Kitchen Sponges Release Microplastics, Water Use Dominates Environmental Impact

Kitchen sponges release microplastics during dishwashing, according to a new study from the University of Bonn. Researchers found that different sponge types shed varying amounts of plastic particles. While microplastic release is a concern, the study indicates that water consumption during manual dishwashing has a much larger environmental impact.

The research team conducted laboratory tests and citizen science experiments. Volunteers in Germany and North America used three types of sponges in their daily routines. Researchers weighed the sponges before and after use to measure material loss. An automated system called "SpongeBot" simulated mechanical stress on sponges in the lab.

Every sponge tested released microplastics. Annual emissions per person ranged from 0.68 grams to 4.21 grams, depending on the sponge type. Sponges with less plastic content released fewer particles. Citizen science provided realistic data on household usage patterns.

Scaling up these findings, researchers estimated that if one particular sponge type were used in every German household, annual microplastic emissions could reach 355 metric tons. Wastewater treatment plants capture many of these particles, but several metric tons could still enter natural environments annually. However, the study found that 85 to 97 percent of the total environmental impact of manual dishwashing comes from water consumption.

Consumers can reduce their environmental footprint by using less water when washing dishes. Choosing sponges with lower plastic content also helps reduce microplastic release. Extending the lifespan of sponges can also decrease overall resource consumption.

The study was published in *Environmental Advances*. Researchers from the University of Bonn, the Fraunhofer Institute for Environmental, Safety and Energy Technology UMSICHT, and Leiden University contributed to the findings.