Melamine foam sponges used to clean households worldwide release trillions of microplastics each month, a new study has warned.
These sponges, known for their ability to remove even stubborn stains effortlessly, rely on their distinctive abrasive properties.
However, a new study published in the Environmental Science & Technology journal, estimates that fibres from these cleaning products release trillions of toxic microplastic particles globally each month, potentially impacting human health.
The sponges are made of a plastic polymer assembled into a soft, lightweight abrasive foam, making it ideal for making scrubby cleaning products.
But as they wear away with use, the foam breaks down into smaller pieces, releasing microplastic fibres (MPF) into sewer systems with each wash.
These toxic microplastics may be consumed by wildlife, making their way back to humans via the food chain.
They have been linked to several health complications in humans, including immune and endocrine system disruptions, as well as several types of cancers.
In the new study, researchers assessed how quickly the melamine foam breaks down and calculated how many microplastic fibres it sheds with use.
They rubbed the foam produced by different brands repeatedly against textured metal surfaces, causing them to wear down.
A single sponge may release over 6.5 million fibres per gram of worn-out sponge, the study found.
“The sponge wear could release 6.5 million MPFs/g, which could suggest a global overall emission of 4.9 trillion MPFs due to sponge consumption,” researchers said.
Sponges made from denser foam wore down more slowly and produced fewer microplastic fibres, they said.
Researchers then made a rough estimate of how many microplastics make their way into the environment from the use of these foams by looking at Amazon’s monthly sales.
They calculated that 1.55 trillion fibres from melamine sponges could be released each month.
“The rate and capability of MPF production generally increased with increasing roughness of the metal surface and density of the struts, respectively,” scientists added.
The actual amount could be much higher as the analysis only took into account one retailer, scientists said.
To overcome the environmental toxicity caused by these products, researchers recommend that manufacturers create denser and tougher sponges which are more resistant to wear.
They recommend that consumers opt for natural cleaning products that do not use plastics.