A shocking report from the United Nations Environment Program (UNEP) reveals that 60% of the clothes that humans use, carry, or wear are made from plastic-based materials like rayon, acrylic, polyester, and nylon. Every time you wash these plastic-based clothes, microfibers (a type of microplastics) containing dangerous chemicals, dyes, and other types of plastic pollutants are released into our environment. 

These microfibers now account for 60 million tons of plastic waste every year, and what’s more surprising is that a new study from Proctor & Gamble (P&G) suggests that drying clothes in the machine (tumble drying) leads to microfiber pollution at levels comparable to the release from washing.

Why machine drying is dangerous for our environment

Neil Lant and his team of researchers at P&G point out that most of the research that focuses on microfibers from laundry considers only the microplastics released during washing. Very little is known about the pollution resulting from tumble drying. Lant told ZME Science, “while the waterborne release of microfibers from washing machines has been researched for over five years now, the issue of airborne release from dryers is only emerging,” and it’s a very serious problem. For instance, in North America only, over 30 billion wash loads are tumble-dried in vented dryers every year. 

This means that 60,000 wash loads go for tumble drying every minute, and thousands of tons of microfibers are released into the air every year. Such amounts of microfibers in the air may cause lung cancer and various breathing-related problems in humans. If the microfibers settle and mix into water or soil, they leak harmful chemicals and carcinogenic substances, disturbing the entire ecosystem’s health.

When asked about how they come across this microfiber problem in the first place? The researchers at P&G revealed that they washed and dried ten polyester and ten cotton T-shirts in normal European and North American domestic drying conditions and then evaluated the microfibers released during washing, captured in lint filters, and released into the air. The researcher noticed that a significant amount of microfibers was released into the air.

“We found very similar levels of release down the drain in the washing process compared to airborne release from dryers. For some dryers, e.g. those with coarse pore size lint filters, release from the dryer could be higher than in the wash but we completed most work with a medium pore size dryer so believe that equal is a good approximation,” said Lant.

What’s the solution?

During their experiment, the scientists at P&G also found out that the microfiber release from tumble dryers can be controlled by using “fabric conditioners and lint filters with smaller pore”. They claim that by employing fully- sealed condenser dryers and modifying the design of their machine’s lint filters, appliance manufacturers can come up with dryers that would put out less microfiber pollution. The researchers wrote in their paper that the airborne fiber pollution from dryers can be significantly reduced by improving the design of vented dryers or using fabric conditioning liquids or sheets. They also highlighted that heat-pump condenser dryers are the best long-term solution for this problem as they are energy efficient and don’t let out any microfibers at all.

Neil Lant further told ZME Science that microfiber pollution from tumble drying can be reduced by over 90% if dryer manufacturers implement the solutions suggested by their team.

“Condenser dryers have no release to the air as the water is condensed back to liquid, so there is no external vent and hence no airborne fiber pollution. If vented dryers moved to highly efficient fiber removal systems we believe that over 90% of fibers could be collected but condenser dryers are the best solution to eliminate air pollution. Condenser dryers are available in conventional and heat pump designs – both do not release any fibers to air, but heat pump appliances are the most energy-efficient. Around 98% of dryers in North America are of the vented design so the appliance industry needs to think about converting this market to condenser dryers,” the researcher notes.

The scientists also agreed that more research is required to better understand the impact microfibers from tumble dryers have on our environment.