Jo. Odland et al., Blood lead and cadmium and birth weight among sub-arctic and arctic populations of Norway and Russia, ACT OBST SC, 78(10), 1999, pp. 852-860
Background. Delivering women and their newborns in the Kola Peninsula of Ru
ssia and the neighboring arctic area of Norway were studied to explore rela
tionships between maternal cadmium and lead status and birth weight as a pr
egnancy outcome.
Methods. Life-style information, maternal blood and cord blood specimens we
re collected from 50 consecutive mother-infant pairs From hospital delivery
departments in three Russian and three Norwegian communities. Pregnancy ou
tcomes were verified by consulting medical records. Lead and cadmium were d
etermined in the blood samples by electrothermal atomic absorption spectrom
etry.
Results. The median blood-cadmium concentration for the Russian mothers was
2.2 nmol/L (n=148) versus 1.8 nmol/L in the Norwegian group (n=114, p=0.55
). A weak association was observed between maternal cadmium and amount smok
ed (r=0.30, p<0.001); no correlation was found between maternal blood cadmi
um and birth weight. The corresponding maternal lead values were 0.14 (Russ
ia) and 0.06 mu mol/L (Norway), p<0.001. The latter lead concentration cons
titutes one of the lowest adult population values reported to date. Materna
l and cord blood lead levels were strongly correlated (r=0.88, p<0.001). In
a multivariate linear regression model, maternal blood lead was recognized
as a negative explanatory variable (p<0.05) for birth weight and child's b
ody mass index (BMIC), with or without adjustment for gestational age. A si
milar association was suggested by ANOVA-analysis of maternal blood lead by
quartiles.
Conclusion. Maternal blood-lead level as an environmental factor is an appa
rent predictor of low birth weight and BMIC. It reduced substantially the c
ontribution of a country factor in explaining the observed differences in b
irth weight.