(RxWiki News) Throughout our entire lives, we interact with chemicals. The vast majority of these chemicals do us good or cause no harm. A small number, however, are linked to mental health issues.
A recent study found that exposure in the womb to flame retardants appeared linked to lower mental and behavior issues in children.
The link was small, and the levels of the chemicals were similar to what most individuals in the US would have been exposed to.
However, the researchers expressed concern about pregnant women's exposure to these chemicals.
"Check product labels for dangerous chemicals."
The study, led by Aimin Chen, MD, PhD, an assistant professor in the Department of Environmental Health at the University of Cincinnati College of Medicine, found that exposure to flame retardants may be related to long-term mental or cognitive disabilities in kids.
The researchers focused on a chemical called polybrominated biphenyl ethers, or PBDEs. These chemicals are flame retardants that were previously used in furniture, carpet padding, car seats and similar products over the past thirty years.
The study involved collecting blood samples from 301 women when they were 16 weeks pregnant. Then the researchers followed the women's children through age 5.
The blood samples were assessed for the amount of BDE-47 (one of the PBDE chemicals) in them and the amount of four other PBDE chemicals together: BDE-47, BDE-99, BDE-100 and BDE-153.
The children were assessed when they were 1, 2 and 3 years old for their cognitive and motor skills and then at age 5 for their intelligence with an IQ test.
The children were also tested at ages 2, 3, 4 and 5 with a behavior assessment tool. The researchers adjusted their analysis to take into account the children's sex, the family's household income, a measurement related to how nurturing the home environment was for the child and a variety of factors related to the child's mother.
The factors related to the child's mother included age, race, education, marital status, IQ, level of lead in the blood, depression symptoms and her smoking status based on a blood test.
The researchers found that children who had been exposed to BDE-47 and the combination of the four PBDEs had lower cognitive skills at ages 2, 3 and 5 when compared to the children with less or no exposure to the flame retardant chemicals.
On average, the mothers had 37 ng/g lipid of the combination of the PBDEs and 20 ng/g lipid of the chemical BDE-47. In 2003-2004, the US national average of BDE-47 was 20 ng/g lipid.
For every 10-fold increase of BDE-47 levels in a woman's blood, the child had 7.5 fewer IQ points at age 5.
The researchers also found that children with exposure in the womb to BDE-47 and the sum of the four PBDEs had higher hyperactivity symptoms.
Each time the amount of chemicals was increased 10 times in the women's blood, the child's hyperactivity score was increased 2.4 points (on a scale of 1 to 100).
Many flame retardants are no longer used in furniture, carpet and different foam products, but older products, even those less than 10 years old, may still contain these chemicals.
"In animal studies, PBDEs can disrupt thyroid hormone and cause hyperactivity and learning problems," Dr. Chen said in a prepared statement.
"Our study adds to several other human studies to highlight the need to reduce exposure to PBDEs in pregnant women," she said.
"Because PBDEs exist in the home and office environment as they are contained in old furniture, carpet pads, foams and electronics, the study raises further concern about their toxicity in developing children."
These findings are preliminary. The study was presented at a conference and has not yet been published in a peer-reviewed journal.
The research was presented May 6 at the Pediatric Academic Societies annual meeting in Washington, D.C. Information regarding funding and disclosures was unavailable.