Lead in blood gives the more recent intake

Lead in urine gives the rate of excretion of new and old intaske

Lead in hair gives a view of total intake and evolution with time.

In blood there is about 2% of lead body burden (Pb recently absorbed) while the skeletal pool contains about 90%  of absorbed lead in a stable condition. k x-ray fluorescence can be used to assess bones Pb accumulation and there are several publications about it. I don't think hair are a good biomarker for Pb exposure, external contamination or hair treatment may affect the result.

Regards,

Stefania

I aggree that hair treatment may affect results ,if lead is added in the treatment.

External contaminants as that coming from the air also affects the lungs etc. and is also discovered in hair.  Commonly metals in hair are parallel to hepatic values. 

I agree with Stefania Squadrone, that hair lead do not represent the total body burden of lead. Bone lead half life is maximum. It is almost 25 to 30 years Hence bone lead is taken as the total body burden of lead, and not Hair or any other organ, or sample.

Thank Luis Bertello for response. If you have any more justification in support of your statement, please go ahead.

Partially true. Hepatic biopse was used for that. But for daily use nobody likes it.

The hair is the other way and is no-invasive .Who will accept a bone biose?

It is always safe to use non invasive methods and procedures for estimating the total body burden of lead. I understand the concern you raised Luis Bertello, as Stefania Squadrone, has rightly said, that when other safe alternatives (x-ray fluorescence) are available then why go for the invasive type of investigation? Further, it is not a procedure to be done on daily basis. Hence, we must choose the correct method and procedure depending on the purpose, situation and resources available to us for the best application.