Lead (element)
From Ganfyd
Lead. Heavy metal. Deleterious to metabolism.
Chelation is capable of removing heavy metals. Whether this is effective is another matter. Most mentions of chelation relate to use by cranks and quacks.
Lead compounds were used in paint in households in at least the 19th century in the UK, and may be exposed by sanding and other decorating or construction work. Children have absorbed sufficient lead from such surfaces to be poisoned. Elemental lead should not be confused with 'lead' in pencils which is made from carbon (graphite).
Tetra-ethyl lead was an early additive to petrol, reducing pre-ignition. This was abandoned in the latter years of the 20th century. A significant amount of lead entered the environment around roads from this source.
The psychometric and behavioral assessments of lead-exposed children who were randomized to outpatient chelation or placebo therapy in the TLC study revealed no benefit of therapy at age 7 years. Unlike our first wave of follow-up, for which assessments were conducted over a relatively broad age range (48–70 months), the testing reported here was conducted in a more carefully controlled age window and after children had entered school. Testing at age 7 allows assessment of cognitive and performance skills that are absent or inaccessible in the preschool-aged child. The absence of benefit at this later age adds credence to the earlier negative findings13 and reiterates the failure of chelation therapy to alter cognitive and behavioral outcomes in preschool children with blood lead levels in the range of 20 to 44 µg/dL. 
- children with lead poisoning
See also Gold (element) and Mercury (element).
Measurement
Blood lead level, in an EDTA venous sample, is probably best. Zinc Protoporphyrin (ZPP) has also been measured but may be less reliable although it has been suggested to correlate to total lead burden.
External links
- DEFRA on lead paint
- CDC guidance on interpreting and managing lead levels in children.[1]
