Natural Fibers: Why Are They Still the Missing Thread in the Textile Fiber Pollution Story?

In 2015, Ladewig et al. (1) suggested for the first time that natural textile fibers (hereafter natural fibers), such as cotton and wool, be considered as pollutants in their own right, alongside microplastic fibers such as polyester and acrylic. Here we define natural textile fibers as biological materials that have been modified for textile applications, excluding fibrous materials derived from the breakdown of plant and animal materials (e.g., leaves and animal hair). Ladewig et al. primarily focused on the potential for natural fibers to act as a source of various polluting chemicals associated with fiber production as they degrade in the environment. (1) In the years that have followed, environmental science research has begun to acknowledge and semiquantify the presence of natural fibers in their environmental samples. (2) The first full textile fiber population assessment in the environmental sciences was published in 2019. (2) Its finding that, when they are looked for, natural textile fibers are more prevalent than plastic fibers has subsequently been repeated across environmental matrices and around the world. These studies have repeatedly found that natural fibers account for >70% of all textile fibers recovered. (2,3) However, natural textile fibers are not regularly looked for. However, although the environmental science literature has quantified entire textile fiber populations for just five years (Figure 1), this is established knowledge in other disciplines. In the forensic sciences, for example, the environmental prevalence of natural fibers has been studied for decades.(4) Here, we implore the scholarly community to continue to develop and diversify natural fiber research.