Lead concentrations in breast milk at various stages of lactation.

A total of 164 breast-milk samples from Thai mothers in different stages of lactation, from one day to over nine months postpartum, and 35 samples of infant milk formulas commercially available were analyzed for their lead concentrations using atomic absorption spectrophotometry. The mean lead concentration in breast milk was 0.0846 +/- 0.0332 microgram per ml which is in the low range and is safe for infants, whereas the mean lead concentration in commercial infant mild formulas was 0.1587 +/- 0.0232 microgram per ml which can become a potential health hazard to infants.