Exposure to Certain Phthalates During Pregnancy May Affect Brain Development in Infant Girls

Authors: Leny Matthew, Craig Newschaffer, et al.

Who sponsored this study?

The Environmental influences on Child Health Outcomes (ECHO) Program, Office of the Director, National Institutes of Health supported this research.

What were the study results?

In this study, researchers found that certain phthalates measured in the infant’s meconium, or first stool, were associated with lower scores on a common test that measures motor, visual, and language skills in girls under age 5.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What was the study's impact?

This study suggests that prenatal exposure to certain types of phthalates may worsen early childhood learning outcomes for girls but have a neutral or slightly positive effect on boys. By studying meconium, instead of maternal urine, the researchers may be able to capture a longer timeframe of potential pre-natal exposure.

Why was the study needed?

Phthalates are widely used in personal care products, cosmetics, plastics, and other household items. These chemicals can cause the body to make substances that are thought to reduce a mother’s level of thyroid hormones, which are critical for fetal brain development. Phthalates are also associated with a reduction in the hormones necessary for sex-specific fetal brain development. Therefore, it is important to test the levels of prenatal phthalate exposure and the potential effects on developing fetuses.

Who was involved?

The study involved 956 mother and child pairs from two ECHO research sites—the Safe Passage study (SPS) and the Early Autism Risk Longitudinal Investigation (EARLI). Researchers focused on children who were higher risk for brain and nervous system disorders based on a family history of Autism or exposure to alcohol during pregnancy.

What happened during the study?

ECHO researchers measured phthalate levels in meconium from children who had a higher risk for developing brain and nervous system disorders. When the children were 12 months old, researchers tested their motor, visual, and language skills. Researchers used meconium samples rather than the mother’s urine to capture longer-term fetal exposure to phthalates.

What happens next?

Future prenatal phthalate exposure studies using meconium samples from newborn infants could investigate the differing effects of phthalate exposure on male versus female infants in order to better understand the reasons why these differences may occur.

Where can I learn more?

Access the full journal article, titled “The associations between prenatal phthalate exposure measured in child meconium and cognitive functioning of 12-month-old children in two cohorts at elevated risk for adverse neurodevelopment,” in Environmental Research.

The content is the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published November 2022

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Exposure to Certain Phthalates During Pregnancy May Affect Brain Development in Infant Girls

ECHO Study Reveals Pregnant Women Are Exposed to Dangerous Chemicals Found in a Variety of Household Products

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ECHO Study Reveals Pregnant Women Are Exposed to Dangerous Chemicals Found in a Variety of Household Products

Authors: Giehae Choi, Jessie Buckley, Tracey Woodruff, et al.

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) Program, Office of The Director, National Institutes of Health.

What were the study results?

Melamine and cyanuric acid were found in over 99% of the study participants. Four types of aromatic amines were also found in nearly all pregnant participants. Levels of these chemicals were higher among Hispanic and non-Hispanic Black participants and in those exposed to tobacco smoke. For example, levels of 3,4-dichloroaniline—a chemical used in the production of dyes and pesticides—were more than 100% higher among Black and Hispanic women compared to White women.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What was the study's impact?

This is the first national study to reveal that pregnant women in the U.S. are widely exposed to melamine, cyanuric acid, and aromatic amines—chemicals that may be harmful to maternal health and child development. This raises concerns for the health of pregnant women and babies.

Why was this study needed?

Chemicals like melamine, cyanuric acid, and aromatic amines are commonly used to make a variety of household products. Melamine can be found in dishware, plastics, flooring, kitchen counters, and pesticides. Cyanuric acid can be found in disinfectants, plastics, and swimming pools. And aromatic amines can be found in hair coloring, mascara, tattoo ink, paints, tobacco smoke, and diesel fumes. People can be exposed to these chemicals through the air, contaminated food, household dust, water, plastics, products that contain dyes and pigments, and many other sources.

