Flame retarding chemicals pollute fetal tissue.

Jan 16, 2009

Doucet J, B Tague, DL Arnold, GM Cooke, S Hayward and CG Goodyer. 2008. Persistent organic pollutant residues in human fetal liver and placenta from greater Montreal, Quebec: a longitudinal study from 1998 - 2006. Environmental Health Perspectives doi:10.1289/ehp.0800205.

Synopsis by Kim Harley, Ph.D.

A new study finds that widely used flame retardant chemicals known as PBDEs can cross the placenta barrier, passing readily from mother to fetus, where they accumulate in the liver.

Researchers found that the chemicals accumulated in the liver of the fetus, which had higher levels of the widely used chemicals than did the placental tissue. PBDE concentrations exceeded those of the more well-known PCBs and organochlorine pollutants.

Although infants are exposed to PBDEs during breastfeeding, this is the first study to show that these compounds are also passing to the fetus in an early stage of pregnancy.

It is not known if and how exposure to these pollutants might affect human development and health later in life.

PBDEs are used to control fire and burning in electronics and furniture. Use of the flame retardants has increased during the past two decades. Early exposure to PBDEs is associated with neurodevelopmental disorders and thyroid hormone disruption in rodent studies, but very few studies in humans exist to date.

PBDEs last for years in the environment and are often present in house dust. Most people have some levels of PBDEs in their bodies, with higher levels observed in North Americans than in Europeans. Although PBDE use is now restricted in many states and countries, exposure is likely to continue for many years as furniture, carpets and electronics in the home age.

PBDE levels varied greatly among the fetuses studied. Some had levels that were 10-100 times greater than the average.

Levels of the chemicals in fetal tissue also appear to be increasing over time.  The PBDE concentration in the fetal tissues increased during the eight years of the study, from 1998 to 2006, following the trend of increasing amounts found in the environment during the same time period.

Levels of other persistent chemicals measured -- PCBs and organochlorine pesticides -- remained fairly constant over time.

Researchers in Quebec, Canada, analyzed fetal liver and placenta tissues from pregnancies that were electively terminated. They measured levels of several persistent chemicals. PCBs were widely used in electronics and banned in the 1970s. Organochlorine pesticides, such as DDT, were also banned in the 1970s. Polybrominated diethyl ethers (PBDEs) are structurally similar compounds widely used as flame retardants in consumer products.