Results
Our research found that microfibers are prevalent in both aquatic and terrestrial habitats, from the bottom of the Indian Ocean to farmland in the United States. Our experimental results found that when synthetic jackets are washed, on average 1,174 milligrams of microfibers are released from the washing machine. These microfibers then travel to local wastewater treatment plant, where up to 40% of them can enter into rivers, lakes, and oceans (depending on local wastewater treatment conditions).
Literature Review
To better understand the emerging issue of microfiber pollution, we compiled an extensive literature review of previous studies. The literature review revealed:
Experimental Results
To quantify microfiber shedding from washing synthetic jackets, we conducted a series of wash experiments with four different types of synthetic Patagonia jackets and one budget fleece jacket for comparison. The budget jacket is comparable in material composition and function to one of the Patagonia jackets. To better understand what factors significantly impact shedding, we evaluated the effects of washing machine type and the age of the garment on the mass of microfibers released.
The investigation revealed that microfibers are a pervasive pollutant and could be affecting ecosystems and human health. The study demonstrates a need for further research on shedding characteristics of apparel and the development of mitigation measures by producers, consumers, waste managers, and policymakers towards addressing the issue of microfiber pollution. Furthermore, the study was specific to four Patagonia jackets and one budget jacket; individual manufacturers would need to conduct their own analyses of their product line in order to assess their contributions to microsynthetic fiber pollution. They can do so using the experimental design developed for this project.
Publication
On September 30th, 2016, our research was successfully published in Environmental Science & Technology under the title "Microfiber Masses Recovered from Conventional Machine Washing of New or Aged Garments".
Literature Review
To better understand the emerging issue of microfiber pollution, we compiled an extensive literature review of previous studies. The literature review revealed:
- Finished apparel products contain large quantities of chemical substances from processing and finishing steps in garment manufacturing, many of which are released from garments during consumer washing. This indicates that microfibers are of particular concern regarding their potential to transport hazardous chemicals into the environment.
- Wastewater treatment plants (WWTPs) receive large amounts of microfibers daily. While most of these microfibers are removed, a significant amount is still released into the local environment. Due to the high capital costs of WWTPS, upgrading WWTPs is not a feasible solution to microfiber pollution in the short term.
- Analysis of global water and sediment sampling data indicates that microfibers are ubiquitous in aquatic environments. Recent evidence supports microfiber pollution pervading terrestrial environments and the atmosphere as well. Although soil systems may be the primary receptors of microfibers, microfiber distribution in aquatic systems is currently the best understood.
- Aquatic organisms throughout the food chain consume microplastics and microfibers both directly and indirectly. Within the food chain, these particles have been found to cause physical and chemical impacts, resulting in starvation and reproductive consequences in species. Microplastics and microfibers have also been found in marine species directly consumed by humans, the effects of which are unknown. They have also been found in abiotic ocean products like sea salt.
Experimental Results
To quantify microfiber shedding from washing synthetic jackets, we conducted a series of wash experiments with four different types of synthetic Patagonia jackets and one budget fleece jacket for comparison. The budget jacket is comparable in material composition and function to one of the Patagonia jackets. To better understand what factors significantly impact shedding, we evaluated the effects of washing machine type and the age of the garment on the mass of microfibers released.
The investigation revealed that microfibers are a pervasive pollutant and could be affecting ecosystems and human health. The study demonstrates a need for further research on shedding characteristics of apparel and the development of mitigation measures by producers, consumers, waste managers, and policymakers towards addressing the issue of microfiber pollution. Furthermore, the study was specific to four Patagonia jackets and one budget jacket; individual manufacturers would need to conduct their own analyses of their product line in order to assess their contributions to microsynthetic fiber pollution. They can do so using the experimental design developed for this project.
Publication
On September 30th, 2016, our research was successfully published in Environmental Science & Technology under the title "Microfiber Masses Recovered from Conventional Machine Washing of New or Aged Garments".
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Abstract
Synthetic textiles can shed numerous microfibers during conventional washing, but evaluating environmental consequences as well as source-control strategies requires understanding mass releases. Polyester apparel accounts for a large proportion of the polyester market, and synthetic jackets represent the broadest range in apparel construction, allowing for potential changes in manufacturing as a mitigation measure to reduce microfiber release during laundering. Here, detergent-free washing experiments were conducted and replicated in both front- and top-load conventional home machines for five new and mechanically aged jackets or sweaters: four from one name-brand clothing manufacturer (three majority polyester fleece, and one nylon shell with nonwoven polyester insulation) and one off-brand (100% polyester fleece). Wash water was filtered to recover two size fractions (>333 μm and between 20 and 333 μm); filters were then imaged, and microfiber masses were calculated. Across all treatments, the recovered microfiber mass per garment ranged from approximately 0 to 2 g, or exceeding 0.3% of the unwashed garment mass. Microfiber masses from top-load machines were approximately 7 times those from front-load machines; garments mechanically aged via a 24 h continuous wash had increased mass release under the same wash protocol as new garments. When published wastewater treatment plant influent characterization and microfiber removal studies are considered, washing synthetic jackets or sweaters as per this study would account for most microfibers entering the environment. |
In reports and research, please cite our work as "Hartline, N.L., Bruce, N.J., Karba S.N., Ruff, E.O., Sonar, S.U., and Holden, P.A. (2016) Microfiber Masses Recovered from Conventional Machine Washing of New or Aged Garments, Environmental Science & Technology, Vol. 50, No.21, pp.11532-11538"