Melamine was globally recognized as toxic after baby formula poisoning incidents in 2007 to 2008, which resulted in health problems in children including kidney stones, kidney failure, and in some cases, death. Research suggests that melamine may also be linked to reduced brain development. There is limited research on the effects of melamine on adults, although preliminary evidence suggests that it may be linked to cancer and other negative health outcomes. Prior studies on melamine were only conducted among pregnant women in Asian countries or limited to non-pregnant women in the U.S. Despite melamine’s potential harm and common use in household products, population-level exposure is not regularly monitored in the U.S.

Who was involved?

This study included 171 pregnant participants from nine ECHO cohorts located in California, Georgia, Illinois, New Hampshire, New York, and Puerto Rico. Of these participants, 40% were Hispanic, 34% were White, 20% were Black, 4% were Asians, and the remaining 2% were from other or multiple racial groups.

What happened during the study?

Researchers measured the levels of 45 chemicals in urine samples collected from participants during pregnancy. They used new methods to capture the levels of these chemicals in the urine samples, even those present in small amounts. Then, the researchers compared chemical levels across participants with different sociodemographic backgrounds.

What happens next?

Researchers are expanding on this study to look at the effects of higher exposures to these chemicals during pregnancy in over 1,700 pregnant participants and investigate whether these exposures are linked with child health outcomes.

Where can I learn more?

Access the full journal article, titled “Exposure to melamine and its derivatives and aromatic amines among pregnant women in the United States: The ECHO Program,” in Chemosphere.

Published August 30, 2022

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ECHO Study Reveals Pregnant Women Are Exposed to Dangerous Chemicals Found in a Variety of Household Products

ECHO Study Suggests Air Pollution, Secondhand Smoke, Formaldehyde Exposure Affect Length of Time to Get Pregnant

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ECHO Study Suggests Air Pollution, Secondhand Smoke, Formaldehyde Exposure Affect Length of Time to Get Pregnant

Author(s): Eva Siegel, Linda Kahn, et al.

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) program, the Office of the Director, the National Institutes of Health, with co-funding from the Office of Behavioral and Social Sciences Research (OBSSR).

What were the study results?

The strongest evidence points to an association between exposures to traffic-related air pollution, secondhand smoke, and a chemical called formaldehyde—a common workplace exposure in construction sites and nail salons—and longer time to pregnancy. Specifically, exposure to particulate matter and nitrogen oxide gases lowered couples’ chances of becoming pregnant. Traffic and the burning of other types of materials besides gas and diesel create particulate matter and nitrogen oxide gases. Volatile organic compounds, which are used in manufacturing processes, did not appear to affect time to pregnancy.

What was the study's impact?

This review suggests that certain chemicals in the air may lengthen the time it takes for couples to become pregnant. More research is needed to better understand how these chemicals affect reproductive health. To collect this information, future studies can provide participants with personal air monitors that can let researchers know about the quality of air participants are actually breathing instead of relying on imprecise data from outdoor monitors or participant recall.

The research team also pointed out that there are remaining questions about whether the air people breathe around the time of conception is what matters most or whether there are certain life stages, such as puberty, when being exposed to air pollution may be especially damaging. The ECHO-wide Cohort, which allows researchers to access information from a large and diverse population, can serve as an important resource for answering these questions.

Why was this study needed?

Previous studies have looked at how air pollution may affect how long it takes to become pregnant. Time to pregnancy is a measure used to estimate a couple’s ability to conceive and is commonly used to diagnose infertility. In this paper, the authors review past studies on air pollution to identify types of air pollutants—including pollution from traffic, chemicals in the workplace, and secondhand smoke—that might affect how long it takes to get pregnant.

Who was involved?

This review includes all papers published in English on this topic from January 1, 1990 to February 11, 2021. The analysis covered 33 articles, of which eight looked at outdoor air quality, six looked at secondhand smoke exposure, and 19 looked at air quality in the workplace.

What happened during the study?

