Environmental toxicologists need to work with scientists from fields as diverse as immunology and geophysics to study the combined risk and make future predictions for the protection of species.

What are the emerging research priorities for this field?

Engineered nanoparticles as well as microplastics and nanoplastics are pollutants that are becoming an important focus of attention.

Nanoparticles used in a range of products and processes are increasingly finding their way into the environment. We need to evaluate how they behave if we are to continue protecting and managing ecosystems.

For example, silver nanoparticles are commonly incorporated in antibacterial socks. Our research has shown these are toxic to native aquatic invertebrates. 

Microplastic and nanoplastic particles result from plastic debris or may be manufactured, such as in the cosmetics industry. They can clog the gills of shrimp and fish, and also cause damage by entering the cells of the body.

Currently, there are no Australian Water Quality guidelines for these toxicants. Our research contributes to the potential for guidelines to protect aquatic ecosystems in the future.

Are there simple actions people can take to reduce the amount of toxic chemicals we produce?

A wise uncle taught me that if an apple has a worm in it, it is good to eat; because if it is safe for the worm it has no pesticide residues and it will be safe for you.

Live simpler, reduce and recycle, and always think before you wash your socks!

Story: Lawrence Martin