Body Burden Monitoring

Exposure Verification · Exposure Verification overview

Body burden monitoring estimates the cumulative quantity of a persistent workplace substance retained in the body. For long-half-life substances such as cadmium, lead and certain organochlorines, it answers the question that single-shift sampling cannot: what has accumulated over years of exposure.

When body burden, not shift exposure, is the question

For substances with biological half-lives measured in months or years, recent-shift biomonitoring describes only a small fraction of the dose already in the body. Cadmium has a renal half-life of 10–30 years; inorganic lead a half-life of 30 years in bone; PCBs and dioxins, multi-year lipid-compartment retention. For these substances, body burden estimation is the only meaningful exposure index.

Surrogate matrices

Urinary cadmium reflects renal cortex burden and is the standard body-burden marker for cadmium. Blood-lead reflects an equilibrium between recent uptake and bone turnover; bone lead by K-shell X-ray fluorescence directly measures the skeletal pool. Adipose biopsies (rare) and serum lipids (more common) are used for persistent organic pollutants.

Programme cadence

Annual or biennial sampling is typical, supplemented by entry-, exit- and post-incident sampling. Body burden trends across years are more informative than absolute values; rising trends in long-service workers should trigger control review even when individual values remain below action levels.