To investigate the relation between umbilical cord blood lead level lower than 10 microgram/dl and neonatal neurobehavioral performance.

Umbilical cord blood lead level, as an indicator for prenatal exposure to lead, and Brazelton neonatal behavioral assessment scale (NBAS), as an indicator for effect, were determined in 86 neonates in Gumi, Kyungpook, Korea. The blood levels were measured by graphite furnace atomic absorption spectrophotometer. Development was assessed by NBAS at birth in 86 neonates and at 1 month in 55 neonates.

The mean cord blood lead levels of the 86 and 55 neonates were 3.90 ± 0.71 microgram/dl (range 2.24 – 5.39 microgram/dl) and 3.88 ± 0.70 microgram/dl (range 2.24~5.03 microgram/dl), respectively. We used the median value of 4 microgram/dl to divide into low- and high-lead level groups. There was a significant difference in the peak of excitement at birth, and in the animate visual, inanimate visual, inanimate auditory, activity level, peak of excitement, and liability of states at one month, between the two groups. For cluster scores, motor system and state organization scores showed significant differences between the two groups. For adjusting the potential confounding effect of intial difference, differences of the scores between the two groups at one month were analysed with ANCOVA. The results of ANCOVA showed the significant difference between the two groups.

The findings suggest that prenatal low-level lead exposure, even lower than 10 microgram/dl, might affect the neonatal neurobehavioral development.