Combined effects of multiple prenatal exposure to pollutants on birth weight: The Mothers and Children's Environmental Health (MOCEH) study

Health effects of air pollutant mixtures (volatile organic compounds, particulate matter, sulfur and nitrogen oxides) - a review of the literature

The health risks associated with individual air pollutant exposures have been studied and documented, but in real-life, the population is exposed to a multitude of different substances, designated as mixtures. A body of literature on air pollutants indicated that the next step in air pollution research is investigating pollutant mixtures and their potential impacts on health, as a risk assessment of individual air pollutants may actually underestimate the overall risks. This review aims to synthesize the health effects related to air pollutant mixtures containing selected pollutants such as: volatile organic compounds, particulate matter, sulfur and nitrogen oxides. For this review, the PubMed database was used to search for articles published within the last decade, and we included studies assessing the associations between air pollutant mixtures and health effects. The literature search was conducted according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A number of 110 studies were included in the review from which data on pollutant mixtures, health effects, methods used, and primary results were extracted. Our review emphasized that there are a relatively small number of studies addressing the health effects of air pollutants as mixtures and there is a gap in knowledge regarding the health effects associated with these mixtures. Studying the health effects of air pollutant mixtures is challenging due to the complexity of components that mixtures may contain, and the possible interactions these different components may have.

The effects of radiofrequency exposure on adverse female reproductive outcomes: A systematic review of human observational studies with dose-response meta-analysis

BACKGROUND

To inform radiofrequency electromagnetic field (RF-EMF) exposure guidelines the World Health Organization (WHO) is bringing together evidence on RF-EMF in relation to health outcomes prioritised for evaluation by experts in this field. Given this, a network of topic experts and methodologists have conducted a series of systematic reviews collecting, assessing, and synthesising data of relevance to these guidelines. Here we present a systematic review of the effect of RF-EMF exposure on adverse pregnancy outcomes in human observational studies which follows the WHO handbook for guideline development and the COSTER conduct guidelines.

METHODS

We conducted a broad, sensitive search for potentially relevant records within the following bibliographic databases: MEDLINE; Embase; and the EMF Portal. Grey literature searches were also conducted through relevant databases (including OpenGrey), organisational websites and via consultation of RF-EMF experts. We included quantitative human observational studies on the effect of RF-EMF exposure in adults' preconception or pregnant women on pre-term birth, small for gestational age (SGA; associated with intrauterine growth restriction), miscarriage, stillbirth, low birth weight (LBW) and congenital anomalies. In blinded duplicate, titles and abstracts then full texts were screened against eligibility criteria. A third reviewer gave input when consensus was not reached. Citation chaining of included studies was completed. Two reviewers' data extracted and assessed included studies for risk of bias using the Office of Health Assessment and Translation (OHAT) tool. Random effects meta-analyses of the highest versus the lowest exposures and dose-response meta-analysis were conducted as appropriate and plausible. Two reviewers assessed the certainty in each body of evidence using the OHAT GRADE tool.

RESULTS

We identified 18 studies in this review; eight were general public studies (with the general public as the population of interest) and 10 were occupational studies (with the population of interest specific workers/workforces). General public studies. From pairwise meta-analyses of general public studies, the evidence is very uncertain about the effects of RF-EMF from mobile phone exposure on preterm birth risk (relative risk (RR) 1.14, 95% confidence interval (CI): 0.97-1.34, 95% prediction interval (PI): 0.83-1.57; 4 studies), LBW (RR 1.14, 95% CI: 0.96-1.36, 95% PI: 0.84-1.57; 4 studies) or SGA (RR 1.13, 95% CI: 1.02-1.24, 95% PI: 0.99-1.28; 2 studies) due to very low-certainty evidence. It was not feasible to meta-analyse studies reporting on the effect of RF-EMF from mobile phone exposure on congenital anomalies or miscarriage risk. The reported effects from the studies assessing these outcomes varied and the studies were at some risk of bias. No studies of the general public assessed the impact of RF-EMF exposure on stillbirth. Occupational studies. In occupational studies, based on dose-response meta-analyses, the evidence is very uncertain about the effects of RF-EMF amongst female physiotherapists using shortwave diathermy on miscarriage due to very low-certainty evidence (OR 1.02 95% CI 0.94-1.1; 2 studies). Amongst offspring of female physiotherapists using shortwave diathermy, the evidence is very uncertain about the effects of RF-EMF on the risk of congenital malformations due to very low-certainty evidence (OR 1.4, 95% CI 0.85 to 2.32; 2 studies). From pairwise meta-analyses, the evidence is very uncertain about the effects of RF-EMF on the risk of miscarriage (RR 1.06, 95% CI 0.96 to 1.18; very low-certainty evidence), pre-term births (RR 1.19, 95% CI 0.32 to 4.37; 3 studies; very low-certainty evidence), and low birth weight (RR 2.90, 95% CI: 0.69 to 12.23; 3 studies; very low-certainty evidence). Results for stillbirth and SGA could not be pooled in meta-analyses. The results from the studies reporting these outcomes were inconsistent and the studies were at some risk of bias.

DISCUSSION

Most of the evidence identified in this review was from general public studies assessing localised RF-EMF exposure from mobile phone use on female reproductive outcomes. In occupational settings, each study was of heterogenous whole-body RF-EMF exposure from radar, short or microwave diathermy, surveillance and welding equipment and its effect on female reproductive outcomes. Overall, the body of evidence is very uncertain about the effect of RF-EMF exposure on female reproductive outcomes. Further prospective studies conducted with greater rigour (particularly improved accuracy of exposure measurement and using appropriate statistical methods) are required to identify any potential effects of RF-EMF exposure on female reproductive outcomes of interest.

Association Between Multiple Metal(loid)s Exposure and Blood Lipid Levels: Evidence from a Cross-Sectional Study of Southeastern China

Exposure to essential and toxic metals occurs simultaneously as a mixture in real-life. However, there is no consensus regarding the effects of co-exposure to multiple metal(loid)s (designated hereafter metals) on blood lipid levels. Thus, blood concentrations of six human essential metals and five toxic metals in 720 general populations from southeastern China were simultaneously determined as a measure of exposure. In addition, quantile g-computation, Bayesian kernel machine regression, elastic net regression, and generalized linear model were used to investigate both the joint and individual effects of exposure to this metal mixture on human blood lipid levels. The significant positive joint effect of exposure to this metal mixture on serum total cholesterol (TC) levels, rather than on serum triglycerides, high-density lipoprotein cholesterol (HDL-C), low-density lipoprotein cholesterol, Castelli risk index I, Castelli risk index II, atherogenic coefficient, and non-HDL-C levels, was found. In addition, the positive effect may be primarily driven by selenium (Se), lead (Pb), and mercury (Hg) exposure. In addition, on the effect of TC levels, the synergistic effect between Pb and Hg and the antagonistic effect between Se and Pb were identified. Our finding suggests that combined exposure to this metal mixture may affect human blood lipid levels. Therefore, reducing exposure to heavy metals, such as Pb and Hg, should be a priority for the general population. In addition, Se supplementation should also be considered with caution.

