An overwhelming 9.5 billion tonnes of plastic was produced by the world in 2019, according to the Global Change Data Lab, a U.K. non-profit.

While some efforts to reduce plastic waste are being made, such as through elimination of plastic bags at grocery stores, or the riddance of plastic straws by Starbucks, one unexpected contributor to the overwhelming amount of microplastics in the environment could be the way clothes are washed.

A new study published in the American Chemical Society (ACS) journal ES&T Water found that handwashing clothing made with plastic-fibres such as polyester and nylon releases less microplastics into the environment as opposed to using a washing machine.

Past research has confirmed the high amounts of microplastics released though laundry machine washing. That’s why a of team of researchers based in the U.S. and China sought to further explore the results of handwashing, according to the ACS study.

WHAT ARE MICROPLASTICS?

Microplastics are the tiny plastic particles, smaller than five millimetres, according to the National Ocean Service, that result from both commercial products, such as cosmetics and clothes, and the breakdown of larger plastics.

The problem with microplastics, is that like all sizes of plastic waste, the fibres do not easily break down into harmless molecules, and will take hundreds or thousands of years to fully decompose.

Until then, it’s estimated there are 24.4 trillion pieces of microplastics that litter our oceans and are extremely harmful to the environment.

One major source of this environmental damage is from the microplastic fibres shed through laundering synthetic fabrics, according to the ACS study.

THE STUDY: METHOD AND FINDINGS

To further understand which washing methods drive higher amounts of microplastic shedding, the researchers cleaned two types of fabric swatches, one made from 100 per cent polyester, and the other made up of 95 per cent polyester and 5 per cent spandex. They ran the fabrics through a washing machine and hand-washed them as well.

They found that manually handwashing methods released significantly few plastic fibres.

It’s all in the numbers: when the first fabric made completely of polyester was washed via machine, it shed an average of 23,723 microplastics, compared to 1,853 microplastic pieces shed on average when hand washed.

The study also found that the fibres released by handwashing tended to be longer. (Officially microplastics are defined as being less than five millimetres (0.2 inches) in diameter.)

Some sneaky ways that the shedding of microplastics were found to increase while handwashing however were by using detergent, pre-soaking fabrics, and using a washboard — but the number of fibres was still less than through the washing machine method.

They also found that factors such as water temperature or amount, type of detergent, and wash time, did not appear to have any substantial impact on how many microplastics shed when handwashing.

The researchers hope that these findings will encourage greener laundry practices in the future, says the press release for the study.