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Long-term study of pregnant women finds increasing chemical exposure

The Illinois Kids Development Study was involved in a national research endeavor that found rising exposure to harmful chemicals in a diverse group of pregnant women.
Published on May 10, 2022

A national, long-term study that enrolled a highly diverse group of pregnant women found rising exposure to chemicals from plastics and pesticides that may be harmful to development.

Many of the chemicals that the women had been exposed to were replacement chemicals: new forms of chemicals that have been banned or phased out that may be just as harmful as the ones they replaced. The study also found many women had been exposed to neonicotinoids, a kind of pesticide that is toxic to bees.

Susan Schantz Susan Schantz, a professor emerita of comparative biosciences at the University of Illinois Urbana-Champaign and a Beckman Institute researcher, is a coauthor on this study.“This study is groundbreaking because it demonstrated that it is possible to measure a very large number of different chemicals in a very small volume of urine,” said Susan Schantz, a professor emerita of comparative biosciences at the University of Illinois Urbana-Champaign and a coauthor on the study.

Researchers measured 103 chemicals, mostly from pesticides, plastics, and replacement chemicals for BPA and phthalates, using a new method that captured dozens of chemicals or chemical traces from a single urine sample.

More than 80% of the chemicals were found in at least one of the women in the study, and more than a third of the chemicals were found in a majority of the participants. The study also found that some of these chemicals were present in higher amounts than seen in earlier studies.

The study, which appears in the May 10, 2022, issue of Environmental Science & Technology, included 171 women.

“This is the first time we’ve been able to measure the amounts of chemicals in such a large and diverse group of pregnant women – not just identify chemicals,” said Tracey J. Woodruff, a professor and director of the University of California, San Francisco Program on Reproductive Health and the Environment and co-director of the UCSF EaRTH Center, and the senior author of the study. “Our findings make clear that the number and scope of chemicals in pregnant women are increasing during a very vulnerable time of development for both the pregnant person and the fetus.”

The pregnant women who participated in this study are from Illinois, California, Georgia, New Hampshire, New York, and Puerto Rico, and are part of the National Institutes of Health Environmental influences on Child Health Outcomes program.

In 2018, the NIH ECHO program awarded $13 million to the University of Illinois to study how maternal exposure to stress and chemicals during pregnancy affect birth outcomes and child development. The resulting project is conducted collaboratively between UIUC and the University of California, San Francisco. Combined, the two institutions are studying over 1,000 children from the Champaign-Urbana and San Francisco communities. Members of the Champaign-Urbana cohort are participants in the Illinois Kids Development Study, otherwise known as IKIDS, housed at the Beckman Institute for Advanced Science and Technology.

IKIDS and the San Francisco cohort are part of the much larger ECHO cohort, which aims to enroll 50,000 children from across the U.S. and create a publicly available database that can be used to study the impact of chemicals and other environmental factors on children’s health from birth through adolescence.

“Now that we know this approach to measuring multiple chemicals all at once in a single small sample of urine is feasible, samples from several thousand additional ECHO women will be analyzed, allowing researchers to investigate the impact of prenatal exposure to these chemicals on child health and development,” said Schantz, who is also a researcher at the Beckman Institute.

Prenatal exposure to industrial chemicals can come from air, food, water, plastics, and other industrial and consumer products. Although these chemicals could be harmful to pregnancy and child development, few of these chemicals are routinely monitored in people.

About one-third (34%) of the women studied were white, 40% were Latina, 20% were Black, and the remaining 6% were from other or multiple groups.

The study found higher exposures for non-white women, those with lower educational attainment, or who were single or had been exposed to tobacco. But Latinas had especially high levels of parabens, which are used as preservatives, as well as phthalates and bisphenols, which are used in plastics.

“While pesticides and replacement chemicals were prevalent in all women, we were surprised to find that Latinas had substantially higher levels of parabens, phthalates and bisphenols,” said Jessie Buckley, an associate professor of environmental health and engineering and epidemiology at Johns Hopkins Bloomberg School of Public Health and the study’s first author. “This could be the result of higher exposures to products with chemicals, such as processed foods or personal care products.”

Editor’s notes:

The paper “Exposure to contemporary and emerging chemicals in commerce among pregnant women in the United States: The Environmental Influences on Child Health Outcome (ECHO) Program” can be accessed at: 

All author information is available in the paper.

Research reported in this publication was supported by the Environmental influences on Child Health Outcomes program, Office of The Director, National Institutes of Health.

Media contact: Jenna Kurtzweil,

Source for this press release: University of California, San Francisco 

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  • Susan Schantz
    Susan Schantz's directory photo.

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