It uses twice as much water and releases 800,000 more plastic microparticles per load than a regular cycle.
Water volume triggers the release of plastic microfibers more than agitation during a laundry cycle, new research has found. When the delicate cycle is used, it releases far more water into a washer than a regular cycle does (up to twice as much), but researchers at Newcastle University have discovered that this releases on average 800,000 more microfibers per load than a regular wash.
The finding is counterintuitive and goes against the advice that's been given to homeowners up until now. Lead researcher and PhD student Max Kelly explained in a press release how his findings, published in the journal Environmental Science and Technology, differ from those of earlier experiments:
"Previous research has suggested the speed the drum spins at, the number of times it changes spinning direction during a cycle and the length of pauses in the cycle – all known as the machine agitation – is the most important factor in the amount of microfibre released.
“But we have shown here that even at reduced levels of agitation, microfibre release is still greatest with higher water-volume-to-fabric ratios. This is because the high volume of water used in a delicate cycle which is supposed to protect sensitive clothing from damage actually 'plucks' away more fibres from the material."
When these fibers come from polyester, nylon, and acrylic clothing, they are a greater concern because they wash out into waterways, lakes, and oceans. Most washing machines are not equipped to filter out the small particles; and because they're made of chemical-laden, non-biodegradable plastic, the particles can enter and poison the food chain. There is concern about the polychlorinated biphenyls (PCBs), which stick to the particles, and that they may help spread viruses and disease in marine environments.
The Guardian reported in 2016, "The fibers’ size also allows them to be readily consumed by fish and other wildlife. These plastic fibers have the potential to bioaccumulate, concentrating toxins in the bodies of larger animals, higher up the food chain."
This discovery should convince you not to use the delicate cycle anymore, but rather stick with a regular cycle whenever possible. Buy a high-efficiency washer and make sure it's full before running a load.