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Microplastic fibers (MPF) have been found to be a major form of microplastic in freshwaters and washing of synthetic textiles has been identified as one of their main sources. The aim of this work was to use a panel of twelve different textiles of representative fiber and textile types to investigate the source(s) of the MPF released during washing. Using standardized washing tests, textile swatches tailored using five different cutting/sewing methods were washed up to 10 times. The MPF quantity and fiber length were determined using image analysis. The 12 textiles demonstrated a great variability in MPF release, ranging from 210 to 72'000 MPF/g textile per wash. The median MPF length ranged from 165 µm to 841 µm. The number of released MPF was influenced by the cutting method that scissor-cut samples released 3 -21 times higher numbers of MPF the laser-cut samples. The textiles with mechanically processed surfaces (i.e. fleece) released significantly more (p-value < 0.001) than the textiles with unprocessed surfaces. For all textiles, the MPF release decreased with repeated wash cycles and a small continuous fiber release was observed after 5-6 washings, accompanied by a slight increase in fiber length. The decrease in the number of MPF released is likely caused by depletion of the production-inherited MPFs trapped within the threads or the textile structure. The comparison of MPF release from laser-cut samples, which had sealed edges, and the other cutting methods allowed us to separate the contributions of the edge-and surface-sourced fibers from the textiles to the total release. On average, 84% (range 49-95%) of the MPF release originated from the edges, highlighting the importance of the edge-to-surface ratio when comparing different release studies. The large contribution of the edges to the total release offers options for technical solutions which have the possibility to control MPF formation throughout the textile manufacturing chain by using cutting methods which minimize MPF formation.

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Fiber fragments are one of the dominant types of microplastics in environmental samples, suggesting that synthetic textiles are a potential source of microplastics to the environment. Whereas the release of microplastics during washing of textiles is already well studied, much less is known about the release during abrasion processes. The abrasion of textiles may induce fibrillation of fibers and therefore result in the formation of much finer fiber fragments. The aim of this study was to investigate the influence of abrasion of synthetic textiles on the formation of microplastic fibers and fibrils. Fleece and interlock textile swatches made of polyester were abraded using abrasion tests with a Martindale tester. The microplastic fibers and fibrils formed during abrasion were extracted from the textiles and characterized in terms of number, length, and diameter. The microplastic fibers demonstrated the same diameter than the fibers found in the textiles (fleece: 12.3 μm; interlock: 12.7 μm), while fibrils with a much smaller diameter (fleece: 2.4 μm; interlock: 4.9 μm) were also found. The number of fibrils formed during abrasion in both textiles was higher than the number of microplastic fibers. The majority of the extracted microplastic fibers had a length between 200 and 800 μm, while most fibrils were between 30 and 150 μm, forming two distinct fiber fragment morphologies. The number of microplastic fibers formed during abrasion was 5 to 30 times higher than the number of microplastic fibers that could be extracted from non-abraded samples. The number of fibrils increased after abrasion by more than a factor of 200 for both fabric types. The fibrils formed during abrasion have diameters that fall within the inhalable size for airborne particles. The potential release of fibrils into air during wear of textiles thus raises questions about the human exposure to these materials. Since the Martindale tester can simulate a daily application scenario of textiles over a prolonged period only in a limited way, future studies are needed to establish the correlation between the test results with a real-world scenario.

The bisphenols S, F, and AF (BPS, BPF, and BPAF) are used to replace the endocrine disrupting chemical bisphenol A (BPA) while exerting estrogenic effects of comparable potency. We assessed the cumulative risk for the aforementioned BPs in Europe and compared the risk before and after the year 2011, which was when the first BPA restrictions became effective. For this, we probabilistically modeled external exposures from food, personal care products (PCPs), thermal paper, and dust (using the tools MCRA and PACEM for exposures from food and PCPs, respectively). We calculated internal concentrations of unconjugated BPs with substance-specific PBPK models and cumulated these concentrations normalized by estrogenic potency. The resulting mean internal cumulative exposures to unconjugated BPs were 3.8 and 2.1 ng/kg bw/day before and after restrictions, respectively. This decline was mainly caused by the replacement of BPA by BPS in thermal paper and the lower dermal uptake of BPS compared to BPA. However, the decline was not significant: the selected uncertainty intervals overlapped (P2.5–P97.5 uncertainty intervals of 2.7–4.9 and 1.3–6.3 ng/kg bw/day before and after restrictions, respectively). The upper uncertainty bounds for cumulative exposure were higher after restrictions, which reflects the larger uncertainty around exposures to substitutes compared to BPA.