Synonyms: Pb
Related tests: protoporphyrin IX, zinc protoporphyrin, ALA dehydratase, full blood count
Clinical significance
Lead is a metal widely used in industry (in metal alloys, paints and dyes, and batteries). It enters the body through the respiratory or digestive tract in the form of dust or fumes. Poisoning can cause blood disorders (lead-induced anaemia), kidney damage (chronic nephropathy) and nervous system damage (encephalopathy). Blood lead measurement is a widely used test for the biological monitoring of exposure to the metal, as there is a good correlation between blood levels and lead concentrations in the workplace. Measuring blood lead is preferable to measuring urinary lead.
Clinical indications
Occupational exposure to lead.
Sample type
The patient must have a blood and/or urine sample taken.
Preparation
No fasting is required. A urine sample is needed, passed at the start or at the end of the work shift.
Notes
Alcohol and cigarette smoking may interfere.
Anaemia causes a relative decrease in blood lead, whereas polycythaemia has the opposite effect: it is therefore useful to carry out a full blood count at the same time. Particularly when blood or urine lead levels are close to the limit values, it is useful to measure a biological indicator of early effect at the same time (see zinc protoporphyrin; delta-aminolevulinic acid, ALA dehydratase).