UC Science Radio: Episode 5

Dr Sally Gaw: Ending our love affair with plastic

UC Science Radio podcast episode 5 Sally Gaw

Lightweight, strong, waterproof – plastic is a wonder material, but it’s not so wonderful for nature.

In this episode, UC environmental chemist Dr Sally Gaw explains the damage plastic is doing to our wildlife and environment, and where it’s ending up – from rainwater and sea salt to tuna and mackerel. Dr Gaw, who has spent her career studying environmental contaminants (including microplastics) also talks about all that antibacterial soap and hand sanitiser we’re using at the moment and why it’s not so great for our waterways.

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In this episode:

01:18 My expertise and interest is in understanding where chemicals come from and where they might go and what kind of impacts they might have. I'm particularly interested in understanding how our everyday lives contribute to environmental contamination.

03:50 I'm interested in a class of chemicals that's called emerging contaminants.

04:06 I'm interested in the ones that we don't know very much about, and so we may not know the effects that they might have. One of the other contaminants that I'm working on in that space is microplastics.

10:07 We are exposed to so much plastic in our everyday lives: most people use a plastic toothbrush, we drink out of plastic containers, people probably chew on their pens while they're thinking.

11:20 We're quite often using a very permanent material for very short-term uses.

13:30 It's going to come down to some conversations as a community, of what is a good use of plastic, what is a frivolous use of plastic, and what is an appropriate use of this material.

14:25 The available evidence is that in controlling disease at home, ordinary soap and water is as good as anti-microbial compounds. That's the evidence that is out there.

21:41 I believe in evidence-based policy. When we get treated in the hospital, we expect the doctors are practicing evidence-based medicine-- that how they treat us and what they decide to do is based on strong evidence and strong science. I want to see the same for our policy: the decisions that we make about how we protect our environment and how we protect our people in New Zealand, I want to be based on strong science and so I want to contribute to that.

Read a transcript of the full interview.

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Meet our speakers

Sally Gaw

Sally Gaw

Dr Sally Gaw is an environmental chemist, Associate Professor in Chemistry at UC's School of Physical and Chemical Sciences and Director of the Environmental Science programme. Dr Gaw decided at age 16 that she wanted to be an environmental chemist. Since then she’s worked in many areas of environmental health including in consulting firms, wastewater treatment plants, the public health service and now as a lecturer and researcher at UC.

Sally's research focuses on contaminants in the environment, including microplastics. Microplastics are so small that they're typically invisible to the naked eye. They’re entering the food chain through a range of species like tuna and mackerel and being found in rainwater, sea salt, air and even in us.

In 2019 Sally contributed to a national report on plastic and New Zealand’s reliance on it and was also part of a team of UC researchers who found microplastics inside green-lipped mussels – a popular Kiwi seafood. Dr Gaw warns that unless we end our love affair with plastic, we could one day end up with more plastic in the sea than we have fish.

Learn more about Sally: Research profile

Molly Magid

Molly Magid

Molly Magid is an MSc student at UC. A recent graduate of Brown University, Molly is working on research in conservation genomics with Associate Professor Tammy Steeves from the School of Biological Sciences. Molly is passionate about finding ways to communicate science to the public in a clear, novel, and engaging ways. Most recently, Molly worked as the lead student producer on the podcast Possibly, which answers listener's questions about sustainability using relevant science research.