Many volatile organic chemicals, including methylene chloride and
tetrachloroethene, are lipophilic (fat soluble) and readily absorbed when
inhaled.  After inhalation, the chemicals are present in blood and
distributed to fatty tissue.  Breastfeeding mom's who are exposed to such
chemicals are likely to have elevated levels in blood, fat and breastmilk
since milk fats are drawn from the mother's fat stores.  However, the
benefits of breastmilk generally far exceed the risks of the relatively
small amounts of chemicals in breastmilk.  I have done considerable work on
tetrachloroethene (the dry cleaning solvent) and have estimated milk levels
based on pharmacokinetic modeling situations and also measured levels in
milk samples from exposed moms.  The 'bad' news is that tetra levels are
elevated in moms exposed to it in indoor air. The good news is that  the
levels, although elevated, do not approach levels of exposure from the air
itself, and that the benefits of breastmilk far exceed the risks.
Methylene chloride's characteristics (volatility, lipid solubility,
excretion) are similar to tetrachoroethene and I would expect a similar
scenario.  Of course, the nursing mom should try to reduce or eliminate any
exposure to chemicals if she can.  Working under a fume hood and avoiding
skin contact are a must.  Hope this helps.  Judy Schreiber, Ph.D., NYS Dept
of Health.  Call if you want more details. 518-458-6405 or email me at
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