Reducing Exposure to Endocrine-Disrupting Chemicals by Improving Environmental Health Literacy

Providing people with information on their exposure to harmful chemicals may motivate them to take actions that reduce their exposures and risks of potential adverse health effects. With this outcome in mind, an NIEHS-supported team made up of a private biotechnology company and academic researchers from the University of Nevada conducted an intervention to reduce participants’ exposure to endocrine-disrupting chemicals (EDCs). EDCs are found in many plastic and personal care products.

The research team measured participants’ EDC levels by urinalysis and reported back the results. In the personalized reports, the team provided participants with details on the health effects associated with certain exposures and ways to reduce contact with those environmental factors. An accomplished goal was to improve environmental health literacy among participants — their ability to understand and use environmental health information.

A July 2024 publication describes the findings from the study which suggested that participants successfully used the information provided to them to reduce exposure to EDCs.

Reporting Back Chemical Exposure Results

The research team at Million Marker, funded by the NIEHS Small Business Innovation Research program, recruited participants from the Healthy Nevada Project, a population health and genetics study that has collected data from 50,000 Nevada residents. While the project has returned genetic testing results to participants since 2018, the researchers had not previously examined environmental exposures. Million Marker produces a direct-to-consumer urine test for EDCs, including bisphenols, such as Bisphenol-A, phthalates, parabens, and oxybenzone. Through this test, it was possible to examine environmental exposures among project participants.

Exposure to some EDCs has been linked to reduced fertility and increased risk of chronic diseases such as type 2 diabetes and heart disease. In fact, the Centers for Disease Control and Prevention found that 93% of people in the U.S. have detectable levels of bisphenol A in their urine.

“The direct-to-consumer mail-in urine tests can help people see the biomarkers of exposures to harmful EDCs, such as the more well-known type, bisphenol A,” stated Jenna Hua, Ph.D., M.P.H., R.D., founder and chief executive officer of Million Marker, and lead researcher on the study. “Our hopes are to expand to grow the field of screening for EDCs and report-back, as well as other harmful environmental chemicals.”

The study examined urine samples and survey results from 56 Healthy Nevada Project enrollees. Participants completed three initial surveys about their environmental health literacy, readiness to change their behavior to reduce exposure to harmful chemicals, and digital literacy to assess their comfort in accessing study information, which was to be provided digitally. The environmental health literacy survey was adapted from the General Environmental Health Scale, and the digital literacy survey was adapted from the Digital Health Literacy Instrument. Participants also provided a urine sample that was analyzed by the research team to determine EDC levels. The team reported these results back to participants along with information to increase participants’ environmental health literacy about EDCs.

Personalized materials provided information on potential health effects, sources of exposure, and recommendations to reduce exposure depending on which EDCs were found in the urine samples. Some participants completed an exposure journal the day before taking the urine sample, and report-back materials for these participants included additional information based on their journal entries.

Participants then completed another urine test. They also completed a second round of surveys to assess environmental health literacy, readiness to change, and usability of the digital report-back features of the study, including the platform that returned the urinalysis results.

Participants Reduced Their Exposure to Phthalates

Participants indicated they had fewer challenges after the intervention, suggesting they learned feasible ways to reduce exposure. Researchers found that women were more likely than men to report they were planning to change or currently changing behaviors to reduce exposures. Other survey results showed more men than women reported their current chemical exposures were not harming them.

“Perhaps the report-back of results reinforced to some participants that they were not exposed to a high number of harmful EDCs, or that the understanding of the health effects of EDCs were not sufficient to warrant behavior change,” reflected Hua. “Either way, the reasons behind the differences here between men and women are unclear, so it is a point that we would like to explore with further research.”

The improved environmental health literacy results were complemented by reductions in phthalates detected in the urine samples. All participants had reduced urine levels of EDCs after receiving their initial test results and the information on EDCs.

The majority of participants also stated that the digital resources were easy to use and that the report-back materials were easy to understand and helpful.

The research team is currently working on expanding the study to a larger number of participants. The study will be a randomized clinical trial to further study the report-back intervention. The team is also testing an environmental health literacy education and coaching curriculum that aims to promote environmental health literacy and behaviors to reduce exposure to EDCs.