Perinatal Outcomes during versus Prior to the COVID-19 Pandemic and the Role of Maternal Depression and Perceived Stress: A Report from the ECHO Program

OBJECTIVE

We sought to evaluate the impact of the coronavirus disease 2019 (COVID-19) pandemic on perinatal outcomes while accounting for maternal depression or perceived stress and to describe COVID-specific stressors, including changes in prenatal care, across specific time periods of the pandemic.

STUDY DESIGN

Data of dyads from 41 cohorts from the National Institutes of Health Environmental influences on Child Health Outcomes Program (N = 2,983) were used to compare birth outcomes before and during the pandemic (n = 2,355), and a partially overlapping sample (n = 1,490) responded to a COVID-19 questionnaire. Psychosocial stress was defined using prenatal screening for depression and perceived stress. Propensity-score matching and general estimating equations with robust variance estimation were used to estimate the pandemic's effect on birth outcomes.

RESULTS

Symptoms of depression and perceived stress during pregnancy were similar prior to and during the pandemic, with nearly 40% of participants reporting mild to severe stress, and 24% reporting mild depression to severe depression. Gestations were shorter during the pandemic (B =  - 0.33 weeks, p = 0.025), and depression was significantly associated with shortened gestation (B =  - 0.02 weeks, p = 0.015) after adjustment. Birth weights were similar (B =  - 28.14 g, p = 0.568), but infants born during the pandemic had slightly larger birth weights for gestational age at delivery than those born before the pandemic (B = 0.15 z-score units, p = 0.041). More women who gave birth early in the pandemic reported being moderately or extremely distressed about changes to their prenatal care and delivery (45%) compared with those who delivered later in the pandemic. A majority (72%) reported somewhat to extremely negative views of the impact of COVID-19 on their life.

CONCLUSION

In this national cohort, we detected no effect of COVID-19 on prenatal depression or perceived stress. However, experiencing the COVID-19 pandemic in pregnancy was associated with decreases in gestational age at birth, as well as distress about changes in prenatal care early in the pandemic.

KEY POINTS

· COVID-19 was associated with shortened gestations.. · Depression was associated with shortened gestations.. · However, stress during the pandemic remained unchanged.. · Most women reported negative impacts of the pandemic..

Exposure to metal mixtures and adverse pregnancy and birth outcomes: A systematic review

BACKGROUND

Prenatal exposure to metal mixtures is associated with adverse pregnancy and birth outcomes like low birth weight, preterm birth, and small for gestational age. However, prior studies have used individual metal analysis, lacking real-life exposure scenarios.

OBJECTIVES

This systematic review aims to evaluate the strength and consistency of the association between metal mixtures and pregnancy and birth outcomes, identify research gaps, and inform future studies and policies in this area.

METHODS

The review adhered to the updated Preferred Reporting Items for Systematic Review and Meta-analysis (PRISMA) checklist, along with the guidelines for conducting systematic reviews and meta-analyses of observational studies of etiology (COSMOS-E). Our data collection involved searching the PubMed, MEDLINE, and SCOPUS databases. We utilized inclusion criteria to identify relevant studies. These chosen studies underwent thorough screening and data extraction procedures. Methodological quality evaluations were conducted using the NOS framework for cohort and case-control studies, and the AXIS tool for cross-sectional studies.

RESULTS

The review included 34 epidemiological studies, half of which focused on birth weight, and the others investigated neonate size, preterm birth, small for gestational age, miscarriage, and placental characteristics. The findings revealed significant associations between metal mixtures (including mercury (Hg), nickel (Ni), arsenic (As), cadmium (Cd), manganese (Mn), cobalt (Co), lead (Pb), zinc (Zn), barium (Ba), cesium (Cs), copper (Cu), selenium (Se), and chromium (Cr)) and adverse pregnancy and birth outcomes, demonstrating diverse effects and potential interactions.

CONCLUSION

In conclusion, this review consistently establishes connections between metal exposure during pregnancy and adverse consequences for birth weight, gestational age, and other vital birth-related metrics. This review further demonstrates the need to apply mixture methods with caution but also shows that they can be superior to traditional approaches. Further research is warranted to deeper understand the underlying mechanisms and to develop effective strategies for mitigating the potential risks associated with metal mixture exposure during pregnancy.

Association of postnatal exposure to mixture of bisphenol A, Di-n-butyl phthalate and Di-(2-ethylhexyl) phthalate with Children's IQ at 5 Years of age: Mothers and Children's environmental health (MOCEH) study

Early childhood is important for neurodevelopment, and exposure to endocrine disruptors such as bisphenol A (BPA) and phthalates in this period may cause neurodevelopmental disorders and delays. The present study examined the association between exposure to mixtures of BPA and three metabolites of phthalates in early childhood and IQ at 5 years of age. The Mother and Children's Environmental Health (MOCEH) study is a prospective birth cohort study conducted in Korea with 1751 pregnant women enrolled from 2006 to 2010. After excluding those without relevant data, 47 children were included in the final analysis. We measured children's urinary concentrations of metabolites of endocrine-disrupting chemicals (Bisphenol A, mono-(2-ethyl-5-oxohexyl) phthalate, mono-(2-ethyl-5-hydroxyhexyl) phthalate and mono-(2-ethyl-5-butyl) phthalate) at ages of 24 and 36 months. We evaluated the children's IQ with the Korean Wechsler Intelligence Test at the age of 5 years. After adjusting for potential confounders, a multiple linear regression was conducted to examine the associations between individual endocrine-disrupting chemicals and the IQ of the children. Weighted Quantile Sum (WQS) regression and quantile-based g-computation were used to assess the association between IQ at age 5 and exposure to mixtures of BPA and phthalates. In the single-chemical analyses, mono-(2-ethyl-5-butyl) phthalate exposure at 36 months was adversely associated with children's IQ (β = -4.93, 95% confidence interval (CI): -9.22, -0.64). In the WQS regression and quantile-based g-computation analyses, exposure to the mixture of BPA and phthalates was associated with lower IQ [β = -9.13 (P-value = 0.05) and β = -9.18 (P-value = 0.05), respectively]. The largest contributor to the overall association was exposure to mono-(2-ethyl-5-butyl) phthalate at 36 months. In the present study, postnatal exposure to mixtures of BPA and three metabolites of phthalates was associated with decreased IQ of children at age 5.

