Metalloids, soil chemistry and the environment

Area of Science:

• Environmental Science
• Geochemistry
• Toxicology

Background:

• Metalloids (Boron, Silicon, Germanium, Arsenic, Antimony, Tellurium, Polonium, Astatine) exhibit intermediate conductivity and form oxides.
• Natural abundance varies significantly, with Silicon being abundant and Astatine extremely rare.
• Environmental relevance is primarily associated with Boron, Silicon, Arsenic, and Antimony due to their higher concentrations.

Purpose of the Study:

• To review the physical-chemical properties, origin, and environmental relevance of metalloids.
• To examine environmental geochemical processes influencing the bioavailability of key metalloids (B, Si, As, Sb).
• To assess current limitations in predicting metalloid toxicity and propose future improvements.

Main Methods:

• Review of existing literature on metalloid properties and environmental behavior.
• Analysis of geochemical factors controlling metalloid partitioning and speciation.
• Critique of current models for metalloid bioavailability and toxicity assessment.

Main Results:

• Metalloid environmental relevance is linked to their natural abundance and geochemical behavior.
• Existing models focusing on metal-ligand complexation and biotic ligand interactions are insufficient for predicting metalloid bioavailability.
• Trace metalloids (Ge, Te, Po, At) are generally of low environmental health concern.

Conclusions:

• Future advancements in predicting metalloid toxicity depend on incorporating surface membrane potentials.
• A comprehensive understanding requires considering both geochemical factors and cellular-level interactions.
• Further research is needed to refine models for accurate metalloid risk assessment.