For this timely Halloween issue of The Update, Dr Nina Wootton, Postdoctoral Researcher at the School of Biological Sciences at the University of Adelaide, shares the results of a recent scientific paper illustrating the misconceptions about the amount of microplastic in seafood.
"Examining Misconceptions about Plastic-Particle Exposure from Ingestion of Seafood and Risk to Human Health" is the somewhat lengthy title of the peer-reviewed research paper published earlier this month in Environmental Science & Technology Letters. This paper is led by Professor Ted Henry from Heriot-Watt University in the UK, and has a list of international co-authors including myself and Professor Bronwyn Gillanders from the University of Adelaide.
Back in 2022, Bronwyn, Erik Poole from the Sydney Fish Market and myself went to the UK to attend an expert meeting with our equivalents in the UK and the US - so experts in microplastic in seafood, and also experts in human health, exposure risks and public perceptions, as well as key seafood representatives. The point of the workshop was to figure out what the actual risk of microplastics are to human health via seafood. We wanted to explore if microplastics are getting into people via seafood, in an amount we should be concerned about as a consumer and also how that might compare with other food sources.
Microplastics in seafood is a bit of a sexy story, and often gets lots of clicks and hyped up by the media. A systematic search of the peer-reviewed literature found that the majority (70%) of studies looking at microplastics in food sources have focused on seafoods. Part of the reason is because if you ask people, "What do you know about plastic pollution?" they'll say straight away that they think it's in our ocean when actually, there's plastic pollution all over land as well.
The term 'microplastic' was first used in 2009. Seafood was probably one of the first foods that scientists tested for microplastic because the gut content of a fish, for example, is much easier to measure than the gut contents of a cow. Microplastic research is relatively recent and it's grown exponentially in the last 15 years or so - because of that, the methods have grown really quickly, too. So we now have much better methods to be able to detect microplastics and also down to the nanoscale as well.
The first takeaway from our research would be that unfortunately we can't escape microplastics anymore. They're found in everything. Exposure from indoor air accounts for 100-1,000 particles per day, which is orders of magnitude higher than estimated via seafood consumption. It's important we still recognise microplastic is in seafood, but levels appear to be similar to those in other foods and beverages. So don't let microplastics turn you off from eating seafood.
The other one that I always say to people is that we still don't know the human health effects and what extent they're occurring. I wouldn't go and eat microplastics with a teaspoon, obviously, but there's still so much more research to be done to understand what they are doing from a human health perspective.
So how do we correct the misperception of microplastic presence within the scientific community and the media? It's not that we should just stop looking at microplastics in seafood - it's important to have that knowledge and those baseline sets of data. But it's important that the results are put in context amongst other food sources.
Another good next step is that scientists need to make sure that when they write about these things, they make it really easy to understand. If you're talking about exposure risk or something similar, you need to put that into context. That's how you get more trust in people and the community.
I've done a lot of work on the perceptions of microplastics where we interviewed a lot of fishers - aquaculture and also wild-catch. For both recreational and commercial fishers, the ocean is their backyard. And fishers are so aware of the issue, making sure they replace gear regularly so they don't lose nets and that sort of thing - they're probably significantly more aware than the general public would be of how important it is to keep the ocean healthy.
Key research takeaways
- Evidence indicates that levels of plastic particles in seafoods are consistent with those of other foods and beverages and that human exposure to plastic particles is higher via indoor air and dust than by ingestion of foods and beverages.
- While uncertainties remain, currently there is minimal evidence of dietary toxicity from plastic particles at relevant exposure levels, and the focus on seafood is unjustified.
- Scientific and public media communications about plastic particle contamination of foods and health effects have led to biased perceptions of health risks and loss of the beneficial health effects of seafood consumption.
Read the full scientific article online.
