Episodic surges in titanium dioxide engineered particle concentrations in surface waters following rainfall events

Quantifying and characterizing engineered particles in environmental systems is key for assessing their risk but remains challenging requires the distinction between natural particles. The objective of this study was to characterize quantify concentrations titanium dioxide Broad River, Columbia, South Carolina, United States during following rainfall events. elemental ratio distributions Ti/Nb, Ti/Fe, Ti/Al, determined on a single particle basis using inductively coupled plasma-time flight-mass spectrometry (SP-ICP-TOF-MS), were similar samples different events, indicating that naturally occurring had same ratios origin. Therefore, changes Ti/Nb bulk water attributed introduction into River with urban runoff total Ti, Fe, Al, Nb, Ce, La followed trend rise fall as discharge/runoff. higher (e.g., 330 565) than average crustal values 320) background surface waters SC 266.4 ± 8.9), suggesting contamination concentration estimated by mass balance calculations increases above ratios. varied 20 140 μg TiO2 L−1 source due absence sewage indicated low size gadolinium anomaly. findings demonstrate major rivers, which results episodic high particles, may pose risks This also highlights importance determining temporal variations more comprehensive assessment