I pulled my reference on lead and reviewed the levels.  Namihira et.al.
 reviewed plasma lead levels in a group of women in Mexico living near a
 group of lead smelters.   Lead was determined by atomic absorption
 spectrometry ("the best way").  In this group,  their average maternal
 plasma level was 45.88 micrograms/dl(SD = 19.88).  In the USA,  this level
 is considered extremely high and is generally treated with chelation
 therapy(BAL, Succimer,EDTA).

 Lead has some really unique pharmacokinetics in the human.   It is
 distributed to three body compartments, the blood and soft tissue are
 considered the active compartments,  and bone is the storage pool.  The lead
 in erythrocytes has a half-life of 35 days and is distributed generally to
 the soft tissues, bones,  and also MILK.  About 10% of the total body burden
 equilibrates in soft tissues, and some would likely distribute to milk. Ruth
 Lawrence's statement that lead in erythrocytes is largely irremoveable,  is
 correct,  but the lead that moves in the plasma compartment is highly mobile
 and from this study apparently enters milk in significant concentrations.

 Chelation therapy only removes the lead dissolve in the  blood,  and slowly
 removes soft tissue levels.  Extensive and long term therapy is required to
 ultimately remove all lead from the body(weeks-months).   What is perhaps
 worse,  is that rapid re-mobilization of lead from the body could
 dramatically raise plasma levels(and presumably MILK levels as well).   So
 this may not be a suitable option for breastfeeding moms.

 From Namihira's study,  he found that the milk lead levels averaged 2.47
 micrograms/100 ml of milk in these women.  Using the mean value of milk
 found in this population,  he estimated the daily intake of lead in
 breastfeeding infants would be 8.1 micrograms/kg/day which is simply too
 high.  The pediatric brain is incredibly sensitive to lead.

 One last comment.   Testing for blood lead is extremely inaccurate.  Samples
 taken by finger-stick are almost always wrong,  and must be confirmed by
 phlebotomy and run in a laboratory that uses Atomic Absorption Spectrometry.
 I would review the method used in this mom,  to confirm that the testing
 method was accurate and that the stated level in this mom was accurate.


 TWHale
 Texas Tech Univ. School of Medicine


 Namihira D, et.al. Lead in human blood and milk from nursing women living
 near a smelter in Mexico City.  J. Toxicology and Envir. Health  38(3):
 225-32, 1993.