Associations between prenatal exposure to phthalates and birth weight: A meta-analysis study

Previous studies have suggested that phthalates are associated with birth weight. However, most phthalate metabolites have not been fully explored. Therefore, we conducted this meta-analysis to assess the relationship between phthalate exposure and birth weight. We identified original studies that measured phthalate exposure and reported its association with infant birth weight in relevant databases. Regression coefficients (β) with 95% confidence intervals (CIs) were extracted and analyzed for risk estimation. Fixed-effects (I² ≤ 50%) or random-effects (I² > 50%) models were adopted according to their heterogeneity. Overall summary estimates indicated negative associations of prenatal exposure to mono-n-butyl phthalate (pooled β = -11.34 g; 95% CI: -20.98 to -1.70 g) and mono-methyl phthalate (pooled β = -8.78 g; 95% CI: -16.30 to -1.27 g). No statistical association was found between the other less commonly used phthalate metabolites and birth weight. Subgroup analyses indicated that exposure to mono-n-butyl phthalate was associated with birth weight in females (β = -10.74 g; 95% CI: -18.70 to -2.79 g). Our findings indicate that phthalate exposure might be a risk factor for low birth weight and that this relationship may be sex specific. More research is needed to promote preventive policies regarding the potential health hazards of phthalates.

Pregnancy and lactation mixed exposure to lead, cadmium, and mercury alters maternal-offspring single heavy metal load: A factorial design

Environmental exposure to heavy metal mixture of lead (Pb), cadmium (Cd), and mercury (Hg) would induce hazardous health effects. However, there is a paucity of data on how exposure to heavy metal mixture alters the metabolic dynamics of individual metals. Considering that the dose plays a key role in determining the toxicity of heavy metals, we performed a factorial design with three heavy metals (Pb, Cd, and Hg) at low exposure levels. Female rats were exposed to Pb, Cd, and (or) Hg from successful mating until pup weaning. Their concentrations in maternal blood, breast milk, and postnatal day 0 (PND0) and PND21 offspring blood and whole brain were measured. Using ANOVA analysis, Pearson correlation, and structural equation model, we demonstrated the complex interactions among heavy metals during their absorption, mother-offspring transport, and target organ accumulation. Among all the explored samples, almost all the highest Pb, Cd, and Hg levels were observed in their respective single heavy metal exposure groups. In addition, Hg was found could antagonize the transport of Pb or Cd, when they cross the placental barrier and blood-brain barriers (BBB). However, the effect of Hg no longer presented when they are absorbed through the digestive system. The antagonistic effect of Pb on Cd was observed when they cross the placental barrier. In addition, Cd was also found to compete the transport pathway of Pb when they cross the BBB after birth. Compared to Pb and Hg, we found that the transport efficiency of Cd in the digestive system was lower, whereas the chelation of Cd by the placental barrier was better. This preliminary information may help researchers to explore the mechanism underlying the hazardous effects of heavy metal mixture exposure, or for regulatory agencies to revise guidelines for heavy metal exposure.

Epigenetics Beyond Fetal Growth Restriction: A Comprehensive Overview

Fetal growth restriction is a pathological condition occurring when the fetus does not reach the genetically determined growth potential. The etiology of fetal growth restriction is expected to be multifactorial and include fetal, maternal, and placental factors, the latter being the most frequent cause of isolated fetal growth restriction. Severe fetal growth restriction has been related to both an increased risk of perinatal morbidity and mortality, and also a greater susceptibility to developing diseases (especially cardio-metabolic and neurological disorders) later in life. In the last decade, emerging evidence has supported the hypothesis of the Developmental Origin of Health and Disease, which states that individual developmental 'programming' takes place via a delicate fine tuning of fetal genetic and epigenetic marks in response to a large variety of 'stressor' exposures during pregnancy. As the placenta is the maternal-fetal interface, it has a crucial role in fetal programming, such that any perturbation altering placental function interferes with both in-utero fetal growth and also with the adult life phenotype. Several epigenetic mechanisms have been highlighted in modulating the dynamic placental epigenome, including alterations in DNA methylation status, post-translational modification of histones, and non-coding RNAs. This review aims to provide a comprehensive and critical overview of the available literature on the epigenetic background of fetal growth restriction. A targeted research strategy was performed using PubMed, MEDLINE, Embase, and The Cochrane Library up to January 2022. A detailed and fully referenced synthesis of available literature following the Scale for the Assessment of Narrative Review Articles guidelines is provided. A variety of epigenetic marks predominantly interfering with placental development, function, and metabolism were found to be potentially associated with fetal growth restriction. Available evidence on the role of environmental exposures in shaping the placental epigenome and the fetal phenotype were also critically discussed. Because of the highly dynamic crosstalk between epigenetic mechanisms and the extra level of complexity in interpreting the final placental transcriptome, a full comprehension of these phenomenon is still lacking and advances in multi-omics approaches are urgently needed. Elucidating the role of epigenetics in the developmental origins of health and disease represents a new challenge for the coming years, with the goal of providing early interventions and prevention strategies and, hopefully, new treatment opportunities.

Paternal Occupational Exposure to Heavy Metals and Welding Fumes and Testicular Germ Cell Tumours in Sons in France

Testicular cancer is the most common cancer in young men. Its causes are largely unknown, although prenatal occupational and environmental exposures have been suggested. We investigated paternal occupational exposure to heavy metals and welding fumes and the risk of testicular germ cell tumors (TGCT) in their offspring. A total of 454 cases and 670 controls were included from a French nationwide case-control study. The INTEROCC job exposure matrix was used to assign occupational exposures (cadmium, chromium, iron, nickel, lead, and welding fumes) to the fathers' jobs. Odds ratios (ORs) for TGCT were estimated using conditional logistic regression models for frequency-matched sets. Three complementary analytical approaches were used: (1) single-agent analysis, (2) analysis by groups, and (3) principal component analysis (PCA). The proportion of paternal exposure to different heavy metals and welding fumes ranged from 0.7% (cadmium) to 11.3% (lead). Based on PCA, three principal components explained 93.5% of the cumulative variance. No associations were found between heavy metals or welding fumes and TGCT. In this study, paternal occupational exposure to heavy metals or welding fumes was not associated with TGCT development in their sons.

