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

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 concentrations of both OCs and toxic elements, and normal levels of essential elements, were generally observed. The Vietnamese study demonstrated relatively high levels of p,p’-DDE and p,p’-DDT, among the highest globally speaking and possibly reflecting recent or current use. In contrast, the concentrations of PCBs were somewhat lower than those found among the Norwegian mothers. For the OCs, age (positive) and parity (negative) were strong predictors, with the latter being strongly associated with lactation. For the elements, the exposure predictors were limited to mercury, namely age (positive) and parity (negative). Place of living was associated with the observed OC concentrations for the Vietnamese participants, and Sámi ethnicity for elements in the North Norwegian survey; both findings probably reflect different dietary patterns. Diet as a source was only assessed for the toxic and essential elements. Fish consumption was found to be a strong predictor for arsenic, mercury and selenium. Although not investigated in detail, fish and seafood intake can also be an important contributor to serum or plasma OCs levels. The lower PCB concentrations observed in Vietnam in combination with published suggestions of higher fish intake suggest the consumption of smaller, younger, and lean fish species in combination with low environmental deposition by long-range transport and minor local sources. It is concluded that precaution (including dietary advice) is still relevant and important. In Vietnam, there is also a need to make pesticide-use restrictions more effective by providing the public with information on their possible health effects. The most important findings are probably the patterns revealed for the concentrations of OCs and the non-essential (toxic) and essential elements as they appeared to be driven by the physiological adaptations during pregnancy. The wet-weight concentrations of the lipid soluble OCs followed the changes in lipid profiles that peaked at birth. In addition to paralleling metabolic, hematological and physiological changes during the gestational and postpartum periods, the concentrations of the elements also reflected their biochemistry and their accumulation preferences within the whole-blood compartment and breast milk. Our systematic approach and findings give a new understanding of the changing concentrations of toxicants and essential elements during pregnancy and have implications for the optimum monitoring time

The Argentinian mother-and-child contaminant study: a cross-sectional study among delivering women in the cities of Ushuaia and Salta

Source at https://doi.org/10.1080/22423982.2017.1364598 .Several ongoing international multidisciplinary projects have examined linkages between environmental chemicals and health. In contrast to Arctic regions, information for the Southern Hemisphere is scarce. Because of the inherent practice of pesticide utilisation and mismanagement, food security is potentially threatened. The most vulnerable period in human life occurs during pregnancy and early childhood, thus a focus on the body burdens of PTS in pregnant or delivering women is warranted. The current study was designed to investigate health risks related to exposure to PTS and food security in two regions of Argentina (Ushuaia and Salta). Our aims were to quantify concentrations of organic and inorganic toxins in serum or whole blood of delivering women and to collect pertinent dietary and medical information. The overall study design, the basic demographic features and essential clinical chemistry findings are described in the current paper. The socioeconomic differences between the two study areas were evident. On average, the women in Ushuaia were 4 years older than those in Salta (28.8 vs. 24.7 years). Respectively, the proportion of current smokers was 4.5 vs. 9.6%; and Salta had a higher birth rate, with 15.6% being para four or more. Saltanean women reported longer breastfeeding periods. Caesarean sections were more frequent in Ushuaia, with 43% of Caesarean deliveries compared with only 6% in Salta. Employment was high in both communities. Recognised environmental pollution sources in the vicinity of participant dwellings were widespread in Salta (56.1%) compared to Ushuaia (9%). The use of pesticides for insect control in homes was most common in Salta (80%). There is an urgent need for a comprehensive assessment of exposures in areas of the Southern Hemisphere. Our data set and the planned publications of observed concentrations of inorganic and organic environmental contaminants in both mothers and their newborns will contribute to this objective

Maternal Blood Levels of Toxic and Essential Elements and Birth Outcomes in Argentina: The EMASAR Study

