Young Children Show Widespread Exposure to Environmental Chemicals, ECHO Study Finds

Children had higher levels of certain replacement chemicals compared to their mothers during pregnancy.

Young children are exposed to a wide range of environmental chemicals, including some emerging and replacement chemicals, according to ECHO Cohort research measuring early childhood exposures. This study found that children aged 2 to 4 years often had higher levels of certain chemicals compared to their mothers during pregnancy, highlighting potential risks for future health.

Researchers measured 111 different chemicals in urine samples from 201 children and their mothers from six ECHO Cohort study sites across the United States. More than half of the children’s samples contained multiple chemicals, such as environmental phenols, pesticides, phthalates, and markers of exposure to polycyclic aromatic hydrocarbons (PAHs). Approximately 34 chemicals were found in over 90% of the samples, including nine of which have not been included in U.S. national biomonitoring.

Compared to their mothers, children showed higher levels of chemicals like bisphenol S (BPS), used in hard plastics and synthetic fibers, and compounds related to pesticides. By contrast, mothers had higher levels of chemicals such as triclosan and monoethyl phthalate (MEP), which are found in some soaps and cosmetics.

“Finding so many chemicals detected in over 90% of young children reinforces the concern that our children are being exposed to a sea of potentially harmful compounds from their earliest years, with little parents can do to protect them”, said Deborah Bennett, PhD of the University of California, Davis.

Over time, exposures to chemicals like triclosan, parabens, phthalates, and PAHs have become less common, likely due to regulations and bans. However, replacement chemicals such as DINCH—a phthalate substitute in some plastics—and certain pesticides have been increasingly detected.

This collaborative research, titled “Early Childhood Exposures to Environmental Chemicals in the Environmental influences on Child Health Outcomes Consortium,” is published in Environmental Science & Technology.

Young Children May Be Exposed to a Variety of Emerging Chemicals Found in Some Consumer Products

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Young Children May Be Exposed to a Variety of Emerging Chemicals Found in Some Consumer Products

Author(s): Jiwon Oh, Deborah H. Bennett, 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.

 

Why was this study needed?

Over time, exposure to chemicals like triclosan, parabens, phthalates, and PAHs became less common, likely because of new rules and bans on their use. However, replacement chemicals—like DINCH, a chemical that has replaced phthalates in some plastic products—and some pesticides have been showing up more often in later years. Exposure to multiple chemicals during pregnancy and early childhood is a concern because these are critical stages of development when children are more vulnerable to harm. Such exposures can increase their risk of health problems later in life. There is limited data tracking young children’s – 2 to 4 years - exposure to environmental chemicals compared to older children. Prenatal and early-life exposure to these chemicals can increase the risk of multiple adverse child health outcomes. This study aimed to investigate early childhood exposures to a variety of environmental chemicals.

 

What were the study results?

Scientists measured 111 different chemicals in urine samples from young children and their mothers during pregnancy. More than half of the samples contained chemicals such as environmental phenols, pesticides, phthalates, and chemical markers of exposure to polycyclic aromatic hydrocarbons (PAH). About 34 chemicals were found in over 90% of the total samples. Compared to their mothers during pregnancy, children had higher amounts of certain chemicals, like bisphenol S (BPS)—a chemical used in some hard plastics and synthetic fibers as a replacement for BPA—and pesticide-related compounds. On the other hand, mothers had higher levels of chemicals like triclosan and monoethyl phthalate (MEP), markers of exposure to chemicals found in some consumer products like soaps and cosmetics.

Certain groups of children, such as younger kids, later-born siblings, and those from families with fewer resources, were exposed to higher levels of chemicals.

 

What was the study's impact?

This study suggests that young children may be exposed to a variety of emerging and replacement chemicals that may affect their health later in life. Continued monitoring in larger populations of young children can help researchers better understand how these exposures affect children’s long-term health.

 

Who was involved?

The study included 201 children aged 2-4 years and their mothers recruited from six ECHO Cohort study sites across the United States.

 

What happened during the study?

