0342 GMT December 12, 2019
People who use triangular nylon tea bags are the latest group to be shocked at their exposure to plastics. According to one study, they could be getting about 11 billion or so particles of plastic with their Earl Grey or breakfast tea, theguardian.com wrote.
Microplastics have turned up pretty much everywhere that scientists have looked for them — from the bottom of the deepest parts of our oceans to the stomachs of whales, seabirds and in our own poo.
What is microplastic?
There’s no agreed definition, but researchers have generally referred to pieces of plastic smaller than about 5mm as microplastic. However, the University of New South Wales’s Mark Browne, who has been researching plastics since 2004, said it’s better to think about plastics relative to the units they’re measured in. So microplastics are between one micrometer and 1,000 micrometers wide (there are 1,000 micrometers in one millimeter).
There’s also an emerging field of research looking at nanoplastics — pieces too small to see with the naked eye — which are measured in nanometers (there are 1,000 nanometers in one micrometer).
What’s important to remember is that the larger pieces of plastic that can entangle wildlife end up in the stomachs of animals and litter our coastlines will in many cases become the microplastics of tomorrow.
What is it doing to our health?
“There’s an absence of science here,” says Browne. “We know that across particle sizes, plastics can cause issues. The critical issue now is what are the concentrations that people and wildlife are being exposed to. We don’t need more studies on which products emit plastics. We need studies that expose organisms or models to these doses to see if they cause problems.”
Environmental scientist Kevin Thomas, director of the Queensland Alliance for Environmental Health Sciences, is researching the different ways our bodies are being exposed to plastics.
He said there is evidence that nanoparticles, not necessarily derived from plastics, can cause our immune system to respond at a cellular level.
Thomas thinks if there is a potential for plastics to harm us, it will be once they have been reduced to those tiny ‘nano-sized’ pieces that could pass through the wall of the gut.
Unfortunately, he said, those particles are so small they’re very hard to measure.
So what does his gut tell him about the potential for harm from microplastics?
“It’s a very tough question,” said Thomas. “Personally, I think there’s little risk to our health based on what we know but then, who knows what we might find in the future.
“I eat seafood, for example, but I don’t use plastic chopping boards at home.
“But I would advocate avoiding plastics and reducing our reliance on them. Releasing plastics into our environment like we are is unacceptable.”
Browne said he has sympathy for the public, who just want answers. “My suggestion is that we need to be managing and reducing our exposure to these polymers and plastics. There’s enough evidence of harm that we should be doing that.”
What should we do?
The experts the Guardian spoke to agreed a wise step here is to reduce our use and exposure to plastics. From an environmental perspective, campaigners say we should be cutting out unnecessary plastic use, including single-use items, and substituting plastics where we can.
But Browne also had words of caution. “If we are going to do that, we should make sure that as we intercept or redesign products we don’t cause more problems,” he said.
“Remembering that some asbestos was used in clothing — it’s a natural fiber but it causes all sorts of serious issues for people.”