Perinatal Health Inequalities in the Industrial Region of Estonia: A Birth Registry-Based Study

Despite the increasing number of studies on industrially contaminated sites (ICS) and their health effects, there are very few studies on perinatal health outcomes in ICSs. In the present study, we examined the perinatal health inequalities by comparing adverse birth outcomes (ABOs) in the oil shale industry region of Ida-Viru County in Estonia with national-level figures and investigated the effects of maternal environmental and sociodemographic factors. Based on the 208,313 birth records from 2004-2018, Ida-Viru ICS has a birth weight 124.5 g lower than the average of 3544 g in Estonia. A higher prevalence of preterm birth (4.3%) and low birth weight (4.8%) in Ida-Viru ICS is found compared to 3.3% on both indicators at the national level. Multiple logistic regression analysis shows the statistically significant association of ABOs with fine particle (PM_2.5) air pollution, mother's ethnicity, and education throughout Estonia. However, in Ida-Viru ICS, the ABOs odds are remarkably higher in these characteristics except for the mother's ethnicity. Furthermore, the ABOs are associated with the residential proximity to ICS. Thus, the Ida-Viru ICS has unequally higher odds of adverse perinatal health across the environmental and sociodemographic factors. In addition to reducing the air pollutants, policy actions on social disparities are vital to address the country's unjustly higher perinatal health inequalities, especially in the Ida-Viru ICS.

Individual and mixed metal maternal blood concentrations in relation to birth size: An analysis of the Japan Environment and Children's Study (JECS)

BACKGROUND

Growth restriction in the prenatal period is a significant public health concern. Metals can negatively affect birth size, and pregnant women may be exposed to metal mixtures. Comprehensive studies analyzing the effects of combined metal exposure with accurate individual blood metal concentrations are limited. The current study investigated the associations between maternal metal exposure and birth size in a large, nationwide Japanese cohort using individual and mixed model approaches.

METHODS

Lead, cadmium, mercury, selenium, and manganese blood concentrations were measured in pregnant women in the Japan Environment and Children's Study (JECS). Measurements of infant birth size-including body weight, body length, and head and chest circumference-were collected. Linear and logistic regressions were used for birth size measurements and the odds of an infant being small in size for gestational age, respectively. Associations between combined metal mixtures and measurements at birth were evaluated using quantile g-computation and Bayesian kernel machine regression (BKMR).

RESULTS

Of the 103,060 JECS pregnancies, 93,739 mother-infant pairs were analyzed. The linear regression models showed that lead, selenium, cadmium, and manganese-but not mercury-were associated with body weight. Cadmium was associated with length and chest circumference and mercury was associated with head circumference. Quantile g-computation revealed that manganese increased infant birth weight, length, head circumference, and chest circumference. Lead was the strongest negative factor for infant birth weight, length, head circumference, and chest circumference. The BKMR analysis revealed that the metals had an additive, rather than a synergistic effect.

CONCLUSION

Metal exposure is associated with infant birth size, with lead and manganese playing a more significant role in Japan. The effects of prenatal combined metal exposure at low levels warrant public health attention.

Urinary phthalate metabolite mixtures in pregnancy and fetal growth: Findings from the infant development and the environment study

BACKGROUND

Prenatal phthalate exposure has been linked to reductions in fetal growth in animal and laboratory studies, but epidemiologic evidence is equivocal.

OBJECTIVE

Examine the association between prenatal phthalate metabolite mixtures and fetal growth and evaluate whether that association is modified by fetal sex or omega-3 intake during pregnancy.

METHODS

Analyses included 604 singleton pregnancies from TIDES, a prospective pregnancy cohort with spot urine samples and questionnaires collected in each trimester. Pregnancy-averaged phthalate exposure estimates were calculated as the geometric means of specific-gravity corrected phthalate metabolites. Fetal growth outcomes included birthweight and length, and ultrasound-derived size and velocity of estimated fetal weight, femur length, abdominal and head circumferences in the second and third trimesters. We used a novel application of quantile g-computation to estimate the joint association between pregnancy-averaged phthalate exposure and fetal growth, and to examine effect modification of that association by infant sex or omega-3 intake during pregnancy.

RESULTS

There were few statistically significant differences in birth size and fetal growth by exposure. A one-quartile increase in the phthalate mixture was modestly associated with reduced birthweight(β [95% confidence interval)]: -54.6 [-128.9, 19.7] grams; p = 0.15) and length (-0.2 [-0.6, 0.2] centimeters; p = 0.40). A one-quartile increase in the phthalate mixture was associated with reduced birth length in males (-0.5 [-1.0, 0.0] centimeters) but not for females (0.1 [-0.2, 0.3] centimeters); interaction p = 0.05. The phthalate metabolite mixture was inversely associated with ultrasound-derived fetal growth among those with adequate omega-3 intake. For example, a one-quartile increase in the phthalate mixture was associated with reduced abdominal circumference in the third trimesters in those with adequate omega-3 intake (-3.3 [-6.8, 0.1] millimeters) but not those with inadequate omega-3 intake (1.8 [-0.8, 4.5] millimeters); interaction p = 0.01.

CONCLUSION

Prenatal phthalate exposure was not significantly associated with fetal growth outcomes, with some exceptions for certain subgroups.

Prenatal Exposure to Traffic-Related Air Pollution and the DNA Methylation in Cord Blood Cells: MOCEH Study

Particulate matter with a diameter of ≤10 µm (PM₁₀) and nitrogen dioxide (NO₂) affect the DNA methylation in the fetus, but epigenetic studies regarding prenatal exposure to air pollution in Asia are lacking. Therefore, this study aimed to assess whether there is any association between the ambient concentrations of PM₁₀ and NO₂ and CpG methylation in the cord blood DNA by using a Korean birth cohort. The concentrations of the air pollutants were incorporated into the final LUR model by using the maternal address data. The methylation level was determined using HumanMethylationEPIC BeadChip and a linear regression analysis model. A multipollutant model including both PM₁₀ and NO₂ and models with single pollutants were used for each trimester exposure. The number of differentially methylated positions was the largest for midpregnancy exposure in both the single pollutant models and the multipollutant regression analysis. Additionally, gene-set analysis regarding midpregnancy exposure revealed four gene ontology terms (cellular response to staurosporine, positive regulation of cytoskeleton organization, neurotransmitter transport, and execution phase of apoptosis). In conclusion, these findings show an association between prenatal PM₁₀ and NO₂ exposure and DNA methylation in several CpG sites in cord blood cells, especially for midpregnancy exposure.

