Preeclampsia is a major cause of maternal and fetal morbidity. Emerging research shows an association with environmental exposures. The present aim was to investigate associations between early pregnancy serum levels of perfluoroalkyl substances (PFAS) and preeclampsia. Within the Swedish SELMA study, eight PFAS were measured at median 10 gestational weeks and cases of preeclampsia were postnatally identified from registers. Associations between individual PFAS and preeclampsia were assessed, adjusting for parity, age, weight and smoking. Out of 1,773 women in the study group, 64 (3.6%), developed preeclampsia. A doubling of PFOS and PFNA exposure, corresponding to an inter-quartile increase, was associated with an increased risk for preeclampsia of about 38-53% respectively. Serum PFOS within the highest quartile was associated with an odds ratio of 2.68 (CI 95%: 1.17-6.12), equal to the increased risk associated with nulliparity, when compared to exposure in the first quartile. The same associations were identified, although with higher risk estimates, in analyses restricted to nulliparous women. For other PFAS, there were no associations. In conclusion and consistent with limited previous research only on PFOS, increasing serum levels of PFOS and PFNA during early pregnancy were associated with a clinically relevant risk of preeclampsia, adjusting for established confounders.

Phthalates are used as plasticizers in polyvinyl chloride (PVC) materials and it is known that phthalates may migrate into the surrounding environment and then become a source for human uptake. The aim of the study was to investigate whether residential PVC flooring was related to the urinary levels of phthalate metabolites determined in pregnant women. The data were from the Swedish SELMA study where sampling was conducted during the time period 2007-2010. Spot urine samples from 1674 women at the end of the first trimester were analyzed for 14 metabolites from seven phthalates and one phthalate alternative. Data on flooring material in the kitchen and the parents' bedrooms as well as potential confounders were collected by postal questionnaires at the same time as the urine samples were taken. Multiple regression modeling by least square geometric mean and weighted quantile sum regression was applied to log-transformed and creatinine-adjusted phthalate metabolite concentrations adjusted for potential confounders from questionnaire data. This study has found significantly higher urinary levels of the BBzP metabolite (MBzP) in pregnant women living in homes with PVC flooring as compared to homes with other flooring materials

Aim: This study examined whether prenatal phthalate exposure was associated with lower or upper airway inflammation in infants. Methods: From 2007 to 2010, we used liquid chromatography-tandem mass spectrometry, adjusted for creatinine, to analyse 14 phthalate metabolites and one phthalate replacement in the urine of 1062 Swedish mothers at a median of 10 weeks of pregnancy. This was used to determine any associations between prenatal phthalate exposure and croup, wheezing or otitis in their offspring until 12 months of age, using logistic regression, adjusted for potential confounders. Results: There were significant associations between phthalate metabolites of butyl-benzyl phthalate (BBzP) and di-ethyl-hexyl phthalate (DEHP) concentrations in maternal prenatal urine and croup in 1062 infants during the first year of life, when adjusted for potential confounders. A dose-response relationship was found between prenatal phthalates exposure and maternal reported croup in the children, with a significant association in boys. There was no clear indication with regard to associations between prenatal phthalate exposure and wheezing or otitis media in the children during the first year of life. Conclusion: Our analysis suggests that exposure to BBzP and DEHP phthalates was associated with maternal reports of croup in infants up to 12 months of age

Background Perfluoroalkyl substances (PFAS) are used in numerous consumer products. They are persistent, bioaccumulating, and suspected to be endocrine disrupting chemicals (EDCs). A growing body of research has reported the association between PFAS exposure and adverse health effects. Concerns have been raised with special focus in childhood development. Methods Perfluoroheptanoic acid (PFHpA), perfluorooctanoic acid (PFOA), perfluorononanoic acid (PFNA), perfluorodecanoic acid (PFDA), perfluoroundecanoic acid (PFUnDA), perfluorododecanoic acid (PFDoDA), perfluorohexane sulfonate (PFHxS) and perfluorooctane sulfonate (PFOS) were analyzed by LC/MS/MS in serum from 1,616 pregnant women in the Swedish SELMA study. The serum samples were collected in the first trimester (median week 10). Least square geometric means (LSGM) of PFAS were estimated for each year period for, adjusted for potential determinants including parity, fish intake in the family, and mother's age. Results Six PFAS (PFNA, PFDA, PFUnDA, PFHxS, PFOA, and PFOS) were detected above levels of detection (LOD) in more than 99% of the SELMA women, while PFHpA, and PFDoDA were detected above LOD in 73.4% and 46.7% respectively. Parity, maternal age, maternal smoking, and fish intake during pregnancy were found to be significantly associated (p<0.05) with serum PFAS levels in the pregnant women. Finally, serum concentration of six PFAS (PFNA, PFDA, PFHxS, PFHpA, PFOA and PFOS) were significantly decreasing (range 14-31%) during the period of 30 months from 2007-2010. Conclusions Our analysis shows that six out of eight PFAS could be identified in serum of more than 99% of SELMA subjects with a significant slightly decreasing trend for five of these compounds. Furthermore, parity, higher fish intake and mothers age are determinants for serum levels of PFAS in pregnant women.

