Niko L. Hartline, Nicholas J. Bruce, Stephanie N. Karba, Elizabeth O. Ruff, Shreya U. Sonar, and Patricia A. Holden* Bren School of Environmental Science and Management, University of California, Santa Barbara, California 93106, United States ABSTRACT Synthetic textiles can shed numerous microfibers during conventional washing, but evaluating environmental consequences as well as source-control strategies…