Prenatal Exposure to PBDEs Linked to Adolescent Behavioral Concerns

Cincinnati Children's experts found that gestational exposure to flame-retardant chemicals leads to long-term mental health consequences

CINCINNATI, July 19, 2024 /PRNewswire/ -- A long-running Cincinnati Children's study that tracks exposures to environmental toxicants reports that 12-year-old children exposed prior to birth to elevated levels of a common type of flame retardant shows continuing associations with increased behavioral problems.

Details were published recently in Environmental Research.

The new findings focus on gestational exposures to polybrominated diphenyl ethers (PBDEs), flame-retardant chemicals that can be found in building materials, upholstered furniture and electronic equipment. Information about children exposed to these chemicals comes from the Health Outcomes and Measures of the Environment (HOME) Study, which Cincinnati Children's launched in 2003.

The PBDE analysis was led by Kimberly Yolton, PhD, Division of General and Community Pediatrics, and Kim Cecil, PhD, Imaging Research Center.

WHAT IS THE HOME STUDY?

The HOME Study at Cincinnati Children's, headed by Yolton, was launched in 2003 to study how exposures to environmental toxicants, from the fetal stage through childhood, can affect health, growth and neurobehavioral outcomes.

The study initially recruited 468 pregnant women from 2003 to 2006. Research staff collected maternal and cord blood samples to detect various toxicants and monitored the children until adolescence. The initial focus was on lead, mercury, polychlorinated biphenyls (PCBs), tobacco smoke and pesticides, but other toxicants have been added over time.

Research on the impact of gestational PBDE exposure began in 2016. Even though PBDEs are no longer produced, Yolton and Cecil say it is essential to track the effects because this group of chemicals is still found in our homes and workplaces and persists in the environment.

GESTATIONAL PBDE CONCENTRATIONS ASSOCIATED WITH BEHAVIOR PROBLEMS

The study included data from 237 adolescents, 56% of whom were female. The team found that two related chemicals, BDE-47 and BDE-28, were the most abundant forms of PBDEs detected—and both demonstrated measurable associations with behavior, including more frequent reports of inattention and hyperactivity, internalizing problems, functional impairments and emotional symptoms that were reported by both the adolescents and their caregivers.

Each 10-fold increase in BDE-28 concentration led to a +1/2 standard deviation on a standard behavioral survey. Moreover, the impact appears to reach back to the gestational exposure because the adolescents' current PBDE blood concentrations did not appear to alter the findings, the researchers found.

While Yolton and Cecil did not focus on the clinical diagnosis of internalizing and externalizing problem behaviors among adolescents, Yolton shared a 2022 study where 17% of HOME Study adolescents had scores that exceeded the clinically significant threshold for generalized anxiety.

Yolton shared unpublished data where 7% of this population reported clinically relevant symptoms of depression. She also noted that based on the test publisher's classification of symptom significance, 11% of that population would have a "very elevated" depression score.

EXPOSURES MAY DWINDLE BUT IMPACTS LINGER

"This research is important with PBDEs because they don't create a chemical bond. The result is that the PBDEs are sprayed on products but then can flake off. Children and people easily take them in through ingestion, inhalation and absorption," Cecil says.

Exposure to PBDEs in the environment will slowly decrease as products containing these flame retardants are recycled or destroyed. But monitoring remains important because so far, there are no known ways to reverse the impact.

Yolton and Cecil predict that the longitudinal findings from the HOME Study will open up avenues of research exploring how to intervene with children and adolescents affected by PBDEs and other toxicants.

"We don't know how these adolescents will respond to standard practices or if there needs to be an adjustment in intervention strategies based on the exposure," Cecil says.

SOURCE Cincinnati Children's Hospital Medical Center