Background: The general population is exposed to phthalates, a group of chemicals with strong evidence for endocrine disrupting properties, commonly used in a large number of consumer products. Based on published research and evidence compiled by environmental agencies, certain phthalate applications and products have become restricted, leading to an increasing number of “new generation compounds” coming onto the market during recent years replacing older phthalates. Some examples of such newer compounds are di-iso-nonyl phthalate (DiNP), di-iso-decyl phthalate (DiDP), and most recently di-isononyl-cyclohexane-1,2-dicarboxylate (DiNCH). Objectives: In order to evaluate temporal trends in phthalate exposure, first trimester urinary biomarkers of phthalates were measured in the Swedish SELMA study over a period of 2.5 years (2007–2010). Methods: We collected first morning void urine samples around week 10 of pregnancy from 1651 pregnant women. Spot samples were analyzed for 13 phthalate metabolites and one phthalate replacement and least square geometric mean (LSGM) levels of the metabolites were compared between the sampling years when adjusted for potential confounders. Results: All 14 metabolites were detectable in more than 99% of the SELMA subjects. The levels were generally comparable to other studies, but the SELMA subjects showed slightly higher exposure to butyl-benzyl phthalate (BBzP) and di-butyl phthalate (DBP). Di-ethyl-hexyl phthalate (DEHP) metabolites levels decreased while DiNP, DiDP/di-2-propylheptyl phthalate (DPHP), and DiNCH metabolites levels increased during the sampling period. Conclusions: Urinary metabolite levels of the older phthalates and more recently introduced phthalate replacement compound changed during the short sampling period in this Swedish pregnancy cohort. Our results indicate that replacement of phthalates can make an impact on human exposure to these chemicals. During this particularly vulnerable stage of life, phthalate exposures are of particular concern as the impacts, though not immediately noticeable, may increase the risk for health effects later in life.

Human health depends on a well-functioning endocrine system to regulate hormone release for normal bodily functions. Endocrine disrupting chemicals (EDCs) constitutes a group of chemicals, included in many commonly used products, (e.g., PVC flooring), with properties proven or suspected to interact with the natural hormone system in humans and animals. EDCs are manmade compounds (there are also natural compounds with such properties) that can bind to cell receptors and mimic or block the functions of natural hormones potentially resulting in adverse human health effects.

One type of widely concerning EDC is phthalates. Since phthalates create weak chemical bonds when they are added into different products, they readily leach into the surrounding environment. Phthalate metabolites can therefore be frequently measured in human biological samples. Major public health concerns regarding EDCs over the past three decades have focused on phthalates. According to the World Health Organization, EDCs are suspected to be associated with altered reproductive function in males and females, increased incidence of breast cancer, abnormal growth patterns and neurodevelopmental delays in children, as well as changes in immune function.

The thesis shows that PVC flooring in the home is a source for human uptake of phthalates, that replacement of phthalates in soft PVC products have an impact on human uptake of these chemicals, and that exposure for phthalates in early life increase the risk for airway disorders in children.

As we have shown, ongoing regulations on phthalates is of importance for human uptake. Ultimately, individuals can make small changes in their consumer product choices that can lead to changes in uptake of chemicals with endocrine disrupting properties. Philosophically, we all have a responsibility to protect future generations from dangerous chemicals.

Human health depends on a well-functioning endocrine system to regulate hormone release for normal bodily functions. Endocrine disrupting chemicals (EDCs) constitutes a group of chemicals, included in many commonly used products, (e.g., PVC flooring), with properties proven or suspected to interact with the natural hormone system in humans and animals.

One type of widely concerning EDC is phthalates. Since phthalates create weak chemical bonds when they are added into different products, they readily leach into the surrounding environment. Phthalate metabolites can therefore be frequently measured in human biological samples. Major public health concerns regarding EDCs over the past three decades have focused on phthalates resulting in implementation of regulations.

The thesis shows that PVC flooring in the home is a source for human uptake of phthalates, that replacement of phthalates in soft PVC products have an impact on human uptake of these chemicals, and that exposure for phthalates in early life increase the risk for airway disorders in children. This means that regulation and consumers’ product choices can lead to changes in uptake of EDCs of importance for human health. Philosophically, we all have a responsibility to protect future generations from dangerous chemicals.

The Canadian Healthy Infant Longitudinal Development birth cohort was designed to elucidate interactions between environment and genetics underlying development of asthma and allergy. Over 3600 pregnant mothers were recruited from the general population in four provinces with diverse environments. The child is followed to age 5 years, with prospective characterization of diverse exposures during this critical period. Key exposure domains include indoor and outdoor air pollutants, inhalation, ingestion and dermal uptake of chemicals, mold, dampness, biological allergens, pets and pests, housing structure, and living behavior, together with infections, nutrition, psychosocial environment, and medications. Assessments of early life exposures are focused on those linked to inflammatory responses driven by the acquired and innate immune systems. Mothers complete extensive environmental questionnaires including time-activity behavior at recruitment and when the child is 3, 6, 12, 24, 30, 36, 48, and 60 months old. House dust collected during a thorough home assessment at 3-4 months, and biological specimens obtained for multiple exposure-related measurements, are archived for analyses. Geo-locations of homes and daycares and land-use regression for estimating traffic-related air pollution complement time-activity-behavior data to provide comprehensive individual exposure profiles. Several analytical frameworks are proposed to address the many interacting exposure variables and potential issues of co-linearity in this complex data set.