Hello from the Breastfeeding Resource Center at Harvard School of Public
Health which just happens to be housed in my office at the Occupational
Health Program!  I asked my professorial colleagues for information on
this topic, and the following are the results:

1.  One professor here at Harvard OHP who does much research on lead
effects on children suggests that the mother should consult Dr. Maureen Paul
at the U.Mass. Medical Center (home of Lactnet!; Ms. Auerbach do you know
this doctor?).

2.  The same professor suggested also contacting the Rose Kennedy Center
here in the Boston area for information (I can't find this listed in the
Boston phonebook, may be located in some surrounding town).

3.  Lastly, he led me to this article by Mary S. Wolff for which I've
attached the abstract following.  Note that this article is 13 years old,
but I'm sure some of the info is still relevant.  (This citation was
retrieved via the Harvard medical library medline research tool.)

Good luck with this working mother!
                                ,,^,,
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! @(*.*)@ !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
                                 `-'
Janna M. Frelich                             [log in to unmask]
Applications Programmer/Analyst
Occupational Health Program
Harvard School of Public Health

Coordinator, Harvard SPH Breastfeeding Resource Center

Medline abstract follows:
************************************************************************

Authors
  Wolff Mary S.
Title
  Occupationally derived chemicals in breast milk. [Review]
Source
  American Journal of Industrial Medicine.  4(1-2):259-81, 1983.
MeSH Subject Headings
  Body Burden
  Breast Feeding
  DDT/an [Analysis]
  *Environmental Exposure
  *Environmental Pollutants/an [Analysis]
  Environmental Pollutants/me [Metabolism]
  Female
  Fetal Blood/an [Analysis]
  Human
  Lead/an [Analysis]
  Mercury/an [Analysis]
  *Milk, Human/an [Analysis]
  Polychlorinated Biphenyls/an [Analysis]
  Pregnancy
  Solvents/an [Analysis]
Abstract
  Exogenously derived chemicals have been widely reported in breast milk.
  Chemicals typically found in occupational exposures, including trace
  metals, solvents, and halogenated hydrocarbons, are reviewed, in terms of
  milk partition factors, potential infant exposures, and possible infant
  health effects. In addition to ingestion of a chemical from breast milk,
  an infant incurs a neonatal body burden of a chemical due to
  transplacental migration from maternal blood. For trace metals, neonatal
  blood levels are similar to maternal blood levels. Partition of metals to
  milk is less efficient, but nevertheless can contribute significantly to
  an infant's body burden. For lipid-soluble pesticide residues and
  halogenated biphenyls, neonatal body burden is much less than that of the
  mother, but transfer to milk is efficient, due to the high proportion of
  milk fat. It is suggested that potential organic mercury toxicity can be
  estimated from concentration in maternal blood or milk. For other
  chemicals, available data are not sufficient to evaluate short- or
  long-term health effects. However, for many halogenated hydrocarbons,
  concentrations in normal human milk would permit infant exposure above
  guidelines for allowable daily intake set by the World Health
  organization. [References: 70]
Registry Numbers
  0 (Environmental Pollutants).  0 (Polychlorinated Biphenyls).  0
  (Solvents).  50-29-3 (DDT).  7439-92-1 (Lead).  7439-97-6 (Mercury).