The effects of radiofrequency exposure on male fertility and adverse reproductive outcomes: A protocol for two systematic reviews of human observational studies with meta-analysis

BACKGROUND

The World Health Organization (WHO) is bringing together evidence on radiofrequency electromagnetic field (RF-EMF) exposure in relation to health outcomes, previously identified as priorities for evaluation by experts in the field, to inform exposure guidelines. A suite of systematic reviews are being undertaken by a network of topic experts and methodologists in order to collect, assess and synthesise data relevant to these guidelines. Here, we present the protocol for the systematic review on the effect of exposure to RF on adverse reproductive outcomes (human observational studies), also referred to as Systematic Review (SR) 3 within the series of systematic reviews currently being commissioned.

OBJECTIVES

Following the WHO handbook for guideline development and the COSTER conduct guidelines, we will systematically review the effect of RF-EMF exposure on both male fertility (SR3A) and adverse pregnancy outcomes (SR3B) in human observational studies. Herein we adhere to the PRISMA-P reporting guidelines.

DATA SOURCES

We will conduct a broad search for potentially relevant records relevant for both reviews within the following bibliographic databases: MEDLINE; Embase; and EMF Portal. We will also conduct searches of grey literature through relevant databases and organisational websites. RF-EMF experts will also be consulted. We will hand search citation and reference lists of included study records.

STUDY ELIGIBILITY CRITERIA

We will include quantitative human observational studies on the effect of RF-EMF exposure: (in SR3A) in adult male participants on infertility, sperm morphology, concentration or total sperm count or motility; and (in SR3B) in preconception adults or pregnant women on preterm birth, small for gestational age (associated with intrauterine growth restriction), miscarriage, stillbirth and congenital anomalies.

STUDY APPRAISAL AND SYNTHESIS METHODS

Titles, abstracts and then full texts will be screened in blinded duplicate against eligibility criteria with input from a third reviewer as required. Data extraction from included studies will be completed by two reviewers as will risk of bias assessment using the Office of Health Assessment and Translation (OHAT) tool. If appropriate we will undertake meta-analysis to pool effect measures and explore heterogeneity using sub-group analyses or meta-regression as feasible. We will conduct sensitivity analysis to assess the impact of any assumptions made throughout the review process. The OHAT methodology, based on the GRADE guidelines for evidence assessment, will be used to evaluate the certainty of evidence per outcome and to conclude the level of evidence of a health effect.

CONCLUSION

This manuscript details the protocols for two systematic reviews. The aims of publishing details of both protocols are to: pre-specify their scope and methods; reduce the impact of reviewer bias; promote transparency and replicability; and improve the review process.

PROSPERO REGISTRATION

CRD42021265401 (SR3A), CRD42021266268 (SR3B).

On Placental Toxicology Studies and Cerium Dioxide Nanoparticles

The human placenta is a transient organ essential for pregnancy maintenance, fetal development and growth. It has several functions, including that of a selective barrier against pathogens and xenobiotics from maternal blood. However, some pollutants can accumulate in the placenta or pass through with possible repercussions on pregnancy outcomes. Cerium dioxide nanoparticles (CeO₂ NPs), also termed nanoceria, are an emerging pollutant whose impact on pregnancy is starting to be defined. CeO₂ NPs are already used in different fields for industrial and commercial applications and have even been proposed for some biomedical applications. Since 2010, nanoceria have been subject to priority monitoring by the Organization for Economic Co-operation and Development in order to assess their toxicity. This review aims to summarize the current methods and models used for toxicology studies on the placental barrier, from the basic ones to the very latest, as well as to overview the most recent knowledge of the impact of CeO₂ NPs on human health, and more specifically during the sensitive window of pregnancy. Further research is needed to highlight the relationship between environmental exposure to CeO₂ and placental dysfunction with its implications for pregnancy outcome.

Cord serum elementomics profiling of 56 elements depicts risk of preterm birth: Evidence from a prospective birth cohort in rural Bangladesh

Maternal exposure to some individual rare earth elements and trace elements is associated with preterm birth, but few elements have been studied and little is known about the potential effect of simultaneous exposure to multiple elements. We examined individual and mixture effects of elements on preterm birth among 745 pregnant women in a prospective birth cohort in Bangladesh (2008-2011). We measured 56 elements in umbilical cord blood collected during delivery using inductively coupled plasma-mass spectrometry. Using elastic net (ENET) regularization and multivariate logistic regression, we examined independent associations between element concentrations and preterm birth. Bayesian kernel machine regression identified mixture effects of elements most critical to preterm birth, accounting for correlated exposure and interaction. ENET identified titanium (Ti), arsenic (As), and barium (Ba) as the most important predictors of shortened gestational age and preterm birth. In adjusted models, cord blood Ti (OR = 2.52; 95% CI: 1.08-5.93; P = 0.033), As (odds ratio (OR) = 1.34; 95% CI: 1.04-1.73; P = 0.023), and Ba (OR = 1.18; 95% CI: 1.02-1.38; P = 0.029) were significantly associated with preterm birth. Bayesian kernel machine regression suggested an interaction effect between As and Ba. Further, we constructed an element risk score (ERS) using estimated weights from a multivariate regression model for Ti, As, and Ba and regressed preterm birth by this score (OR = 2.72, 95% CI: 1.57-4.69; P = 3.35 × 10-4). Additionally, we observed a significant modification effect of child marriage on ERS, which means marriage before the age of 18 (Pinteraction = 0.0438). This study identified element exposures profiles in cord blood and constructed metal risk score that are jointly associated with the risk of preterm birth. Ti, As, and Ba exposure may adversely affect birth outcomes as well as child marriage may be a modifiable factor potentially affecting environmental element exposure and preterm birth.

Prenatal Exposure to Nonpersistent Chemical Mixtures and Fetal Growth: A Population-Based Study

BACKGROUND

Prenatal exposure to mixtures of nonpersistent chemicals is universal. Most studies examining these chemicals in association with fetal growth have been restricted to single exposure models, ignoring their potentially cumulative impact.

OBJECTIVE

We aimed to assess the association between prenatal exposure to a mixture of phthalates, bisphenols, and organophosphate (OP) pesticides and fetal measures of head circumference, femur length, and weight.