The research team searched six leading science libraries and identified 33 human studies related to exposure to outdoor and indoor air pollutants and time to pregnancy. The team read each article, assigned it a score based on the quality of the study design, and created summary tables containing the most important findings of each study. They then compared the consistency of results between studies, especially among high-quality papers, about whether certain types of air pollution affected time to pregnancy.

What happens next?

This is the third review this team of authors has written on chemicals and time to pregnancy. Individual authors will continue to fill in the research gaps previously mentioned, including conducting studies where women will be wearing personal air monitors.

Where can I learn more?

Access the full journal article, titled “Indoor and outdoor air pollution and couple fecundability: a systematic review” in Human Reproduction Update.

The content is the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

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Published July 27, 2022

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ECHO Study Suggests Air Pollution, Secondhand Smoke, Formaldehyde Exposure Affect Length of Time to Get Pregnant

Study Reveals Rising Levels of Plastics, Pesticides, and Replacement Chemicals in Pregnant Women

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Study Shows Rising Levels of Plastics, Pesticides, and Replacement Chemicals in Pregnant Women

Authors: Jessie P. Buckley, Tracey J. Woodruff, et al.

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) program, Office of The Director, National Institutes of Health.

What were the study results?

Most of the chemicals were found in at least one of the women in the study and about a third of the chemicals were found in greater than half of the participants. One fifth of the chemicals were detected in over 90% of the pregnant women indicating widespread exposure to the chemicals measured.

The study found some chemicals were detected more often or were present in higher amounts in non-white women, those with lower education, those who were single, and those exposed to tobacco. Hispanic women had higher levels of some chemicals not included in previous biomonitoring studies including parabens (preservatives) as well as phthalates and bisphenols (from plastics).

The study found that levels of some of the chemicals used as replacements for more toxic ones that were banned or phased out, increased over time and were present in higher amounts than have been seen in previous studies. The levels of several phased out chemicals were found to remain stable or decrease over time.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What was the study's impact?

This is the largest study to date to measure exposure to a wide variety of environmental chemicals in a diverse group of pregnant women across the U.S. The results of this study highlight the widespread and unequal exposure of pregnant women to chemicals from air pollution, food, water, plastics, and other industrial and consumer products.

Why was this study needed?

There is little data on exposure of pregnant women to many pesticides and industrial chemicals, even those that could be harmful during pregnancy and throughout childhood development.

Who was involved?

The study included 171 women from five U.S. states and Puerto Rico who were part of an ECHO cohort. Of these women, 60% were Black or Hispanic.

What happened during the study?

Research team members measured 89 biomarkers for more than 100 chemicals in urine samples from pregnant women in nine ECHO cohorts. Most of the chemicals can be found in pesticides, plastics, sunscreens, personal care products, and flame retardants. Many of the chemicals measured are replacement chemicals: chemicals meant to replace other harmful chemicals (e.g., BPA, phthalates). The team used a new method that measured multiple chemicals in a single urine sample to determine if pregnant women were exposed to the chemicals. The researchers then studied how different factors—such as age, race, education level, and the year the sample was collected—related to the levels of chemicals found.

What happens next?

The research team will continue to study exposures in a larger, diverse population of pregnant women (more than 6,500) to see whether these prenatal chemical exposures are linked to negative birth outcomes. This data will be important for understanding the factors that may contribute to additional negative health effects during pregnancy and childhood.

Where can I learn more?

Access the full journal article titled, “Exposure to contemporary and emerging chemicals in commerce among pregnant women in the United States: The Environmental influences on Child Health Outcomes (ECHO) Program” in Environment Science & Technology.

The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published May 10, 2022

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Study Reveals Rising Levels of Plastics, Pesticides, and Replacement Chemicals in Pregnant Women

Informed Mothers More Likely to Engage in Collective Action, Reduce Family- and Community-Level Chemical Exposures

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Informed Mothers More Likely to Engage in Collective Action, Reduce Family- and Community-Level Chemical Exposures

Authors: Amy Padula, Rachel Morello-Frosch, et al.

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) program, the Office of the Director, and the National Institutes of Health.

What were the study results?

