Multi-cascade physiologically based kinetic (PBK) matrix model: Simulating chemical bioaccumulation across food webs

Area of Science:

• Environmental Chemistry
• Ecotoxicology
• Computational Biology

Background:

• Chemicals biomagnifying in food webs pose ecological risks.
• High-throughput screening methods are needed for assessing contemporary chemicals.

Purpose of the Study:

• Develop a physiologically-based kinetic (PBK) matrix model for bioaccumulation and biomagnification.
• Estimate biotransfer factors (BTFs) and biomagnification factors (BMFs) for 3,074 organic chemicals.

Main Methods:

• Utilized a multi-cascade PBK matrix model to simulate chemical transfer along food chains.
• Validated the model against literature data for biomagnification factors (BMFs).
• Analyzed 3,074 organic chemicals to determine their BTFs and BMFs.

Main Results:

• Model predictions showed acceptable bias compared to empirical BMFs.
• Consistent biotransfer factor (BTF) trends were observed across tissues within species.
• Moderate lipophilicity and low diffusivity correlated with higher chemical retention and BMFs.
• Mammals showed higher sensitivity to persistent organic pollutants compared to birds and ectotherms.

Conclusions:

• Animal physiological parameters and chemical properties are key drivers of bioaccumulation and toxicity.
• Organism's trophic position is less critical than its intrinsic factors.
• Future work should refine PBK models with detailed physiological data and exposure pathways.