Objective: To understand the correlation of blood lead levels in infant, in maternal blood and in breast milk as to providing evidence for prevention of potential infant hazard from lead.
Methods: Lead levels were measured by using graphite stove atom absorption spectrographic methods in maternal breast milk, maternal blood and infant blood in infants aged 0 to 11 months and their mothers between November and December 2002 in Xiamen City. Blood samples were collected from both mother and infant's fingertips. Questionnaires were also used to collect information about childbirth, mothers, families and other related environmental factors.
Results: All 177 infants and their mothers were enrolled in the study. Infant blood lead levels reached a range from 0.12 micromol/L to 1.36 micromol/L, with a geometric mean (GM) of 0.37 micromol/L. There were 46 infants (21.64%) having blood lead levels over 0.48 micromol/L. And the maternal blood lead levels ranged from 0.21 micromol/L to 2.38 micromol/L (GM = 0.50 micromol/L). Among the 177 infants, 160 (93.8%) were breastfed; breast milk was collected from 105 (63.3%) of these mothers. Infant blood lead level was significantly correlated with the levels of maternal blood lead and breast milk lead, which indicated that maternal blood lead level might influence the infant blood lead levels through the breast milk. Blood lead levels in infants living in old business district and the breast milk lead levels of their mothers were higher than those in any other areas (P < 0.01); partial correlation analysis showed that infant blood lead levels were positively associated with the maternal blood lead level, infant's age and mother's work, and negatively associated with mother's height.
Conclusion: The infant blood lead levels should not only relate to the maternal blood lead and the breast milk lead levels, so regards should be had to the other environmental factors, when selecting the feeding pattern and family rearing behaviors.