Researchers collected urine samples from each child and their mother during pregnancy. These samples were analyzed for the levels of 111 different chemicals related to environmental exposures. The concentrations of these chemicals were compared between child and prenatal maternal samples. The researchers also examined social and environmental factors that may have influenced the concentration of each chemical in children's urine samples, such as race, ethnicity, maternal education, maternal age, and neighborhood opportunity.

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 happens next?

Additional studies tracking early childhood exposures to a variety of contemporary and emerging chemicals could help researchers better understand the potential effects these exposures may have on children’s short and long-term health.

 

Where can I learn more?

Access the full journal article, titled “Exposures to Contemporary and Emerging Chemicals Among Children Aged 2-4 Years in the United States Environmental Influences on Child Health Outcomes (ECHO) Cohort,” in Environmental Science & Technology.

 

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

Published June 30, 2025

 

Read the associated article.

 

ECHO Researchers Investigate Association of Early Childhood Phthalate Exposures with ADHD Behaviors in Childhood and Adolescence

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ECHO Researchers Investigate Association of Early Childhood Phthalate Exposures with ADHD Behaviors in Childhood and Adolescence

Authors: Jiwon Oh, Julie B. Schweitzer, Deborah H. Bennett, 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.

 

Why was this study needed?

Phthalates are widely used chemicals found in many everyday items such as food packaging, flooring, building materials, medicine coatings, medical supplies, cosmetics, and personal care products. When phthalates enter the body, they are metabolized and converted into various smaller molecules, known as metabolites.

Animal studies suggest that exposure to phthalates during early life may negatively affect the nervous system, but there has been limited investigation into potential associations between early childhood phthalate exposure and attention-deficit/hyperactivity disorder (ADHD) behaviors in later childhood and adolescence.

For this study, ECHO researchers wanted to investigate whether exposure to phthalates in children at ages 2-5 years was associated with ADHD symptoms when these children were ages 8-18 years.

Learn how to say phthalate.

 

What were the study results?

ECHO Cohort researchers evaluated the levels of several metabolites that result from phthalate exposure. They saw that in children ages 2-5 years, most of these molecules were not associated with ADHD behaviors in these children at ages 8-18 years.

However, among children who had been diagnosed with autism spectrum disorder (ASD), one of these metabolites—mono-2-heptyl phthalate (MHPP)—was associated with more ADHD behaviors. Among typically developing children, a different small molecule—mono-carboxy isooctyl phthalate (MCiOP)—was associated with more hyperactive/impulsive behaviors.

 

What was this study's impact?

This study suggests that early childhood exposure to certain phthalates may be associated with having both ASD and ADHD traits. Since ADHD behaviors are more commonly found in children with ASD, deepening the understanding of how exposure to environmental chemicals, such as phthalates, could contribute to this comorbidity may be important for managing and treating these conditions effectively.

Note: The results reported here are from a single study. Other or future studies may provide new information or different results. You should consult with a qualified healthcare provider for diagnosis and for answers to your personal questions.

 

Who was involved?

This study included 243 children living in Northern California and taking part in the ReCHARGE (Revisiting Childhood Autism Risks from Genetics and Environment) study. This study included both neurotypical and neurodiverse children, with about 60% of them having ever had neurodevelopmental concerns. Therefore, the children included in the study tended to have more ADHD behaviors compared with children in the general population.

 

What happened during the study?

Phthalate metabolites can be measured in biological samples, such as urine, to assess exposure to phthalates. In this study, the researchers measured 15 phthalate metabolites in urine samples of young children ages 2-5 years. Parents answered questions about each child’s ADHD symptoms at ages 8-18 years.

 

What happens next?

While the metabolite MHPP and the phthalate it’s derived from, di-n-heptyl phthalate (DHPP), are commonly found in children’s urine, their influence on neurodevelopment has not been studied as much as other phthalates. Since exposure to DHPP has been linked to problems with development and behavior in animals, further studies need to look more closely at this compound to understand its effects on how the brain develops in children.

 

Where can I learn more?

Read the full research article, titled “Early childhood exposures to phthalates in association with attention-deficit/hyperactivity disorder behaviors in middle childhood and adolescence in the ReCHARGE study,” in the journal International Journal of Hygiene and Environmental Health.