METHODS

Within the Generation R Study, a population-based cohort in Netherlands (n=776), urinary concentrations of 11 phthalate metabolites, 3 bisphenols, and 5 dialkylphosphate (DAP) metabolites were measured at <18, 18-25, and >25 weeks of gestation and averaged. Ultrasound measures of head circumference, femur length, and estimated fetal weight (EFW) were taken at 18-25 and >25 weeks of gestation, and measurements of head circumference, length, and weight were performed at delivery. We estimated the difference in each fetal measurement per quartile increase in all exposures within the mixture with quantile g-computation.

RESULTS

The average EFW at 18-25 wk and >25wk was 369 and 1,626g, respectively, and the average birth weight was 3,451g. Higher exposure was associated with smaller fetal and newborn growth parameters in a nonlinear fashion. At 18-25 wk, fetuses in the second, third, and fourth quartiles of exposure (Q2-Q4) had 26g [95% confidence intervals (CI):-38, -13], 35g (95% CI: -55, -15), and 27g (95% CI: -54, 1) lower EFW compared with those in the first quartile (Q1). A similar dose-response pattern was observed at >25wk, but all effect sizes were smaller, and no association was observed comparing Q4 to Q1. At birth, we observed no differences in weight between Q1-Q2 or Q1-Q3. However, fetuses in Q4 had 91g (95% CI: -258, 76) lower birth weight in comparison with those in Q1. Results observed at 18-25 and >25wk were similar for femur length; however, no differences were observed at birth. No associations were observed for head circumference.

DISCUSSION

Higher exposure to a mixture of phthalates, bisphenols, and OP pesticides was associated with lower EFW in the midpregnancy period. In late pregnancy, these differences were similar but less pronounced. At birth, the only associations observed appeared when comparing individuals from Q1 and Q4. This finding suggests that even low levels of exposure may be sufficient to influence growth in early pregnancy, whereas higher levels may be necessary to affect birth weight. Joint exposure to nonpersistent chemicals may adversely impact fetal growth, and because these exposures are widespread, this impact could be substantial. https://doi.org/10.1289/EHP9178.

Urinary Concentrations of Bisphenol Mixtures during Pregnancy and Birth Outcomes: The MAKE Study

Bisphenols are endocrine disruptors that may be associated with altered fetal growth in humans, and they have similar biological functions to mimic hormones. In addition, aggregated chemicals showed an adverse effect although individual concentration was at a low level. However, most studies between bisphenols and birth outcomes have focused on the effect of individual bisphenol. Thus, we explored the associations of urinary bisphenol mixtures with birth outcomes. We conducted a prospective birth cohort study in South Korea. One hundred eighty mother-infant pairs were recruited from 2017 to 2019. Bisphenol A (BPA), bisphenol F (BPF), and bisphenol S (BPS) in one spot urine were analyzed using ultra-performance liquid chromatography-tandem mass spectrometry. We used two statistical approaches to examine potential associations of BPA, BPF, and BPS with birth weight and gestational age: (1) multivariable linear regression; (2) Bayesian kernel machine regression (BKMR). The geometric means of BPA, BPF, and BPS were 2.1, 0.2, and 0.1 μg/L, respectively. In stratified linear analyses by each median value, a higher BPF was positively associated with birth weight (g) (β = 125.5; 95% CI: 45.0 to 205.9). Mixture analyses using BKMR suggested an inverse association between bisphenol mixtures and birth weight. Our findings suggest that in utero bisphenol exposure may influence birth weight and that such relationships may differ considering non-linearity and the combined effect.

Performance of urine, blood, and integrated metal biomarkers in relation to birth outcomes in a mixture setting

BACKGROUND

Studies on the health effects of metal mixtures typically utilize biomarkers measured in a single biological medium, such as blood or urine. However, the ability to evaluate mixture effects are limited by the uncertainty whether a unified medium can fully capture exposure for each metal. Therefore, it is important to compare and assess metal mixtures measured in different media in epidemiology studies.

OBJECTIVES

The aim of this study was to examine the mixture predictive performance of urine and blood metal biomarkers and integrated multi-media biomarkers in association with birth outcomes.

METHODS

In our analysis of 847 women from the Puerto Rico PROTECT Cohort, we measured 10 essential and non-essential metals in repeated and paired samples of urine and blood during pregnancy. For each metal, we integrated exposure estimates from paired urine and blood biomarkers into multi-media biomarkers (MMBs), using intraclass-correlation coefficient (ICC) and weighted quantile sum (WQS) approaches. Using Ridge regressions, four separate Environmental risk scores (ERSs) for metals in urine, blood, MMBICC, and MMBWQS were computed as a weighted sum of the 10 metal concentrations. We then examined associations between urine, blood, and multi-media biomarker ERSs and birth outcomes using linear and logistic regressions, adjusting for maternal age, maternal education, pre-pregnancy body mass index (BMI), and second-hand smoke exposure. The performance of each ERS was evaluated with continuous and tertile estimates and 95% confidence intervals of the odds ratio of preterm birth using area under the curve (AUC).

RESULTS

Pb was the most important contributor of blood ERS as well as the two integrated multi-media biomarker ERSs. Individuals with high ERS (3rd tertile) showed increased odds of preterm birth compared to individuals with low ERS (1st tertile), with 2.8-fold (95% CI, 1.49 to 5.40) for urine (specific gravity corrected); 3.2- fold (95% CI, 1.68 to 6.25) for blood; 3.9-fold (95% CI, 1.72 to 8.66) for multi-media biomarkers composed using ICC; and 5.2-fold (95% CI, 2.34 to 11.42) for multi-media biomarkers composed using WQS. The four ERSs had comparable predictive performances (AUC ranging from 0.64 to 0.68) when urine is examined with specific gravity corrected concentrations.

CONCLUSIONS

Within a practical metal panel, measuring metals in either urine or blood may be an equally good approach to evaluate the metals as a mixture. Applications in practical study design require validation of these methods with other cohorts, larger panels of metals and within the context of other adverse health effects of interest.

Associations of prenatal exposure to phthalates and one phthalate substitute with anthropometric measures in early life: Results from the German LIFE Child cohort study

Exposure to phthalates is widespread and especially early life stages represent a critical window of exposure. In the present study, we investigated the effect of prenatal exposure to phthalates on birth outcomes and weight development in early life. In 130 mother-child pairs, we estimated the association of concentrations of 13 phthalates in spot-urine samples collected during pregnancy and birth outcomes and weight gain in the first two years of life using robust linear regression. High molecular weight phthalates were inversely associated with birth weight in girls but not in boys. Thus, prenatal exposure to phthalates may affect birth weight in a sex-specific manner.

