Minimal Risk Level Derivation for Cadmium: Acute and Intermediate Duration Exposures

Area of Science:

• Environmental Toxicology
• Public Health Risk Assessment

Background:

• Cadmium is a priority hazardous substance identified by the Agency for Toxic Substances and Disease Registry (ATSDR).
• A comprehensive literature review informed the development of a toxicological profile for cadmium.
• Health guidance values, or minimal risk levels (MRLs), were established to identify safe exposure thresholds.

Purpose of the Study:

• To describe the methodology used by ATSDR to derive minimal risk levels (MRLs) for cadmium.
• To detail the specific MRLs established for acute inhalation and intermediate oral exposure routes.

Main Methods:

• Utilized the traditional no observed adverse effect level/lowest observed adverse effect level (NOAEL/LOAEL) approach for acute inhalation MRL derivation.
• Employed the benchmark dose (BMD) approach for intermediate oral MRL derivation.
• Focused on sensitive, non-lethal, non-cancer endpoints supported by robust data.

Main Results:

• Established an acute inhalation MRL of 0.03 µg Cd/m³ for effects like alveolar histiocytic infiltration.
• Established an intermediate oral MRL of 0.5 µg Cd/kg/day for decreased bone mineral density.

Conclusions:

• ATSDR successfully derived MRLs for cadmium using established toxicological approaches.
• The derived MRLs provide crucial benchmarks for assessing health risks associated with cadmium exposure via inhalation and ingestion.