This study found that participants knew about the dangers of chemical exposures and were motivated to act to protect the health of their families and communities, although they have busy family lives, and the pandemic has further prevented them from participating in collective action. Participants requested strategies that were time-efficient and included straightforward, accessible information on how to reduce exposures at the personal and community level.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What was the study's impact?

Researchers have an opportunity to directly learn from participants about how to improve the way in which chemical exposure results are reported in future studies. Report-back systems, or ways that study results are returned to participants, can present valuable information for participants about environmental health and how to lower chemical exposures in their homes and communities, and hold policy makers responsible for protecting parents and children from harmful chemical exposures. Researchers can use tools like the Digital Exposure Report Back Interface (DERBI) to give their participants access to individualized chemical results with information about how to take individual and collective action to reduce exposures.

Why was this study needed?

Participants in chemical exposure studies who receive reports on their personal exposures often look for information to reduce those exposures. Many chemical exposures are the result of policies, regulations, and practices, not individual behaviors and lifestyles. Individuals can address those policies and regulations through collective action, which is working with others to reach a common goal. Researchers wanted to understand the role of personal exposure reports in a participant’s interest in engagement in collective action.

Who was involved?

In summer 2020, the researchers held three online focus groups in English and Spanish with a diverse group of 18 participants from pregnancy cohorts in Illinois and California.

What happened during the study?

This study aimed to understand how much participants know about sources of potentially harmful chemical exposures and their experience and interest in participating in collective action. Focus group participants talked about some of the barriers and strategies to participating in collective action, and their preferences for receiving and using their personalized reports about environmental chemical exposures. Input from these focus groups can be used to help design tools and content to report results of exposure research to ECHO participants.

What happens next?

The researchers are currently studying participant surveys from before and after participants received their chemical exposure reports to learn more about how participants use DERBI. These surveys may also reveal how DERBI reports may influence participant efforts to reduce exposure in their homes and communities through collective action.

Where can I learn more?

More information about the Digital Exposure Report Back Interface (DERBI) can be found on the Silent Spring Institute website.

Access the full journal article, titled “Perspectives of peripartum people on opportunities for personal and collective action to reduce exposure to everyday chemicals: Focus groups to inform exposure report-back” in Environmental Research.

The content is the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published March 26, 2022

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Informed Mothers More Likely to Engage in Collective Action, Reduce Family- and Community-Level Chemical Exposures

ECHO Study Suggests Antimony Exposure During Pregnancy Contributes to Lower Birth Weight

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ECHO Study Suggests Antimony Exposure During Pregnancy Contributes to Lower Birth Weight

Authors: Caitlin Howe, Margaret R. Karagas, et al.

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) program, Office of The Director, National Institutes of Health.

What were the study results?

Researchers found that combined exposure to all metals in the mixture did not affect birth weight. Mothers with high levels of the metal antimony in their urine had smaller babies across all three of the ECHO cohorts. Two other metals – cadmium and molybdenum – had no impact on fetal growth. Findings for other metals (cobalt, mercury, nickel, tin) varied depending on the study population and whether the baby was male or female.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What was the study's impact?

This study used an approach that looked at multiple chemicals at once, in contrast to previous studies that have typically evaluated one chemical at a time. The findings suggest that antimony, an understudied metalloid, may harm fetal growth in different populations across the United States.

Why was this study needed?

Exposure to toxic metals can harm fetal growth (how much a baby grows during pregnancy), while nutritionally essential metals can support fetal growth. Previous research studying the effects of metals during pregnancy on fetal growth has usually focused on one metal at a time. However, most people are exposed to multiple metals, which may have complex effects on fetal growth. Therefore, combining data from three ECHO cohorts representing different geographic regions in the U.S., the research team looked at how maternal exposure to multiple metals affects fetal growth, an important indicator of future health.

Who was involved?

This study included approximately 1,000 pairs of mothers and newborns who are participating in three ECHO cohorts:

The MADRES study, a predominantly lower income Hispanic cohort in Los Angeles, California
The NHBCS, a primarily non-Hispanic white cohort in northern New England
The PROTECT study, a Hispanic cohort in northern Puerto Rico.

