environmental exposures

NIH Study Highlights Potential Disparities in Birthweight Outcomes Linked to Environmental Exposures in Vulnerable Populations

Posted on by Jodi Snare

A new study from the Environmental influences on Child Health Outcomes (ECHO) Program sheds light on how environmental exposures may have a larger impact on birth outcomes in vulnerable populations, particularly those defined by race, ethnicity, and maternal education. Researchers wanted to understand when the effect of these exposures becomes clinically significant and how different levels of exposure impact various groups differently.

To explore this, researchers used statistical models to simulate four potential scenarios in which average birthweights in a population could be reduced by varying amounts: 50g, 125g, 167g, and 250g. The study found that the percentage of children with low birthweight (LBW) (birthweight<2500g) varied by socioeconomic categories with the greatest percentage LBW seen in the most vulnerable socioeconomic groups. After analyzing the four scenarios, a clear trend was seen such that the greatest impact of an exposure was seen in the most vulnerable sub-populations. This trend was observed for all scenarios including the impact of a small environmental exposure. The most striking disparity among all scenarios was found in racial sub-populations.

This study showed how vulnerable groups, who already face higher risks of poor health, are more affected by small environmental exposures compared to the general population. Read a research summary here.

Vulnerable Populations More Likely to be Impacted by Small Environmental Effects, ECHO Study Finds

Vulnerable Populations More Likely to be Impacted by Small Environmental Effects, ECHO Study Finds

Authors: Janet L. Peacock, 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?

A challenge in public health is determining when the effect of an environmental exposure is large enough to be clinically important. Vulnerable populations—defined by sociodemographic factors such as race, ethnicity, and maternal education—tend to have a higher risk of poor health outcomes than the general population when exposed to the same environmental exposures. This study aimed to interpret the differences in outcomes between different population types, particularly focusing on vulnerable sub-populations, by analyzing differences arising from hypothetical small effects on these groups.

 

What were the study results?

The researchers used statistical models to examine how different levels of exposures would affect different sub-populations within the nationwide ECHO Cohort. Specifically, the study team considered a hypothetical environmental exposure that could affect a child’s birthweight. They considered four scenarios in which the hypothetical exposure could affect average birthweights in a population: a very small effect reducing average birthweight by 50g, a small effect reducing it by 125g, a medium effect reducing it by 167g, and a large effect reducing it by 250g.

The study found that the percentage of children with low birthweight (LBW) (birthweight<2500g) varied by socioeconomic categories with the greatest percentage LBW seen in the most vulnerable socioeconomic groups. After analyzing the four scenarios, a clear trend was seen such that the greatest impact of an exposure was seen in the most vulnerable sub-populations. This trend was observed for all scenarios including the impact of a small environmental exposure.

 

What was this study's impact?

This study showed how vulnerable groups, who already face higher risks of poor health, may be more affected by small environmental exposures than the general population. This demonstrates why small effects, which may be overlooked, are actually important when considering vulnerable populations. These results can be used in planning future studies and for designing preventive programs. The findings also help explain how exposures impact vulnerable groups and highlight the need to stratify by socioeconomic variables when assessing health outcomes.

 

Who was involved?

This simulation study modeled data from more than 28,000 mother-child pairs from the ECHO Cohort.

 

What happened during the study?

The research team conducted a simulation using data from ECHO Cohort participants to explore how hypothetical exposures could affect babies’ average birthweight and LBW in vulnerable subgroups. The study calculated average birthweight in groups by sociodemographic categories, and then compared the differences in average birthweight and the percentage of LBW.

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?

These findings are relevant for studies where researchers aim to identify the adverse effects of environmental exposures. Future research that uses more social factors and/or outcomes is needed to understand the impact of small environmental exposures on the general population and vulnerable sub-populations, and how these effects contribute to health disparities.

 

Where can I learn more?

