Weathering induced surface transformation and trace metal affinities of plastic nurdles discharged from the X-Press Pearl ship accident (2021–2024)

This study evaluated the pollution level at Sarakkuwa Beach and examined weathering-induced volume loss and surface chemical changes in nurdles compared to pristine nurdles. Sand samples were collected at four time points (16, 24, 28, and 40 months), following initial nurdle spillage. Chemical composition of nurdles were analyzed using Fourier transform infrared (FTIR) spectroscopy and X-ray photoelectron spectroscopy (XPS), while digital microscopic imaging was used to reveal surface morphology. Volume reduction of randomly selected nurdles was quantified using densitometric titration. Conducted Pellet Pollution Index (PPI) analysis shows that after 40 months still Sarakkuwa beach highly contaminated with the nurdles (11.71 ± 7.47 pellets per m). FTIR spectra showed new absorption bands corresponding to C=O, S=O, -C=C stretching, and C-O-C bending vibrations that were absent in pristine nurdles, evidencing chemical alterations resulting from weathering. The XPS spectra of nurdles revealed peaks corresponding to As3d, N1s, Li1s, and S2p, indicating prolonged chemical exposure. The percent volume reductions of weathered nurdles collected at four time points after the accident were 47.92 ± 18.79, 57.1 ± 14.98, 61.22 ± 20.65 and 64.87 ± 17.23%, respectively, indicating ongoing size reduction and the release of micro/nanoplastics into the environment. Rapid weathering onset is attributed to the immediate exposure to hazardous chemicals and fire, followed by a gradual degradation over time, influenced by factors like UV irradiation, atmospheric oxygen exposure, and wave action. This study elucidated the enduring presence of nurdles from the MV-XPP ship, suggesting long-term implications on size reduction and their interaction with aquatic organisms and human health.