Particle size-driven rare earth elements pollution, source and child health risks in Beijing kindergarten dust

The concentrations and sources of rare earth elements (REEs) in urban dust are strongly affected by particle size. This study investigates the contamination, sources, and health risks of REEs in re-suspended dust (RPD) and fine dust (FD) from Beijing kindergartens. Results indicate Ce and Eu concentrations in RPD, and La, Ce, Pr, Nd, Sm, Eu, Gd, and Tb concentrations in FD slightly exceed local background levels. Both RPD and FD are classified as non-polluted levels, with notable enrichment of light rare earth elements (LREEs). Although RPD and FD share similar anthropogenic and natural sources, their contributions differ significantly: RPD reflects stronger anthropogenic influences on RPD and FD demonstrate heightened REE affinity due to its finer particle size. Health risk assessments reveal that children face higher exposure to health risks than adults, primarily through with oral ingestion. Despite elevated risks associated with FD compared to RPD, both remain within negligible thresholds. These findings underscore the importance of implementing particle-specific strategies for mitigating REE pollution in urban environments, providing a scientific foundation for safeguarding children's health in kindergarten settings.