Keywords: perinatal dioxin exposure, follow-up study, prospective cohort study, breast development, thyroid hormone metabolism, brain development, immunotoxicity, lung function, environmental pollution, The Netherlands, breastfeeding, children, child health, liver, haematology, immunology, retinol binding protein
Perinatal dioxin exposure in The Netherlands – a long-term follow-up
In 1987, a cohort study was initiated in the Amsterdam/Zaandam region of The Netherlands to study possible effects of dioxins on development and growth in a population of breastfed children selected after an optimal pregnancy and delivery and birth weight above 2500 grams. Effects on thyroid hormone metabolism, liver, haematology and immunology, and retinol binding protein were found in neonates. Follow-up was performed at the age of 2½ years, 8?12 years and 13?18 years. Neonatally an increase in free thyroxine and thyroid stimulating hormone was found, indicating a change in set point. An enhanced psychomotor maturation was seen at the age of 2½ years. Negative effects on lung function and on brain development (studied with neurophysiological tests of visuo-motoric and cognitive performance) were demonstrated in the age of 8?12 years. In adolescence preliminary results show a delay of almost 1 year in breast development in girls in association with higher (above 40 ng International Toxic Equivalents dioxin) prenatal dioxin exposure and again a negative effect on innate immunity. The abnormalities found indicate an increased vulnerability for more stressful circumstances. New chemicals comparable to dioxins or contaminated with dioxins should not be allowed on the market, or if already there, must be banned.