Washing machines not only consume energy and water, they also pollute the environment in other ways. Detergents and softeners may contain, among other substances, microplastic. This can then get back into the waters via the sewage, as sewage treatment plants do not have a corresponding technology. In addition, when washing some textiles such as fleece pullovers solve tiny synthetic fibers that also pollute the environment.
Remedy could be here the gentle washing program of washing machine – at least that seems to promise the name. Although you usually give less laundry in the drum than the standard program, but more water is used and spun at a lower speed. The friction under the laundry decreases. One might therefore assume that fewer fibers are released.
But a study by researchers at Newcastle University comes to a different conclusion: According to this, on machine gentle washing, an average of 800,000 tiny microfibers get into the wastewater more than programs with higher speeds when spinning.
To classify: Earlier studies had revealed that washing synthetic garments could release between 500,000 and six million microfibers per wash, according to a Guardian report. The garment industry produces more than 40 million tons of synthetic fibers every year.
"The result surprised us," says study director Grant Burgess. The work of the marine biologist has appeared in the journal "Environmental Science and Technology". The researchers had expected that more water in the machine would lead to less plastic emissions. But the opposite was the case.
Researchers had tested polyester T-shirts first in experimental setups in the lab and then in washing machines with various programs. The amount of water, temperature, washing time and movement of the laundry were considered.
Subsequently, released fibers were collected from the wash water with a filter and weighed. It showed that a lot more polyester fibers were released in the gentle cycle. Why this is so, is not fully understood. But it could only be due to the higher amount of water, the researchers said. "Apparently, the less water swirls the laundry and the water itself can pull the fibers out of the clothing, because the t-shirts were soaked up, and during the spin cycle, the fibers are then pressed out of the clothing together with the water.
With the study, the scientists want to find out which way microplastics enter the environment. Especially in the waters, the entry has increased significantly in recent years. According to the World Conservation Union (IUCN), about 1.5 million tons of microplastics are released into the sea each year, and most of the plastic is flushed into the oceans via rivers in Asia.
It is still unclear what impact the particles have on the environment. But researchers have been able to prove plastic in the Arctic ice and even in the deep sea.
The entry of microplastic from washing machines can in principle be reduced by clothing made of wool, cotton, silk or linen. But in the environmental balance, these substances are also not without problems, since for the production of some large quantities of water are needed.