Pregnant women’s levels of toxic and essential minerals have been linked to birth outcomes yet have not been adequately investigated in South America. In Argentina, n = 696 maternal whole blood samples from Ushuaia (n = 198) and Salta (n = 498) were collected in 2011–2012 among singleton women at 36 ± 12 h postpartum and analyzed for blood concentrations of arsenic (As), cadmium (Cd), mercury (Hg), lead (Pb), copper (Cu), manganese (Mn), selenium (Se) and zinc (Zn). This study examined the associations between maternal elements levels and birth outcomes, and sociodemographic factors contributing to elements levels. Maternal age, parity, body mass index, smoking, and education were linked to concentrations of some but not all elements. In adjusted models, one ln-unit increase in Pb levels was associated with increased gestational age (0.2 weeks, 95% CI = 0.01–0.48) and decreased birth weight (−88.90 g, 95% CI = −173.69 to −4.11) and birth length (−0.46 cm, 95% CI = −0.85 to −0.08) in the Salta sample. Toxic elements concentrations were not associated with birth outcomes in Ushuaia participants. Birth outcomes are multifactorial problems, and these findings provide a foundation for understanding how the body burden of toxic and essential elements, within the socioeconomic context, may influence birth outcomes

Assessing the relationship between perfluoroalkyl substances, thyroid hormones and binding proteins in pregnant women; a longitudinal mixed effects approach

Accepted manuscript version. Published version available at https://doi.org/10.1016/j.envint.2015.01.007. Accepted manuscript version, licensed CC BY-NC-ND 4.0.The mechanisms involved in thyroid homeostasis are complex, and perfluoroalkyl substances (PFASs) have been indicated to interfere at several levels in this endocrine system. Disruption of the maternal thyroid homeostasis during early pregnancy is of particular concern, where subclinical changes in maternal thyroid hormones (THs) may affect embryonic and foetal development. The present study investigated associations between THs, thyroid binding proteins (TH-BPs) and PFAS concentrations in pregnant women from Northern Norway. Women participating in The Northern Norway Mother-and-Child contaminant Cohort Study (MISA) donated a blood sample at three visits related to their pregnancy and postpartum period (during the second trimester, 3 days and 6 weeks after delivery) in the period 2007–2009. Participants were assigned to quartiles according to PFAS concentrations during the second trimester and mixed effects linear models were used to investigate potential associations between PFASs and repeated measurements of THs, TH-BPs, thyroxin binding capacity and thyroid peroxidase antibodies (anti-TPOs). Women within the highest perfluorooctane sulfonate (PFOS) quartile had 24% higher mean concentrations of thyroid stimulating hormone (TSH) compared to the first quartile at all sampling points. Women within the highest quartiles of perfluorodecanoate (PFDA) had 4% lower mean concentrations of triiodothyronine (T3) and women within the highest quartile of perfluoroundecanoate (PFUnDA) had 3% lower mean concentrations of free triiodothyronine (FT3). Further, the difference in concentrations and the changes between three time points were the same for the PFAS quartiles. Thyroxin binding capacity was associated with all the THs and TH-BPs, and was selected as a holistic adjustment for individual changes in TH homeostasis during pregnancy. Finally, adjusting for maternal iodine status did not influence the model predictions. Findings in the present study suggest modifications of TH homeostasis by PFASs in a background exposed maternal population. The variation in levels of THs between PFAS quartiles was within normal reference ranges and may not be of clinical significance in the pregnant woman. However, subtle individual changes in maternal THs may have significant consequences for foetal health

Persistent Organic Pollutants and the Association with Maternal and Infant Thyroid Homeostasis: A Multipollutant Assessment

