Recent studies have raised concerns about the effect of environmental toxins on breast milk, but according to a recent international conference on pollution and lactation, there's no need to worry. "Levels of chemical contaminants in breast milk are low," says Philip Landrigan, M.D., director of the Center for Children's Health and the Environment at Mount Sinai School of Medicine, in New York City. "That's why doctors continue to advise mothers to nurse."

Breast milk itself may protect against contamination: A Dutch study of around 400 infants found that while exposure to polychlorinated biphenyls (PCBs) in utero could cause motor and cognitive problems at age 6, it showed up only in formula-fed kids¿¿- even though breastfed babies were exposed to PCBs in the milk. "Breastfeeding counteracts the adverse developmental effects of PCBs," say researchers.

Purer breast milk is best, of course, so follow these steps:

Reduce home and garden pesticides. A few weeds are better than many toxins, says Dr. Landrigan.

Redecorate next year. Wall-to-wall carpeting, synthetic wood furniture, and paint emit gases that are easily absorbed into breast milk. So does dry cleaning: Remove the plastic and let clothes air out for 24 hours before you put them in your room.

Eat right, within reason. While a long-term diet rich in fruits and veggies and low in animal fats reduces persistent organic pollutants (POPs) in breast milk, short-term changes do little. But do avoid swordfish or polluted local fish.

Don't smoke or drink. And call your doctor about any prescription drugs.