Sam Athey has studied both synthetic and natural microfibres. We asked about her recent studies.
Samantha Athey is a PhD student at the University of Toronto's School of Earth Sciences, and an expert on how washing clothes is generating pollution in the environment.
Sam specialises in research examining how microfibres and chemicals from clothing are contaminating the Great Lakes and oceans around Canada.
She has just published important research showing how microfibres from denim jeans are polluting the farthest reaches of the planet....
You specialise in studying microfibre and chemical loss from clothing. What led you to this area?
During my undergraduate and Masters programs at the University of North Carolina Wilmington, I conducted research on the impacts of microplastics on marine and estuarine organisms (read more about this work here).
What interested me most about this work, was how chemical contaminants interact with microplastics / microfibers and the implications of this phenomenon in the environment.
For my PhD dissertation research at the University of Toronto, I am investigating the release pathways of microfibers and associated chemical contaminants.
More specifically, I am interested in the role that microfibers play in the release of chemical contaminants to the environment.
Microfibre pollution is a significant environmental issue. Can you give us a sense of just how big it is?
Microfibers, a majority of which come from textiles, are a widespread form of anthropogenic pollution.
These small fibers have been documented in nearly every environment on Earth, from indoor air in Australian homes to remote Canadian Arctic sediments.
They have also been found in products destined for human consumption - e.g. tap water, beer and seafood.
As I am typing this, I can see microfibers in the dust between my keyboard keys!
Do you think people know about microfibres... and that they are unwittingly causing pollution just by wearing and washing clothes?
Awareness of the microfiber pollution issue is growing.
However, I do believe there is a general misunderstanding of the source and general nature of microfiber pollution.
Most research and communication on the issue has focused on plastic microfibers. The problem with this view is that it neglects a large portion of anthropogenic microfibers that we find in the environment.
Microfibers can also consist of natural or semi-synthetic materials (e.g. cotton, rayon) that are modified using synthetic chemical additives.
While these fibers do degrade faster than their plastic counterparts, ‘natural’ fibers are sufficiently persistent to potentially cause impacts to ecosystems.
These ‘natural’ fibers have been found to be widespread in the environment and, in many cases, are more abundant than their plastic counterparts.
This means that research, communication and solutions devised to address this issue need to have consideration for the complete suite of anthropogenic microfibers (i.e. not simplifying the solution to just switching to natural textiles).
You recently published research into the extent of 'natural' microfibre pollution from denim jeans. Why did you choose to study denim?
This study came about in a rather unique way. My co-authors and I focus on different environments and in a lab meeting we were discussing the type of anthropogenic fibers we were finding in our samples.
Cotton dyed with indigo was a common type of fiber throughout all of our samples.
As the group was wondering where or what these fibers were coming from, Miriam Diamond - Professor and corresponding author on the study - said something along the lines of:
Oh my - I bet it's blue jeans!
Thus, the goal of tracing these fibers to their source was born.
Ultimately, denim provides a prime and personal example of how the remnants of our clothing is far-reaching (from your washing machine to the Arctic Ocean).
What did you find?
We found microfibers to be abundant across all environments and sites that we sampled in our study - from the Canadian Arctic to the Great Lakes.
One of the most common types of microfibers we found were cotton fibers dyed with synthetic indigo dye.
Because these fibers were also prevalent in effluent samples taken from wastewater treatment plants, we concluded that clothes washing may be a source of these fibers to the aquatic environment via wastewater.
To determine if washing blue jeans was in fact a source of these fibers to the environment, we conducted a series of controlled washing experiments.
We captured and analyzed the types of fibers released from washing denim and compared them to the fibers found in the environment - and they matched!
So, we were able to conclude that blue jeans are a source of microfibers to the environment via wastewater from suburban to remote areas.
Were you surprised by the extent of the denim fibres you found?
Sadly, we were not surprised to find denim fibers throughout our environmental samples.
Blue jeans are a widely popular garment across the globe (with approximately 450 million pairs sold annually in the US alone).
We know that fibers can be released from our clothing (including denim) during normal wear and tear, as well as washing and drying.
These dislodged fibers can then enter the environment through several different pathways (e.g., wastewater).
Do we know how long these fibres can last in the environment and the ocean?
While we know that ‘natural’ fibers, like denim, do not last as long in the environment as plastic microfibers, our study provides evidence for the long-range transport of denim fibers (potentially via atmospheric or oceanic currents), as well as ingestion by biota.
This means that these types of microfibers are sufficiently persistent to contaminate remote areas across the globe, where they could be of concern to wildlife.
Could these microfibres be harmful to wildlife - and potentially us?
This is a good question – and one of the questions that we have coming from our study!
Now that we know these fibers are widespread in the environment and being ingested by biota, our next steps are to investigate the effects and implications for wildlife.
Denim is made from cotton - classed as a natural fibre. From an environmental perspective, should we be choosing natural fibre clothing over synthetic fabrics?
In terms of microfiber pollution, research is relatively limited, but past studies that have compared fabric types have found cotton sheds more microfibers than synthetic fabrics (e.g., polyester).
This makes sense since one of the reasons synthetic fabrics are so popular is their durability.
However, because all fabrics shed microfibers that contaminate the environment, the solution to microfiber pollution is more complicated than simply switching fabric types.
When considering the environmental impact of the material that your clothing is created from, you should also consider other factors, such as greenhouse gas emissions, water and pesticide usage, etc.
Science has done an amazing job highlighting microfibre pollution. But it hasn't really told us whether it matters - whether it could be harmful. Should we be concerned?
Research on the impacts of microfibers is just now coming out and the impacts of plastic fibers (let alone non-plastic fibers) to humans and wildlife are still not fully understood.
However, as we have shown in our study, this form of anthropogenic pollution is widespread.
Until we understand the impacts, we should be taking preventative steps to mitigate the potential impact of microfibers on the environment.
How can we stop, or at least reduce microfibre pollution?
We have identified a couple of steps that a person could take to reduce the quantity of microfibers released from their laundering:
- Wash your jeans less often (manufacturers recommend washing once a month at most, if possible)
- Use a washing machine filter or other device to trap microfibers released during washing
- When in the market for a new pair of jeans, purchase used or second hand (our study shows used jeans shed less fibers than new jeans).
For the most part, these best practices hold true for other types of garment as well.
Should washing machines change to include filters to catch microfibres?
In the past, some washing machines made in North America had lint filters similar to those found in tumble dryers.
So washing machines certainly can be manufactured with filters to remove lint (including microfibers) and other debris from the wash.
Research from our group has shown that washing machine filters are effective at diverting microfibers from entering the aquatic environment through wastewater discharge via washing.
Politicians have done a lot of work on reducing plastic waste such as bags and straws. In your opinion, should they also be focusing on microfibre pollution?
Because microfibers are one of the most common forms of anthropogenic particles (e.g., microplastics) that we find in environmental samples, I do think that legislative action on this issue is possible (as seen in California, Connecticut and New York).
This may involve the establishment of diverse working groups to address the problem, establishing requirements for clothing manufacturers and evaluating microfiber filtration systems.
All images have been reproduced with the kind permission of Sam Athey, who retains all copyright.