Higher infant blood lead levels with longer duration of breastfeeding.
OBJECTIVE
To determine whether longer breastfeeding is associated with higher infant lead concentrations.


METHODS
Data were analyzed from 3 studies of developmental effects of iron deficiency in infancy: Costa Rica (1981-1984), Chile (1991-1996), and Detroit (2002-2003). The relation between duration of breastfeeding and lead levels was assessed with Pearson product-moment or partial correlation coefficients.


RESULTS
More than 93% of the Costa Rica and Chile samples was breastfed (179 and 323 breastfed infants, respectively; mean weaning age, 8-10 months), as was 35.6% of the Detroit sample (53 breastfed infants; mean weaning age, 4.5 months). Lead concentrations averaged 10.8 microg/dL (Costa Rica, 12-23 months), 7.8 microg/dL (Chile, 12 months), and 2.5 microg/dL (Detroit, 9-10 months). Duration of breastfeeding as sole milk source and total breastfeeding correlated with lead concentration in all samples (r values = 0.14-0.57; P values = .06-<.0001).


CONCLUSIONS
Longer breastfeeding was associated with higher infant lead concentration in 3 countries, in 3 different decades, in settings differing in breastfeeding patterns, environmental lead sources, and infant lead levels. The results suggest that monitoring lead concentrations in breastfed infants be considered.
Lozoff
Betsy
B
Center for Human Growth and Development, Department of Pediatrics and Communicable Diseases, University of Michigan, Ann Arbor, MI, USA.
Jimenez
Elias
E
Wolf
Abraham W
AW
Angelilli
Mary Lu
ML
Zatakia
Jigna
J
Jacobson
Sandra W
SW
Kaciroti
Niko
N
Clark
Katy M
KM
Tao
Min
M
Castillo
Marcela
M
Walter
Tomas
T
Pino
Paulina
P
D000367:Age Factors; D001942:Breast Feeding / Q000009:adverse effects*; D002657:Child Development / Q000502:physiology; D002677:Chile; D015331:Cohort Studies; D003364:Costa Rica; D005260:Female; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D007854:Lead / Q000097:blood*; D020264:Lead Poisoning, Nervous System, Childhood / Q000209:etiology / Q000517:prevention & control; D008297:Male; D008895:Milk, Human / Q000737:chemistry*; D011336:Probability; D018570:Risk Assessment; D013997:Time Factors; D014481:United States
D007854:Lead