Lead in umbilical cord blood correlated with the blood lead of the mother in areas with low, medium or high atmospheric pollution.

Lead concentrations in 541 samples of umbilical cord blood from different parts of Sweden were determined. The mean concentration was 7.6 mug lead/100 ml (=0.367 mumol/l). The blood lead values were also determined for 297 mothers and a mean value of 8.7 mug/100 ml (=0.420 mumol/l) was found. There was a significant correlation between the blood lead level of the mother and the infant as studied in 253 pairs. The slope of the regression line was 0.5 r (r=0.6). Significantly lower blood values for both mother and infant were found in areas with low pollution as estimated from the lead content in moss. No seasonal variation could be ascertained. Hematocrit versus lead concentration was also studied. A flameless atomic absorption method was used with a standard deviation of 0.9 mug lead/100 ml. The storage time and sample treatment were also studied.