Polybrominated Diphenyl Ethers in the Environment and in People: A Meta-Analysis of Concentrations

Abstract

Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in many types of consumer products. Perhaps as a result of their widespread use and their lipophilicity, these compounds have become ubiquitous in the environment and in people. This review summarizes PBDE concentrations measured in several environmental media and analyzes these data in terms of relative concentrations, concentration trends, and congener profiles. In human blood, milk, and tissues, total PBDE levels have increased exponentially by a factor of ∼100 during the last 30 yr; this is a doubling time of ∼5 yr. The current PBDE concentrations in people from Europe are ∼2 ng/g lipid, but the concentrations in people from the United States are much higher at ∼35 ng/g lipid. Current PBDE concentrations in marine mammals from the Canadian Arctic are very low at ∼5 ng/g lipid, but they have increased exponentially with a doubling time of ∼7 yr. Marine mammals from the rest of the world have current PBDE levels of ∼1000 ng/g lipid, and these concentrations have also increased exponentially with a doubling time of ∼5 yr. Some birds' eggs from Sweden are also highly contaminated (at ∼2000 ng/g lipid) and show PBDE doubling times of ∼6 yr. Herring gull eggs from the Great Lakes region now have PBDE concentrations of ∼7000 ng/g lipid, and these levels have doubled every ∼3 yr. Fish from Europe have ∼10 times lower PBDE concentrations than fish from North America. From these and other data, it is clear that the environment and people from North America are very much more contaminated with PBDEs as compared to Europe and that these PBDE levels have doubled every 4−6 yr. Analyses of the relative distributions of the most abundant PBDE congeners (using category averages and principal component analysis) indicated that these patterns cannot yet be used to assign sources to these pollutants.