Innovative integration of field experiments and flux modeling for predicting atmospheric cadmium accumulation risk in...

Quantifying the effect of atmospheric deposition on cadmium (Cd) contamination in soils near the nonferrous metal smelters is challenging. Here, we integrated field-based datasets from in situ experiments and a flux model to evaluate the Cd accumulation risk. The field experiments effectively improved the accuracy of atmospheric Cd deposition flux estimates (103 ± 47.2 g ha^-1 in 2022-2023) by minimizing the uncertainties inherent in deposition samplers and directly linking deposition fluxes with the soil Cd accumulation. Field-based datasets guaranteed the precision of flux model, with deviations between predicted and observed values ranging from -1.06 % to -0.173 %. Historical emission trends based on field experiments aligned with the actual emissions in the study area, indicating the validity of this method. The results from the long-term model prediction demonstrated that soil Cd continued to accumulate for up to 35 years, despite a 7 % annual reduction in Cd emissions. To mitigate the potential health concerns in local populations, we propose a comprehensive zoning framework as a remediation strategy to protect 75 % of the local wheat-producing area over the next 30 years. This innovative approach to evaluating changes in soil Cd concentrations provides a precise and scientifically grounded basis for agricultural field safety management in China.