vLead has
no known biological function.
vThere is
no proven safe lower limit for lead.
vLead Pb++, competes with Ca++, Fe++
vIt is
cheap, useful, easy to mine, therefore
vLead is
ubiquitous- in air, food, water, soil, ceilings etc.
vLeaded
petrol means that all environmental dusts are high in lead- contaminating ceiling dust,
topsoil, window wells
etc.