TY - JOUR
T1 - Dioxin effects on neonatal and infant thyroid function
T2 - Routes of perinatal exposure, mechanisms of action and evidence from epidemiology studies
AU - Giacomini, Sara Mariasole
AU - Hou, Lifang
AU - Bertazzi, Pier Alberto
AU - Baccarelli, Andrea
PY - 2006/5/1
Y1 - 2006/5/1
N2 - 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.
AB - 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.
KW - Child
KW - Dioxins
KW - Environmental exposure
KW - Infant
KW - Thyroid gland
UR - http://www.scopus.com/inward/record.url?scp=33645145031&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=33645145031&partnerID=8YFLogxK
U2 - 10.1007/s00420-005-0049-4
DO - 10.1007/s00420-005-0049-4
M3 - Article
C2 - 16217675
AN - SCOPUS:33645145031
VL - 79
SP - 396
EP - 404
JO - International Archives of Occupational and Environmental Health
JF - International Archives of Occupational and Environmental Health
SN - 0340-0131
IS - 5
ER -