Access the full journal article, titled “Do Small Effects Matter More in Vulnerable Populations? An Investigation Using Environmental influences on Child Health Outcomes (ECHO) Cohorts,” in BMC Public Health.

 

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

 

Published September 28, 2024

 

Read the associated research alert.

Download this summary

Vulnerable Populations More Likely to be Impacted by Small Environmental Effects, ECHO Study Finds

Read More Research Summaries

ECHO Study Evaluates Influence of Neighborhood-Level Poverty and Food Insecurity During Pregnancy on Birthweight

Authors: Izzuddin Aris, Emily Oken, et al.

Weight Gain During Infancy in Children Born Preterm Associated with Higher Risk of Obesity, According to New ECHO Research

Authors: Michael O’Shea, et al.

ECHO Study Suggests No Association Between Maternal Stress in the First Year After Birth and Childhood BMI

Authors: Callie Brown, Charles Wood, et al.

New ECHO Research Develops a National Exposure Index for Combined Environmental Hazards and Social Stressors

Posted on by Jodi Snare

Collaborative ECHO research led by Sheena Martenies, PhD, MPH of the University of Illinois Urbana-Champaign developed a national exposure index for easier analysis of multiple factors at once. This research, titled “Developing a National-Scale Exposure Index for Combined Environmental Hazards and Social Stressors and Applications to the Environmental influences on Child Health Outcomes (ECHO) Cohort,” is published in the International Journal of Environmental Research and Public Health.

There is growing interest in understanding the combined effect of multiple environmental hazards and social stressors on the health and development of children. While there are a number of tools for assessing these factors, they can be limiting when trying to analyze the cumulative effects of various exposures.

In this study, researchers developed a combined exposure index with national coverage that compiled data from several environmental and social indicators during prenatal and early-life periods. The data included variables such as air pollution and neighborhood socioeconomic status and analyzed how combined exposure to several factors during pregnancy may impact health.

The combined exposure index, which facilitated ECHO-wide analyses considering exposures to multiple neighborhood-level hazards and stressors at the same, differed by region. The level of combined exposure was highest in the western and northeastern regions of the United States. Researchers found that pregnant participants who identified as Black and Hispanic were more likely to have higher exposures to hazards compared to White and non-Hispanic participants. Exposure values were also higher for pregnant participants with lower educational attainment.

“Our study results complement those from a previous study that found these combined exposures were associated with a higher risk of adverse birth outcomes for some demographic groups,” Dr. Martenies said. “The results of these studies suggest there is a role for neighborhood quality in healthy pregnancy outcomes. More work is needed to identify interventions that might reduce prenatal exposures and improve pregnancy outcomes.”

Researchers may use this exposure index in future studies to look at how neighborhood features influence child health outcomes. Future studies would benefit from national datasets for key environmental health concerns, such as water contaminants and pesticides, and social stressors that may disproportionally affect certain groups.

Read the research summary.

ECHO Researchers Develop a National Exposure Index for Combined Environmental Hazards and Social Stressors

<< Back to Research Summaries

ECHO Researchers Develop a National Exposure Index for Combined Environmental Hazards and Social Stressors

Authors: Sheena Martenies, 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?

There is growing interest in understanding the combined effect of environmental hazards and social stressors on the health and development of children. While there are a number of tools for assessing the impact of environmental and social stressors, these tools can be limiting in the number of indicators they measure, the geographical area they cover, or the period of time they include for their observations. In this study, researchers developed a combined exposure index with national coverage that compiled available data on several environmental and social indicators during prenatal and early-life periods. This index is now being used to facilitate ECHO-wide analyses that consider multiple neighborhood-level exposures at the same time.

 

What were the study results?

The combined exposure index, which summarized exposures to multiple environmental hazards and social stressors at the neighborhood level, differed by region. The level of combined exposures were highest in the western and northeastern regions of the United States. Researchers also found that pregnant participants who identified as Black and Hispanic had higher exposures compared to White and non-Hispanic participants. Exposure values were also higher for pregnant participants with lower educational attainment.

