1. 1 Lead Poisoning  Lead has no known biological function.  There is no proven safe lower limit for lead.  Lead Pb ++, competes with Ca ++, Fe ++  It is cheap, useful, easy to mine.  Lead is available in air, food, water& soil.  Leaded petrol means that all environmental dusts are high in lead-contaminating ceiling dust, topsoil, etc.

2. 2 Absorption of Lead  Lead goes down iron or calcium absorption pathway in GIT.  Children absorb lead well if taken orally (~50%) Children also have more hand to mouth activity.  Lead absorption is enhanced if diet is poor in iron or calcium.  Pica is one of the worst risk factors.  Lead can be inhaled.  Tetraethyl lead can be absorbed via skin.

3. 3 Absorption of Lead

4. 4 Contribution of Sources

5. 5 Distribution of Lead  95% long bones.  4% brain, liver, kidneys.  1% blood.  Crosses placenta, foetal BBB is open