Neonatal serum p,p'-DDE concentrations in Germany: chronological changes during the past 20 years and proposed...

p,p'-DDE, the main metabolite of the insecticide DDT, is prenatally transmitted from mother to fetus. Many potential effects of low-level exposure have been reported, including preterm delivery, growth retardation and neurological impairment, although scientific evidence is still lacking. We present p,p'-DDE concentrations in full-term human neonates over a time period of 20 years in Germany. Peripheral venous blood samples were taken from neonates born in 1984-85 (n=80) and 1994-95 (n=80), as well as cord blood samples from neonates born in 1998 (n=199), and peripheral venous blood samples from neonates born in 2002 (n=20). Blood specimens were immediately centrifuged, and serum was stored at -20 degrees C until analysis. Serum p,p'-DDE concentrations were determined with capillary gas chromatography followed by electron capture detection. Differences between study groups were tested for mean differences with the Kruskal-Wallis test. There were no differences between the study groups with regard to sex distribution, birthweight, gestational age, age of the mother, and smoking behaviour of the parents. We found a significant (P <0.0001) chronological decline of neonatal serum p,p'-DDE concentrations, with the highest values in 1984-85 (mean=1.49 microg/L; range: 0.30-5.58) and the lowest in 2002 [mean=0.18 microg/L; range: 0.07-0.54; tolerance level (95th percentile by rank)=0.30 microg/L]. Neonatal p,p'-DDE concentrations today are significantly lower than in the mid-1990s, when many studies of adverse side effects of p,p'-DDE were performed. The present results suggest that the neonatal burden of p,p'-DDE now is so low that there may be no attendant health risks for newborns and children, however, further studies are warranted to elucidate possible long-term health effects even of low-level organochlorine pollution.