Effects of p,p'-DDE on immature cells in culture at concentrations relevant to the Alaskan environment

Arctic Alaskan Natives who maintain a traditional lifestyle have a disease profile that is significantly different from the general US population. There is concern that food sources containing environmental pollutants may contribute to this profile. In a preliminary study, umbilical cord blood was examined for the presence of several environmental contaminants. All cord blood samples analyzed thus far contain p,p'-DDE (1,1-dichloro-2,2-bis(p-chlorophenyl)ethylene) with an average concentration of 0.33 microg/l. This study was undertaken to ascertain if this concentration of p,p'-DDE had detectable effects on immature cells in culture. NIH 3T3 (embryonic mouse fibroblast) and WS1 (human fetal fibroblast) cultures were exposed to media containing either 1 or 10 times the average cord blood concentration of p,p'-DDE. Initial experiments indicated that exposure to p,p'-DDE resulted in a decrease in the cell number of both cell types. Subsequent analysis revealed that the decrease in cell number was due to cell death in NIH 3T3 cells and to cell-cycle arrest in WS1 cells. Furthermore, p,p'-DDE decreased the long-term survival of NIH 3T3 but not WS1 cells. This study has demonstrated that p,p'-DDE, at relevant environmental concentrations, has significant effects on two immature mammalian cell types in culture. In addition, these results highlight the necessity for further studies to address the specific effects of p,p'-DDE on developing fetal systems.