ENVIRONMENTAL EXPOSURE TO CADMIUM AND HUMAN BIRTH-WEIGHT

Fetal toxicity of cadmium (Cd) is well documented in rodents. However, little information is available regarding the human fetus. To investi gate the effect of low levels of Cd on the human placenta and the cons equences on birthweight, we conducted a study of 102 mothers and their newborns in an obstetrical care unit. Placental and hair samples were collected at delivery to determine Cd concentrations. The main findin g of this study was the relationship between a decrease in birthweight and an increase of newborn hair Cd which varied in the presence of pl acental calcification. In cases of parenchymal calcifications, placent al Cd levels were higher (Wilcoxon test, P < 0.05) and newborn hair Cd levels were lower (Wilcoxon test, P < 0.01) than in the absence of ca lcification. These relationships remained significant even after takin g into account smoking habits and gestational age. In the presence of calcification, an increase in the level of Cd in newborn hair was rela ted to a decrease in birthweight which was independent of placental Cd concentration (r(partial) = -0.49, P < 0.01). In the absence of calci fication, a decrease in birthweight was observed for the upper values of newborn hair Cd (r = -0.44, P < 0.05 when Cd greater-than-or-equal- to 0.3 ppm). The difference in birthweight between infants in the firs t and last quartiles of newborn hair Cd was 472 g in cases of calcific ations and 122 g in the absence of calcification. Other placental para meters were not significantly related to placental Cd concentration.