Developmental origins of metabolic diseases

Almost 2 billion adults in the world are overweight, and more than half of them are classified as obese, while nearly one-third of children globally experience poor growth and development. Given the vast amount of knowledge that has been gleaned from decades of research on growth and development, a number of questions remain as to why the world is now in the midst of a global epidemic of obesity accompanied by the "double burden of malnutrition," where overweight coexists with underweight and micronutrient deficiencies. This challenge to the human condition can be attributed to nutritional and environmental exposures during pregnancy that may program a fetus to have a higher risk of chronic diseases in adulthood. To explore this concept, frequently called the developmental origins of health and disease (DOHaD), this review considers a host of factors and physiological mechanisms that drive a fetus or child toward a higher risk of obesity, fatty liver disease, hypertension, and/or type 2 diabetes (T2D). To that end, this review explores the epidemiology of DOHaD with discussions focused on adaptations to human energetics, placental development, dysmetabolism, and key environmental exposures that act to promote chronic diseases in adulthood. These areas are complementary and additive in understanding how providing the best conditions for optimal growth can create the best possible conditions for lifelong health. Moreover, understanding both physiological as well as epigenetic and molecular mechanisms for DOHaD is vital to most fully address the global issues of obesity and other chronic diseases.

Prenatal heavy metal exposures and atopic dermatitis with gender difference in 6-month-old infants using multipollutant analysis

BACKGROUND

Prenatal exposure to heavy metals during critical developmental phases has been implicated in allergic phenotypes. However, few studies have been conducted on the gender-specific association of prenatal heavy metal exposure with atopic dermatitis (AD) in infants.

OBJECTIVE

To examine the gender-specific association of prenatal exposure to multiple heavy metals with AD incidence in 6-month-old infants using data from the Mothers and Children's Environmental Health (MOCEH).

METHODS

We evaluated 738 mother-child pairs from the MOCEH study, an ongoing prospective birth cohort. The concentrations of three heavy metals (lead, mercury and cadmium) in maternal blood samples were measured during early and late pregnancy. Each quartile of heavy metal concentration was used to consider the possible nonlinear association with AD. For assessing the multi-pollutant model, we constructed the multivariate regression model including all three heavy metals at both early and late pregnancy. Further, the group Lasso model was used to perform the variable selection with categorized exposures and assess the effect of multiple pollutants including their pairwise interactions.

RESULTS

A total of 200 incident cases of AD were diagnosed in 6-month-old infants. In the multivariate regression model of the boy group, adjusted odds ratios comparing the second, third and fourth quartile of lead exposure in boys with the first quartile were 1.83 (95% CI: 1.00, 3.38), 1.04 (0.91, 3.32) and 2.40 (1.18, 4.90), respectively. However, the only second quartile of lead exposure compared to first quartile was significantly associated with AD in girls. In addition, the results of the group Lasso model were similar with the results of multivariate regression model.

CONCLUSION

The results suggest that lead exposure in late pregnancy increases risk of AD in 6-month-old boys although the strength of association is weak. Further studies are needed to confirm the susceptibility window and gender differences in lead-induced AD.

Prenatal exposure to endocrine disrupting chemical mixtures and infant birth weight: A Bayesian analysis using kernel machine regression

BACKGROUND

Pregnant women are regularly exposed to a multitude of endocrine disrupting chemicals (EDCs). EDC exposures, both individually and as mixtures, may affect fetal growth. The relationship of EDC mixtures with infant birth weight, however, remains poorly understood. We examined the relations between prenatal exposure to EDC mixtures and infant birth weight.

METHODS

We used data from the Maternal-Infant Research on Environmental Chemicals (MIREC) Study, a pan-Canadian cohort of 1857 pregnant women enrolled between 2008 and 2011. We quantified twenty-one chemical concentrations from five EDC classes, including organochlorine compounds (OCs), metals, perfluoroalkyl substances (PFAS), phenols and phthalate metabolites that were detected in >70% of urine or blood samples collected during the first trimester. In our primary analysis, we used Bayesian kernel machine regression (BKMR) models to assess variable importance, explore EDC mixture effects, and identify any interactions among EDCs. Our secondary analysis used traditional linear regression to compare the results with those of BKMR and to quantify the changes in mean birth weight in relation to prenatal EDC exposures.

RESULTS

We found evidence that mixtures of OCs and metals were associated with monotonic decreases in mean birth weight across the whole range of exposure. trans-Nonachlor from the OC mixture and lead (Pb) from the metal mixture had the greatest impact on birth weight. Our linear regression analysis corroborated the BKMR results and found that a 2-fold increase in trans-nonachlor and Pb concentrations reduced mean birth weight by -38 g (95% confidence interval (CI): -67, -10) and -39 g (95% CI: -69, -9), respectively. A sex-specific association for OC mixture was observed among female infants. PFAS, phenols and phthalates were not associated with birth weight. No interactions were observed among the EDCs.

CONCLUSIONS

Using BKMR, we observed that both OC and metal mixtures were associated with decreased birth weight in the MIREC Study. trans-Nonachlor from the OC mixture and Pb from the metal mixture contributed most to the adverse effects.

Prenatal exposure to multiple metals and birth outcomes: An observational study within the National Children's Study cohort

BACKGROUND

Prenatal exposure to metals may play an important role in fetal growth. However, the epidemiologic evidence for certain metals is sparse, and most of the existing research has focused on evaluating single metals in highly exposed target populations.

OBJECTIVES

We evaluated associations of cadmium, lead, manganese, selenium, and total mercury exposures during pregnancy with fetal growth using data from mother-infant pairs participating in the National Children's Study.

METHODS

Prenatal metal exposures were measured using maternal blood collected from 6 to 32 weeks of gestation. Birth outcomes, including gestational age, birthweight, birth length, head circumference, and ponderal index, were ascertained through physical measurement at birth or abstraction from medical records. Regression coefficients and their 95% confidence intervals were estimated from multivariable linear regression models in the overall study population as well as among male and female infants. We further evaluated pairwise metal-metal interactions.

