Maternal concentrations, predictors and change in profiles of organochlorines, toxic and essential elements during pregnancy and postpartum : the Vietnamese mother-and-child study and the Northern Norwegian mother-and-child study

• Main Author: Hansen, Solrunn
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universitetet i Tromsø 2011
• Subjects: Environmental Pollutants; Chlorine Compounds; Pregnancy; Postpartum Period; Vietnam; Nord-Norge; Norway; Northern Norway
• Online Access: https://hdl.handle.net/10037/26318

Persistent toxic substances like organochlorines (OCs) and certain toxic metals have been or are extensively used, and can be globally distributed by long-range transport. The fetus and growing child are exposed via the placenta and breast milk and are vulnerable to their negative health effects. Concentrations measured in maternal blood or breast milk are thus potential indicators of risk for the next generation. Internal and external factors contribute to the maternal body burden of these toxicants including: age, parity, lactation, diet, past and current exposures, and the half-life of the contaminant in the body. Essential elements can modify the gastrointestinal absorption of toxic elements and thereby influence the negative impact of the latter. During the gestational and postpartum periods, remarkable physiological adaptions occur, and such changes have the potential to affect the maternal blood levels of persistent toxic substances and essential elements during these critical windows. The main objectives of this thesis research were to: investigate maternal concentrations of OCs and non-essential (toxic) and essential elements in the context of a northern-southern latitude perspective; identify exposure predictors: and investigate the influence of physiological changes and related pregnancy adaptations during the gestational and postpartum periods. The present work included pregnant and delivering women from two mother-and-child studies from Northern Norway (participant subsets of 50 and 211) and two communities in Southern Vietnam (total participants of 189), carried out respectively in 2007-09 and 2005. A suite of selected OC contaminants were analyzed in both study groups, and 5 toxic and 5 essential elements were additionally analyzed in the Northern Norwegian group. For the latter, changes in concentrations of all substances were investigated between three different collection periods: during the 21 trimester, and at 3 days and 6 weeks postpartum. In the North Norwegian study, low maternal ...