It is common knowledge that microfibers are ubiquitously distributed in our environment. They have already been found in our food and in the air we breathe. Recently published studies reported that microfibers have even been detected in human lungs and blood. [1][2] What can we all do to minimize the microfibers coming from textiles?
Microfibers include both microplastics, defined as solid and insoluble synthetic polymers (plastics), and microfibers derived from natural fiber shedding’s, that are smaller than five millimeters. Sources of microplastics are mainly distinguished between primary, those emitted into the environment in the above-mentioned size, and secondary, those generated in the environment from degradation and fragmentation processes of larger plastic parts. Even though it is challenging to estimate and measure the quantities of microplastics (different sampling, test methods and lack of standardization), there is a broad consensus that textiles play a big part in their generation. This part is estimated to be between 200-500.000 tons per year in addition to the amount that has already accumulated. Possible sources which can develop microplastics from textiles are the yarn- and fabric construction, production steps with mechanical stress, the use phase and the end-of-life disposal method whereby the majority are released, specifically the first few times textiles are washed. Since approximately two thirds of all textile articles are now synthetic, microplastic generation will be dominated by polymers such as polyester, polyamide and acrylic.[3][4][5]
Natural fibers also contribute to fiber shedding, but the main differences are that in many cases natural fibers are much more biodegradable than synthetic fibers (although the biodegradation of natural fibers is slower in sea water than in freshwater [6]) and secondly the share is much smaller. But nevertheless, even if biodegradation takes places it contributes to the leaching out of dyes and finishing chemicals incorporated in fibers. Wastewater treatment plants can filter out microfibers even when not originally designed to do so. Studies show that by a normal primary treatment method (e.g., by coagulation and flocculation) up to 80 % of microfibers are transferred to the sludge. Further technologies used in secondary or tertiary treatment can reach 90 % respective >95 % [7][8]. It has been reported that a membrane bioreactor (MBR) with a downstream installation of an ultrafiltration or reverse osmosis can prevent the release of microfibers to aquatic bodies [9].
Depending on the subsequent disposal method, it can be largely eliminated (e.g. by incineration) or returned to the environment (e.g. uncontrolled agricultural landfill).
It is estimated that approximately only 50 % of the total global wastewater consumption (domestic and industrial) will be safely treated [10][11]. In Europe alone nearly 40% is spread on land for agricultural use. [12]
There are many possible sustainable solutions found throughout the textile supply chain which generally follow the principles of waste management:[13][14]
