Combining multi-surface and biotoxicity models to predict cadmium bioavailability and accumulation in a soil...

Area of Science:

• Environmental Chemistry
• Ecotoxicology
• Soil Science

Background:

• Metal bioavailability in soil animals is crucial for ecotoxicity testing.
• Soil cadmium (Cd) pollution poses significant environmental concerns.
• Understanding Cd transfer from soil interfaces to organisms is essential.

Purpose of the Study:

• To determine Cd bioavailability to Folsomia candida in naturally contaminated soils.
• To evaluate chemical extraction methods and mechanism-based models for predicting Cd bioavailability.
• To develop and validate combined models for mechanistic prediction of Cd bioaccumulation.

Main Methods:

• Utilized chemical extraction methods (0.01 M CaCl2, 0.43 M HNO3, soil solution, DGT, total soil Cd).
• Employed mechanism-based multi-surface models (MSMs) and three combined models (MSMs-FIAM, MSMs-rBLM, MSMs-GCSM).
• Assessed Cd bioaccumulation in Folsomia candida under varying soil conditions.

Main Results:

• MSMs provided better predictions of Cd bioavailability (R² = 0.667) than traditional chemical extraction methods.
• Calculated dissolved Cd using MSMs effectively indicated bioavailability to F. candida across diverse soil properties.
• The combined MSMs-rBLM model demonstrated superior prediction of Cd bioaccumulation (R² = 0.793, RMSE = 0.172, MAPE = 15.4%).

Conclusions:

• MSMs are effective tools for predicting Cd bioavailability to soil invertebrates.
• The MSMs-rBLM model accurately predicts Cd bioaccumulation and links soil-liquid interfaces to organism surfaces.
• MSMs-rBLM offers a novel approach for assessing Cd ecological risks in soil ecosystems.