Source: doi: 10.1289/EHP152.Reproduced with permission from Environmental Health Perspectives.Background:Disruption of thyroid homeostasis has been indicated in human studies targeting effects of persistent organic pollutants (POPs). Influence on the maternal thyroid system by POPs is of special interest during pregnancy because such effects could impair infant thyroid homeostasis. Objectives:We investigated the association between POPs and thyroid-stimulating hormone (TSH) and thyroid hormones (THs) in mother and child pairs from the Northern Norway Motherand- Child Contaminant Cohort Study (MISA). Methods:Nineteen POPs and 10 thyroid parameters were analyzed in serum from 391 pregnant women in their second trimester. In addition, TSH concentrations in heel-prick samples from the infants were analyzed by the Norwegian Newborn Screening program. Association studies with a multipollutant approach were performed using multivariate analyses; partial least squares (PLS) regression, hierarchical clustering, and principal component analysis (PCA). Results:Several POPs were significantly associated with TSH and THs: a) PFOS was positively associated with TSH; b) PCBs, HCB, and nonachlors were inversely associated with T3, T4, and FT4; and, c) PFDA and PFUnDA were inversely associated with T3 and FT3. After mutual adjustments for the other contaminants, only PFDA and PFUnDA remained significantly associated with T3 and FT3, respectively. Infants born to mothers within the highest TSH quartile had 10% higher mean concentrations of TSH compared with children born to mothers in the lowest TSH quartile. Conclusion:The present results suggest that background exposures to POPs can alter maternal thyroid homeostasis. This research contributes to the understanding of multipollutant exposures using multivariate statistical approaches and highlights the complexity of investigating environmental concentrations and mixtures in regard to maternal and infant thyroid function

Overview of ongoing cohort and dietary studies in the Arctic

Published version. Source at http://dx.doi.org/10.3402/ijch.v75.33803 This article gives an overview of the ongoing cohort and dietary studies underlying the assessment of population health in the Arctic. The emphasis here is on a description of the material, methods and results or preliminary results for each study. Detailed exposure information is available in an article in this journal, whereas another paper describes the effects associated with contaminant exposure in the Arctic. The cohort descriptions have been arranged geographically, beginning in Norway and moving east to Finland, Sweden, Russia and the other Arctic countries and ultimately to the Faroe Islands. No cohort studies have been reported for Alaska or Iceland

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

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 concentrations of both OCs and toxic elements, and normal levels of essential elements, were generally observed. The Vietnamese study demonstrated relatively high levels of p,p’-DDE and p,p’-DDT, among the highest globally speaking and possibly reflecting recent or current use. In contrast, the concentrations of PCBs were somewhat lower than those found among the Norwegian mothers. For the OCs, age (positive) and parity (negative) were strong predictors, with the latter being strongly associated with lactation. For the elements, the exposure predictors were limited to mercury, namely age (positive) and parity (negative). Place of living was associated with the observed OC concentrations for the Vietnamese participants, and Sámi ethnicity for elements in the North Norwegian survey; both findings probably reflect different dietary patterns. Diet as a source was only assessed for the toxic and essential elements. Fish consumption was found to be a strong predictor for arsenic, mercury and selenium. Although not investigated in detail, fish and seafood intake can also be an important contributor to serum or plasma OCs levels. The lower PCB concentrations observed in Vietnam in combination with published suggestions of higher fish intake suggest the consumption of smaller, younger, and lean fish species in combination with low environmental deposition by long-range transport and minor local sources. It is concluded that precaution (including dietary advice) is still relevant and important. In Vietnam, there is also a need to make pesticide-use restrictions more effective by providing the public with information on their possible health effects. The most important findings are probably the patterns revealed for the concentrations of OCs and the non-essential (toxic) and essential elements as they appeared to be driven by the physiological adaptations during pregnancy. The wet-weight concentrations of the lipid soluble OCs followed the changes in lipid profiles that peaked at birth. In addition to paralleling metabolic, hematological and physiological changes during the gestational and postpartum periods, the concentrations of the elements also reflected their biochemistry and their accumulation preferences within the whole-blood compartment and breast milk. Our systematic approach and findings give a new understanding of the changing concentrations of toxicants and essential elements during pregnancy and have implications for the optimum monitoring time

