In a collaborative research effort involving participants from nine ECHO cohorts, Jessie P. Buckley, PhD, of Johns Hopkins Bloomberg School of Public Health, and Tracey J. Woodruff, PhD, of the University of California San Francisco led a research team that examined chemical exposures in pregnant women. This is the largest exposure study to measure more than 100 contemporary and emerging chemicals simultaneously in a diverse population of pregnant women in the U.S. The researchers used a new method for measuring multiple chemicals in a small amount of urine.
The research team found that more than 80% of the chemicals were present in at least one of the women in the study, and about a third of the chemicals were found in a majority of the participants. The study found that the women had been exposed to rising levels of certain chemicals, especially replacement chemicals: chemicals meant to replace other chemicals that have been banned or phased out. Many of the women had also been exposed to neonicitinoids, a widely used type of pesticide.
Their research, 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” is published in Environment Science & Technology.
This multi-cohort ECHO Program study included 171 pregnant women from California, Georgia, Illinois, New Hampshire, New York, and Puerto Rico. Approximately 34% of participants were white, 40% were Hispanic, and 20% were Black. To collect data, the research team used a new method that can identify up to 103 chemicals or chemical metabolites —mainly pesticides, plastics, and BPA/phthalate replacements—simultaneously from a single urine sample. The team determined detection frequencies and concentrations for each chemical in urine samples from women in each of nine ECHO cohorts and assessed how demographic characteristics and the year of sample collection related to measured levels of the chemicals.
The research team identified demographic and sociodemographic trends in chemical exposures, observing higher exposure levels among non-white women, those with lower educational attainment, those who were single, and those exposed to tobacco. Of note, Hispanic women had especially high levels of parabens (preservatives) as well as phthalates and bisphenols (from plastics) compared to National Health and Nutrition Examination Survey data.
“Currently, there is a lack of data on multiple chemical exposures, particularly those that have been identified as potentially hazardous during pregnancy and fetal development,” said Buckley. “This study highlights the importance of including pregnant women in biomonitoring studies and creating policies and practices to decrease overall chemical exposure.”
In the future, the team plans to look at a larger sample of pregnant women. “We aim to increase the number of participants from about 200 to 6,500,” said Woodruff. “We would like to assess whether higher prenatal chemical exposures are related to adverse birth outcomes. This data will be foundational for evaluating contributions to additional adverse pregnancy and child health outcomes.”