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?

The study analyzed how the combined exposure to several environmental hazards and social stressors during pregnancy may impact health. Researchers found that pregnant participants from minority groups were more likely to have higher exposures to these hazards. These results support findings from similar studies that suggest that neighborhood quality might influence maternal and child health outcomes, and may contribute to health disparities.

 

Who was involved?

This study included data from 14,072 pregnancies from 46 different ECHO research sites across the United States.

 

What happened during the study?

Researchers developed a combined exposure index using publicly available data on environmental hazards and social stressors. The data included variables such as air pollution, features of the built environment, and neighborhood socioeconomic status, and then estimated the likelihood of exposure to these variables for participants in the study, based on where they lived.

 

What happens next?

Researchers can use this exposure index in future studies to look at how neighborhood features influence child health outcomes. Future studies would benefit from national datasets for key environmental health concerns, such as water contaminants and pesticides, and social stressors that may disproportionally affect certain groups.

 

Where can I learn more?

Access the full journal article, titled “Developing a National-Scale Exposure Index for Combined Environmental Hazards and Social Stressors and Applications to the Environmental Influences on Child Health Outcomes (ECHO) Cohort,” in the International Journal of Environmental Research and Public Health.

 

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

Published July 10, 2023

Access the associated article.

Download this summary

ECHO Researchers Develop a National Exposure Index for Combined Environmental Hazards and Social Stressors

ECHO Researchers Examine Incidence Rates for Childhood Asthma With Recurrent Exacerbations and Suggest Possible Social and Environmental Risk Factors

Posted on by Jodi Snare

Collaborative ECHO research led by Rachel L. Miller, MD of Icahn School of Medicine at Mount Sinai and Christine C. Johnson, PhD, MPH of Henry Ford Health System investigates the factors that influence the rates of childhood asthma with recurrent exacerbations (ARE)—a subtype of asthma where children experience frequent, severe episodes of asthma. The researchers leveraged data from over 17,000 children born between 1990 and 2017 and found that children ages 2-4 years old, non-Hispanic Black and Hispanic Black children, and children who lived in the Northeast and Midwest had the highest incidence rates of ARE. Additionally, children with a parental history of asthma had ARE rates almost 3 times greater compared to those with no parental history. This research, titled “Incidence Rates of Childhood Asthma with Recurrent Exacerbations in the U.S. Environmental influences on Child Health Outcomes (ECHO) Program,” is published in The Journal of Allergy and Child Immunology.

While the prevalence of asthma has been reported widely in the United States and elsewhere, studies on childhood asthma incidence rates within specific populations and across various types of asthma and age ranges have been limited. “Describing the incidence rates of ARE across a large, diverse population of children is a critical first step for identifying potential risk factors and causes,” explained Dr. Johnson.

To conduct this research, the research team leveraged data from children enrolled in 60 ECHO cohorts across the U.S. and Puerto Rico. Child participants or their caregivers reported whether and when the child had an asthma diagnosis and any corticosteroids prescribed over time from their health care providers.  Recurrent exacerbations of asthma were based on reports of systemic (not inhaled) corticosteroid use. The researchers calculated incidence rates of ARE for the study population overall, along with rates for subsets of the population defined by the years the ARE were diagnosed, the decade children were born, their age and sex, their race and ethnicity, their residence at birth, and their parents’ history of asthma.

“While children with ARE are all different, these findings suggest that we should examine in the future key elements of the early environment, including viral respiratory tract infections, indoor allergens, environmental tobacco smoke, air pollution, stress, and socioeconomic status, which could contribute to ARE,” said Dr. Miller. “Understanding these causes will help researchers determine how to best prevent ARE and associated asthma outcomes.”

