You thought washing machines were polluting? Tumble dryers take it one step further.

Before that you could read that every time you do a wash, countless microplastics end up in the wastewater. Synthetic clothing consists of millions of tiny plastic microfibres that break down and are washed away in the washing machine. But what about his little brother; the dryer? The answer is already obvious…

Washing machine

In recent years, there has been an increasing amount of research into how microfibers end up in the environment. Microfibers come from natural materials – such as cotton – and synthetic materials – such as polyester – which are also referred to as microplastics. Several studies have shown that washing machines are major culprits. “A single full wash drum can sometimes release more than 137,951 microfibres,” said researcher Kai Zhang in conversation with These microfibres then end up in our wastewater and, because they are difficult to filter out of the water due to their small size, also in our waterways.

Clothes dryer

However, many people don’t just have a washing machine in the attic, it is often accompanied by a tumble dryer. However, very little is known about the question of whether dryers, where air flows through a duct and is thus discharged directly outside, also discharge microplastics into nature. And so researchers decided in a new study to study exactly how polluting this household appliance is.


The researchers placed several pieces of polyester and cotton one after the other in the dryer, which was connected to the outside air by a vent pipe. While the machine ran a short fifteen-minute program, the team collected and counted the particles in the air that set out from the vent.

120 million microfibres

It leads to a disturbing discovery. For example, it appears that a particularly large amount of microfibres are produced during the drying of both types of clothing; more so than by washing machines. For example, 1.4 to 40 more microscopic fibers are released in the dryer than in the washing machine with the same amount of clothing. The team suspects this is because the garments rub against each other as they tumble around in the dryer. And those are huge numbers. “After 15 minutes of drying, between 70,878 and 433,128 microfibers (on 6 pounds of cotton clothing) and between 102,156 and 561,810 microfibers (on 7 pounds of polyester clothing) can be released,” Zhang says. After doing some math, the researchers estimate that one tumble dryer blows between 90 and 120 million microfibres into the air every year.

It also matters how full you put the dryer. The more polyester garments there are in the machine, the more microfibres are produced. Surprisingly, the release of cotton microfibres remains the same even with a full drum.

The fact that even more microplastics end up in nature due to dryers than washing machines is quite worrying. That’s because we don’t drink water all day long, but we do breathe air continuously. In short, we are much more exposed to the microplastics that are blown into the air by clothes dryers than to the microplastics that end up in the water via washing machines.


Whether the microfibres released by dryers are actually harmful to our health remains to be investigated. “Our next step is to take air samples near laundromats,” Zhang says. “In this way, we want to study the amount of microfibres in real environments – outside the lab. At the moment we have not yet mapped out the ecological risk of the released microfibres. However, it is known that microplastics in the air can be associated with a number of health conditions, including the lung disease COPD.”

“Reduce the use of the dryer”

You can do this

According to the researchers, it is important that we tackle the problem. And that can be done very easily. “Reduce the use of the dryer,” emphasizes Zhang. “Or at least don’t put any more artificial substances in it. In addition, you can also place a filter at the end of the pipe, in order to minimize the release of microfibres.”

In addition, the study is also an important lesson for the clothing industry. Especially cheap items of clothing often fall apart after a few washing and drying cycles. And those little bits of fabric and stitching then easily find their way out. “It is therefore essential to produce better clothing with good abrasion resistance, longer wear time and improved environmental friendliness,” concludes Zhang.