Learn more about ECHO’s other chemical exposure research.

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

Published June 2024

ECHO Cohort Study Finds Association Between PFAS and Bioactive Lipids

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ECHO Cohort Study Finds Association Between PFAS and Bioactive Lipids

Authors: Himal Suthar, Max Aung, 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.

 

Why was this study needed?

Per- and polyfluoroalkyl substances (PFAS) are a large, complex group of synthetic chemicals that have been used in consumer products around the world since about the 1950s. They are ingredients in various everyday products. For example, PFAS are used to keep food from sticking to packaging or cookware, make clothes and carpets resistant to stains, and create firefighting foam that is more effective. People are most likely exposed to these chemicals by consuming PFAS-contaminated water or food, using products made with PFAS, or breathing air containing PFAS.

Because PFAS break down slowly, if at all, people and animals are repeatedly exposed to them, and blood levels of some PFAS can build up over time. Scientific studies have identified multiple health effects associated with PFAS exposure.[1] Women exposed to PFAS during pregnancy are at increased risk for adverse birth outcomes and pregnancy complications.

Lipids are fatty molecules that perform a variety of functions in the body—from forming the membranes of cells to serving as a building block for certain hormones. Changes in bioactive lipids—broadly defined as a category of lipids with signaling properties that cause biological effects and changes in the body—have been linked to PFAS exposure and adverse pregnancy outcomes. This study aimed to compare the concentration of PFAS in the blood of pregnant participants with levels of bioactive lipids in three important metabolic pathways.

[1] National Institute of Environmental Health Sciences: Perfluoroalkyl and Polyfluoroalkyl Substances (PFAS) (nih.gov)

 

What were the study results?

The research team analyzed the associations between 12 types of PFAS, in pairs and as mixtures, and 50 bioactive lipids in blood plasma in pregnant participants across three ECHO Cohort Study Sites. When researchers looked at data from different study sites, they found that higher levels of PFAS in blood were often linked with higher levels of certain bioactive lipids. The research team also noticed differences in the distribution of bioactive lipid compounds between individual study sites, possibly driven by variations in the genetic makeup and sociodemographic characteristics of the populations or differences in environmental exposures due to diet.

Footnote: Results reported here are for a single study and reflect an observed correlation. Other or future studies may provide new information or different results. You should always consult with a qualified healthcare provider for diagnosis and for answers to your personal questions.

 

What was this study's impact?

The similarity of results researchers found from the analysis of mixtures of PFAS chemicals and individual PFAS chemicals indicate that specific bioactive lipids could be useful biomarkers of PFAS exposure. Biomarkers are biological indicators of a particular health effect or status – in this case, PFAS exposure. They can be found in blood, urine, or other body fluids and can be substances, characteristics, genes, or proteins. This insight could help in understanding and addressing the health effects of PFAS by expanding screening methods.

The bioactive lipids measured in this study have not yet been tested as routine biomarkers in clinical settings. However, these findings aid in advancing the future of healthcare as additional and more complex lipid biomarkers become measurable and are tested for clinical use.

These findings encourage researchers to prioritize the study of PFAS and bioactive lipids pairs in future testing in addition to individually studying the effect of different types of PFAS. Additionally, this study highlights the importance of regulating the 12 types of PFAS observed.

 

Who was involved?

This study included 414 pregnant participants from three ECHO Cohort study sites: Chemicals in Our Bodies based in San Francisco, ECHO-PROTECT based in Puerto Rico, and Illinois Kids Development Study based in Chicago.

 

What happened during the study?

The research team estimated associations between prenatal PFAS exposure and bioactive lipids, measuring the levels of 12 types of PFAS and 50 bioactive lipids in 414 pregnant participants. Researchers quantified associations by using various statistical analyses while controlling for several factors (e.g., maternal age, gestational age at sample collection, maternal education, pre-pregnancy BMI).

 

What happens next?

The researchers plan to measure associations between bioactive lipids and peri- and prenatal mental health outcomes including perinatal and postpartum depression. Future studies could also look at the influence of other variables on this relationship. For example, researchers could investigate the influence of diet, which has been linked to changes in both PFAS and bioactive lipid concentrations.