Read the research summary.­­

NIH Study Investigates Factors Affecting Asthma With Frequent Symptom Flare Ups in Young Children

Posted on by Jodi Snare

FOR IMMEDIATE RELEASE

 

Young children, ages 2 to 4 years, especially those with parental history of asthma, suffered the highest rates of asthma with recurrent exacerbations (ARE) over a nearly 30-year period studied in new research funded by the Environmental influences on Child Health Outcomes Program (ECHO) at the National Institutes of Health.

“Describing the incidence rates of ARE across a large, diverse population of children is a critical first step for identifying potential risk factors and causes,” explained Christine Johnson, PhD, MPH, an ECHO Program investigator at Henry Ford Health.

During this study, ECHO researchers looked at data from over 17,000 children between 1990 and 2017 from across the U.S. including Puerto Rico in order to learn which factors influenced the rates of childhood ARE—a subtype of asthma where children experience frequent, severe episodes of asthma. They found that non-Hispanic Black and Hispanic Black children, children ages 2 to 4 years old, and children who lived in the Northeast and Midwest had the highest rates of ARE.

These findings suggest that different environmental and social factors may play a significant role in the onset of recurring asthma issues in children.

“Understanding these causes will help researchers determine how to best prevent ARE and associated asthma outcomes,” said Rachel L. Miller, MD, an ECHO Program investigator at the Icahn School of Medicine at Mount Sinai.

Drs. Miller and Johnson led this collaborative research published in the Journal of Allergy and Clinical Immunology.

Miller, R. et al. Incidence Rates of Childhood Asthma with Recurrent Exacerbations in the U.S. Environmental influences on Child Health Outcomes (ECHO) Program. DOI: 10.1016/j.jaci.2023.03.016

###

About ECHO: ECHO is a nationwide research program supported by the NIH. Launched in 2016, ECHO aims to enhance the health of children for generations to come. ECHO investigators study the effects of a broad range of early environmental influences on child health and development. For more information, visit echochildren.org.

About the NIH: NIH, the nation’s medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information, visit www.nih.gov.

Media Contacts

For information or to request an interview, contact Rebekah Yeager,  rebekah.yeager@nih.gov.

If you are not a member of the media, but have a general inquiry, please contact  NIHKidsandEnvironment@od.nih.gov.

Connect With Us

echo connectorCheck out the recent issues of our bi-monthly newsletter, the ECHO Connector, for program news and the latest research findings.

To receive the ECHO Connector through email, subscribe here.

Follow @ECHOChildHealth for the latest ECHO Program updates on Twitter.

ECHO Researchers Investigate the Effect of Family Hardships and Newborn Health Outcomes on the Behavior and Well-being of Young Children

Posted on by Jodi Snare

Collaborative ECHO research led by Julie Hofheimer, PhD of the University of North Carolina at Chapel Hill and Monica McGrath, ScD and Rashelle Musci, PhD, both of Johns Hopkins Bloomberg School of Public Health, investigates the link between family hardships, newborn health outcomes, and the behavior of young children. The researchers collected information on the behavior of 3,934 children between the ages of 18 and 72 months and used that data to identify early factors that increase a child’s risk for experiencing behavioral and emotional difficulties. The study found that children born preterm and those whose families had been exposed to more social, economic, or environmental hardships were more likely to experience continuous behavioral difficulties. This research, titled “Psychosocial and Neonatal Risk Factors Associated with Behavioral Dysregulation Trajectories Among Young Children from 18 through 72 Months of Age,” is published in JAMA Network Open.

Adverse conditions and family hardships have steadily increased over the past two decades, challenging the emotional and behavioral well-being of children and their families. To understand how health and environmental hardships affect a child’s risk for developing continuous behavioral problems, ECHO researchers collected early childhood behavior data from 20 ECHO cohorts from across the United States. About 20% of these children were born preterm (before 37 weeks of gestation).

