STUDY: Flame Retardants Linked to Lower IQs, Hyperactivity in Children

Polybrominated diphenyl ether, PBDE, flame retardants are now a world-wide pollution problem reaching even remote areas. But the most common exposure is more personal that you might think. It is most commonly found at home in household products, furniture, and even clothing.

Research is finding that exposure in the womb to fire-beating chemicals in furniture and carpet pads may hinder child development. One new study found that spikes in the levels of one class of flame retardant, polybrominated diphenyl ethers (PBDEs) is correlated with behavior and cognition difficulties during early childhood.

What are behavior and cognition difficulties?

First, let’s clarify this catch-all term that is becoming a catchphase in many childhood issues.

Behavior and cognition difficulties can refer to any behaviours that create problems with social interactions, such as: disorders of attachment, disruptive behavior disorders, attention-deficit/hyperactivity disorder (ADHD), anxiety and mood disorders, and disorders of self-regulation of sleep and feeding in children younger than 6 years.

When children have such difficulties, it can greatly interfere with not only how they play and interact with others, but also harm parent–child relationships, physical safety, their ability to participate in child care, and school readiness at later ages.

It is a huge concern because these cognitive behaviours are linked to measurable abnormalities in brain functioning and persistent emotional and behavioral problems.

The study

Researchers investigating the health impacts of prenatal exposure to flame retardants collected blood samples from 309 pregnant women early in their second trimester.

The researchers tracked children through the first five years of their lives, looking at a battery of tests for IQ and behavior. They found that children of mothers who had high PBDE levels during their second trimester showed cognition deficits when the children were five years old as well as higher rates of hyperactivity at ages two to five.

the findings

If the mother’s blood had a 10-fold increase in PBDEs, the average five-year-old had about a four-point IQ deficit.

“A four-point IQ difference in an individual child may not be perceivable in…ordinary life. However, in a population, if many children are affected, the social and economic impact can be huge due to the shift of IQ distribution and productivity,” —lead author Aimin Chen, an assistant professor of environmental health at the University of Cincinnati College of Medicine.

The researchers did not track the children’s PBDE blood levels after they were born, so the deficits could also have resulted, at least in part, from the additional exposures to the chemical that the children encountered directly after they were born. However, although the lack of blood level data in the children is a limitation, other researchers have measured both mother and child PBDE levels and found similar deficits, strengthening his conclusions.

The team also found that association of PBDEs and child IQ and behavior did not result from the mother’s blood levels of lead, a well-known neurotoxic metal.

exposure to flame retardants is linked to lower IQs

The findings are similar to what two recent large U.S. studies found, showing that the greater the prenatal exposure to flame retardants, the greater the developmental deficits and the lower of IQ of the child.

children are most vulnerable

Children are at high risk of encountering this poison because they spend so much time close to the floor and often put their hands in their mouths.

They are also being exposed during critical windows of development in utero and in the early years of childhood. If you mess up development when brain structures or neuropathways are forming there may not be an ability to repair them later on.

Products treated with PBDE are usually not labeled. You can take precautions to reducing exposure by having children wash their hands to diminish dust ingestion, and by replacing old furniture and changing old carpet padding.

Toxic home exposure

Polybrominated diphenyl ether (PBDEs) flame retardant chemicals, used in the manufacture of furniture, infant products, and electronics, are ubiquitous in most.

For example, did you know your infant car seat may contain such hazardous PBDEs?

Unfortunately, the side effect of fire safety regulations mean that many clothing, household products are made to “resist fire”. For example, California’s Technical Bulletin 117 (TB 117)—a fire safety law promulgated in the 1970s requires that furniture, baby, and other household products resist open flame (California Department of Consumer Affairs 2000; Zota et al. 2008). The unintended consequence is that PBDE concentrations in California children are now among the highest measured worldwide (Eskenazi et al. 2011).

Babies all the way through toddlerhood want to explore everything and you’re setting yourself up for a near-impossible task to police what they put into their mouths! The best policy for such environmental toxins is to reduce and eliminate the sources AT HOME as much as you can.

References & resources

1. Chen’s findings are similar to two recent large U.S. studies that showed associations between prenatal exposure to flame retardants and developmental deficits and reduced IQ. One of those earlier studies, from the University of California, Berkeley, looked at children and PBDE levels through age seven, and was published online last fall in Environmental Health Perspectives. https://ehp.niehs.nih.gov/doi/10.1289/ehp.1205597

2. Polybrominated diphenyl ethers (PBDE), which are used as flame retardants, have been found to be higher in residents of California than of other parts of the United States.