 

Where can I learn more?

Access the full journal article, titled “Cross-Sectional Associations between Prenatal Per- and Poly-Fluoroalkyl Substances and Bioactive Lipids in Three Environmental Influences on Child Health Outcomes (ECHO) Cohorts,” in Environmental Science and Technology.

 

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

 

Published May 14, 2024

 

Read the associated article.

Read More Research Summaries about Exposures and Pregnancy

ECHO Study Finds Flame-Retardant Chemicals May Increase Risk Of Preterm Birth and Higher Birth Weight

Authors: Deborah Bennett, Jiwon Oh, et al.

Does prenatal PFAS exposure affect a child’s risk for developing autism-related traits?

Authors: Jennifer Ames, Ghassan Hamra, et al.

Exposures to environmental chemicals and their effect on important molecules during pregnancy

Author(s): Brett T. Doherty, Megan E. Romano, et al.

Do chemicals that break down slowly in the environment affect how long it takes to become pregnant?  

Author(s): Linda Kahn, Alison Hipwell, Kim Harley, Pam Factor-Litvak, Michele Klein-Fedyshin, Christine Porucznik, Eva Siegel, Yeyi Zhu

A review of studies that look at whether exposure to common non-persistent chemicals in consumer products delays the time it takes to become pregnant

Author(s): Alison E. Hipwell, Linda G. Kahn, Pam Factor-Litvak, et al

ECHO Study Finds Link Between Phthalate Exposure and Preterm Birth, Estimates Potential Costs

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ECHO Study Finds Link Between Phthalate Exposure and Preterm Birth, Estimates Potential Costs

Authors: Leonardo Trasande, 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.

 

Why was this study needed?

Phthalates are widely used chemicals found in some consumer products, and previous research has linked phthalate exposure to preterm birth. In response, the use of di-2-ethylhexyl phthalate (DEHP), a common type of phthalate, has decreased in recent years. However, there is limited research on the effects of the replacement phthalates, and the costs associated with phthalate exposure remain unquantified. ECHO Cohort researchers wanted to learn about the potential connections between phthalates, their metabolites in the urine of pregnant individuals, and birth outcomes—including birth weight and length of pregnancy. The study also sought to estimate the potential costs associated with adverse birth outcomes.

 

What were the study results?

When the researchers grouped mothers based on the amount of DEHP metabolites (substances produced when the body breaks down DEHP) found in their urine, they found that the 10 percent with the highest levels had a 50 percent higher chance of giving birth before the 37th week of pregnancy compared to the 10 percent with the lowest levels.

Some common alternatives to DEHP were associated with even higher risk of preterm birth. Women exposed to the highest amounts of these alternative chemicals—phthalic acid, di-isodecyl phthalate (DIDP), di-n-octyl phthalate (DnOP), and diisononyl phthalate (DiNP)—had twice the risk of preterm birth compared to those with little to no exposure to these alternatives.

Researchers estimated that the number of premature births in the U.S. that could be linked to phthalate exposure in 2018 was between 24,000 and 120,000, potentially costing between $1.6 billion and $8.1 billion in medical expenses over the lifetime of the children.

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 this study's impact?

This ECHO Cohort research examines the effect of phthalates on birth outcomes such as preterm birth and birth weight. These findings associated adverse birth outcomes with exposure to DEHP and its chemically similar substitutes, which can inform the development of policies, programs, and practices that can help prevent or lessen potentially harmful exposures during pregnancy.

 

Who was involved?

The study included 5,006 mother-child pairs from 13 ECHO Cohort Study Sites across the U.S.  Researchers included individuals with information on up to 20 urinary phthalate metabolites. The pregnant participants were aged 25 to 34 at the time they gave birth.

 

What happened during the study?

The researchers analyzed levels of 20 phthalate metabolites in urine samples collected at three points during each participant’s pregnancy. They also investigated the differences between specific types of phthalates, comparing DEHP with several newer alternatives developed to replace it. Then, the team looked for associations between these metabolite levels and preterm births. They also calculated the number of premature births that could be linked to phthalate exposure and the possible associated costs over the lifetime of the child.