The researchers collected caregiver self-reports, demographics, and medical and environmental data about the children and their mothers before and during pregnancy and from infancy through age six. Caregivers completed the Child Behavior Checklist at several study visits, and the researchers compared the children’s combined difficulty with anxiety, depression, attention, and aggression to their behavioral well-being across the first six years of life.

Some children who experienced less family adversity showed improved behavior over time. Importantly, some children were able to overcome hardships and improve their behavior. Through this study, the researchers were able identify early factors that increase a child’s risk for experiencing behavioral and emotional difficulties.

“Conditions during pregnancy and early infancy can identify toddlers who may benefit from early enriched services,” said Dr. Hofheimer. “Family support services tailored to the individual needs of children may prevent later behavioral problems and improve future outcomes for vulnerable children and their families.”

Future ECHO research may examine how childhood behavior continues to develop from six years onward, examining the link between early risk factors and behavioral patterns in middle school and adolescence.

Read the research summary.

ECHO Researchers Investigate Effects of Preterm Birth, Environmental Exposures on Child Health

<< Back to Research Summaries

ECHO Researchers Investigate Effects of Preterm Birth, Environmental Exposures on Child Health

Authors: Michael O’Shea, Monica McGrath, Judy Aschner, Barry Lester, 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?

ECHO researchers are collecting extensive data from very preterm infants, including data on learning and intellectual impairments, asthma, obesity, sleep health, and the effects of the COVID-19 pandemic. This article provides an overview of how data from ECHO cohorts are being used to address questions about the combined effects of preterm birth and environmental exposures on child health outcomes.

 

What was the study's impact?

Researchers can use the information in this review to enhance their knowledge of the ECHO Program’s resources to study preterm infants. Researchers can use ECHO data to investigate the relationship between preterm birth, environmental exposures, and childhood risk of chronic and developmental health conditions.

 

Why was this study needed?

Infants who are born premature (before 32 weeks of pregnancy) are at a high risk for multiple health disorders. This review paper outlines resources available within the ECHO Program for researchers seeking to study the effects of preterm birth and environmental exposures on child health outcomes.

 

Who was involved?

This review article includes ECHO cohorts that enrolled infants who were born premature. These cohorts enrolled almost 1,800 preterm infants across 14 states that were born between April 2002 and March 2020, including three ECHO cohorts that are almost exclusively comprised of preterm infants.

 

What happened during the study?

A team of experts reviewed the characteristics of the ECHO cohorts that are collecting data on preterm infants. Through this review, they sought to describe the research goals, participant selection criteria, key environmental exposures, and child health outcomes of each cohort.

 

What happens next?

ECHO researchers will continue to investigate early life factors and environmental exposures that may affect children’s health outcomes later in life. Researchers not participating in the ECHO Program will be able to obtain de-identified data from preterm children in the ECHO-wide Cohort, along with data from around 30,000 children born at term through a controlled-access public use database. This data will include information about a broad range of environmental exposures and outcomes related to chronic illness among children in the United States. Using this data, researchers can continue to build off of ECHO’s mission to enhance the health of children for generations to come.

 

Where can I learn more?

Access the full journal article, titled “Environmental influences on Child Health Outcomes: Cohorts of Individuals Born Very Preterm,” in Pediatric Research.

 

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

Published August 10, 2022

Access the associated article.

Download this summary

ECHO Researchers Investigate Effects of Preterm Birth, Environmental Exposures on Child Health

Read More Research Summaries about Exposures and Pregnancy

Effects of Metal Mixture Exposure During Pregnancy on Fetal Growth

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

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

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

How Chemical Exposures in Pregnancy Affect Gene Changes in the Placenta

Author(s): Alison Paquette, Sheela Sathyanarayana, MD, MPH, et al.