What happened during the study?

The research team combined data from the three cohorts to measure multiple metals in the mothers’ urine samples collected during pregnancy. They then looked at associations between seven metals and birth weight for gestational age using a multi-chemical mixture approach. Birth weight for gestational age is commonly used as a measure for fetal growth.

What happens next?

Since antimony may harm fetal growth, it is important to identify major sources of exposure to this metal so that exposure can be reduced for pregnant women. In future studies, the team would like to include more ECHO cohorts in their research, explore other indicators of metal exposures (such as placental measures of metals), and identify time periods when toxic and essential metal exposures are most harmful or beneficial for pregnant women and their children.

Where can I learn more?

The full journal article, titled “Prenatal metal(loid) mixtures and birth weight for gestational age: a pooled analysis of three cohorts participating in the ECHO Program” is published in Environment International.

The content is the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published March 01, 2022

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ECHO Study Suggests Antimony Exposure During Pregnancy Contributes to Lower Birth Weight

ECHO Study Links PFAS Exposure During Pregnancy to Lower Birth Weight for Black Mothers

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ECHO Study Links PFAS Exposure During Pregnancy to Lower Birth Weight for Black Mothers

Authors: Che-Jung Chang, Donghai Liang, et al.

Who sponsored this study?

This work was supported by the Environmental Influences on Child Health Outcomes (ECHO) program Opportunities and Infrastructure Fund, Office of the Director, National Institutes of Health, and the Environmental Protection Agency (USEPA).

Footnote: The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

What were the study results?

Some PFAS exposures were linked to a greater risk of low birth weight for babies that African American women delivered. PFAS exposures were also associated with the changes in the levels of small molecules needed for the baby’s development. These molecules included amino acids, lipid/fatty acids, bile acids, and sex hormones.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What was the study's impact?

This is one of the first studies researching the connections and relationships between exposures to PFAS, metabolomic changes during the baby’s development, and the baby’s growth. The chemical analysis showed that changes in the levels of the molecules may be responsible for the effects on birth weight. Future studies may target the important chemical mechanisms of the molecules, which may help develop early detection and intervention strategies for babies with low birth weight due to PFAS.

Why was this study needed?

Per- and polyfluoroalkyl substances (PFAS) are called “forever chemicals” because they stay in the environment a long time. PFAS exposures have been linked to adverse pregnancy and birth outcomes, such as lower birth weights, but there is little information on why this relationship exists and how PFAS exposures affect the body. Also, African American women and children are exposed to higher levels of environmental pollutants and have a higher risk of negative birth outcomes, so studies focusing on this population are very important for reducing heath disparities.

Who was involved?

This study included 313 participants enrolled in the Atlanta African American Maternal-Child ECHO cohort between March 2014 and May 2018.

What happened during the study?

Researchers collected blood samples from participants and measured the levels of PFAS and small molecules essential to a baby’s development. Using this information, the researchers calculated how the levels of the molecules changed in response to PFAS exposures and how these exposures affected the birth weight of babies.

What happens next?

The research team is working on additional analyses on the impact of exposures to PFAS before birth and the levels of essential small molecules in newborns. They are also planning to conduct larger analyses in order to get a more holistic view of the connection between PFAS exposures and adverse birth outcomes.

Where can I learn more?

For research updates, follow them on Twitter @donghai_liang, @chejung_chang, @EmoryRollins, and @EmoryHERCULES, and check out the Environmental Metabolomics Research Group’s website.

Access the full journal article, titled “Per- and polyfluoroalkyl substance (PFAS) exposure, maternal metabolomic perturbation, and fetal growth in African American women: A meet-in-the-middle approach” in Environment International.

The content is the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published November 1, 2021

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See ECHO's PFAS research.

