Decrease of internal exposure to chlororganic compounds and heavy metals in children in Baden-Württemberg between 1996/1997 and 2008/2009.

From 1996/1997 to 2008/2009, blood and urine were sampled from 9- to 11-year-old pupils in the state of Baden-Württemberg, South-West Germany. In blood samples the chlororganics DDE, HCB, PCB-138, PCB-153 and PCB-180 were analysed by gas chromatography and ECD detection. PCDD/PCDF were measured in pooled blood samples using GC/MS. Lead concentrations in blood were quantified by graphite furnace atomic absorption spectrometry (AAS), mercury in urine by using cold vapour AAS. For all chlororganics and heavy metals a distinct decrease of the internal concentration could be shown within the 12-year investigation period. For DDE, the median decreased from 0.32 µg/l to 0.11 µg/l. The median of HCB fell from 0.19 µg/l to 0.07 µg/l. The median of the sum of the three PCB-congeners PCB-138, PCB-153 and PCB-180 decreased from 0.47 µg/l to 0.18 µg/l. The burden of PCDD/PCDF in pooled blood samples resulted in approximately half the concentration after the 12-year period. The internal concentrations of the chlororganics were distinctly higher in breastfed children than in non-breastfed children. In 2008/2009, these differences were strongest for PCB and DDE (2-fold), moderate for PCDD/PCDF (1.6-fold), and slight for HCB (1.2-fold). The median of lead concentrations in blood dropped from 23.6 µg/l to 15.9 µg/l. The median of mercury concentrations in urine decreased from 0.25 µg/l to a value below the limit of quantification of 0.2 µg/l; the 95th percentile was reduced from 3.1 µg/l to less than 0.2 µg/l. The decline of amalgam fillings in children during the investigation period had a strong influence on internal concentrations of mercury. The internal concentration of the persistent xenobiotics investigated here decreased to a low level not likely to be of concern for human health.