Kitchen sponge releases microplastics. You do this every time you wash dishes

Clean plates, but polluted water. Washing dishes is never environmentally neutral. Scientists from the University of Bonn have confirmed that a worn kitchen sponge releases trace amounts of microplastics into wastewater. When these amounts are added together, the emissions reach hundreds of tons per year.

From the sink to the sea: hundreds of tons of microplastics every year

The fact that a kitchen sponge gradually wears out and erodes over time is visible to the naked eye. However, the particles that end up in the sink drain had not previously been the subject of detailed research. Scientists from the University of Bonn decided to investigate the issue. They recruited participants from Germany and North America, who used three types of kitchen sponges: one commonly used sponge from each region and one organic sponge.

After each washing session, the researchers weighed the sponges and recorded their loss of mass. They found that the amount of microplastics entering wastewater ranged from 0.68 to as much as 4.21 g per person annually. The findings were further verified under laboratory conditions, where researchers compressed the sponges using a special device to simulate wear and tear.

The measured quantities may appear insignificant. However, when extrapolated to households across Germany, dishwashing could be responsible for releasing as much as 355 tons of microplastics into wastewater each year.

Not all sponges are the same: which one causes the most harm?

It is not surprising that sponges with a high plastic content released the greatest amounts of microplastics. The differences between individual sponge types were substantial. The sponges that released the fewest microplastic particles contained 15.9 percent plastic. Those responsible for the highest emissions contained as much as 59.3 percent plastic.

Conventional sponges released up to six times more microplastics than organic sponges. This is an important factor to consider when shopping. Choosing kitchen sponges made from better materials can significantly reduce the amount of microplastics entering wastewater and, ultimately, aquatic environments.

Hand washing dishes is the main concern

Microplastics entering ecosystems can cause a wide range of negative effects. In living organisms, they have been associated with oxidative stress as well as disruptions to the digestive, respiratory, hormonal, reproductive, and immune systems. However, the scientists from Bonn point out that, in the case of dishwashing, microscopic plastic particles are not the greatest environmental burden.

Far more important are the amounts of water consumed and the energy required to heat the water, deliver it, and subsequently treat the wastewater. Therefore, anyone wishing to reduce the environmental impact of dishwashing should primarily focus on lowering water consumption. One effective solution is to replace frequent hand washing with a fully loaded dishwasher. When using a dishwasher, it is best to select the eco program, which uses less water and energy.

The kitchen sponge is not the only source of microplastics in the home kitchen. Researchers noted that even larger quantities of plastic particles, between 7 and 50 g per year, may come from plastic cutting boards. This finding suggests that reducing the number of plastic kitchen accessories and choosing products made from natural materials more often could help limit microplastic pollution.

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Source:

Leandra Hamann, Christina Galafton, Peter T. Rühr, Alexander Blanke, Nils Thonemann, From Sink to Sea: Microplastic Release from Kitchen Sponges and Potential Environmental Effects, Environmental Advances, Volume 23, 2026, 100693, ISSN 2666-7657, https://doi.org/10.1016/j.envadv.2026.100693