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ECHO Study Links PFAS Exposure During Pregnancy to Lower Birth Weight for Black Mothers

ECHO Study Maps Environmental Exposures During Pregnancy to Molecular Changes Associated with Key Health Processes

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ECHO Study Maps Environmental Exposures During Pregnancy to Molecular Changes Associated with Key Health Processes

Authors: Brett T. Doherty, Megan E. Romano, et al.

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) program, Office of The Director, National Institutes of Health, under Award Numbers U2COD023375 (Coordinating Center), U24OD023382 (Data Analysis Center), and UH3 OD023275, and NIH NIEHS P42ES007373. Additional supporting entities include the Dartmouth Center for Molecular Epidemiology NIGMS, P20 GM104416) and the RTI Children’s Health Exposure Analysis Resource (CHEAR) Exposure Assessment Hub (NIEHS, U2CES026544, Fennell PI), among others

What were the study results?

Some of the chemical exposures were related to changes in the amounts of certain small molecules in the blood. Specifically, chemical exposures had the most impact on the amounts of a certain amino acids, which are the building blocks of many proteins that are important to both mother and child. When considered together, these molecule changes suggest that some of the chemical exposures may impact key health processes.

Footnote: Results reported here are for a single study. Other or future studies may provide new information or different results. You should not make changes to your health without first consulting your healthcare professional.

What was the study's impact?

This study used new tools to study how chemical exposures can affect important small molecules during pregnancy. The study results provide clues to the potential impact of these chemical exposures on the health of both mother and baby. In the future, further investigation of these chemical exposures may reveal more about their link to specific health endpoints.

Why was this study needed?

Pregnant women are exposed to chemicals in their environment. It is important to know how these chemicals might impact their health and the health of their babies. New tools can help us study how these chemicals affect health.

Who was involved?

This study included pregnant women in the New Hampshire Birth Cohort Study (NHBCS), who lived in north-central New England. A total of 177 women participated in this specific study within NHBCS.

What happened during the study?

During early pregnancy, women wore silicone wristbands for one week that captured chemicals in their environment. About three months later, the same women provided a blood sample, which was used to measure important molecules in their blood. Researchers looked at the link between environmental chemicals and the amounts of different molecules in the blood in order to better understand the health effects of these chemical exposures.

What happens next?

Going forward, it may be helpful to look for a link between the changes in molecules and related health processes and outcomes. Researchers may also want to reproduce these findings in other cohorts to better understand these environmental effects.

Where can I learn more?

Access the full journal article, titled “Chemical co-exposures assessed via silicone wristbands and endogenous plasma metabolomics during pregnancy,” is published in the Journal of Exposure Analysis and Environmental Epidemiology.

Learn about silicone wristbands at the MyExposome website.

Learn about small molecules and the methods to measure them through The UNC Nutrition Obesity Research Center (NORC) Metabolism and Metabolomics Core.

The content is the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published October 26, 2021

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ECHO Study Maps Environmental Exposures During Pregnancy to Molecular Changes Associated with Key Health Processes

ECHO Study Finds Pregnant Women Exposed to Variety of Chemicals—Some May Affect Birth Weights

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ECHO Study Finds Pregnant Women Exposed to Variety of Chemicals—Some May Affect Birth Weights

Author(s): John L. Pearce, Brian Neelon, Michael S. Bloom, Jessie P. Buckley, Cande V. Ananth, Frederica Perera, John Vena, and Kelly Hunt

Who sponsored this study?

The Environmental influences on Child Health Outcomes (ECHO) program, Office of The Director, National Institutes of Health.

What were the study results?

Findings from the study revealed that moms experienced a broad range of chemical exposure profiles with marked variability in exposure magnitudes across chemical classes and exposure frequencies. Evaluation of health effects found that maternal exposure profiles dominated by higher levels of flame-retardants (i.e., polybrominated diphenyl ethers, PBDEs) were associated to lower birth weights. Exposure profiles with higher levels of polychlorinated biphenyls (PCBs) and perfluoroakyl (PFAS) substances were associated with increased birth weights. PCBs are man-made chemicals that are often found in industrial and commercial products, such as electrical and hydraulic equipment and plasticizers in paints, plastics, and rubber products. PFAS substances can often be found in food packaging, commercial household products, drinking water, and living organisms.

