Placental transfer of cadmium.
Cadmium levels in blood have been determined in mother-newborn pairs from the surroundings of a copper smelter and a control area in Northern Sweden. The smelter's cadmium emissions to the air have decreased substantially since the 1970s, and in 1989 the emission was one ton. Venous blood was sampled from the mothers during delivery and from the umbilical cords, and analysed for cadmium by flameless atomic absorption spectrophotometry. There were no significant differences in cadmium levels, as between exposed women and controls, and blood levels were low, even in an industrial area. The most important environmental exposure seemed to be smoking. There was, however, a significant increase in cadmium levels during pregnancy among non-smoking women in both groups, p < 0.01. The cadmium levels in the newborn babies were about 70% of those in the mothers. Cadmium levels in the babies of non-smoking mothers were significantly higher in the vicinity of the smelter than in the control area (p < 0.05).