ENVIRONMENTAL CONTRIBUTION TO BLOOD LEAD LEVELS IN INFANCY

Abstract

Data have not previously been presented which allow for separation of the relative role of pica from general environmental lead contamination in the development of high blood lead levels in childhood. This study has examined the lead levels in cord and maternal blood and related these values to sources of maternal environmental lead exposure. Infants were then followed prospectively to assess subsequent lead accumulation. Mean maternal blood lead level (n=114) was 1.29 ± .51 μ moles/LRBC and values were significantly influenced (p < .05) by race (Puerto Rican > Black > White), urban location, and age of dwelling, but not by social class or smoking. Mean newborn blood lead level (n=182) was 1.00 ± .51 μ moles/LRBC and values were similarily influenced by maternal race, location and age of dwelling as well as by direct proximity of dwelling to high traffic flow. There was linear relationship between paired maternal and newborn lead levels (r=.687., p < .001). After birth the rise in subsequent blood lead determinations was gradual over the first 18 months of life without evidence of a sudden rise at the age of ambulation. These data suggest that certain environmental factors play a major role in defining a group of infants who are “at risk” for developing high blood lead levels even prior to the development of pica. Exposure to this environment starts in utero.