 

What happens next?

Future research could look at how exposure to replacement phthalates affects child development after birth. The European Union has prohibited the use of certain phthalates in some consumer products—as have California and a few other U.S. states.

 

Where can I learn more?

Access the full journal article, titled “Prenatal phthalate exposure and adverse birth outcomes in the USA: a prospective analysis of births and estimates of attributable burden and costs,” in The Lancet Planetary Health.

 

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

 

Published February, 2024

 

Access the associated article.

Read More Research Summaries about Exposures and Pregnancy

ECHO Study Finds Flame-Retardant Chemicals May Increase Risk Of Preterm Birth and Higher Birth Weight

Authors: Deborah Bennett, Jiwon Oh, et al.

Does prenatal PFAS exposure affect a child’s risk for developing autism-related traits?

Authors: Jennifer Ames, Ghassan Hamra, et al.

Exposures to environmental chemicals and their effect on important molecules during pregnancy

Author(s): Brett T. Doherty, Megan E. Romano, et al.

Do chemicals that break down slowly in the environment affect how long it takes to become pregnant?  

Author(s): Linda Kahn, Alison Hipwell, Kim Harley, Pam Factor-Litvak, Michele Klein-Fedyshin, Christine Porucznik, Eva Siegel, Yeyi Zhu

A review of studies that look at whether exposure to common non-persistent chemicals in consumer products delays the time it takes to become pregnant

Author(s): Alison E. Hipwell, Linda G. Kahn, Pam Factor-Litvak, et al

ECHO Cohort Researchers Find Association Between Some Prenatal Chemical Exposures and Postpartum Depression

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ECHO Cohort Researchers Find Association Between Some Prenatal Chemical Exposures and Postpartum Depression

Authors: Melanie Jacobson, 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.

 

Why was this study needed?

Postpartum depression affects up to 20% of new mothers, making it the most common pregnancy complication to occur after delivery. Postpartum depression can impact a mother’s daily functioning, quality of life, and long-term health. Furthermore, it is associated with poor mother-child attachment, which can impact child health and development.

Factors like genetics and stress can make some people more likely to experience postpartum depression, but researchers are still trying to understand how synthetic chemicals might also play a role. Chemicals such as phenols, phthalates, and parabens can be found in plastics and personal care products. While these chemicals are nonpersistent, meaning that they don’t linger in the environment, their presence is widespread due to frequent exposure through diet, absorption through skin, and inhalation. The investigators in this study wanted to examine the extent to which exposure to these chemicals might be associated with postpartum depression symptoms.

 

What were the study results?

Prenatal phthalate concentrations were associated with increased odds of slightly higher postpartum depression scores, and the condition was observed to be more likely in people who were Hispanic, had lower education levels, and had prenatal depression.

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?

Of the many synthetic chemicals investigated, only prenatal phthalate concentrations were associated with increased odds of postpartum depression. This suggests that finding ways to reduce prenatal exposure to phthalates might reduce the frequency of postpartum depression.

 

Who was involved?

Researchers used data from 2,174 pregnant individuals across five study sites. This information included data on urinary chemical concentrations from at least one point during the pregnancy and a self-reported postnatal depression assessment between two weeks and 12 months after delivery.

 

What happened during the study?

Researchers measured the concentrations of nonpersistent chemicals in urine samples. Researchers also collected, between two weeks and 12 months after delivery, data using self-reported postnatal depression assessments completed by the same individuals. Screening instruments indicated the presence or absence of postnatal depressive symptoms. Data was then harmonized to the Patient-Reported Measurement Information System (PROMIS) Depression scale.

 

What happens next?

While this is believed to be the largest study to-date examining the effects of environmental chemicals on postpartum depression, future studies are needed to replicate this research with larger sample sizes in diverse populations.

 

Where can I learn more?

Access the full journal article, titled “Prenatal exposure to nonpersistent environmental chemicals and postpartum depression,” in JAMA Psychiatry.

 

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

Published September 20, 2023

 

Access the associated article.

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

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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

Read More Research Summaries about Chemical Exposures and Pregnancy

Does prenatal PFAS exposure affect a child’s risk for developing autism-related traits?