The second clinical survey of the population-based study on health and living conditions in regions with Sami and Norwegian populations – the SAMINOR 2 Clinical Survey: Performing indigenous health research in a multiethnic landscape

Background - Globally, there is a huge lack of relevant research about widespread lifestyle diseases and living conditions in indigenous communities. Northern and Middle Norway have a history of multiple ethnic groups and the Sami has been acknowledged as the indigenous people of Norway by the Norwegian State. The SAMINOR 2 Clinical Survey, a part of the SAMINOR Study, was carried out to provide health information about the Sami population in Norway. Methods - The cross-sectional population-based SAMINOR 2 Clinical Survey consists of both questionnaires and a clinical examination performed in 10 municipalities during 2012–2014. Results - In total, 6004 men and women (participation rate 48%) aged 40–79 years took part in this study. In inland Finnmark, the Sami are in the majority (80–90%) as opposed to the coastline of Troms and Nordland, where the Sami population form a minority (20%). More women than men participated (54% versus 43%, respectively). Obesity was prevalent in this sample and a high mean glycated haemoglobin was observed. Conclusions - This article describes the methods and data collection of the SAMINOR 2 Clinical Survey and presents some characteristics of the sample. The definition of ethnic groups is a core question in the survey and includes several criteria. To ensure that indigenous values and priorities are reflected in the research themes, we recommend that future research projects be directed in close collaboration with the Sami Parliament and the local communities

A population-based study on health and living conditions in areas with mixed Sami and Norwegian settlements - The SAMINOR 2 questionnaire study

Objectives: To describe the method, data collection procedure and participation in The Population-based Study on Health and Living Conditions in Areas with both Sami and Norwegian Settlements – the SAMINOR 2 questionnaire study. Study design: Cross-sectional and semi-longitudinal. Methods: In 2012, all inhabitants aged 18–69 and living in selected municipalities with both Sami and Norwegian settlements in Mid and Northern Norway were posted an invitation to participate in a questionnaire survey covering several topics related to health and living conditions. The geographical area was similar to the area where the SAMINOR 1 study was conducted in 2003/2004 with the exception of one additional municipality. Participants could alternatively use a web-based questionnaire with identical question and answer categories as the posted paper version. Results: In total, 11,600 (27%) participated (16% used the web-based questionnaire), with a higher participation rate among those over 50 (37% for women and 32% for men). Some geographical variation in participation rates was found. In addition, for those invited who also participated in the SAMINOR 1 study, we found that the participation rates increased with the level of education and income, while there was little difference in participation rates across ethnic groups. Conclusion: The knowledge generated from future theme-specific research utilizing the SAMINOR 2 database has the potential to benefit the general population in this geographical area of Norway, and the Sami people in particular, by providing knowledge-based insight into the health and living conditions of the multi-ethnic population in these parts of Norway

Midwives and public health nurses' knowledge and clinical practice in securing sufficient iodine status in relation to pregnancy: A cross‐sectional study

Abstract Aim To investigate midwives' (MWs) and public health nurses' (PHNs) clinical practice and knowledge related to nutrition, with a particular focus on iodine in northern parts of Norway. Maternal iodine status prior to and during pregnancy, and the lactating period, is crucial for brain development and growth of the foetus and infant, from conception up until the first two years of life. In Norway, studies have documented mild to moderate iodine deficiency in this group. Design/Methods MWs (n = 128) and PHNs (n = 154) responded to a survey regarding nutrition and iodine. Descriptive data and non‐parametric tests were used to analyse data. Results Around half of the participants provided dietary guidance to a great extent. Practice of iodine‐specific recommendations was lower, particularly regarding lactating women. Compared to other nutrients, iodine was not a priority. Conclusion The study indicates a lack of knowledge and poor clinical practice about iodine among MWs and PHNs