Exposure risk assessment of rare earth element in vegetables from typical rare earth mining areas across four provinces in China

ObjectiveTo investigate the distribution patterns and population exposure risks of rare earth elements （REEs） in vegetables from typical rare earth mining areas across four provincial-level administrative divisions in China （Guangdong， Guangxi， Shandong， Sichuan）， and to provide scientific evidence for establishing regulatory policies on REEs in food.MethodsA total of 963 vegetable samples were collected from mining and non-mining areas in these four provinces （autonomous region）， where China’s major rare earth deposits are located. Inductively coupled plasma mass spectrometry （ICP-MS） was employed to quantify 16 REEs， followed by systematic analysis and exposure risk assessment using a simple distribution assessment model.ResultsREE concentrations in vegetables from mining areas were significantly higher than those from non-mining areas （P<0.05）， with the most pronounced differences observed in cerium （Ce）， lanthanum （La）， and neodymium （Nd）. The average concentrations of 16 REEs in mining area vegetables， ranked in descending order， were Ce > La > Nd. Light rare earth elements （LREEs） predominated over heavy rare earth elements （HREEs）. Significant variations in REE levels were identified across vegetable categories： bulb and leafy vegetables exhibited universally higher concentrations， whereas cucurbitaceous （Cucurbitaceae） and Brassica vegetables （e.g.， cole crops） showed relatively lower levels. The average daily dietary exposure to REEs through vegetable consumption for residents in mining areas was 4.4 times higher than that for non-mining area residents， accounting for 4.12% of the acceptable daily intake （ADI）， indicating health risks remain within acceptable limits.ConclusionElevated REE levels in vegetables from rare earth mining areas and significantly higher population exposure risks highlight the urgent need to evaluate the impacts of natural environmental factors and mining/smelting activities on REE exposure in these regions.