RESULTS

Sex-specific associations were observed for lead, with inverse associations for birthweight, birth length, head circumference, and gestational age observed only among female infants. Sex-specific associations were also observed for selenium, with a positive association for birthweight observed among male infants; selenium was also positively associated with ponderal index and inversely associated with birth length among female infants. Overall, total mercury was inversely associated with birthweight and ponderal index, and the association with birthweight was stronger among female infants. No significant associations were observed with cadmium and manganese. In the metal-metal interaction analyses, we found evidence of a synergistic interaction between lead and total mercury and antagonistic interaction between selenium and total mercury with selected birth outcomes.

CONCLUSIONS

Our findings suggest that prenatal exposure to metals may be related to birth outcomes, and infant sex may modify these associations.

Early-life exposure to multiple persistent organic pollutants and metals and birth weight: Pooled analysis in four Flemish birth cohorts

BACKGROUND AND AIMS

Prenatal chemical exposure has frequently been associated with reduced fetal growth although results have been inconsistent. Most studies associate single pollutant exposure to this health outcome, even though this does not reflect real life situations as humans are exposed to many pollutants during their life time. The objective of this study is to investigate the association between prenatal exposure to a mixture of persistent environmental chemicals and birth weight using multipollutant models.

METHODS

We combined exposure biomarker data measured in cord blood samples of 1579 women from four Flemish birth cohorts collected over a 10 years' time period. The common set of available and detectable exposure measures in these cohorts are three polychlorinated biphenyls (PCB) congeners (138, 153 and 180), hexachlorobenzene (HCB), dichlorodiphenyldichloroethylene (p,p'-DDE) and the metals cadmium and lead. Multiple linear regression (MLR), Bayesian Information Criterion (BIC), penalized regression using minimax concave penalty (MCP) and Bayesian Adaptive Sampling (BAS) were applied to assess the influence of multiple pollutants in a single analysis on birth weight, adjusted for a priori selected covariates.

RESULTS

In the pooled dataset, a median (P25-P75) birth weight and gestational age of 3420 (3140-3700) grams and 39 (39-40) weeks was observed respectively. The median contaminant levels in cord blood were: 15.8, 26.5, 18.0, 16.9 and 91.5 ng/g lipid for PCB 138, PCB 153, PCB 180, HCB and p,p'-DDE, respectively, 0.075 µg/L for cadmium and 9.7 µg/L for lead. According to the applied statistical methods for multipollutant assessment, p,p'-DDE and PCB 180 were most consistently associated with birth weight. In addition, PCB 153 was selected when applying MCP and BAS. An inverse association with birth weight was found for the PCB congeners, while an increased birth weight was observed for elevated levels of p,p'-DDE.

CONCLUSIONS

Assessing the health risk of combinations of exposure biomarkers reflects better real-world situations and thereby allows more effective risk assessment. Our results add to the existing evidence based on detrimental effects of PCBs on birth weight and indicate a possible increase in birth weight due to p,p'-DDE (while correcting for PCBs).

Exposure of nursing mothers to polycyclic aromatic hydrocarbons: Levels of un-metabolized and metabolized compounds in breast milk, major sources of exposure and infants' health risks

In this study, biomonitoring of nursing Portuguese mothers to polycyclic aromatic hydrocarbons (PAHs) exposure and assessment of potential health risks of their infants were performed through determination of 18 PAHs and 6 major metabolites (OH-PAHs) in breast milk. Concentrations of total PAHs ranged between 55.2 and 1119 ng/g fat, being naphthalene, dibenz(a,h)anthracene, benzo(g,h,i)perylene, and phenanthrene the most abundant compounds (68.4% of ∑PAHs). Benzo(a)pyrene, known carcinogenic, was not detected. Total levels of OH-PAHs ranged from 6.66 to 455 ng/g fat with 1-hydroxyphenanthrene, 1-hydroxynaphthalene and 1-hydroxyacenaphthene as major compounds (96% of ∑OH-PAHs). Concentrations of ∑PAHs and ∑OH-PAHs were strongly correlated between each other (r = 0.692; p ≤ 0.001) and moderately-to-strongly associated with individual compounds (0.203 < r < 0.841; p ≤ 0.001). The attained data suggest increased levels of PAHs in older nursing mothers (>30 years) and in those whose child had lower weight (up to 3.0 kg). Breast-fed infant presented a median PAHs daily intake of 1.41 μg/kg body weight (total benzo(a)pyrene equivalents of 0.0679 μg/kg) and were exposed to 0.024 μg/kg body weight of ∑PAH4 [benz(a)anthracene, benzo(b)fluoranthene, benzo(j)fluoranthene, and chrysene]. Although breast milk is a secure food for newborns, un-metabolized and metabolized PAHs should be included in biomonitoring surveillance studies during breastfeeding to prevent potential health risks for infants.

Phthalate metabolites concentrations in amniotic fluid and maternal urine: Cumulative exposure and risk assessment

Phthalates are used in industry as plasticizers or additives in everyday products and they have been considered as endocrine disrupting chemicals. Maternal exposure during pregnancy has been associated with neonatal exposure, preterm birth and impacts in the reproductive and respiratory systems. The aim of this study is to determine six phthalate metabolites (mono isobutyl phthalate, miBP, mono n-butyl phthalate, mnBP, mono benzyl phthalate, mBzP, mono ethylhexyl phthalate, mEHP, mono 2-ethyl-5-hydroxyhexyl phthalate, mEHHP, mono 2-ethyl-5-oxohexyl-phthalate, mEOHP) in amniotic fluid and urine from 100 pregnant women. Participants answered questionnaires for the use of plastics and cosmetics, dietary habits, health effects, pregnancy problems, health and infant development. Positive amniotic fluid samples ranged from 1% to 21% and urine from 27% to 54%. The median levels for amniotic fluid were 2.3 μg/L - 10.7 μg/L and for urine 4.9 μg/L - 46.7 μg/L. The major results include significant correlations between urinary phthalates indicating their common sources of exposure, the frequent use of deodorant was significantly associated with higher urinary miBP (p = 0.050) and mnBP (p = 0.028) and a weak inverse association was found for the use of make-up products with mBzP (p = 0.053). The frequent use of plastic food containers was significantly associated with urinary mEHP (p = 0.026), and a positive trend was noticed for mEHP in amniotic fluid (p = 0.093). An association although weak was found between urinary mEHP and lower birth length (rs = 0.396, p = 0.062). No other associations were found for infant health problems or development. The daily intake of the total phthalates was calculated 5.4 μg/kg body weight/day which corresponds to hazard index 0.10 and exposure follows the declining trend that has been observed the last decades.