Study: Effects of Biomonitoring Report-back on Health Knowledge and Behavior

This Environmental Health Perspectives study investigates environmental health knowledge about endocrine disruptors (ECDs); concerns about health effects; and exposure-reducing behaviors before and after the return of individual-level exposure results or only study-wide results.

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Endocrine-disrupting chemicals (EDCs) are all around us, specifically found in many consumer products such as pesticides, flame retardants, ingredients in plastics and personal care products, and per- and polyfluoroalkyl substances (PFAS). EDCs have been associated with obesity, diabetes, detrimental impacts on male and female reproduction, hormonal cancers, thyroid disruption and neurodevelopmental effects.
EDC exposures are influenced by personal behaviors, corporate decisions, and policies and laws from the local to national level. Because members of the public can in turn influence each of these factors, public understanding of EDCs is an important foundation for environmental public health.

“The Effect of Individual or Study-Wide Report-Back on Knowledge, Concern, and Exposure-Reducing Behaviors Related to Endocrine-Disrupting Chemicals,” a study published in Environmental Health Perspectives and co-authored by PHI’s Dr. Barbara Cohn, investigates environmental health knowledge about EDCs; concerns about health effects; and exposure-reducing behaviors before and after the return of individual-level exposure results or only study-wide results.

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Participants were interviewed before and after report-back to assess environmental health knowledge, concern, and exposure-reducing behaviors. The study also included a Participant Advisory Council in report development, which provided actions for prosocial engagement such as joining an advocacy group working to restrict exposures to toxic chemicals or telling a family member, friend, or neighbor about what participants learned from their report about chemicals and health.

The study was a community research collaboration comprising academically trained researchers at PHI’s Child Health and Development Studies program (CHDS), the CHDS Participant Advisory Council and Silent Spring Institute. PHI’s CHDS investigates how health and disease are passed on between generations—not only genetically, but also through social, personal, and environmental surroundings. Studies spanning over 60 years enable CHDS scientists to study health across generations and seek ways to prevent disease early in life.

Key takeaways

  • Baseline knowledge about key environmental health principles was better than we expected, forming a foundation for understanding personal results. For example, more than 90% of participants understood that babies can be exposed to harmful chemicals during pregnancy.
  • On the other hand, participants were not aware of gaps in U.S. chemical safety testing. At baseline, more than three-fourths of participants incorrectly believed that chemicals must be tested for safety before being used in products.
  • Report-back improved knowledge scores, including gains on the two questions that had the poorest results at baseline.
  • Participants acted to reduce their exposures after report-back, particularly for behaviors related to PFAS.


To make informed decisions about endocrine-disrupting chemicals (EDCs), people need functional understanding of exposures and health and an ability to act on their knowledge. The return of biomonitoring results is an opportunity to educate people about EDCs and motivate exposure reduction.


This study investigates environmental health knowledge about EDCs, concerns about health effects, and exposure-reducing behaviors before and after the return of individual-level exposure results or only study-wide results.


Women in the Child Health and Development Studies who were biomonitored for 42 EDCs were randomly assigned to receive a report with personal chemical results or only study-wide findings. We interviewed participants before and after report-back about their knowledge and concerns about EDCs and how frequently they performed exposure-related behaviors. We investigated baseline differences by education and race and examined changes after report-back by race and report type.


Participants (n=135) demonstrated general understanding of exposure pathways and health impacts of EDCs. For 9 out of 20 knowledge questions, more than 90% of participants (n≥124) gave correct responses at baseline, including for questions about chemicals’ persistence in the body and effects of early-life exposure. Most participants held two misconceptions—about chemical safety testing in the United States and what doctors can infer from EDC results—although errors decreased after report-back. Initially, concern was higher for legacy pollutants, but report-back increased concern for consumer product chemicals. After report-back, participants took some actions to reduce exposures, particularly to per- and polyfluoroalkyl substances, and total behavior was associated with knowledge and concern but not race, education, or report type.


This study demonstrated that participants had foundational knowledge about EDCs and that report-back further built their environmental health literacy. We conclude that future communications should target misconceptions about chemicals regulation in the United States, because information about regulations is crucial for people to evaluate risks posed by consumer product chemicals and decide whether to engage with public policy.

Originally published by Environmental Health Perspectives

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