Tumble dryers, common to many homes, of both the condenser and heat pump design, are significant contributors to aquatic microfiber pollution.
This means so-called ‘sustainable’ condenser tumble dryers are not as environmentally friendly as their marketing suggests. These domestic appliances actually create hundreds of tons of waterborne microfiber pollution.
The research from Northumbria University finds that drying laundry using a condenser tumble dryer leads to hundreds of tons of potentially harmful microfibers being released into waterways and oceans. The research relates to an examination of the waterways across the U.K. and the European Union.
In waterways and the oceans, microfibers are ubiquitous contaminants of emerging concern. It has been established that large numbers of fibres are discharged into wastewater from washing clothes; the new research extends this concern to drying clothes as well. Swallowed by fish and other sea life, these pollutants travel up the food chain, where they end up on our plates.
The researchers did establish that condenser dryers can reduce the volume of airborne microfibers being released compared to vented dryers. However, these items of household equipment remain a significant contributor of waterborne microfiber pollution.
Condenser dryers collect moisture from wet clothes into a container, rather than exhausting microfibers into the air as vented dryers do, which lowers the pollution impact. Despite this, condenser dryers produce more than 7,200 tonnes of microfiber annually throughout Europe.
Around 90 percent of the released material is collected in the lint filter. The remaining microfibers are collected in the condenser and poured down the drain.
A further risk arises when consumers seek to clean their lint filters under a tap. This activity leads to further large quantities of microfibers entering the waterways. The preferred way of cleaning the lint filter is to simply clean the filter either by hand, a light brush, cloth, or vacuum cleaner, and dispose of the collected fibres, as dry waste.
The Northumbria University’s Department of Applied Sciences scientists tested loads of new, clean garments and dirty laundry sourced from volunteers in Newcastle upon Tyne. The proceeded to collect and analyse the released microfibers from several components of each type of dryer.
The researchers are calling on the domestic appliance industry and legislators to recognise that all types of tumble dryer can be significant contributors to the problem of environmental microfiber pollution. They hope this will lead to improved appliance design, to minimise the release of microfibers.
The research appears in the journal PLOS ONE, titled “Impact of vented and condenser tumble dryers on waterborne and airborne microfiber pollution.”
