ABSTRACT
OBJECTIVE: To study possible adverse effects of environmental exposure to polychlorinated biphenyls (PCB) and dioxins on cognitive functioning in young children. METHODS: In a follow-up of the Dutch PCB/Dioxin study, cognitive abilities were assessed with the Kaufman Assessment Battery for Children in 42-month-old children (n = 395). In a subgroup (n = 193) verbal comprehension was assessed with the Reynell Language Developmental Scales. Prenatal PCB exposure was estimated from the sum of PCBs 118, 138, 153, and 180 (SigmaPCB) in maternal plasma. Lactational exposure was assessed from breast milk PCB and dioxin concentrations, multiplied by the number of weeks of breast-feeding. Current PCB body burden was estimated from SigmaPCB in 42-month-old plasma samples. RESULTS: After adjustment was done for covariables, maternal SigmaPCB was associated with lower scores on the overall cognitive and sequential and simultaneous processing scales of the Kaufman Assessment Battery for Children (all P <.05). The highest exposed group (SigmaPCB >/= 3 microg/L) scored 4 points lower on all 3 scales of the K-ABC when compared with the lowest exposed group (SigmaPCB < 1.5 microg/L). Both lactational exposure and current exposure to PCBs and dioxins were not related to 42-month cognitive performance. CONCLUSIONS: In utero exposure to "background" PCB concentrations is associated with poorer cognitive functioning in preschool children. Children of mothers at the upper end of exposure are especially at risk. Therefore maternal PCB body burden should be reduced, and breast-feeding should not be discouraged.
Subject(s)
Cognition/drug effects , Dioxins/adverse effects , Environmental Exposure/adverse effects , Polychlorinated Biphenyls/adverse effects , Prenatal Exposure Delayed Effects , Breast Feeding , Child, Preschool , Dioxins/analysis , Female , Fetal Blood/chemistry , Follow-Up Studies , Humans , Linear Models , Maternal Exposure/adverse effects , Maternal-Fetal Exchange , Milk, Human/chemistry , Netherlands , Polychlorinated Biphenyls/analysis , Polychlorinated Biphenyls/blood , PregnancyABSTRACT
In this retrospective study the following information was recorded for all 1,296 infants born in 1990 and admitted to the neonatal ward, General Hospital, Port-of-Spain: date of birth, gestational age, birthweight, Apgar scores after one and five minutes, type of delivery, foetal presentation, mother's address and data concerning death. The annual perinatal mortality rate was 25.2 per 1,000 live births. The neonatal mortality rate (NMR) equaled 12.8 per 1,000 live births and the still birth rate was 15.0 per 1,000 births. The NMR for the month of August was remarkably high. During the past ten years, the NMR showed a sharp decline since 1982. From a regression analysis, birthweight (R2 = .27), Apgar score after five minutes (R2 = .26) and gestational age (R2 = .22) emerged as predictors of neonatal mortality. Birthweight-specific NMRs in infants born in a regional hospital were equal to or higher than our monthly, yearly and interhospital variations in mortality rates, although the effects of differences in the study populations cannot be completely excluded (AU)