Key takeaways
- New research maps the scale of microplastics moving from packaging into food and drinks
- It estimates packaging releases around 1,000 tons of plastic particles a year
- Most particles identified are smaller than 150 micrometers, small enough to penetrate cell barriers and thus interact with biological systems.
- Change to design and storage of PET bottles could help reduce emissions
Microplastics and nanoplastics are an increasing concern to consumers. These are small plastic particles - invisible to the naked eye - than come from the degradation of plastics.
Research shows they’re now found in everything from marine life to food.
And now a new study from Earth Action and rePurpose Global has looked specifically at their proliferation in food: finding that 1,000 tonnes of microplastic and nanoplastics move from plastic packaging into food and drinks every year. That’s roughly equivalent to the weight of more than 600 cars.
This equates to an average of 130mg per person annually, rising to over 1g for high-use consumers and equivalent to hundreds of millions to billions of particles being ingested.
In fact, food packaging is one of the most direct and recurrent pathways of plastic exposure in everyday life, says the report.
Unlike most environmental sources of micro and nanoplastics, packaging is in continuous contact with the products that are then ingested.
That means even comparatively small emissions can translate into systematic exposure for humans.
Irradiation risk
While often viewed as inert, food packaging degrades and releases micro and nanoplastics into food.
And the beverage industry in in the limelight: PET bottles account for a third of total packaging related exposure.
And there are three factors that exacerbate the release of microplastics.
Irradiation is the primary driver: with sunlight and UV exposure increasing release by up to two orders of magnitude.
Then there’s the mechanical stress and abrasion: opening and closing bottles or containers, with the friction generating microplastics.
And then there’s what’s called thermal stress amplification: microwaving and hot-filling weaken the polymer matrix, accelerating the detachment of particles.
Julien Boucher, co-founder of Earth Action, uses the analogy of a cold bowl of leftover spaghetti: which congeals in a block in the fridge. But warm it up, and the strands start to loosen up, move and separate.
But it’s not just about the microplastics. Additives are added to plastic to change the colour or properties: so this chemical leaching is another factor.
Finding solutions
While the report makes for alarming reading, Boucher says that’s not the intention. By quantifying the problem and - most importantly - identifying the biggest sources of microplastics, brands can start to do something about reducing the problem.
“This is not a report with bad news about a hopeless situation: it’s showing emissions can go up very easily and quickly if you don’t make the right decisions,” he said.
Simple choices can make a difference: for example, in PET bottles closures, continuous rings emit fewer microplastics than segmented ones.
How to keep PET bottles
For PET bottles, exposure to heat and light;
and repeated opening/
closing or squeezing can exacerbate the release of microplastics.
And the report also raises the ‘critical’ gap in food safety regulation in the area. Ingesting 100 - 200 milligrams of micro- and nanoplastics is associated with around 50 milligrams of chemical exposure: but current food-contact regulations rarely acknowledge this.
How dangerous are microplastics?
While Earth Action’s report has quantified the problem, proponents of plastic will cite a lack of research into health impacts and how bad microplastics actually are.
“Absence of proof is not evidence of safety,” counters Boucher.
“I think what we can say, to be fact-based, is that we know the emission of microplastics and nanoplastics in food is widespread. You find microplastics and nanoplastics everywhere.
“The second thing is that we’re learning, more and more, that these same microplastics are being found in the human body. So it’s there, and demonstrates there’s a clear pathway connection from packaging to food to human body.”
Most particles identified are smaller than 150 micrometers, small enough to penetrate cell barriers and thus interact with biological systems.
There is also the question of where most microplastics are emitted. Are they coming from agriculture, or manufacturing, or elsewhere in the supply chain? Or are they released once products reach the consumer and they’re kept in suboptimal conditions such as under heat or UV light?
Chemical leaching is another issue as well: with endocrine-disrupting and carciogenic substances.
“There is a high probability that these emissions matter a lot,” said Boucher. “I think we’ll see more and more studies coming.”
