Exposure Biomarker Interpretation

Exposure Indices · Exposure Indices overview

Exposure biomarker interpretation requires understanding the biomarker's specificity, its toxicokinetic relationship to the parent substance, the matrix and timing on which the reference value is based, and the realistic confounders for the workforce being sampled.

Specificity hierarchy

Specific biomarkers (S-PMA for benzene, MDA for MDI, mandelic + phenylglyoxylic for styrene) allow direct interpretation against the reference value. Non-specific biomarkers (hippuric acid, urinary phenol, t,t-MA) require background characterisation and confounder documentation.

Toxicokinetic alignment

Sample timing must match the biomarker half-life and the reference value's specified timing. A sample collected outside the specified window is uninterpretable, not 'approximately correct'.

Realistic confounders

Smoking (cadmium, benzene), diet (hippuric acid, total arsenic, mandelic acid), genetic polymorphisms (CYP2E1, NAT2), and concurrent medication (paracetamol affects mercapturate excretion) are documented routinely against samples.