Microplastics are in our food, water and air. How can we minimise our exposure to them?

Australia Broadcast Center

10 hours ago

The scourge of plastic pollution will continue to grow, at least for now, after talks to strike a global treaty fell apart this month.
It was the sixth round of such negotiations in three years, but despite a last-ditch scramble on Friday, delegates could not reach agreement.
Meanwhile, new research continues to expose plastic's quiet presence in our food, tap water and the air we breathe.
A study published last month found higher-than-expected levels of inhalable plastic particles in a handful of apartments and cars in France.
Recent Australian research found even compost contains teeny plastic fragments, which may eventually make their way into agricultural soils and food crops.
These are a couple of the latest studies into microplastics: fragments or fibres of plastic between a micron (one millionth of a metre) up to 5 millimetres in size.
Microplastics can be created as a result of larger pieces of plastic shedding or breaking apart, or be added to products, such as plastic powders added to some cosmetics.
Along with microplastics, there are also nanoplastics.
These are plastic particles less than a micron wide. For context, a human hair is about 50 microns in diameter.
Being so tiny, nanoplastics might more easily infiltrate human cells and tissues such as our blood, "so they're the ones scientists are interested in", University of Queensland microplastics researcher Cassandra Rauert said.
So considering micro- and nanoplastics are everywhere, from the summit of Everest to the deepest ocean, how can we minimise our exposure without living in a cave?
The short answer is: we don't yet know.
Part of that stems from the fact that we don't know a whole lot about microplastics in general, such as where they come from, how many are in our environment, how they might get into our body, what they do once they're in there, and how much we excrete.
"Unfortunately, microplastics is a very new field of research," Dr Rauert said.
Compared to other everyday pollutants such as pesticides, scientists don't have a good handle on the potential effects of microplastic or nanoplastic exposure.
And current techniques to identify micro- and nanoplastics in various organs "are not perfect".
"We really don't have good data showing that plastics are ending up in our brains or our liver or our placenta and things like that.
"There's a lot of reactive media to those studies and it's causing a lot of concern, which is very understandable, but … we really don't have a good grip on if plastics are actually getting into our bodies yet."
So what do we know? More research needs to be done, but it seems that micro- and nanoplastics can generate inflammation, Dr Rauert said.
It's not just the physical presence of plastic particles in the body that may affect our health — it's also the chemicals they bring with them, she added: "You're getting a double hit when you're exposed to these things."
Such chemicals can be picked up by plastic particles from the environment, or are additives used during manufacturing that make the plastic more malleable, for instance.
These chemicals can disrupt hormones, and "there's evidence coming out now that they're linked to type 2 diabetes", Dr Rauert said.
"It's these chemicals that we … are more concerned about exposure to [than the plastic itself]."
Despite not yet having definitive evidence that microplastics cause harm to our health, researchers suggest avoiding them as much as possible.
That can be hard, considering just how much plastic is all around us all the time.
When it comes to food, there is some good news: there's probably less plastic in what we eat than originally feared.
One of Dr Rauert's students surveyed food a typical Australian would buy from the supermarket and found low concentrations of nano- and microplastics in them.
Any plastic present in food probably comes from the packaging around it.
But it's what we do with the food when we bring it home that can contribute to microplastic levels, Dr Rauert added.
"If you're using a plastic chopping board, every time you use that [and] you can see it's deforming and degrading as you're using it, there are small pieces of plastic that are going to be coming off that board and end up in the food you're eating."
The same goes with plastic ladles and the like. So if possible, try to use wooden chopping boards and metal or wood utensils.
Tap water is a potentially bigger source of microplastics than food.
These plastic particles can come from any number of sources, from the water treatment process to the PVC pipes that plumb your home.
Putting tap water through a filter may be helpful in removing some of the larger microplastics, Dr Rauert said, even if some of the smaller microplastics and nanoplastics slip through.
"I reckon in the next couple of years there probably will be some [microplastic-filtering devices] on the market."
The air inside our home and the dust that settles on surfaces could well be teeming with micro- and nanoplastics small enough to get into our lungs.
Synthetic textiles such as polyester and nylon shed tiny fragments and fibres of plastic, and they are found everywhere from furniture to clothes to manchester and carpet.
"A lot of our carpets are polypropylene, so when pieces of the carpet are just wearing off over time, then you're getting small pieces of polypropylene in the air," Dr Rauert said.
It might sound boring, but wiping down dusty surfaces and vacuuming regularly can reduce microplastics in your home.
Another big source of microplastics in the home, Dr Rauert said, is the clothes dryer, especially if you use it to dry synthetic materials.
As they tumble in the hot air, synthetic materials release plastic fibres that aren't captured by the dryer filter. And if that hot air blows out into your home, it carries all those fibres with it.
It's often not available to people in apartments, but having a dryer that exhausts to the outside environment instead of inside your house can help keep microplastics down, as can avoiding using the dryer for synthetic materials altogether.
Generally, the air outside has fewer microplastics than indoor air, especially in winter when windows might remain closed to keep the warmth in.
So it's worth periodically opening windows and doors to ventilate the air in your home and let microplastics out.
While we can take individual action to keep our home environment as microplastic-free as possible, plastic pollution will continue to be a problem until large-scale changes are made, such as tougher action from governments, Dr Rauert said.
"There are small things we can do, but we really need a bigger, collective global effort to try and really cut down the amount of unnecessary plastic that we keep on producing every year.
"You don't actually consider how much plastic you use in your everyday life. It's always there. It's just you don't think about it."
For more on microplastics, check out the full episode of Lab Notes.