Authors: Jennifer Ames, Ghassan Hamra, et al.

Exposures to environmental chemicals and their effect on important molecules during pregnancy

Author(s): Brett T. Doherty, Megan E. Romano, et al.

Do chemicals that break down slowly in the environment affect how long it takes to become pregnant?  

Author(s): Linda Kahn, Alison Hipwell, Kim Harley, Pam Factor-Litvak, Michele Klein-Fedyshin, Christine Porucznik, Eva Siegel, Yeyi Zhu

A review of studies that look at whether exposure to common non-persistent chemicals in consumer products delays the time it takes to become pregnant

Author(s): Alison E. Hipwell, Linda G. Kahn, Pam Factor-Litvak, et al

ECHO Study Links Phthalate Exposure During Pregnancy With Genetic Changes in the Placenta

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ECHO Study Links Phthalate Exposure During Pregnancy With Genetic Changes in the Placenta

Authors: Alison Paquette, Sheela Sathyanarayana, 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 several phthalates were associated with changes in the expression of 38 genes within the placenta. Some of these changes in gene expression were only significant in male or female infants. This shows that phthalates may change how the placenta works in different ways for the two sexes. The team also studied which biological pathways were connected to these changes in gene expression. They found 27 specific pathways that may have been affected by phthalate exposure. These pathways involved important building blocks for the developing infant.

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?

Exposure to phthalate chemicals is related to changes in gene expression in placentas. This is important because these changes in gene expression may affect the growing baby.

 

Why was this study needed?

There is a lot we still don’t know about how phthalates affect the placenta. Phthalates are a group of chemicals used in plastics and household products. The placenta is an organ in pregnant women that provides their growing baby with oxygen and nutrients. It also helps mothers and babies share information. Exposure to phthalates during pregnancy may harm the placenta and affect how the baby develops. Looking at changes in how genes are expressed when exposed to phthalates during pregnancy can help researchers measure the effect on how the placenta works. Genes are expressed when DNA is converted into proteins, which perform a variety of important functions and play critical roles in development.

 

Who was involved?

The study involved pregnant women from Memphis, Tennessee who enrolled in the CANDLE study during their pregnancy. Researchers collected urine and placentas from mothers just after their babies were born. These participants were between 16-40 years old, mostly Black, and had relatively healthy pregnancies.

 

What happened during the study?

Researchers measured the amount of 16 phthalates in urine collected from the participants during the 2nd and 3rd trimester of pregnancy.

Researchers collected the placenta from the mother after having the baby and measured the expression of each gene in the placenta. For each gene, the researchers tried to figure out if higher phthalate concentrations were related to more or less gene expression in the placenta. This information was used to understand how phthalates may have affected how the placenta worked.

 

What happens next?

This research team will study how changes in the placenta are related to pregnancy complications like preterm birth within this same group of pregnant women. They will also use new tools and technologies to study how phthalates may cause these changes in gene expression.

It is also important to look at the effect of phthalates on other groups of women and see how these changes in placental function impact infant and childhood health.

 

Where can I learn more?

Read more information about how people are exposed to phthalates and how to decrease exposures.

 

Access the full journal article, titled “A Comprehensive Assessment of Associations between Prenatal Phthalate Exposure and The Placental Transcriptomic Landscape” in Environmental Health Perspectives.

 

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

 

Published September 3, 2021

 

Access the associated article.

Read More Research Summaries about Chemical Exposures and Pregnancy

Exposures to environmental chemicals and their effect on important molecules during pregnancy

Author(s): Brett T. Doherty, Megan E. Romano, et al.

Do chemicals that break down slowly in the environment affect how long it takes to become pregnant?  

Author(s): Linda Kahn, Alison Hipwell, Kim Harley, Pam Factor-Litvak, Michele Klein-Fedyshin, Christine Porucznik, Eva Siegel, Yeyi Zhu

A review of studies that look at whether exposure to common non-persistent chemicals in consumer products delays the time it takes to become pregnant

Author(s): Alison E. Hipwell, Linda G. Kahn, Pam Factor-Litvak, et al