PBK modeling for metals. Examples with lead, uranium, and chromium

Area of Science:

• Environmental toxicology
• Biokinetics
• Physiologically-based pharmacokinetic modeling

Background:

• Physiologically-based models for metals diverge from those for organic compounds.
• Metal kinetics are not influenced by metabolism or fat accumulation.
• Bone-seeking elements necessitate models that include bone turnover and metabolism due to long residence times.

Purpose of the Study:

• To highlight key differences in physiologically-based models for metals versus organic compounds.
• To emphasize the importance of incorporating bone turnover and metabolism for bone-seeking elements.
• To demonstrate the application of these models for lead, chromium, and uranium.

Main Methods:

• Development of physiologically-based kinetic models tailored for bone-seeking elements.
• Inclusion of mechanisms such as rapid exchange at bone/blood interfaces, incorporation into forming bone, and slow exchange within bone volume.
• Application of models to analyze bioavailability, distribution, and data interpretation for specific elements.

Main Results:

• Physiologically-based models for metals require distinct approaches compared to organic compounds.
• Bone turnover and metabolism are critical components for modeling bone-seeking elements.
• The models successfully addressed practical questions regarding lead, chromium, and uranium kinetics.

Conclusions:

• Physiologically-based kinetic models are essential for understanding the behavior of bone-seeking metals.
• Accurate modeling requires consideration of bone-specific processes.
• These models provide valuable insights into metal bioavailability and distribution, aiding risk assessment.