Objectives: Animal experiments suggest that thyroid function alterations in newborns and infants may represent one of the most sensitive markers of toxicity from 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD). Dioxin can be transferred from the mother to the offspring either in utero or through lactation. It has been suggested that thyroid-hormone alterations produced by dioxin in utero or shortly after birth may underlie long-term effects, such as cognitive-ability and neurodevelopment impairment. In the present review article, we appraise available evidence on the effects of perinatal exposure to dioxin on fetal and infant thyroid function. Methods: We summarized the routes of perinatal dioxin exposure and research results on possible mechanisms of dioxin toxic effects on thyroid function. We performed a systematic review of epidemiology studies conducted on mother-child pairs exposed to background environmental levels to investigate dioxin effects on neonatal and infant thyroid function. Results: Toxicological and mechanistic data in dicate that dioxin may impair thyroid function in exposed newborns and infants. Investigations on background-exposed children have not consistently demonstrated an association between perinatal TCDD exposure and thyroid function, although some of the studies suggest that sub-clinical hypothyroidism may be induced by perinatal dioxin exposure within 3 months from birth. Between studies inconsistencies may be related to lab method differences, mixed exposures, and small sample size of the populations evaluated. Conclusion: Epidemiology studies have as yet failed to demonstrate an association between perinatal TCDD exposure and thyroid function alterations in human subjects, although suggestive evidence from animal and in-vitro experimental data is available.
Dioxin effects on neonatal and infant thyroid function : routes of perinatal exposure, mechanisms of action and evidence from epidemiology studies / S.M. Giacomini, L. Hou, P.A. Bertazzi, A. Baccarelli. - In: INTERNATIONAL ARCHIVES OF OCCUPATIONAL AND ENVIRONMENTAL HEALTH. - ISSN 0340-0131. - 79:5(2006 May), pp. 396-404.
|Titolo:||Dioxin effects on neonatal and infant thyroid function : routes of perinatal exposure, mechanisms of action and evidence from epidemiology studies|
GIACOMINI, SARA MARIASOLE (Primo)
BERTAZZI, PIETRO ALBERTO (Penultimo)
BACCARELLI, ANDREA (Ultimo)
|Parole Chiave:||Child; Dioxins; Environmental exposure; Infant; Thyroid gland|
|Settore Scientifico Disciplinare:||Settore MED/44 - Medicina del Lavoro|
|Data di pubblicazione:||mag-2006|
|Digital Object Identifier (DOI):||http://dx.doi.org/10.1007/s00420-005-0049-4|
|Appare nelle tipologie:||01 - Articolo su periodico|