Homes no microplastic haven
Kiwis are probably breathing in more tiny pieces of plastic in their own homes than they are while outside, new research suggests.
The new study by a Canterbury scientist found about 10 times more tiny pieces of plastic in the air of New Zealand homes than outdoors.
The source of the airborne microplastics was mainly tiny fibres from synthetic materials used in everything from carpets, to curtains, to clothing.
They got into the air a number of ways, including clothes going through the dryer and being stirred up by people walking across the carpet.
University of Canterbury atmospheric chemist Dr Laura Revell revealed preliminary results from an as-of-yet unpublished study on microplastics at a public lecture last night.
Microplastics are defined as any piece of plastic smaller than 5 millimetres in length.
Revell said the study involved four people putting out collectors in their homes – in both hightraffic areas like living rooms, and low-traffic areas like bedrooms.
The collectors picked between 400 and 900 tiny fibres per square metre each day, she said.
Closer inspection revealed about 30% of them were microplastics – between 120 and 270 particles.
In comparison, when they first measured airborne microplastics outdoors last year, about 10 to 20 tiny pieces of plastic would settle per square metre over the course of a day.
‘‘Given that most people spend most of their time indoors, that’s probably where people are inhaling the most microplastics.
‘‘These are very, very tiny particles, perhaps one-tenth the width of a human hair.’’
While microplastic particles in the sea have been known about and studied since the 1970s, airborne microplastics were a fairly new field of research, Revell said, only being discovered in 2015.
But she said if her previous work has shown anything, it is that they were almost everywhere.
‘‘We’ve found microplastics are really ubiquitous in the air – wherever we look, we find them.’’
One of the things Revell found really concerning was that they could only detect microplastic particles down to a certain size – meaning their real density could be much, much higher.
‘‘[Microplastics] have recently been found in human blood for the first time, and in the lungs of living people undergoing surgery.’’
Another recent study, which exposed human lung cells to microplastics in a laboratory setting, found cell growth slowed, and the cells themselves changed shape, she said.
‘‘It has very real and very negative consequences for human health.’’
Revell was part of a team who detected microplastics floating in New Zealand’s air for the first time in March last year.
She also led a world-first study which found airborne microplastics could have a direct impact on climate change.
Researchers could only detect microplastic particles down to a certain size – meaning their real density could be much, much higher.