EFFECTS OF ENVIRONMENTAL EXPOSURE TO POLYCHLORINATED-BIPHENYLS AND DIOXINS ON BIRTH SIZE AND GROWTH IN DUTCH CHILDREN

Lower birth weight and growth retardation has been found in studies wi th laboratory animals, in children born of mothers exposed to accident al high levels of polychlorinated biphenyls (PCBs) and related compoun ds, and in children born of mothers who consumed PCB-contaminated fish . The effect of background exposure to PCBs and dioxins on birth size and growth in human newborns, however, is still unknown. This study ex amined birth size and postnatal growth of term newborns in relation to their background PCB and dioxin exposure. Birth weight and weight, le ngth, and head circumference were measured at 10 d and 3, 7, 18, and 4 2 mo of age in 207 children, of whom 105 were breast-fed and 102 were formula-fed during infancy. The effect of in utero exposure to PCBs on birth size, assessed by cord and maternal plasma PCB levels, was inve stigated in the whole group. The effect of prenatal PCB exposure on po stnatal growth was studied in the formula-fed group, whereas the effec t of prenatal as well as lactational exposure to PCBs and dioxins on p ostnatal growth was studied in the breast-fed group. After adjustment for covariates, cord and maternal plasma PCB levels where both negativ ely associated with birth weight. Infants with high cord plasma PCB le vels (P-90 = 0.80 mu g/L) weighed 165 g less compared with infants wit h low cord plasma PCB levels (P-10 = 0.20 mu g/L). Cord and maternal p lasma PCB levels where both significantly associated with lower growth rate, defined as change in SD score (SDS) of weight, length, and head circumference from birth to 3 mo in the formula-fed group tall p valu es <0.05). No negative effects of prenatal PCB exposure on growth rate were found from 3 to 42 months of age. Postnatal PCB and dioxin expos ure was not negatively associated with growth rate in the breast-fed g roup. In utero exposure to environmental levels of PCBs is negatively associated with birth weight and postnatal growth until 3 mo of age. A lthough this growth delay was described in healthy term born infants, intrauterine and postnatal growth retardation are potentially harmful to the developing human and should be avoided by reducing maternal PCB and dioxin body burden, and consequently fetal exposure to these poll utants.