What was the study's impact?

ECM provides a promising framework for supporting studies of other exposure mixtures as the resulting mapping benefits visualization and assessment of relationships in complex data.

Why was this study needed?

Pregnant women often encounter numerous chemicals that may pose a risk to them and their baby. Studies seeking to identify health effects in populations that experience such complex exposure scenarios remains difficult. With this study, the researchers tried to improve research of multiple exposures by presenting a mixtures methodology, defined as exposure continuum mapping (ECM), that allows investigators to identify complex exposure patterns (i.e., mixtures) within their study population and evaluate complex health effects.

Who was involved?

The team involved a diverse mother-child cohort over 600 women participating in ECHO that also enrolled in the Eunice Kennedy Shriver National Institute of Child Health and Human Development's (NICHD) Fetal Growth Studies from 2009-2012.

What happened during the study?

To begin, the team obtained data previously collected from the study population during their participation in the Eunice Kennedy Shriver National Institute of Child Health and Human Development's (NICHD) Fetal Growth Studies. These data included concentrations of endocrine disrupting chemicals (EDCs) measured in blood samples collected from mothers 8-12 weeks into their pregnancy and their infant’s weight at birth. Then, the team analyzed these data with ECM in order to identify the range of EDC exposure profiles experienced by moms during their pregnancy and to examine the relationship to the birth weight of their children.

What happens next?

The team will apply ECM to assist investigations of exposure mixtures and other child health outcomes, with particular interest on obesity.

Where can I learn more?

For access to software tools see: https://github.com/johnlpearce/

Access the full journal article, titled “Exploring associations between prenatal exposure to multiple endocrine disruptors and birth weight with exposure continuum mapping.”

The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published June 2, 2021

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ECHO Study Finds Pregnant Women Exposed to Variety of Chemicals—Some May Affect Birth Weights

ECHO Review Finds Air Pollution May Be Associated with Child Brain Development, Behavior

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ECHO Review Finds Air Pollution May Be Associated with Child Brain Development, Behavior

Author(s): Heather E. Volk, Frederica Perera, Joseph M. Braun, Samantha L. Kingsley, Kim Gray, Jessie Buckley, Jane E. Clougherty, Lisa A. Croen, Brenda Eskenazi, Megan Herting, Allan C. Just, Itai Kloog, Amy Margolis, Leslie A. McClure, Rachel Miller, Sarah Levine, Rosalind Wright

Who sponsored this study?

This research was supported by the Environmental influences on Child Health Outcomes (ECHO) Program, Office of The Director, National Institutes of Health.

What were the study results?

ECHO provides a unique opportunity to study how air pollution can affect children’s brain development and behavior in a large, diverse study population. It also has the ability to study pollutant exposures by geographic area, which has been a limitation in previous research.

What was the study's impact?

This study sets up the possibility of future work in ECHO on the effect of prenatal air pollution exposure on brain development in children.

Why was this study needed?

This study summarized information on different ways to measure prenatal air pollution exposure and what we know about how air pollution affects children’s behavior and brain development. It also helps create a plan for ECHO to study how being exposed to air pollution in the womb may affect children’s behavior.

Who was involved?

This paper uses summary data from ECHO to learn if there may be enough participants in the future to study how air pollution can affect children’s brain development and behavior.

What happened during the study?

Researchers reviewed earlier papers on air pollution and child development to summarize what those studies found. Then, they used that information to develop a plan that ECHO might use to fill gaps in that earlier work to advance children’s health.

What happens next?

Future studies will do the work described here – to examine air pollution exposure in ECHO participants by geographic area to determine how air pollution can affect the brain.

Where can I learn more?

Access the full journal article , titled “Prenatal air pollution exposure and neurodevelopment: A review and blueprint for a harmonized approach within ECHO.”

The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Published: May 2021

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ECHO Review Finds Air Pollution May Be Associated with Child Brain Development, Behavior