Studies have shown that handwashing emits less microplastics than using a washing machine.
The question is whether all laundry can be hand washed in the 21st century.
In other words, it causes the same worries as driving around in a car even though it emits pollutants and greenhouse gases.
Researchers at Hangzhou University of Electronics and Technology and the University of Massachusetts in China recently published a paper in the journal Environmental Science and Technology-Water comparing the number and amount of microplastics emitted when washing machines and hand-washing.
The research team explained, "Microplastic fiber (MPF) produced when washing synthetic fiber products is one of the main sources of microplastics," adding, "It accounts for up to 35% of microplastics emitted to the world's oceans."
In particular, as of 2015, the primary microplastics emitted from China reached 737,290 tons, of which 37.15% came from synthetic fibers.
In addition, more than 120,000 tons, or one-sixth of China's primary microplastic emissions, flow into the water system.
Primary microplastics refer to plastics that are emitted in small sizes of less than 5mm from the beginning, and secondary microplastics refer to large plastics that are broken into small pieces in nature.
Since these data are from experiments using washing machines, the research team points out that experiments on hand washing are also necessary to know the exact amount of microplastics emitted.
In developing countries, handwashing still remains, and in China, the rate of handwashing still reaches 37%.
The research team cut two fabrics, a 100% polyester fabric and a 95% polyester-5% spandex blend, into 15cm by 15cm and used them in the experiment.
For hand washing, the liquid detergent was soaked in water dissolved at a concentration of 1,5 g per liter for 20 minutes and rubbed 18 times per minute on a wooden washboard for 5 minutes.
In addition, it was carried out by rinsing until the foam completely fell out.
The microplastic emissions were determined by filtering all water from washing, including soapy water, rinsed water, and even washed washboards.
The washing machine used in the experiment was a small washing machine favored by young Chinese people, and it used a course of washing for five minutes and then rinsing twice.
According to the research team's analysis, the average number of microplastics emitted per piece of 100% polyester fabric sample was 1853 for hand washing and 23,723 for washing machines.
The average mass of microplastics emitted was 37.84mg for hand washing and 222.84mg for washing machines per kilogram of fabric.
Washing machines produced 12.8 times more microplastics in number and 5.9 times more in mass than hand washing.
Likewise, in the case of mixed fabrics, an average of 28,672 microplastics per piece of fabric and 224.29mg per kilogram of fiber were emitted from washing machines.
The average number of microplastics released when handwashing mixed fabrics was 2240 per piece and 38.09mg per kilogram of fiber.
In the case of mixed fabrics, washing machines produced 12.8 times the number and 5.9 times the mass.
The research team said, "The length of microplastic fibers discharged when using a washing machine tends to be short," adding, "There is a possibility that the fibers may break because washing proceeds under more severe conditions."
Washing machines can be more harmful to the environment because shorter microplastic fibers are released.
Repeated washing also gradually reduces the amount of microplastics emitted and stabilizes emissions.
When using a washing machine, after washing it six to eight times repeatedly, the emission of microplastics stabilized to 11,000 per piece of fabric and 110mg per kilogram of fabric.
In the case of hand washing, it stabilized at a lower level than the first time after repeated washing four to six times.
The research team argued that if more than 1.5g of detergent is used per liter, or if the time to soak in water in advance exceeds 20 minutes, more microplastics are emitted.
He also pointed out that using a washboard when handwashing produces a lot of microplastics, but it is not comparable to washing machines.
The research team added that the temperature of water, the type of detergent (solid or liquid), and the amount of water used do not significantly affect microplastic emissions.
While presenting the number of microplastic emissions, the research team implicitly emphasized that handwashing is more "environmentally friendly" than using washing machines.
The problem is that it is never easy to avoid the use of washing machines to reduce microplastic emissions with washing machines already widely available.
In other words, comprehensive efforts in each field must be made to improve or replace the materials of textile and clothing products, improve washing machine structure and performance, and improve sewage treatment plant facilities to reduce microplastic emissions.
Experts suggest, "If you reduce the number of laundry times and use drying rack and laundry line instead of forced dehydration, you can reduce microplastic emissions."
In addition, it is possible to filter out microplastics by attaching a filter to the washing machine or turning the "plastic ball" together when washing.
(Picture of Plastic Ball)
France made it mandatory in 2000 to attach microplastic filters to new washing machines from 2025.
Lee Soo-jin, a member of the National Assembly's Environment and Labor Committee, proposed a revision to the "Act on Resource Circulation of Electrical, Electronic Products and Automobiles" last fall to reduce microplastics emitted into the ocean and atmosphere.
The revision included "Electrical and electronic products and automobile manufacturers and importers should follow guidelines on material and structure improvement jointly announced by the Minister of Environment and the Minister of Trade, Industry and Energy to reduce microplastics and harmful substances that may occur in the use process."
Writer: Yeyoung Jeon
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