How Environmental Exposures Affect Child Health Across Multiple Generations

Author(s): Carrie Breton, 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

The Effect of Air Pollution on Time to Pregnancy

Posted on by Jodi Snare

Linda Kahn, PhD, MPH

Collaborative ECHO research, led by Linda Kahn, PhD, MPH at NYU Langone Health, suggests traffic-related air pollution, secondhand smoke, and formaldehyde are associated with 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, such as wildfires or other sources of combustion, create particulate matter and nitrogen oxide gases.

These results are based on a systematic review of 33 articles pertaining to air pollution and time to pregnancy, an indicator of a couple’s reproductive health. The team’s research, titled “Indoor and outdoor air pollution and couple fecundability: a systematic review,” is published in Human Reproduction Update.

Mounting evidence suggests an association between air pollution and longer time to pregnancy. The goal of this review was to compare results from previous studies and identify whether different types of pollution, such as pollution from traffic, chemicals in the workplace, and secondhand smoke, are consistently related to time to pregnancy.

To conduct this research, the team searched six science libraries and reviewed 33 relevant articles published in English between January 1, 1990 and February 11, 2021. Of these 33 articles, eight examined air quality, six looked at secondhand smoke exposure, and 19 studied air quality in the workplace. Researchers assigned each article a quality score based on the study design and extracted relevant data on time to pregnancy.

“This review shows that certain chemicals can increase the amount of time it takes for a couple to conceive, which may cause stress and lead them to seek fertility treatments,” said Dr. Kahn.

Researchers still need more insight into exactly how these chemicals affect reproduction. Future studies should be designed to collect more accurate exposure data, ideally from personal air monitors.

“Our team is still uncertain about whether the air people breathe around time of conception is most important or if there are certain life stages such as puberty when individuals may be especially susceptible to the harmful effects of air pollution,” Dr. Kahn added.

The ECHO Program will provide a useful framework for collecting more detailed information on how chemical exposures across the life course affect reproduction.

Read the research summary.

ECHO researchers study the effects of neighborhood environmental and social conditions on pregnancy and infant health

Posted on by Jodi Snare

Collaborative ECHO research led by Sheena Martenies, PhD, MPH of the University of Illinois at Urbana-Champaign investigates the combined effects of environmental hazards and social stressors on pregnancy and infant health. This research included information on more than 13,000 infants born between 2010 and 2019 from 41 ECHO cohorts located throughout the United States. In this study, researchers found that pregnant women living in neighborhoods with higher combined exposures had shorter pregnancies and smaller babies. This research, titled “Associations between combined exposure to environmental hazards and social stressors at the neighborhood level and individual perinatal outcomes in the ECHO-wide cohort,” is published in Health & Place.

Previous studies have found that neighborhood conditions can influence pregnancy and infant health, but few have examined the effects of exposure to a combination of environmental and social conditions. It is important to look at multiple exposures simultaneously because this more closely mirrors real-world experiences. There are existing tools for looking at combined exposures to environmental hazards and social stressors in neighborhoods, but they either do not have national coverage or they do not cover the time frames needed.

ECHO researchers developed an exposure index which combined data on multiple environmental hazards and social circumstances—including air pollutants, vehicle traffic, poverty, and crowded housing—into a single measure of neighborhood conditions. Pregnant participants were assigned an index score based on where they lived during their pregnancy. Then, the researchers looked at how this index score was associated with birthweight, length of pregnancy, and other pregnancy outcomes.

The researchers found that pregnant women living in neighborhoods with higher combined exposures had shorter pregnancies and smaller babies. For Black pregnant participants, there was a higher risk of preterm birth associated with increased combined exposures during pregnancy compared to White pregnant participants. The researchers also found that pregnant participants living in rural areas had shorter pregnancies and smaller babies compared to pregnant participants living in urban areas who had similar index scores.

More research is needed to determine which factors included in the exposure index are most important in pregnancy and child health outcomes. Some members of the research team are currently studying data from two ECHO cohorts (Healthy Start and MADRES) to explore how neighborhood-level exposures might interact to influence obesity later in life.

Read the research summary.